[PATCH 0/2] git-gui: revert untracked files by deleting them

[PATCH 0/2] git-gui: revert untracked files by deleting them

[Jonathan Gilbert via GitGitGadget]

My development environment sometimes makes automatic changes that I don't
want to keep. In some cases, this involves new files being added that I
don't want to commit or keep (but I also don't want to outright .gitignore 
forever). I have typically had to explicitly delete those files externally
to Git Gui, which is a context switch to a manual operation, and I want to
be able to just select those newly-created untracked files in the UI and
"revert" them into oblivion.

This change updates the revert_helper proc to check for untracked files as
well as changes, and then changes to be reverted and untracked files are
handled by independent blocks of code. The user is prompted independently
for untracked files, since the underlying action is fundamentally different
(rm -f). If after deleting untracked files, the directory containing them
becomes empty, then the directory is removed as well. A new proc 
delete_files takes care of actually deleting the files, using the Tcler's
Wiki recommended approach for keeping the UI responsive.

This is the second revision of this change, which differs from the first
version in the following ways:

 * The change is now based on git-gui/master.
 * With one exception, all lines are at most 80 characters long. The
   exception has a string literal in it that pushes it to 82 characters. I
   think it would be messy to try to split it, and I got advice on 
   #git-devel to just let it go to 82 characters.
 * camelCase is eliminated. I eliminated it from existing code in a separate
   commit.
 * try is no longer used anywhere. The code that cares about the result (had
   code in a catch after a try) uses [catch].
 * Deletion of files and removal of empty directories is now handled by
   separate procs.
 * The deletion of a large number of files does not block the UI during its
   execution any more.
 * The revert_helper code no longer uses an epilogue of generic statements
   to be evaluated on exit.
 * When deleting files, the UI is notified about the deletion directly
   instead of doing a full rescan.

Jonathan Gilbert (2):
  git-gui: consolidate naming conventions
  git-gui: revert untracked files by deleting them

 lib/index.tcl | 343 ++++++++++++++++++++++++++++++++++++++------------
 1 file changed, 266 insertions(+), 77 deletions(-)


base-commit: b524f6b399c77b40c8bf2b6217585fde4731472a
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-436%2Flogiclrd%2Fgit-gui-revert-untracked-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-436/logiclrd/git-gui-revert-untracked-v1
Pull-Request: https://github.com/gitgitgadget/git/pull/436
-- 
gitgitgadget

[PATCH 1/2] git-gui: consolidate naming conventions

[Jonathan Gilbert via GitGitGadget]

From: Jonathan Gilbert <JonathanG@iQmetrix.com>

A few variables in this file use camelCase, while the overall standard
is snake_case. A consistent naming scheme will improve readability of
future changes. To avoid mixing naming changes with semantic changes,
this commit contains only naming changes.

Signed-off-by: Jonathan Gilbert <JonathanG@iQmetrix.com>
---
 lib/index.tcl | 92 +++++++++++++++++++++++++--------------------------
 1 file changed, 46 insertions(+), 46 deletions(-)

diff --git a/lib/index.tcl b/lib/index.tcl
index e07b7a3762..28d4d2a54e 100644
--- a/lib/index.tcl
+++ b/lib/index.tcl
@@ -56,15 +56,15 @@ proc _close_updateindex {fd after} {
 	uplevel #0 $after
 }
 
-proc update_indexinfo {msg pathList after} {
+proc update_indexinfo {msg path_list after} {
 	global update_index_cp
 
 	if {![lock_index update]} return
 
 	set update_index_cp 0
-	set pathList [lsort $pathList]
-	set totalCnt [llength $pathList]
-	set batch [expr {int($totalCnt * .01) + 1}]
+	set path_list [lsort $path_list]
+	set total_cnt [llength $path_list]
+	set batch [expr {int($total_cnt * .01) + 1}]
 	if {$batch > 25} {set batch 25}
 
 	$::main_status start $msg [mc "files"]
@@ -78,26 +78,26 @@ proc update_indexinfo {msg pathList after} {
 	fileevent $fd writable [list \
 		write_update_indexinfo \
 		$fd \
-		$pathList \
-		$totalCnt \
+		$path_list \
+		$total_cnt \
 		$batch \
 		$after \
 		]
 }
 
-proc write_update_indexinfo {fd pathList totalCnt batch after} {
+proc write_update_indexinfo {fd path_list total_cnt batch after} {
 	global update_index_cp
 	global file_states current_diff_path
 
-	if {$update_index_cp >= $totalCnt} {
+	if {$update_index_cp >= $total_cnt} {
 		_close_updateindex $fd $after
 		return
 	}
 
 	for {set i $batch} \
-		{$update_index_cp < $totalCnt && $i > 0} \
+		{$update_index_cp < $total_cnt && $i > 0} \
 		{incr i -1} {
-		set path [lindex $pathList $update_index_cp]
+		set path [lindex $path_list $update_index_cp]
 		incr update_index_cp
 
 		set s $file_states($path)
@@ -119,18 +119,18 @@ proc write_update_indexinfo {fd pathList totalCnt batch after} {
 		display_file $path $new
 	}
 
-	$::main_status update $update_index_cp $totalCnt
+	$::main_status update $update_index_cp $total_cnt
 }
 
-proc update_index {msg pathList after} {
+proc update_index {msg path_list after} {
 	global update_index_cp
 
 	if {![lock_index update]} return
 
 	set update_index_cp 0
-	set pathList [lsort $pathList]
-	set totalCnt [llength $pathList]
-	set batch [expr {int($totalCnt * .01) + 1}]
+	set path_list [lsort $path_list]
+	set total_cnt [llength $path_list]
+	set batch [expr {int($total_cnt * .01) + 1}]
 	if {$batch > 25} {set batch 25}
 
 	$::main_status start $msg [mc "files"]
@@ -144,26 +144,26 @@ proc update_index {msg pathList after} {
 	fileevent $fd writable [list \
 		write_update_index \
 		$fd \
-		$pathList \
-		$totalCnt \
+		$path_list \
+		$total_cnt \
 		$batch \
 		$after \
 		]
 }
 
-proc write_update_index {fd pathList totalCnt batch after} {
+proc write_update_index {fd path_list total_cnt batch after} {
 	global update_index_cp
 	global file_states current_diff_path
 
-	if {$update_index_cp >= $totalCnt} {
+	if {$update_index_cp >= $total_cnt} {
 		_close_updateindex $fd $after
 		return
 	}
 
 	for {set i $batch} \
-		{$update_index_cp < $totalCnt && $i > 0} \
+		{$update_index_cp < $total_cnt && $i > 0} \
 		{incr i -1} {
-		set path [lindex $pathList $update_index_cp]
+		set path [lindex $path_list $update_index_cp]
 		incr update_index_cp
 
 		switch -glob -- [lindex $file_states($path) 0] {
@@ -190,18 +190,18 @@ proc write_update_index {fd pathList totalCnt batch after} {
 		display_file $path $new
 	}
 
-	$::main_status update $update_index_cp $totalCnt
+	$::main_status update $update_index_cp $total_cnt
 }
 
-proc checkout_index {msg pathList after} {
+proc checkout_index {msg path_list after} {
 	global update_index_cp
 
 	if {![lock_index update]} return
 
 	set update_index_cp 0
-	set pathList [lsort $pathList]
-	set totalCnt [llength $pathList]
-	set batch [expr {int($totalCnt * .01) + 1}]
+	set path_list [lsort $path_list]
+	set total_cnt [llength $path_list]
+	set batch [expr {int($total_cnt * .01) + 1}]
 	if {$batch > 25} {set batch 25}
 
 	$::main_status start $msg [mc "files"]
@@ -221,26 +221,26 @@ proc checkout_index {msg pathList after} {
 	fileevent $fd writable [list \
 		write_checkout_index \
 		$fd \
-		$pathList \
-		$totalCnt \
+		$path_list \
+		$total_cnt \
 		$batch \
 		$after \
 		]
 }
 
-proc write_checkout_index {fd pathList totalCnt batch after} {
+proc write_checkout_index {fd path_list total_cnt batch after} {
 	global update_index_cp
 	global file_states current_diff_path
 
-	if {$update_index_cp >= $totalCnt} {
+	if {$update_index_cp >= $total_cnt} {
 		_close_updateindex $fd $after
 		return
 	}
 
 	for {set i $batch} \
-		{$update_index_cp < $totalCnt && $i > 0} \
+		{$update_index_cp < $total_cnt && $i > 0} \
 		{incr i -1} {
-		set path [lindex $pathList $update_index_cp]
+		set path [lindex $path_list $update_index_cp]
 		incr update_index_cp
 		switch -glob -- [lindex $file_states($path) 0] {
 		U? {continue}
@@ -253,7 +253,7 @@ proc write_checkout_index {fd pathList totalCnt batch after} {
 		}
 	}
 
-	$::main_status update $update_index_cp $totalCnt
+	$::main_status update $update_index_cp $total_cnt
 }
 
 proc unstage_helper {txt paths} {
@@ -261,7 +261,7 @@ proc unstage_helper {txt paths} {
 
 	if {![lock_index begin-update]} return
 
-	set pathList [list]
+	set path_list [list]
 	set after {}
 	foreach path $paths {
 		switch -glob -- [lindex $file_states($path) 0] {
@@ -269,19 +269,19 @@ proc unstage_helper {txt paths} {
 		M? -
 		T? -
 		D? {
-			lappend pathList $path
+			lappend path_list $path
 			if {$path eq $current_diff_path} {
 				set after {reshow_diff;}
 			}
 		}
 		}
 	}
-	if {$pathList eq {}} {
+	if {$path_list eq {}} {
 		unlock_index
 	} else {
 		update_indexinfo \
 			$txt \
-			$pathList \
+			$path_list \
 			[concat $after [list ui_ready]]
 	}
 }
@@ -305,7 +305,7 @@ proc add_helper {txt paths} {
 
 	if {![lock_index begin-update]} return
 
-	set pathList [list]
+	set path_list [list]
 	set after {}
 	foreach path $paths {
 		switch -glob -- [lindex $file_states($path) 0] {
@@ -321,19 +321,19 @@ proc add_helper {txt paths} {
 		?M -
 		?D -
 		?T {
-			lappend pathList $path
+			lappend path_list $path
 			if {$path eq $current_diff_path} {
 				set after {reshow_diff;}
 			}
 		}
 		}
 	}
-	if {$pathList eq {}} {
+	if {$path_list eq {}} {
 		unlock_index
 	} else {
 		update_index \
 			$txt \
-			$pathList \
+			$path_list \
 			[concat $after {ui_status [mc "Ready to commit."]}]
 	}
 }
@@ -393,7 +393,7 @@ proc revert_helper {txt paths} {
 
 	if {![lock_index begin-update]} return
 
-	set pathList [list]
+	set path_list [list]
 	set after {}
 	foreach path $paths {
 		switch -glob -- [lindex $file_states($path) 0] {
@@ -401,7 +401,7 @@ proc revert_helper {txt paths} {
 		?M -
 		?T -
 		?D {
-			lappend pathList $path
+			lappend path_list $path
 			if {$path eq $current_diff_path} {
 				set after {reshow_diff;}
 			}
@@ -420,12 +420,12 @@ proc revert_helper {txt paths} {
 	# as they have quite complex plural-form rules. Unfortunately,
 	# msgcat doesn't seem to support that kind of string translation.
 	#
-	set n [llength $pathList]
+	set n [llength $path_list]
 	if {$n == 0} {
 		unlock_index
 		return
 	} elseif {$n == 1} {
-		set query [mc "Revert changes in file %s?" [short_path [lindex $pathList]]]
+		set query [mc "Revert changes in file %s?" [short_path [lindex $path_list]]]
 	} else {
 		set query [mc "Revert changes in these %i files?" $n]
 	}
@@ -444,7 +444,7 @@ proc revert_helper {txt paths} {
 	if {$reply == 1} {
 		checkout_index \
 			$txt \
-			$pathList \
+			$path_list \
 			[concat $after [list ui_ready]]
 	} else {
 		unlock_index
-- 
gitgitgadget

Re: [PATCH 1/2] git-gui: consolidate naming conventions

[Pratyush Yadav]

Hi Jonathan,

On 30/10/19 06:48AM, Jonathan Gilbert via GitGitGadget wrote:
> From: Jonathan Gilbert <JonathanG@iQmetrix.com>
> 
> A few variables in this file use camelCase, while the overall standard
> is snake_case. A consistent naming scheme will improve readability of
> future changes. To avoid mixing naming changes with semantic changes,
> this commit contains only naming changes.

Thanks for the cleanup. Looks good.
 
> Signed-off-by: Jonathan Gilbert <JonathanG@iQmetrix.com>

-- 
Regards,
Pratyush Yadav

[PATCH 2/2] git-gui: revert untracked files by deleting them

[Jonathan Gilbert via GitGitGadget]

From: Jonathan Gilbert <JonathanG@iQmetrix.com>

Updates the revert_helper procedure to also detect untracked files. If
files are present, the user is asked if they want them deleted. A new
proc delete_files with helper delete_helper performs the deletion in
batches, to allow the UI to remain responsive.

Signed-off-by: Jonathan Gilbert <JonathanG@iQmetrix.com>
---
 lib/index.tcl | 255 +++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 222 insertions(+), 33 deletions(-)

diff --git a/lib/index.tcl b/lib/index.tcl
index 28d4d2a54e..9661ddb556 100644
--- a/lib/index.tcl
+++ b/lib/index.tcl
@@ -393,11 +393,20 @@ proc revert_helper {txt paths} {
 
 	if {![lock_index begin-update]} return
 
+	# The index is now locked. Some of the paths below include calls that
+	# unlock the index (e.g. checked_index). If we reach the end and the
+	# index is still locked, we need to unlock it before returning.
+	set need_unlock_index 1
+
 	set path_list [list]
+	set untracked_list [list]
 	set after {}
 	foreach path $paths {
 		switch -glob -- [lindex $file_states($path) 0] {
 		U? {continue}
+		?O {
+			lappend untracked_list $path
+		}
 		?M -
 		?T -
 		?D {
@@ -409,45 +418,225 @@ proc revert_helper {txt paths} {
 		}
 	}
 
+	set path_cnt [llength $path_list]
+	set untracked_cnt [llength $untracked_list]
 
-	# Split question between singular and plural cases, because
-	# such distinction is needed in some languages. Previously, the
-	# code used "Revert changes in" for both, but that can't work
-	# in languages where 'in' must be combined with word from
-	# rest of string (in different way for both cases of course).
-	#
-	# FIXME: Unfortunately, even that isn't enough in some languages
-	# as they have quite complex plural-form rules. Unfortunately,
-	# msgcat doesn't seem to support that kind of string translation.
-	#
-	set n [llength $path_list]
-	if {$n == 0} {
-		unlock_index
-		return
-	} elseif {$n == 1} {
-		set query [mc "Revert changes in file %s?" [short_path [lindex $path_list]]]
-	} else {
-		set query [mc "Revert changes in these %i files?" $n]
-	}
+	if {$path_cnt > 0} {
+		# Split question between singular and plural cases, because
+		# such distinction is needed in some languages. Previously, the
+		# code used "Revert changes in" for both, but that can't work
+		# in languages where 'in' must be combined with word from
+		# rest of string (in different way for both cases of course).
+		#
+		# FIXME: Unfortunately, even that isn't enough in some languages
+		# as they have quite complex plural-form rules. Unfortunately,
+		# msgcat doesn't seem to support that kind of string
+		# translation.
+		#
+		if {$path_cnt == 1} {
+			set query [mc \
+				"Revert changes in file %s?" \
+				[short_path [lindex $path_list]] \
+				]
+		} else {
+			set query [mc \
+				"Revert changes in these %i files?" \
+				$path_cnt]
+		}
 
-	set reply [tk_dialog \
-		.confirm_revert \
-		"[appname] ([reponame])" \
-		"$query
+		set reply [tk_dialog \
+			.confirm_revert \
+			"[appname] ([reponame])" \
+			"$query
 
 [mc "Any unstaged changes will be permanently lost by the revert."]" \
-		question \
-		1 \
-		[mc "Do Nothing"] \
-		[mc "Revert Changes"] \
-		]
-	if {$reply == 1} {
-		checkout_index \
-			$txt \
+			question \
+			1 \
+			[mc "Do Nothing"] \
+			[mc "Revert Changes"] \
+			]
+
+		if {$reply == 1} {
+			checkout_index \
+				$txt \
+				$path_list \
+				[concat $after [list ui_ready]]
+
+			set need_unlock_index 0
+		}
+	}
+
+	if {$need_unlock_index} { unlock_index }
+
+	if {$untracked_cnt > 0} {
+		# Split question between singular and plural cases, because
+		# such distinction is needed in some languages.
+		#
+		# FIXME: Unfortunately, even that isn't enough in some languages
+		# as they have quite complex plural-form rules. Unfortunately,
+		# msgcat doesn't seem to support that kind of string
+		# translation.
+		#
+		if {$untracked_cnt == 1} {
+			set query [mc \
+				"Delete untracked file %s?" \
+				[short_path [lindex $untracked_list]] \
+				]
+		} else {
+			set query [mc \
+				"Delete these %i untracked files?" \
+				$untracked_cnt \
+				]
+		}
+
+		set reply [tk_dialog \
+			.confirm_revert \
+			"[appname] ([reponame])" \
+			"$query
+
+[mc "Files will be permanently deleted."]" \
+			question \
+			1 \
+			[mc "Do Nothing"] \
+			[mc "Delete Files"] \
+			]
+
+		if {$reply == 1} {
+			delete_files $untracked_list
+		}
+	}
+}
+
+# Delete all of the specified files, performing deletion in batches to allow the
+# UI to remain responsive and updated.
+proc delete_files {path_list} {
+	# Enable progress bar status updates
+	$::main_status start [mc "Deleting"] [mc "files"]
+
+	set path_index 0
+	set deletion_errors [list]
+	set deletion_error_path "not yet captured"
+	set batch_size 50
+
+	delete_helper \
+		$path_list \
+		$path_index \
+		$deletion_errors \
+		$deletion_error_path \
+		$batch_size
+}
+
+# Helper function to delete a list of files in batches. Each call deletes one
+# batch of files, and then schedules a call for the next batch after any UI
+# messages have been processed.
+proc delete_helper \
+	{path_list path_index deletion_errors deletion_error_path batch_size} {
+	global file_states
+
+	set path_cnt [llength $path_list]
+
+	set batch_remaining $batch_size
+
+	while {$batch_remaining > 0} {
+		if {$path_index >= $path_cnt} { break }
+
+		set path [lindex $path_list $path_index]
+
+		set deletion_failed [catch {file delete -- $path} deletion_error]
+
+		if {$deletion_failed} {
+			lappend deletion_errors $deletion_error
+
+			# Optimistically capture the path that failed, in case
+			# there's only one.
+			set deletion_error_path $path
+		} else {
+			remove_empty_directories [file dirname $path]
+
+			# Don't assume the deletion worked. Remove the file from
+			# the UI, but only if it no longer exists.
+			if {![lexists $path]} {
+				unset file_states($path)
+				display_file $path __
+			}
+		}
+
+		incr path_index 1
+		incr batch_remaining -1
+	}
+
+	# Update the progress bar to indicate that this batch has been
+	# completed. The update will be visible when this procedure returns
+	# and allows the UI thread to process messages.
+	$::main_status update $path_index $path_cnt
+
+	if {$path_index < $path_cnt} {
+		# The Tcler's Wiki lists this as the best practice for keeping
+		# a UI active and processing messages during a long-running
+		# operation.
+
+		after idle [list after 0 [list \
+			delete_helper \
 			$path_list \
-			[concat $after [list ui_ready]]
+			$path_index \
+			$deletion_errors \
+			$deletion_error_path \
+			$batch_size \
+			]]
 	} else {
-		unlock_index
+		# Finish the status bar operation.
+		$::main_status stop
+
+		# Report error, if any, based on how many deletions failed.
+		set deletion_error_cnt [llength $deletion_errors]
+
+		if {$deletion_error_cnt == 1} {
+			error_popup [mc \
+				"File %s could not be deleted: %s" \
+				$deletion_error_path \
+				[lindex $deletion_errors 0] \
+				]
+		} elseif {$deletion_error_cnt == $path_cnt} {
+			error_popup [mc \
+				"None of the selected files could be deleted." \
+				]
+		} elseif {$deletion_error_cnt > 1} {
+			error_popup [mc \
+				"%d of the selected files could not be deleted." \
+				$deletion_error_cnt]
+		}
+
+		reshow_diff
+		ui_ready
+	}
+}
+
+# This function is from the TCL documentation:
+#
+#   https://wiki.tcl-lang.org/page/file+exists
+#
+# [file exists] returns false if the path does exist but is a symlink to a path
+# that doesn't exist. This proc returns true if the path exists, regardless of
+# whether it is a symlink and whether it is broken.
+proc lexists name {
+	expr {![catch {file lstat $name finfo}]}
+}
+
+# Remove as many empty directories as we can starting at the specified path.
+# If we encounter a directory that is not empty, or if a directory deletion
+# fails, then we stop the operation and return to the caller. Even if this
+# procedure fails to delete any directories at all, it does not report failure.
+proc remove_empty_directories {directory_path} {
+	set parent_path [file dirname $directory_path]
+
+	while {$parent_path != $directory_path} {
+		set contents [glob -nocomplain -dir $directory_path *]
+
+		if {[llength $contents] > 0} { break }
+		if {[catch {file delete -- $directory_path}]} { break }
+
+		set directory_path $parent_path
+		set parent_path [file dirname $directory_path]
 	}
 }
 
-- 
gitgitgadget

Re: [PATCH 2/2] git-gui: revert untracked files by deleting them

[Pratyush Yadav]

Hi Jonathan,

Thanks for the quality re-roll. It was a pleasant read :)

I would have suggested just handing off the paths to `git clean`, but it 
unfortunately does not do what we want it to do.

Say we have a directory 'foo' which has one file called 'bar.txt'. That 
file is untracked. Now, I expected `git clean -fd foo/bar.txt` to delete 
'bar.txt' _and_ 'foo/', but it only deletes bar.txt, and leaves 'foo/' 
intact. What's worse is that since 'foo' is an empty directory, it 
doesn't appear in git-status anymore, and so there is no way the user 
can tell the directory exists unless they go there and do a `ls`.

Maybe something to fix upstream?

On 30/10/19 06:48AM, Jonathan Gilbert via GitGitGadget wrote:
> From: Jonathan Gilbert <JonathanG@iQmetrix.com>
> 
> Updates the revert_helper procedure to also detect untracked files. If

Typo: s/Updates/Update/ ?

> files are present, the user is asked if they want them deleted. A new
> proc delete_files with helper delete_helper performs the deletion in
> batches, to allow the UI to remain responsive.
> 
> Signed-off-by: Jonathan Gilbert <JonathanG@iQmetrix.com>
> ---
>  lib/index.tcl | 255 +++++++++++++++++++++++++++++++++++++++++++-------
>  1 file changed, 222 insertions(+), 33 deletions(-)
> 
> diff --git a/lib/index.tcl b/lib/index.tcl
> index 28d4d2a54e..9661ddb556 100644
> --- a/lib/index.tcl
> +++ b/lib/index.tcl
> @@ -393,11 +393,20 @@ proc revert_helper {txt paths} {
>  
>  	if {![lock_index begin-update]} return
>  
> +	# The index is now locked. Some of the paths below include calls that
> +	# unlock the index (e.g. checked_index). If we reach the end and the

Typo: s/checked_index/checkout_index/

> +	# index is still locked, we need to unlock it before returning.
> +	set need_unlock_index 1
> +
>  	set path_list [list]
> +	set untracked_list [list]
>  	set after {}
>  	foreach path $paths {
>  		switch -glob -- [lindex $file_states($path) 0] {
>  		U? {continue}
> +		?O {
> +			lappend untracked_list $path
> +		}
>  		?M -
>  		?T -
>  		?D {
> @@ -409,45 +418,225 @@ proc revert_helper {txt paths} {
>  		}
>  	}
>  
> +	set path_cnt [llength $path_list]
> +	set untracked_cnt [llength $untracked_list]
>  
> -	# Split question between singular and plural cases, because
> -	# such distinction is needed in some languages. Previously, the
> -	# code used "Revert changes in" for both, but that can't work
> -	# in languages where 'in' must be combined with word from
> -	# rest of string (in different way for both cases of course).
> -	#
> -	# FIXME: Unfortunately, even that isn't enough in some languages
> -	# as they have quite complex plural-form rules. Unfortunately,
> -	# msgcat doesn't seem to support that kind of string translation.
> -	#
> -	set n [llength $path_list]
> -	if {$n == 0} {
> -		unlock_index
> -		return
> -	} elseif {$n == 1} {
> -		set query [mc "Revert changes in file %s?" [short_path [lindex $path_list]]]
> -	} else {
> -		set query [mc "Revert changes in these %i files?" $n]
> -	}
> +	if {$path_cnt > 0} {
> +		# Split question between singular and plural cases, because
> +		# such distinction is needed in some languages. Previously, the
> +		# code used "Revert changes in" for both, but that can't work
> +		# in languages where 'in' must be combined with word from
> +		# rest of string (in different way for both cases of course).
> +		#
> +		# FIXME: Unfortunately, even that isn't enough in some languages
> +		# as they have quite complex plural-form rules. Unfortunately,
> +		# msgcat doesn't seem to support that kind of string
> +		# translation.
> +		#
> +		if {$path_cnt == 1} {
> +			set query [mc \
> +				"Revert changes in file %s?" \
> +				[short_path [lindex $path_list]] \
> +				]
> +		} else {
> +			set query [mc \
> +				"Revert changes in these %i files?" \
> +				$path_cnt]
> +		}
>  
> -	set reply [tk_dialog \
> -		.confirm_revert \
> -		"[appname] ([reponame])" \
> -		"$query
> +		set reply [tk_dialog \
> +			.confirm_revert \
> +			"[appname] ([reponame])" \
> +			"$query
>  
>  [mc "Any unstaged changes will be permanently lost by the revert."]" \
> -		question \
> -		1 \
> -		[mc "Do Nothing"] \
> -		[mc "Revert Changes"] \
> -		]
> -	if {$reply == 1} {
> -		checkout_index \
> -			$txt \
> +			question \
> +			1 \
> +			[mc "Do Nothing"] \
> +			[mc "Revert Changes"] \
> +			]
> +
> +		if {$reply == 1} {
> +			checkout_index \
> +				$txt \
> +				$path_list \
> +				[concat $after [list ui_ready]]
> +
> +			set need_unlock_index 0
> +		}
> +	}
> +
> +	if {$need_unlock_index} { unlock_index }

Are you sure you want to unlock the index _before_ the cleanup of 
untracked files is done? While it makes sense to unlock the index since 
our "clean" operation would only touch the working tree, and not the 
index, it would also mean people can do things like "Revert hunk" (from 
the context menu). Right now, this operation can not be done on 
untracked files (so this won't be a problem for now), but I do plan on 
adding this in the future, and it wouldn't be obvious from that patch's 
POV that this could be an issue. If someone does a "Revert hunk" on a 
while that is queued for deletion, there might be problems.

Also, would doing an `unlock_index` early allow people to run multiple 
"clean" jobs at the same time? Will that create race conditions that we 
aren't ready to handle?

It also makes sense to evaluate what the downsides of keeping the index 
locked are. So, does keeping the index locked prevent meaningful usage 
of git-gui, making your batched deletion pointless? Is there some reason 
for unlocking it early that I'm missing?

If we do decide keeping the index locked is a good idea, it would be 
troublesome to implement. `checkout_index` is asynchronous. So, when it 
returns, the index won't necessarily be unlocked. It would get unlocked 
some time _after_ the return. I'm not sure how to work around this.

> +
> +	if {$untracked_cnt > 0} {
> +		# Split question between singular and plural cases, because
> +		# such distinction is needed in some languages.
> +		#
> +		# FIXME: Unfortunately, even that isn't enough in some languages
> +		# as they have quite complex plural-form rules. Unfortunately,
> +		# msgcat doesn't seem to support that kind of string
> +		# translation.
> +		#
> +		if {$untracked_cnt == 1} {
> +			set query [mc \
> +				"Delete untracked file %s?" \
> +				[short_path [lindex $untracked_list]] \
> +				]
> +		} else {
> +			set query [mc \
> +				"Delete these %i untracked files?" \
> +				$untracked_cnt \
> +				]
> +		}
> +
> +		set reply [tk_dialog \
> +			.confirm_revert \
> +			"[appname] ([reponame])" \
> +			"$query
> +
> +[mc "Files will be permanently deleted."]" \
> +			question \
> +			1 \
> +			[mc "Do Nothing"] \
> +			[mc "Delete Files"] \
> +			]
> +
> +		if {$reply == 1} {
> +			delete_files $untracked_list
> +		}
> +	}
> +}
> +
> +# Delete all of the specified files, performing deletion in batches to allow the
> +# UI to remain responsive and updated.
> +proc delete_files {path_list} {
> +	# Enable progress bar status updates
> +	$::main_status start [mc "Deleting"] [mc "files"]
> +
> +	set path_index 0
> +	set deletion_errors [list]
> +	set deletion_error_path "not yet captured"
> +	set batch_size 50
> +
> +	delete_helper \
> +		$path_list \
> +		$path_index \
> +		$deletion_errors \
> +		$deletion_error_path \
> +		$batch_size
> +}
> +
> +# Helper function to delete a list of files in batches. Each call deletes one
> +# batch of files, and then schedules a call for the next batch after any UI
> +# messages have been processed.
> +proc delete_helper \
> +	{path_list path_index deletion_errors deletion_error_path batch_size} {
> +	global file_states
> +
> +	set path_cnt [llength $path_list]
> +
> +	set batch_remaining $batch_size
> +
> +	while {$batch_remaining > 0} {
> +		if {$path_index >= $path_cnt} { break }
> +
> +		set path [lindex $path_list $path_index]
> +
> +		set deletion_failed [catch {file delete -- $path} deletion_error]
> +
> +		if {$deletion_failed} {
> +			lappend deletion_errors $deletion_error
> +
> +			# Optimistically capture the path that failed, in case
> +			# there's only one.
> +			set deletion_error_path $path

I don't see why you would do this for _only_ one path. Either do it for 
every path. And since you're recording errors for each path, it makes 
sense to record the corresponding path too. Or, just count how many 
paths failed, and report that. I don't see why we'd want to be between 
those two.

> +		} else {
> +			remove_empty_directories [file dirname $path]
> +
> +			# Don't assume the deletion worked. Remove the file from
> +			# the UI, but only if it no longer exists.
> +			if {![lexists $path]} {
> +				unset file_states($path)
> +				display_file $path __
> +			}
> +		}
> +
> +		incr path_index 1
> +		incr batch_remaining -1
> +	}
> +
> +	# Update the progress bar to indicate that this batch has been
> +	# completed. The update will be visible when this procedure returns
> +	# and allows the UI thread to process messages.
> +	$::main_status update $path_index $path_cnt
> +
> +	if {$path_index < $path_cnt} {
> +		# The Tcler's Wiki lists this as the best practice for keeping
> +		# a UI active and processing messages during a long-running
> +		# operation.
> +
> +		after idle [list after 0 [list \
> +			delete_helper \
>  			$path_list \
> -			[concat $after [list ui_ready]]
> +			$path_index \
> +			$deletion_errors \
> +			$deletion_error_path \
> +			$batch_size \
> +			]]

Using `after idle` means in theory we put an undefined maximum time 
limit on the deletion process. Though I suspect in real life it would be 
a pretty short time.

Nonetheless, should you instead do this asynchronously, instead of 
waiting for the event loop to enter an idle state? This means using 
`after 0` directly, instead of doing `after idle [list after 0...`. I 
haven't tested it, but AFAIK this should also keep the UI active while 
not depending on the state of the event loop.

What benefits does your way have over just passing the entire list 
(without batching) to an async script to do processing in the 
background?

>  	} else {
> -		unlock_index
> +		# Finish the status bar operation.
> +		$::main_status stop
> +
> +		# Report error, if any, based on how many deletions failed.
> +		set deletion_error_cnt [llength $deletion_errors]
> +
> +		if {$deletion_error_cnt == 1} {
> +			error_popup [mc \
> +				"File %s could not be deleted: %s" \
> +				$deletion_error_path \
> +				[lindex $deletion_errors 0] \
> +				]
> +		} elseif {$deletion_error_cnt == $path_cnt} {
> +			error_popup [mc \
> +				"None of the selected files could be deleted." \
> +				]
> +		} elseif {$deletion_error_cnt > 1} {
> +			error_popup [mc \
> +				"%d of the selected files could not be deleted." \
> +				$deletion_error_cnt]
> +		}

The same comment as above applies here: either show error messages for 
all paths, or for none. I don't see why you want to make a single error 
path a special case.

> +
> +		reshow_diff
> +		ui_ready
> +	}
> +}
> +
> +# This function is from the TCL documentation:
> +#
> +#   https://wiki.tcl-lang.org/page/file+exists

Why include the link? My guess is "to give proper credit". Do I guess 
correctly?

> +#
> +# [file exists] returns false if the path does exist but is a symlink to a path
> +# that doesn't exist. This proc returns true if the path exists, regardless of
> +# whether it is a symlink and whether it is broken.
> +proc lexists name {

Nitpick: wrap the "name" in braces like:

  proc lexists {name} {

Also, maybe re-name it to 'path_exists'? 'lexists' is not very intuitive 
unless being used _specifically_ in the context of links. Its _use_ is 
in context of paths, even though it is used to work around links.

> +	expr {![catch {file lstat $name finfo}]}
> +}
> +
> +# Remove as many empty directories as we can starting at the specified path.

Nitpick: maybe change it to something like this?

  Remove as many empty directories as we can starting at the specified 
  path, going up in the directory tree.

It was not obvious to me from reading the comment that you were going up 
the directory tree. I thought you were going across the breadth of the 
directory, and was puzzled why you'd do that.

But maybe that's just me. So, I don't mind if you keep it the way it is 
either.

> +# If we encounter a directory that is not empty, or if a directory deletion
> +# fails, then we stop the operation and return to the caller. Even if this
> +# procedure fails to delete any directories at all, it does not report failure.
> +proc remove_empty_directories {directory_path} {
> +	set parent_path [file dirname $directory_path]
> +
> +	while {$parent_path != $directory_path} {
> +		set contents [glob -nocomplain -dir $directory_path *]
> +
> +		if {[llength $contents] > 0} { break }
> +		if {[catch {file delete -- $directory_path}]} { break }
> +
> +		set directory_path $parent_path
> +		set parent_path [file dirname $directory_path]
>  	}
>  }

I did some quick testing on my system, and it works fine. Thanks.

-- 
Regards,
Pratyush Yadav

Re: [PATCH 2/2] git-gui: revert untracked files by deleting them

[Jonathan Gilbert]

On Sun, Nov 3, 2019 at 1:48 AM Pratyush Yadav me-at-yadavpratyush.com
|GitHub Public/Example Allow| <172q77k4bxwj0zt@sneakemail.com> wrote:
> Hi Jonathan,
>
> Thanks for the quality re-roll. It was a pleasant read :)
>
> I would have suggested just handing off the paths to `git clean`, but it
> unfortunately does not do what we want it to do.
>
> Say we have a directory 'foo' which has one file called 'bar.txt'. That
> file is untracked. Now, I expected `git clean -fd foo/bar.txt` to delete
> 'bar.txt' _and_ 'foo/', but it only deletes bar.txt, and leaves 'foo/'
> intact. What's worse is that since 'foo' is an empty directory, it
> doesn't appear in git-status anymore, and so there is no way the user
> can tell the directory exists unless they go there and do a `ls`.
>
> Maybe something to fix upstream?

Possibly, but I think the implications of such a change in the core
tool are far greater than UI features in Git Gui.

> On 30/10/19 06:48AM, Jonathan Gilbert via GitGitGadget wrote:
> > From: Jonathan Gilbert <JonathanG@iQmetrix.com>
> >
> > Updates the revert_helper procedure to also detect untracked files. If
>
> Typo: s/Updates/Update/ ?

It wasn't a typo, I wrote it as an abbreviated form of basically "This
change updates the revert_helper procedure to ...". But, if that
choice of linguistic construct goes against convention I can change
it. :-)

> > +     # The index is now locked. Some of the paths below include calls that
> > +     # unlock the index (e.g. checked_index). If we reach the end and the
>
> Typo: s/checked_index/checkout_index/

Fixed. :-)

> > +     if {$need_unlock_index} { unlock_index }
>
> Are you sure you want to unlock the index _before_ the cleanup of
> untracked files is done? While it makes sense to unlock the index since
> our "clean" operation would only touch the working tree, and not the
> index, it would also mean people can do things like "Revert hunk" (from
> the context menu). Right now, this operation can not be done on
> untracked files (so this won't be a problem for now), but I do plan on
> adding this in the future, and it wouldn't be obvious from that patch's
> POV that this could be an issue. If someone does a "Revert hunk" on a
> while that is queued for deletion, there might be problems.
>
> Also, would doing an `unlock_index` early allow people to run multiple
> "clean" jobs at the same time? Will that create race conditions that we
> aren't ready to handle?
>
> It also makes sense to evaluate what the downsides of keeping the index
> locked are. So, does keeping the index locked prevent meaningful usage
> of git-gui, making your batched deletion pointless? Is there some reason
> for unlocking it early that I'm missing?
>
> If we do decide keeping the index locked is a good idea, it would be
> troublesome to implement. `checkout_index` is asynchronous. So, when it
> returns, the index won't necessarily be unlocked. It would get unlocked
> some time _after_ the return. I'm not sure how to work around this.

Yeah, when I wrote this I was looking at the fact that the locking of
the index, on the surface, only seems to interact with Git working
copy operations, and as you mention the fact that both tails of the
function (`checkout_index` and `delete_files`) operate asynchronously
means that figuring out _when_ to unlock the index is a bit tricky.
But, based on what you've written I understand that locking the index
also disables UI interaction while it's locked, and that may be
desirable, so we probably do want to keep it locked until both
operations are complete.

What we need here is something I have seen referred to as a "chord" --
conceptually, a function with multiple entrypoints that get called
from different threads, and then the body of the function runs only
when all "notes" on the "chord" have been activated. So in this case,
an object that has one entry-point for "the checkout is complete" and
one entry-point for "the deletion is complete". The body of the
function is `unlock_index`, and then the two asynchronous functions
both call into their "note" on the "chord" instead of directly calling
`unlock_index`. This would mean that the `_close_updateindex` call
that `checkout_index` ultimately drills down to would have to, in some
circumstances, _not_ unlock the index itself. I'll take a hack at this
and see what transpires. :-)

> > +             if {$deletion_failed} {
> > +                     lappend deletion_errors $deletion_error
> > +
> > +                     # Optimistically capture the path that failed, in case
> > +                     # there's only one.
> > +                     set deletion_error_path $path
>
> I don't see why you would do this for _only_ one path. Either do it for
> every path. And since you're recording errors for each path, it makes
> sense to record the corresponding path too. Or, just count how many
> paths failed, and report that. I don't see why we'd want to be between
> those two.
[..]
> > +             } elseif {$deletion_error_cnt == $path_cnt} {
> > +                     error_popup [mc \
> > +                             "None of the selected files could be deleted." \
> > +                             ]
> > +             } elseif {$deletion_error_cnt > 1} {
> > +                     error_popup [mc \
> > +                             "%d of the selected files could not be deleted." \
> > +                             $deletion_error_cnt]
> > +             }
>
> The same comment as above applies here: either show error messages for
> all paths, or for none. I don't see why you want to make a single error
> path a special case.

Consistency -- the prompt that asks whether you want to do a revert
(checkout) or deletion (clean) in the first place has the same split,
where if only one file matches, it identifies the file, but if
multiple files match, it shows the number. For consistency with that,
I used the same logic in the error handling path.

> > -                     [concat $after [list ui_ready]]
> > +                     $path_index \
> > +                     $deletion_errors \
> > +                     $deletion_error_path \
> > +                     $batch_size \
> > +                     ]]
>
> Using `after idle` means in theory we put an undefined maximum time
> limit on the deletion process. Though I suspect in real life it would be
> a pretty short time.
>
> Nonetheless, should you instead do this asynchronously, instead of
> waiting for the event loop to enter an idle state? This means using
> `after 0` directly, instead of doing `after idle [list after 0...`. I
> haven't tested it, but AFAIK this should also keep the UI active while
> not depending on the state of the event loop.
>
> What benefits does your way have over just passing the entire list
> (without batching) to an async script to do processing in the
> background?

I'm not familiar with async scripts, I'm pretty new to Tcl. Is that
basically a mechanism like threads? I wrote the batching simply
because doing the call synchronously meant that if thousands of files
were selected, the UI would freeze hard for several seconds and that
seemed like a bad experience. If there's a better way to delete
thousands of files while keeping the UI responsive and providing
feedback, that'd make more sense, but I don't know how to do it :-)

> > +# This function is from the TCL documentation:
> > +#
> > +#   https://wiki.tcl-lang.org/page/file+exists
>
> Why include the link? My guess is "to give proper credit". Do I guess
> correctly?

Actually it's more to say, "If you're reading through this code and
the specific nuances of this procedure aren't obvious, here's the
procedure's origin. I believe it to be a reliable source, so if that's
good enough for you too, then you don't need to concern yourself with
the implementation details, you can just trust that somebody else put
time into the definition of this above and beyond the scope of the
change where I'm using it." :-)

> > +# [file exists] returns false if the path does exist but is a symlink to a path
> > +# that doesn't exist. This proc returns true if the path exists, regardless of
> > +# whether it is a symlink and whether it is broken.
> > +proc lexists name {
>
> Nitpick: wrap the "name" in braces like:
>
>   proc lexists {name} {
>
> Also, maybe re-name it to 'path_exists'? 'lexists' is not very intuitive
> unless being used _specifically_ in the context of links. Its _use_ is
> in context of paths, even though it is used to work around links.

I can make those changes. I had initially copy/pasted it with no
changes at all, so that, in the context of the preceding explanation,
a future reader could easily verify that, "Yes, this really is exactly
the same procedure definition." :-)

> > +# Remove as many empty directories as we can starting at the specified path.
>
> Nitpick: maybe change it to something like this?
>
>   Remove as many empty directories as we can starting at the specified
>   path, going up in the directory tree.
>
> It was not obvious to me from reading the comment that you were going up
> the directory tree. I thought you were going across the breadth of the
> directory, and was puzzled why you'd do that.
>
> But maybe that's just me. So, I don't mind if you keep it the way it is
> either.

That's legitimate :-) I knew exactly what the function did _before_ I
wrote the comment, after all.

Let me know about those few things, and I'll send in another iteration:

* Is it preferable to use imperative rather than third person singular
in commit messages? ("[I] make the change" vs. "[It] makes the
change")
* Should I simplify the error messages, rather than having parity with
the prompts w.r.t. one vs. multiple items?
* Async scripts for longer background operations, rather than batching
on the UI thread? Can they post ongoing status updates too?
* Should I modify `lexists` to fit the file's conventions, or keep it
an exact copy/paste from the external source?

Thanks very much,

Jonathan Gilbert

Re: [PATCH 2/2] git-gui: revert untracked files by deleting them

[Jonathan Gilbert]

On Sun, Nov 3, 2019 at 1:48 AM Pratyush Yadav me-at-yadavpratyush.com
|GitHub Public/Example Allow| <172q77k4bxwj0zt@sneakemail.com> wrote:
> > +             after idle [list after 0 [list \
> > +                     delete_helper \
> >                       $path_list \
> > -                     [concat $after [list ui_ready]]
> > +                     $path_index \
> > +                     $deletion_errors \
> > +                     $deletion_error_path \
> > +                     $batch_size \
> > +                     ]]
>
> Using `after idle` means in theory we put an undefined maximum time
> limit on the deletion process. Though I suspect in real life it would be
> a pretty short time.
>
> Nonetheless, should you instead do this asynchronously, instead of
> waiting for the event loop to enter an idle state? This means using
> `after 0` directly, instead of doing `after idle [list after 0...`. I
> haven't tested it, but AFAIK this should also keep the UI active while
> not depending on the state of the event loop.
>
> What benefits does your way have over just passing the entire list
> (without batching) to an async script to do processing in the
> background?

I forgot to include this in my point-form list at the end of the
preceding e-mail. What should I be looking into to achieve the same
sort of behaviour, where the UI isn't frozen and the user is getting
period updates about the progress of a large deletion, without using
batches on the UI thread? Is that a thing, or am I misunderstanding
you w.r.t. to doing this asynchronously?

For what it's worth, I used `after idle {after 0 ..}` based on the
recommendation of the Tcler's Wiki [0]:

> An after idle that reschedules itself causes trouble, as the manual warns (PYK 2012-09: the docs no-longer contain this warning, but it still applies):
>
>      At present it is not safe for an idle callback to reschedule itself
>      continuously.  This will interact badly with certain features of
>      Tk that attempt to wait for all idle callbacks to complete.
>      If you would like for an idle callback to reschedule itself
>      continuously, it is better to use a timer handler with a zero
>      timeout period.
>
> Even this warning is oversimplified. Simply scheduling a timer handler with a zero timeout period can mean that the event loop will never be idle, keeping other idle callbacks from firing. The truly safe approach combines both:
>
>     proc doOneStep {} {
>      if { [::sim::one_step] } {
>          after idle [list after 0 doOneStep]
>          #this would work just as well:
>          #after 0 [list after idle doOneStep]
>      }
>      return
>     }
>     sim::init .c 640 480
>     doOneStep
>
> This skeleton should be considered the basic framework for performing long running calculations within a single Tcl interpreter.

Thanks,

Jonathan Gilbert

[0] https://wiki.tcl-lang.org/page/Keep+a+GUI+alive+during+a+long+calculation

Re: [PATCH 0/2] git-gui: revert untracked files by deleting them

[Bert Wesarg]

On Wed, Oct 30, 2019 at 7:48 AM Jonathan Gilbert via GitGitGadget
<gitgitgadget@gmail.com> wrote:
>
> My development environment sometimes makes automatic changes that I don't
> want to keep. In some cases, this involves new files being added that I
> don't want to commit or keep (but I also don't want to outright .gitignore
> forever). I have typically had to explicitly delete those files externally
> to Git Gui, which is a context switch to a manual operation, and I want to
> be able to just select those newly-created untracked files in the UI and
> "revert" them into oblivion.

in Git speak, that operation is called 'clean' (see 'git clean') why
should we overload the 'revert' operation here?

Bert

>
> This change updates the revert_helper proc to check for untracked files as
> well as changes, and then changes to be reverted and untracked files are
> handled by independent blocks of code. The user is prompted independently
> for untracked files, since the underlying action is fundamentally different
> (rm -f). If after deleting untracked files, the directory containing them
> becomes empty, then the directory is removed as well. A new proc
> delete_files takes care of actually deleting the files, using the Tcler's
> Wiki recommended approach for keeping the UI responsive.
>
> This is the second revision of this change, which differs from the first
> version in the following ways:
>
>  * The change is now based on git-gui/master.
>  * With one exception, all lines are at most 80 characters long. The
>    exception has a string literal in it that pushes it to 82 characters. I
>    think it would be messy to try to split it, and I got advice on
>    #git-devel to just let it go to 82 characters.
>  * camelCase is eliminated. I eliminated it from existing code in a separate
>    commit.
>  * try is no longer used anywhere. The code that cares about the result (had
>    code in a catch after a try) uses [catch].
>  * Deletion of files and removal of empty directories is now handled by
>    separate procs.
>  * The deletion of a large number of files does not block the UI during its
>    execution any more.
>  * The revert_helper code no longer uses an epilogue of generic statements
>    to be evaluated on exit.
>  * When deleting files, the UI is notified about the deletion directly
>    instead of doing a full rescan.
>
> Jonathan Gilbert (2):
>   git-gui: consolidate naming conventions
>   git-gui: revert untracked files by deleting them
>
>  lib/index.tcl | 343 ++++++++++++++++++++++++++++++++++++++------------
>  1 file changed, 266 insertions(+), 77 deletions(-)
>
>
> base-commit: b524f6b399c77b40c8bf2b6217585fde4731472a
> Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-436%2Flogiclrd%2Fgit-gui-revert-untracked-v1
> Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-436/logiclrd/git-gui-revert-untracked-v1
> Pull-Request: https://github.com/gitgitgadget/git/pull/436
> --
> gitgitgadget

Re: [PATCH 0/2] git-gui: revert untracked files by deleting them

[Jonathan Gilbert]

On Wed, Oct 30, 2019 at 4:09 AM Bert Wesarg
bert.wesarg-at-googlemail.com |GitHub Public/Example Allow|
<xlwsizdz58ciy7t@sneakemail.com> wrote:
> in Git speak, that operation is called 'clean' (see 'git clean') why
> should we overload the 'revert' operation here?

It's less about overloading the 'revert' operation as overloading the
UI action which is currently called "Revert". I think it would be a
worse experience to have to activate a different option to remove
unwanted files as to remove unwanted changes. Maybe the UI option
could be renamed "Revert & Clean" or something?

As a side note, `git clean untracked-file` won't do anything with a
default configuration, you have to explicitly `-f` it. Not sure if
that's relevant, but it does feel like a higher barrier to entry than
`git revert`.

Thanks,

Jonathan Gilbert

Re: [PATCH 0/2] git-gui: revert untracked files by deleting them

[Pratyush Yadav]

On 30/10/19 12:16PM, Jonathan Gilbert wrote:
> On Wed, Oct 30, 2019 at 4:09 AM Bert Wesarg
> bert.wesarg-at-googlemail.com |GitHub Public/Example Allow|
> <xlwsizdz58ciy7t@sneakemail.com> wrote:
> > in Git speak, that operation is called 'clean' (see 'git clean') why
> > should we overload the 'revert' operation here?
> 
> It's less about overloading the 'revert' operation as overloading the
> UI action which is currently called "Revert". I think it would be a
> worse experience to have to activate a different option to remove
> unwanted files as to remove unwanted changes. Maybe the UI option
> could be renamed "Revert & Clean" or something?

I disagree. There are valid workflows where you want to remove all 
changes to tracked files, but leave untracked ones alone. As an example, 
say you wrote a small script to fix some textual things, like your 
variable re-name patch. Now you run a diff before you commit those 
changes just to be sure, and notice that your script was overzealous and 
made some changes it shouldn't have. So, you clean up all tracked files,
and give your script a fresh start. Here, you don't want to delete your 
script.

And in the other direction, say you want to delete all untracked files 
but have unstaged changes in your tracked files. Combining "Revert" and 
"Clean" does not give you an option to only delete untracked files. So 
you now either have to stash your changes, or run `git clean` from the 
command line.
 
> As a side note, `git clean untracked-file` won't do anything with a
> default configuration, you have to explicitly `-f` it. Not sure if
> that's relevant, but it does feel like a higher barrier to entry than
> `git revert`.

`git revert` is different from our "Revert", though I admit the naming 
is quite confusing. `git revert` creates a new commit that "reverses" 
the changes made in an earlier commit(s). The important point to note 
here is that `git revert` is used when you publish some commits, and 
then realise later they had some bugs. Now you can't just drop those 
commits because that would re-write the history, and it would change all 
the commit hashes since that commit. So, you use `git revert` to create 
a new commit that _textually_ reverses those changes. The buggy commit 
still exists in the tree, but its changes don't.

In contrast, git-gui's "Revert" works on unstaged changes. It does not 
create a new commit. In fact, our revert does something similar to `git 
checkout -- <file>` (it uses `git checkout-index` to be precise).

So I don't think you should, or _can_, use `git revert` for what you 
want to do. And so, I don't see why it is being factored in with this 
discussion. Am I missing something?

-- 
Regards,
Pratyush Yadav

Re: [PATCH 0/2] git-gui: revert untracked files by deleting them

[Jonathan Gilbert]

On Sat, Nov 2, 2019, 8:12 PM Pratyush Yadav, <me@yadavpratyush.com> wrote:
> On 30/10/19 12:16PM, Jonathan Gilbert wrote:
> > It's less about overloading the 'revert' operation as overloading the
> > UI action which is currently called "Revert". I think it would be a
> > worse experience to have to activate a different option to remove
> > unwanted files as to remove unwanted changes. Maybe the UI option
> > could be renamed "Revert & Clean" or something?
>
> I disagree. There are valid workflows where you want to remove all
> changes to tracked files, but leave untracked ones alone. As an example,
> say you wrote a small script to fix some textual things, like your
> variable re-name patch. Now you run a diff before you commit those
> changes just to be sure, and notice that your script was overzealous and
> made some changes it shouldn't have. So, you clean up all tracked files,
> and give your script a fresh start. Here, you don't want to delete your
> script.
>
> And in the other direction, say you want to delete all untracked files
> but have unstaged changes in your tracked files. Combining "Revert" and
> "Clean" does not give you an option to only delete untracked files. So
> you now either have to stash your changes, or run `git clean` from the
> command line.

But, since this is in this GUI interface, you can clearly see which
are which and select only the files you want to affect. If you have so
many files that you have to select indiscriminately, then the
command-line is probably a better choice anyway. In any case, my
proposed change prompts for each part of the change, so you _can_ just
select everything, press ^J, and then say "Yes" to only one of the
prompts.

> > As a side note, `git clean untracked-file` won't do anything with a
> > default configuration, you have to explicitly `-f` it. Not sure if
> > that's relevant, but it does feel like a higher barrier to entry than
> > `git revert`.
>
> `git revert` is different from our "Revert", though I admit the naming
> is quite confusing.
[..]
> So I don't think you should, or _can_, use `git revert` for what you
> want to do. And so, I don't see why it is being factored in with this
> discussion. Am I missing something?

You are entirely correct, this was just a massive brain fart. Every
time I wrote `git revert` in my head I was actually thinking of
exactly what Git Gui does, reverting working copy changes by checking
out the file. I should have written "reverting using `git checkout`".
My apologies!

In my defence, I have over the past few days found myself digging into
code hosted in SVN repositories, and `svn revert` does exactly what
`git checkout` does to an unstaged modified file. :-)

Jonathan Gilbert

On Sat, Nov 2, 2019 at 8:12 PM Pratyush Yadav <me@yadavpratyush.com> wrote:
>
> On 30/10/19 12:16PM, Jonathan Gilbert wrote:
> > On Wed, Oct 30, 2019 at 4:09 AM Bert Wesarg
> > bert.wesarg-at-googlemail.com |GitHub Public/Example Allow|
> > <xlwsizdz58ciy7t@sneakemail.com> wrote:
> > > in Git speak, that operation is called 'clean' (see 'git clean') why
> > > should we overload the 'revert' operation here?
> >
> > It's less about overloading the 'revert' operation as overloading the
> > UI action which is currently called "Revert". I think it would be a
> > worse experience to have to activate a different option to remove
> > unwanted files as to remove unwanted changes. Maybe the UI option
> > could be renamed "Revert & Clean" or something?
>
> I disagree. There are valid workflows where you want to remove all
> changes to tracked files, but leave untracked ones alone. As an example,
> say you wrote a small script to fix some textual things, like your
> variable re-name patch. Now you run a diff before you commit those
> changes just to be sure, and notice that your script was overzealous and
> made some changes it shouldn't have. So, you clean up all tracked files,
> and give your script a fresh start. Here, you don't want to delete your
> script.
>
> And in the other direction, say you want to delete all untracked files
> but have unstaged changes in your tracked files. Combining "Revert" and
> "Clean" does not give you an option to only delete untracked files. So
> you now either have to stash your changes, or run `git clean` from the
> command line.
>
> > As a side note, `git clean untracked-file` won't do anything with a
> > default configuration, you have to explicitly `-f` it. Not sure if
> > that's relevant, but it does feel like a higher barrier to entry than
> > `git revert`.
>
> `git revert` is different from our "Revert", though I admit the naming
> is quite confusing. `git revert` creates a new commit that "reverses"
> the changes made in an earlier commit(s). The important point to note
> here is that `git revert` is used when you publish some commits, and
> then realise later they had some bugs. Now you can't just drop those
> commits because that would re-write the history, and it would change all
> the commit hashes since that commit. So, you use `git revert` to create
> a new commit that _textually_ reverses those changes. The buggy commit
> still exists in the tree, but its changes don't.
>
> In contrast, git-gui's "Revert" works on unstaged changes. It does not
> create a new commit. In fact, our revert does something similar to `git
> checkout -- <file>` (it uses `git checkout-index` to be precise).
>
> So I don't think you should, or _can_, use `git revert` for what you
> want to do. And so, I don't see why it is being factored in with this
> discussion. Am I missing something?
>
> --
> Regards,
> Pratyush Yadav

Re: [PATCH 0/2] git-gui: revert untracked files by deleting them

[Pratyush Yadav]

[Dropping "Jonathan Gilbert <logic@deltaq.org>" from the To: list because 
my mail server says "Domain not found". Putting the GGG address in To: 
instead.]

On 02/11/19 11:41PM, Jonathan Gilbert wrote:
> On Sat, Nov 2, 2019, 8:12 PM Pratyush Yadav, <me@yadavpratyush.com> wrote:
> > On 30/10/19 12:16PM, Jonathan Gilbert wrote:
> > > It's less about overloading the 'revert' operation as overloading the
> > > UI action which is currently called "Revert". I think it would be a
> > > worse experience to have to activate a different option to remove
> > > unwanted files as to remove unwanted changes. Maybe the UI option
> > > could be renamed "Revert & Clean" or something?
> >
> > I disagree. There are valid workflows where you want to remove all
> > changes to tracked files, but leave untracked ones alone. As an example,
> > say you wrote a small script to fix some textual things, like your
> > variable re-name patch. Now you run a diff before you commit those
> > changes just to be sure, and notice that your script was overzealous and
> > made some changes it shouldn't have. So, you clean up all tracked files,
> > and give your script a fresh start. Here, you don't want to delete your
> > script.
> >
> > And in the other direction, say you want to delete all untracked files
> > but have unstaged changes in your tracked files. Combining "Revert" and
> > "Clean" does not give you an option to only delete untracked files. So
> > you now either have to stash your changes, or run `git clean` from the
> > command line.
> 
> But, since this is in this GUI interface, you can clearly see which
> are which and select only the files you want to affect. If you have so
> many files that you have to select indiscriminately, then the
> command-line is probably a better choice anyway. In any case, my
> proposed change prompts for each part of the change, so you _can_ just
> select everything, press ^J, and then say "Yes" to only one of the
> prompts.

Ah yes! Makes sense. I got too tunnel-visioned when thinking about this, 
and lost context. Sorry.
 
> > > As a side note, `git clean untracked-file` won't do anything with a
> > > default configuration, you have to explicitly `-f` it. Not sure if
> > > that's relevant, but it does feel like a higher barrier to entry than
> > > `git revert`.
> >
> > `git revert` is different from our "Revert", though I admit the naming
> > is quite confusing.
> [..]
> > So I don't think you should, or _can_, use `git revert` for what you
> > want to do. And so, I don't see why it is being factored in with this
> > discussion. Am I missing something?
> 
> You are entirely correct, this was just a massive brain fart. Every
> time I wrote `git revert` in my head I was actually thinking of
> exactly what Git Gui does, reverting working copy changes by checking
> out the file. I should have written "reverting using `git checkout`".
> My apologies!
> 
> In my defence, I have over the past few days found myself digging into
> code hosted in SVN repositories, and `svn revert` does exactly what
> `git checkout` does to an unstaged modified file. :-)

I have never used svn, but I can imagine now confusing that might be ;)

-- 
Regards,
Pratyush Yadav

[PATCH v2 0/2] git-gui: revert untracked files by deleting them

[Jonathan Gilbert via GitGitGadget]

My development environment sometimes makes automatic changes that I don't
want to keep. In some cases, this involves new files being added that I
don't want to commit or keep (but I also don't want to outright .gitignore 
forever). I have typically had to explicitly delete those files externally
to Git Gui, which is a context switch to a manual operation, and I want to
be able to just select those newly-created untracked files in the UI and
"revert" them into oblivion.

This change updates the revert_helper proc to check for untracked files as
well as changes, and then changes to be reverted and untracked files are
handled by independent blocks of code. The user is prompted independently
for untracked files, since the underlying action is fundamentally different
(rm -f). If after deleting untracked files, the directory containing them
becomes empty, then the directory is removed as well. A new proc 
delete_files takes care of actually deleting the files, using the Tcler's
Wiki recommended approach for keeping the UI responsive.

Since the checkout_index and delete_files calls are both asynchronous and
could potentially complete in any order, a "chord" is used to coordinate
unlocking the index and returning the UI to a usable state only after both
operations are complete.

This is the third revision of this change, which differs from the second
version in the following ways:

 * A new construct called a "chord" is used to coordinate the completion of
   multiple asynchronous operations that can be kicked off by revert_helper.
   A chord is, conceptually, a procedure with multiple entrypoints whose
   body only executes once all entrypoints have been activated. The 
   chord.tcl file includes comprehensive documentation of how to use the
   chord classes.
   
   
 * Since we might not yet be ready to unlock the index when checkout_index 
   returns, the _close_updateindex proc where it was ultimately unlocking
   the index has been modified so that unlocking the index is the
   responsibility of the caller. Since the $after functionality ran after 
   unlock_index, that is also hoisted out. Nothing in _close_updateindex 
   appears to be asynchronous, so the caller can simply make the calls
   itself upon its return.
   
   
 * lexists has been renamed to path_exists.
   
   
 * Up to 10 deletion errors are now shown simultaneously. I also confirmed
   that Tcl's file delete code will always return a nicely-formatted error
   including the filename, and changed the message so that it isn't also 
   injecting the filename.

Jonathan Gilbert (2):
  git-gui: consolidate naming conventions
  git-gui: revert untracked files by deleting them

 lib/chord.tcl | 137 ++++++++++++++++++
 lib/index.tcl | 376 +++++++++++++++++++++++++++++++++++++++-----------
 2 files changed, 429 insertions(+), 84 deletions(-)
 create mode 100644 lib/chord.tcl


base-commit: b524f6b399c77b40c8bf2b6217585fde4731472a
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-436%2Flogiclrd%2Fgit-gui-revert-untracked-v2
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-436/logiclrd/git-gui-revert-untracked-v2
Pull-Request: https://github.com/gitgitgadget/git/pull/436

Range-diff vs v1:

 1:  da1704c56e = 1:  da1704c56e git-gui: consolidate naming conventions
 2:  0190f6f2f9 ! 2:  9469beb599 git-gui: revert untracked files by deleting them
     @@ -2,24 +2,233 @@
      
          git-gui: revert untracked files by deleting them
      
     -    Updates the revert_helper procedure to also detect untracked files. If
     -    files are present, the user is asked if they want them deleted. A new
     -    proc delete_files with helper delete_helper performs the deletion in
     -    batches, to allow the UI to remain responsive.
     +    Update the revert_helper procedure to also detect untracked files. If
     +    files are present, the user is asked if they want them deleted. Perform
     +    the deletion in batches, using new proc delete_files with helper
     +    delete_helper, to allow the UI to remain responsive. Coordinate the
     +    completion of multiple overlapping asynchronous operations using a new
     +    construct called a "chord". Migrate unlocking of the index out of
     +    _close_updateindex to a responsibility of the caller, to permit paths
     +    that don't directly unlock the index.
      
          Signed-off-by: Jonathan Gilbert <JonathanG@iQmetrix.com>
      
     + diff --git a/lib/chord.tcl b/lib/chord.tcl
     + new file mode 100644
     + --- /dev/null
     + +++ b/lib/chord.tcl
     +@@
     ++# SimpleChord class:
     ++#   Represents a procedure that conceptually has multiple entrypoints that must
     ++#   all be called before the procedure executes. Each entrypoint is called a
     ++#   "note". The chord is only "completed" when all the notes are "activated".
     ++#
     ++#   Constructor:
     ++#     set chord [SimpleChord new {body}]
     ++#       Creates a new chord object with the specified body script. The body
     ++#       script is evaluated at most once, when a note is activated and the
     ++#       chord has no other non-activated notes.
     ++#
     ++#   Methods:
     ++#     $chord eval {script}
     ++#       Runs the specified script in the same context (namespace) in which the
     ++#       chord body will be evaluated. This can be used to set variable values
     ++#       for the chord body to use.
     ++#
     ++#     set note [$chord add_note]
     ++#       Adds a new note to the chord, an instance of ChordNote. Raises an
     ++#       error if the chord is already completed, otherwise the chord is updated
     ++#       so that the new note must also be activated before the body is
     ++#       evaluated.
     ++#
     ++#     $chord notify_note_activation
     ++#       For internal use only.
     ++#
     ++# ChordNote class:
     ++#   Represents a note within a chord, providing a way to activate it. When the
     ++#   final note of the chord is activated (this can be any note in the chord,
     ++#   with all other notes already previously activated in any order), the chord's
     ++#   body is evaluated.
     ++#
     ++#   Constructor:
     ++#     Instances of ChordNote are created internally by calling add_note on
     ++#     SimpleChord objects.
     ++#
     ++#   Methods:
     ++#     [$note is_activated]
     ++#       Returns true if this note has already been activated.
     ++#
     ++#     $note
     ++#       Activates the note, if it has not already been activated, and completes
     ++#       the chord if there are no other notes awaiting activation. Subsequent
     ++#       calls will have no further effect.
     ++#
     ++# Example:
     ++#
     ++#   # Turn off the UI while running a couple of async operations.
     ++#   lock_ui
     ++#
     ++#   set chord [SimpleChord new {
     ++#     unlock_ui
     ++#     # Note: $notice here is not referenced in the calling scope
     ++#     if {$notice} { info_popup $notice }
     ++#   }
     ++#
     ++#   # Configure a note to keep the chord from completing until
     ++#   # all operations have been initiated.
     ++#   set common_note [$chord add_note]
     ++#
     ++#   # Pass notes as 'after' callbacks to other operations
     ++#   async_operation $args [$chord add_note]
     ++#   other_async_operation $args [$chord add_note]
     ++#
     ++#   # Communicate with the chord body
     ++#   if {$condition} {
     ++#     # This sets $notice in the same context that the chord body runs in.
     ++#     $chord eval { set notice "Something interesting" }
     ++#   }
     ++#
     ++#   # Activate the common note, making the chord eligible to complete
     ++#   $common_note
     ++#
     ++# At this point, the chord will complete at some unknown point in the future.
     ++# The common note might have been the first note activated, or the async
     ++# operations might have completed synchronously and the common note is the
     ++# last one, completing the chord before this code finishes, or anything in
     ++# between. The purpose of the chord is to not have to worry about the order.
     ++
     ++oo::class create SimpleChord {
     ++	variable Notes
     ++	variable Body
     ++	variable IsCompleted
     ++
     ++	constructor {body} {
     ++		set Notes [list]
     ++		set Body $body
     ++		set IsCompleted 0
     ++	}
     ++
     ++	method eval {script} {
     ++		namespace eval [self] $script
     ++	}
     ++
     ++	method add_note {} {
     ++		if {$IsCompleted} { error "Cannot add a note to a completed chord" }
     ++
     ++		set note [ChordNote new [self]]
     ++
     ++		lappend Notes $note
     ++
     ++		return $note
     ++	}
     ++
     ++	method notify_note_activation {} {
     ++		if {!$IsCompleted} {
     ++			foreach note $Notes {
     ++				if {![$note is_activated]} { return }
     ++			}
     ++
     ++			set IsCompleted 1
     ++
     ++			namespace eval [self] $Body
     ++			namespace delete [self]
     ++		}
     ++	}
     ++}
     ++
     ++oo::class create ChordNote {
     ++	variable Chord IsActivated
     ++
     ++	constructor {chord} {
     ++		set Chord $chord
     ++		set IsActivated 0
     ++	}
     ++
     ++	method is_activated {} {
     ++		return $IsActivated
     ++	}
     ++
     ++	method unknown {} {
     ++		if {!$IsActivated} {
     ++			set IsActivated 1
     ++			$Chord notify_note_activation
     ++		}
     ++	}
     ++}
     +
       diff --git a/lib/index.tcl b/lib/index.tcl
       --- a/lib/index.tcl
       +++ b/lib/index.tcl
     +@@
     + 	}
     + }
     + 
     +-proc _close_updateindex {fd after} {
     ++proc _close_updateindex {fd} {
     + 	global use_ttk NS
     + 	fconfigure $fd -blocking 1
     + 	if {[catch {close $fd} err]} {
     +@@
     + 	}
     + 
     + 	$::main_status stop
     +-	unlock_index
     +-	uplevel #0 $after
     + }
     + 
     + proc update_indexinfo {msg path_list after} {
     +@@
     + 	global file_states current_diff_path
     + 
     + 	if {$update_index_cp >= $total_cnt} {
     +-		_close_updateindex $fd $after
     ++		_close_updateindex $fd
     ++		unlock_index
     ++		uplevel #0 $after
     + 		return
     + 	}
     + 
     +@@
     + 	global file_states current_diff_path
     + 
     + 	if {$update_index_cp >= $total_cnt} {
     +-		_close_updateindex $fd $after
     ++		_close_updateindex $fd
     ++		unlock_index
     ++		uplevel #0 $after
     + 		return
     + 	}
     + 
     +@@
     + 	global file_states current_diff_path
     + 
     + 	if {$update_index_cp >= $total_cnt} {
     +-		_close_updateindex $fd $after
     ++		_close_updateindex $fd $do_unlock_index $after
     ++		uplevel #0 $after
     + 		return
     + 	}
     + 
      @@
       
       	if {![lock_index begin-update]} return
       
     -+	# The index is now locked. Some of the paths below include calls that
     -+	# unlock the index (e.g. checked_index). If we reach the end and the
     -+	# index is still locked, we need to unlock it before returning.
     -+	set need_unlock_index 1
     ++	# Common "after" functionality that waits until multiple asynchronous
     ++	# operations are complete (by waiting for them to activate their notes
     ++	# on the chord).
     ++	set after_chord [SimpleChord new {
     ++		unlock_index
     ++		if {$should_reshow_diff} { reshow_diff }
     ++		ui_ready
     ++	}]
     ++
     ++	$after_chord eval { set should_reshow_diff 0 }
     ++
     ++	# We don't know how many notes we're going to create (it's dynamic based
     ++	# on conditional paths below), so create a common note that will delay
     ++	# the chord's completion until we activate it, and then activate it
     ++	# after all the other notes have been created.
     ++	set after_common_note [$after_chord add_note]
      +
       	set path_list [list]
      +	set untracked_list [list]
     @@ -33,7 +242,12 @@
       		?M -
       		?T -
       		?D {
     -@@
     + 			lappend path_list $path
     + 			if {$path eq $current_diff_path} {
     +-				set after {reshow_diff;}
     ++				$after_chord eval { set should_reshow_diff 1 }
     + 			}
     + 		}
       		}
       	}
       
     @@ -110,14 +324,10 @@
      +			checkout_index \
      +				$txt \
      +				$path_list \
     -+				[concat $after [list ui_ready]]
     -+
     -+			set need_unlock_index 0
     ++				[$after_chord add_note]
      +		}
      +	}
      +
     -+	if {$need_unlock_index} { unlock_index }
     -+
      +	if {$untracked_cnt > 0} {
      +		# Split question between singular and plural cases, because
      +		# such distinction is needed in some languages.
     @@ -152,35 +362,40 @@
      +			]
      +
      +		if {$reply == 1} {
     -+			delete_files $untracked_list
     ++			$after_chord eval { set should_reshow_diff 1 }
     ++
     ++			delete_files $untracked_list [$after_chord add_note]
      +		}
      +	}
     ++
     ++	# Activate the common note. If no other notes were created, this
     ++	# completes the chord. If other notes were created, then this common
     ++	# note prevents a race condition where the chord might complete early.
     ++	$after_common_note
      +}
      +
      +# Delete all of the specified files, performing deletion in batches to allow the
      +# UI to remain responsive and updated.
     -+proc delete_files {path_list} {
     ++proc delete_files {path_list after} {
      +	# Enable progress bar status updates
      +	$::main_status start [mc "Deleting"] [mc "files"]
      +
      +	set path_index 0
      +	set deletion_errors [list]
     -+	set deletion_error_path "not yet captured"
      +	set batch_size 50
      +
      +	delete_helper \
      +		$path_list \
      +		$path_index \
      +		$deletion_errors \
     -+		$deletion_error_path \
     -+		$batch_size
     ++		$batch_size \
     ++		$after
      +}
      +
      +# Helper function to delete a list of files in batches. Each call deletes one
      +# batch of files, and then schedules a call for the next batch after any UI
      +# messages have been processed.
     -+proc delete_helper \
     -+	{path_list path_index deletion_errors deletion_error_path batch_size} {
     ++proc delete_helper {path_list path_index deletion_errors batch_size after} {
      +	global file_states
      +
      +	set path_cnt [llength $path_list]
     @@ -195,17 +410,13 @@
      +		set deletion_failed [catch {file delete -- $path} deletion_error]
      +
      +		if {$deletion_failed} {
     -+			lappend deletion_errors $deletion_error
     -+
     -+			# Optimistically capture the path that failed, in case
     -+			# there's only one.
     -+			set deletion_error_path $path
     ++			lappend deletion_errors [list "$deletion_error"]
      +		} else {
      +			remove_empty_directories [file dirname $path]
      +
      +			# Don't assume the deletion worked. Remove the file from
      +			# the UI, but only if it no longer exists.
     -+			if {![lexists $path]} {
     ++			if {![path_exists $path]} {
      +				unset file_states($path)
      +				display_file $path __
      +			}
     @@ -231,8 +442,8 @@
      -			[concat $after [list ui_ready]]
      +			$path_index \
      +			$deletion_errors \
     -+			$deletion_error_path \
      +			$batch_size \
     ++			$after
      +			]]
       	} else {
      -		unlock_index
     @@ -242,27 +453,33 @@
      +		# Report error, if any, based on how many deletions failed.
      +		set deletion_error_cnt [llength $deletion_errors]
      +
     -+		if {$deletion_error_cnt == 1} {
     -+			error_popup [mc \
     -+				"File %s could not be deleted: %s" \
     -+				$deletion_error_path \
     -+				[lindex $deletion_errors 0] \
     -+				]
     ++		if {($deletion_error_cnt > 0) && ($deletion_error_cnt <= [MAX_VERBOSE_FILES_IN_DELETION_ERROR])} {
     ++			set error_text "Encountered errors deleting files:\n"
     ++
     ++			foreach deletion_error $deletion_errors {
     ++				append error_text "* [lindex $deletion_error 0]\n"
     ++			}
     ++
     ++			error_popup $error_text
      +		} elseif {$deletion_error_cnt == $path_cnt} {
      +			error_popup [mc \
     -+				"None of the selected files could be deleted." \
     ++				"None of the %d selected files could be deleted." \
     ++				$path_cnt \
      +				]
      +		} elseif {$deletion_error_cnt > 1} {
      +			error_popup [mc \
     -+				"%d of the selected files could not be deleted." \
     -+				$deletion_error_cnt]
     ++				"%d of the %d selected files could not be deleted." \
     ++				$deletion_error_cnt \
     ++				$path_cnt \
     ++				]
      +		}
      +
     -+		reshow_diff
     -+		ui_ready
     ++		uplevel #0 $after
      +	}
      +}
      +
     ++proc MAX_VERBOSE_FILES_IN_DELETION_ERROR {} { return 10; }
     ++
      +# This function is from the TCL documentation:
      +#
      +#   https://wiki.tcl-lang.org/page/file+exists
     @@ -270,14 +487,15 @@
      +# [file exists] returns false if the path does exist but is a symlink to a path
      +# that doesn't exist. This proc returns true if the path exists, regardless of
      +# whether it is a symlink and whether it is broken.
     -+proc lexists name {
     ++proc path_exists {name} {
      +	expr {![catch {file lstat $name finfo}]}
      +}
      +
     -+# Remove as many empty directories as we can starting at the specified path.
     -+# If we encounter a directory that is not empty, or if a directory deletion
     -+# fails, then we stop the operation and return to the caller. Even if this
     -+# procedure fails to delete any directories at all, it does not report failure.
     ++# Remove as many empty directories as we can starting at the specified path,
     ++# walking up the directory tree. If we encounter a directory that is not
     ++# empty, or if a directory deletion fails, then we stop the operation and
     ++# return to the caller. Even if this procedure fails to delete any
     ++# directories at all, it does not report failure.
      +proc remove_empty_directories {directory_path} {
      +	set parent_path [file dirname $directory_path]
      +

-- 
gitgitgadget

[PATCH v2 1/2] git-gui: consolidate naming conventions

[Jonathan Gilbert via GitGitGadget]

From: Jonathan Gilbert <JonathanG@iQmetrix.com>

A few variables in this file use camelCase, while the overall standard
is snake_case. A consistent naming scheme will improve readability of
future changes. To avoid mixing naming changes with semantic changes,
this commit contains only naming changes.

Signed-off-by: Jonathan Gilbert <JonathanG@iQmetrix.com>
---
 lib/index.tcl | 92 +++++++++++++++++++++++++--------------------------
 1 file changed, 46 insertions(+), 46 deletions(-)

diff --git a/lib/index.tcl b/lib/index.tcl
index e07b7a3762..28d4d2a54e 100644
--- a/lib/index.tcl
+++ b/lib/index.tcl
@@ -56,15 +56,15 @@ proc _close_updateindex {fd after} {
 	uplevel #0 $after
 }
 
-proc update_indexinfo {msg pathList after} {
+proc update_indexinfo {msg path_list after} {
 	global update_index_cp
 
 	if {![lock_index update]} return
 
 	set update_index_cp 0
-	set pathList [lsort $pathList]
-	set totalCnt [llength $pathList]
-	set batch [expr {int($totalCnt * .01) + 1}]
+	set path_list [lsort $path_list]
+	set total_cnt [llength $path_list]
+	set batch [expr {int($total_cnt * .01) + 1}]
 	if {$batch > 25} {set batch 25}
 
 	$::main_status start $msg [mc "files"]
@@ -78,26 +78,26 @@ proc update_indexinfo {msg pathList after} {
 	fileevent $fd writable [list \
 		write_update_indexinfo \
 		$fd \
-		$pathList \
-		$totalCnt \
+		$path_list \
+		$total_cnt \
 		$batch \
 		$after \
 		]
 }
 
-proc write_update_indexinfo {fd pathList totalCnt batch after} {
+proc write_update_indexinfo {fd path_list total_cnt batch after} {
 	global update_index_cp
 	global file_states current_diff_path
 
-	if {$update_index_cp >= $totalCnt} {
+	if {$update_index_cp >= $total_cnt} {
 		_close_updateindex $fd $after
 		return
 	}
 
 	for {set i $batch} \
-		{$update_index_cp < $totalCnt && $i > 0} \
+		{$update_index_cp < $total_cnt && $i > 0} \
 		{incr i -1} {
-		set path [lindex $pathList $update_index_cp]
+		set path [lindex $path_list $update_index_cp]
 		incr update_index_cp
 
 		set s $file_states($path)
@@ -119,18 +119,18 @@ proc write_update_indexinfo {fd pathList totalCnt batch after} {
 		display_file $path $new
 	}
 
-	$::main_status update $update_index_cp $totalCnt
+	$::main_status update $update_index_cp $total_cnt
 }
 
-proc update_index {msg pathList after} {
+proc update_index {msg path_list after} {
 	global update_index_cp
 
 	if {![lock_index update]} return
 
 	set update_index_cp 0
-	set pathList [lsort $pathList]
-	set totalCnt [llength $pathList]
-	set batch [expr {int($totalCnt * .01) + 1}]
+	set path_list [lsort $path_list]
+	set total_cnt [llength $path_list]
+	set batch [expr {int($total_cnt * .01) + 1}]
 	if {$batch > 25} {set batch 25}
 
 	$::main_status start $msg [mc "files"]
@@ -144,26 +144,26 @@ proc update_index {msg pathList after} {
 	fileevent $fd writable [list \
 		write_update_index \
 		$fd \
-		$pathList \
-		$totalCnt \
+		$path_list \
+		$total_cnt \
 		$batch \
 		$after \
 		]
 }
 
-proc write_update_index {fd pathList totalCnt batch after} {
+proc write_update_index {fd path_list total_cnt batch after} {
 	global update_index_cp
 	global file_states current_diff_path
 
-	if {$update_index_cp >= $totalCnt} {
+	if {$update_index_cp >= $total_cnt} {
 		_close_updateindex $fd $after
 		return
 	}
 
 	for {set i $batch} \
-		{$update_index_cp < $totalCnt && $i > 0} \
+		{$update_index_cp < $total_cnt && $i > 0} \
 		{incr i -1} {
-		set path [lindex $pathList $update_index_cp]
+		set path [lindex $path_list $update_index_cp]
 		incr update_index_cp
 
 		switch -glob -- [lindex $file_states($path) 0] {
@@ -190,18 +190,18 @@ proc write_update_index {fd pathList totalCnt batch after} {
 		display_file $path $new
 	}
 
-	$::main_status update $update_index_cp $totalCnt
+	$::main_status update $update_index_cp $total_cnt
 }
 
-proc checkout_index {msg pathList after} {
+proc checkout_index {msg path_list after} {
 	global update_index_cp
 
 	if {![lock_index update]} return
 
 	set update_index_cp 0
-	set pathList [lsort $pathList]
-	set totalCnt [llength $pathList]
-	set batch [expr {int($totalCnt * .01) + 1}]
+	set path_list [lsort $path_list]
+	set total_cnt [llength $path_list]
+	set batch [expr {int($total_cnt * .01) + 1}]
 	if {$batch > 25} {set batch 25}
 
 	$::main_status start $msg [mc "files"]
@@ -221,26 +221,26 @@ proc checkout_index {msg pathList after} {
 	fileevent $fd writable [list \
 		write_checkout_index \
 		$fd \
-		$pathList \
-		$totalCnt \
+		$path_list \
+		$total_cnt \
 		$batch \
 		$after \
 		]
 }
 
-proc write_checkout_index {fd pathList totalCnt batch after} {
+proc write_checkout_index {fd path_list total_cnt batch after} {
 	global update_index_cp
 	global file_states current_diff_path
 
-	if {$update_index_cp >= $totalCnt} {
+	if {$update_index_cp >= $total_cnt} {
 		_close_updateindex $fd $after
 		return
 	}
 
 	for {set i $batch} \
-		{$update_index_cp < $totalCnt && $i > 0} \
+		{$update_index_cp < $total_cnt && $i > 0} \
 		{incr i -1} {
-		set path [lindex $pathList $update_index_cp]
+		set path [lindex $path_list $update_index_cp]
 		incr update_index_cp
 		switch -glob -- [lindex $file_states($path) 0] {
 		U? {continue}
@@ -253,7 +253,7 @@ proc write_checkout_index {fd pathList totalCnt batch after} {
 		}
 	}
 
-	$::main_status update $update_index_cp $totalCnt
+	$::main_status update $update_index_cp $total_cnt
 }
 
 proc unstage_helper {txt paths} {
@@ -261,7 +261,7 @@ proc unstage_helper {txt paths} {
 
 	if {![lock_index begin-update]} return
 
-	set pathList [list]
+	set path_list [list]
 	set after {}
 	foreach path $paths {
 		switch -glob -- [lindex $file_states($path) 0] {
@@ -269,19 +269,19 @@ proc unstage_helper {txt paths} {
 		M? -
 		T? -
 		D? {
-			lappend pathList $path
+			lappend path_list $path
 			if {$path eq $current_diff_path} {
 				set after {reshow_diff;}
 			}
 		}
 		}
 	}
-	if {$pathList eq {}} {
+	if {$path_list eq {}} {
 		unlock_index
 	} else {
 		update_indexinfo \
 			$txt \
-			$pathList \
+			$path_list \
 			[concat $after [list ui_ready]]
 	}
 }
@@ -305,7 +305,7 @@ proc add_helper {txt paths} {
 
 	if {![lock_index begin-update]} return
 
-	set pathList [list]
+	set path_list [list]
 	set after {}
 	foreach path $paths {
 		switch -glob -- [lindex $file_states($path) 0] {
@@ -321,19 +321,19 @@ proc add_helper {txt paths} {
 		?M -
 		?D -
 		?T {
-			lappend pathList $path
+			lappend path_list $path
 			if {$path eq $current_diff_path} {
 				set after {reshow_diff;}
 			}
 		}
 		}
 	}
-	if {$pathList eq {}} {
+	if {$path_list eq {}} {
 		unlock_index
 	} else {
 		update_index \
 			$txt \
-			$pathList \
+			$path_list \
 			[concat $after {ui_status [mc "Ready to commit."]}]
 	}
 }
@@ -393,7 +393,7 @@ proc revert_helper {txt paths} {
 
 	if {![lock_index begin-update]} return
 
-	set pathList [list]
+	set path_list [list]
 	set after {}
 	foreach path $paths {
 		switch -glob -- [lindex $file_states($path) 0] {
@@ -401,7 +401,7 @@ proc revert_helper {txt paths} {
 		?M -
 		?T -
 		?D {
-			lappend pathList $path
+			lappend path_list $path
 			if {$path eq $current_diff_path} {
 				set after {reshow_diff;}
 			}
@@ -420,12 +420,12 @@ proc revert_helper {txt paths} {
 	# as they have quite complex plural-form rules. Unfortunately,
 	# msgcat doesn't seem to support that kind of string translation.
 	#
-	set n [llength $pathList]
+	set n [llength $path_list]
 	if {$n == 0} {
 		unlock_index
 		return
 	} elseif {$n == 1} {
-		set query [mc "Revert changes in file %s?" [short_path [lindex $pathList]]]
+		set query [mc "Revert changes in file %s?" [short_path [lindex $path_list]]]
 	} else {
 		set query [mc "Revert changes in these %i files?" $n]
 	}
@@ -444,7 +444,7 @@ proc revert_helper {txt paths} {
 	if {$reply == 1} {
 		checkout_index \
 			$txt \
-			$pathList \
+			$path_list \
 			[concat $after [list ui_ready]]
 	} else {
 		unlock_index
-- 
gitgitgadget

[PATCH v2 2/2] git-gui: revert untracked files by deleting them

[Jonathan Gilbert via GitGitGadget]

From: Jonathan Gilbert <JonathanG@iQmetrix.com>

Update the revert_helper procedure to also detect untracked files. If
files are present, the user is asked if they want them deleted. Perform
the deletion in batches, using new proc delete_files with helper
delete_helper, to allow the UI to remain responsive. Coordinate the
completion of multiple overlapping asynchronous operations using a new
construct called a "chord". Migrate unlocking of the index out of
_close_updateindex to a responsibility of the caller, to permit paths
that don't directly unlock the index.

Signed-off-by: Jonathan Gilbert <JonathanG@iQmetrix.com>
---
 lib/chord.tcl | 137 ++++++++++++++++++++++++
 lib/index.tcl | 288 +++++++++++++++++++++++++++++++++++++++++++-------
 2 files changed, 385 insertions(+), 40 deletions(-)
 create mode 100644 lib/chord.tcl

diff --git a/lib/chord.tcl b/lib/chord.tcl
new file mode 100644
index 0000000000..2d13af14fc
--- /dev/null
+++ b/lib/chord.tcl
@@ -0,0 +1,137 @@
+# SimpleChord class:
+#   Represents a procedure that conceptually has multiple entrypoints that must
+#   all be called before the procedure executes. Each entrypoint is called a
+#   "note". The chord is only "completed" when all the notes are "activated".
+#
+#   Constructor:
+#     set chord [SimpleChord new {body}]
+#       Creates a new chord object with the specified body script. The body
+#       script is evaluated at most once, when a note is activated and the
+#       chord has no other non-activated notes.
+#
+#   Methods:
+#     $chord eval {script}
+#       Runs the specified script in the same context (namespace) in which the
+#       chord body will be evaluated. This can be used to set variable values
+#       for the chord body to use.
+#
+#     set note [$chord add_note]
+#       Adds a new note to the chord, an instance of ChordNote. Raises an
+#       error if the chord is already completed, otherwise the chord is updated
+#       so that the new note must also be activated before the body is
+#       evaluated.
+#
+#     $chord notify_note_activation
+#       For internal use only.
+#
+# ChordNote class:
+#   Represents a note within a chord, providing a way to activate it. When the
+#   final note of the chord is activated (this can be any note in the chord,
+#   with all other notes already previously activated in any order), the chord's
+#   body is evaluated.
+#
+#   Constructor:
+#     Instances of ChordNote are created internally by calling add_note on
+#     SimpleChord objects.
+#
+#   Methods:
+#     [$note is_activated]
+#       Returns true if this note has already been activated.
+#
+#     $note
+#       Activates the note, if it has not already been activated, and completes
+#       the chord if there are no other notes awaiting activation. Subsequent
+#       calls will have no further effect.
+#
+# Example:
+#
+#   # Turn off the UI while running a couple of async operations.
+#   lock_ui
+#
+#   set chord [SimpleChord new {
+#     unlock_ui
+#     # Note: $notice here is not referenced in the calling scope
+#     if {$notice} { info_popup $notice }
+#   }
+#
+#   # Configure a note to keep the chord from completing until
+#   # all operations have been initiated.
+#   set common_note [$chord add_note]
+#
+#   # Pass notes as 'after' callbacks to other operations
+#   async_operation $args [$chord add_note]
+#   other_async_operation $args [$chord add_note]
+#
+#   # Communicate with the chord body
+#   if {$condition} {
+#     # This sets $notice in the same context that the chord body runs in.
+#     $chord eval { set notice "Something interesting" }
+#   }
+#
+#   # Activate the common note, making the chord eligible to complete
+#   $common_note
+#
+# At this point, the chord will complete at some unknown point in the future.
+# The common note might have been the first note activated, or the async
+# operations might have completed synchronously and the common note is the
+# last one, completing the chord before this code finishes, or anything in
+# between. The purpose of the chord is to not have to worry about the order.
+
+oo::class create SimpleChord {
+	variable Notes
+	variable Body
+	variable IsCompleted
+
+	constructor {body} {
+		set Notes [list]
+		set Body $body
+		set IsCompleted 0
+	}
+
+	method eval {script} {
+		namespace eval [self] $script
+	}
+
+	method add_note {} {
+		if {$IsCompleted} { error "Cannot add a note to a completed chord" }
+
+		set note [ChordNote new [self]]
+
+		lappend Notes $note
+
+		return $note
+	}
+
+	method notify_note_activation {} {
+		if {!$IsCompleted} {
+			foreach note $Notes {
+				if {![$note is_activated]} { return }
+			}
+
+			set IsCompleted 1
+
+			namespace eval [self] $Body
+			namespace delete [self]
+		}
+	}
+}
+
+oo::class create ChordNote {
+	variable Chord IsActivated
+
+	constructor {chord} {
+		set Chord $chord
+		set IsActivated 0
+	}
+
+	method is_activated {} {
+		return $IsActivated
+	}
+
+	method unknown {} {
+		if {!$IsActivated} {
+			set IsActivated 1
+			$Chord notify_note_activation
+		}
+	}
+}
diff --git a/lib/index.tcl b/lib/index.tcl
index 28d4d2a54e..64046d6833 100644
--- a/lib/index.tcl
+++ b/lib/index.tcl
@@ -7,7 +7,7 @@ proc _delete_indexlock {} {
 	}
 }
 
-proc _close_updateindex {fd after} {
+proc _close_updateindex {fd} {
 	global use_ttk NS
 	fconfigure $fd -blocking 1
 	if {[catch {close $fd} err]} {
@@ -52,8 +52,6 @@ proc _close_updateindex {fd after} {
 	}
 
 	$::main_status stop
-	unlock_index
-	uplevel #0 $after
 }
 
 proc update_indexinfo {msg path_list after} {
@@ -90,7 +88,9 @@ proc write_update_indexinfo {fd path_list total_cnt batch after} {
 	global file_states current_diff_path
 
 	if {$update_index_cp >= $total_cnt} {
-		_close_updateindex $fd $after
+		_close_updateindex $fd
+		unlock_index
+		uplevel #0 $after
 		return
 	}
 
@@ -156,7 +156,9 @@ proc write_update_index {fd path_list total_cnt batch after} {
 	global file_states current_diff_path
 
 	if {$update_index_cp >= $total_cnt} {
-		_close_updateindex $fd $after
+		_close_updateindex $fd
+		unlock_index
+		uplevel #0 $after
 		return
 	}
 
@@ -233,7 +235,8 @@ proc write_checkout_index {fd path_list total_cnt batch after} {
 	global file_states current_diff_path
 
 	if {$update_index_cp >= $total_cnt} {
-		_close_updateindex $fd $after
+		_close_updateindex $fd $do_unlock_index $after
+		uplevel #0 $after
 		return
 	}
 
@@ -393,61 +396,266 @@ proc revert_helper {txt paths} {
 
 	if {![lock_index begin-update]} return
 
+	# Common "after" functionality that waits until multiple asynchronous
+	# operations are complete (by waiting for them to activate their notes
+	# on the chord).
+	set after_chord [SimpleChord new {
+		unlock_index
+		if {$should_reshow_diff} { reshow_diff }
+		ui_ready
+	}]
+
+	$after_chord eval { set should_reshow_diff 0 }
+
+	# We don't know how many notes we're going to create (it's dynamic based
+	# on conditional paths below), so create a common note that will delay
+	# the chord's completion until we activate it, and then activate it
+	# after all the other notes have been created.
+	set after_common_note [$after_chord add_note]
+
 	set path_list [list]
+	set untracked_list [list]
 	set after {}
 	foreach path $paths {
 		switch -glob -- [lindex $file_states($path) 0] {
 		U? {continue}
+		?O {
+			lappend untracked_list $path
+		}
 		?M -
 		?T -
 		?D {
 			lappend path_list $path
 			if {$path eq $current_diff_path} {
-				set after {reshow_diff;}
+				$after_chord eval { set should_reshow_diff 1 }
 			}
 		}
 		}
 	}
 
+	set path_cnt [llength $path_list]
+	set untracked_cnt [llength $untracked_list]
 
-	# Split question between singular and plural cases, because
-	# such distinction is needed in some languages. Previously, the
-	# code used "Revert changes in" for both, but that can't work
-	# in languages where 'in' must be combined with word from
-	# rest of string (in different way for both cases of course).
-	#
-	# FIXME: Unfortunately, even that isn't enough in some languages
-	# as they have quite complex plural-form rules. Unfortunately,
-	# msgcat doesn't seem to support that kind of string translation.
-	#
-	set n [llength $path_list]
-	if {$n == 0} {
-		unlock_index
-		return
-	} elseif {$n == 1} {
-		set query [mc "Revert changes in file %s?" [short_path [lindex $path_list]]]
-	} else {
-		set query [mc "Revert changes in these %i files?" $n]
-	}
+	if {$path_cnt > 0} {
+		# Split question between singular and plural cases, because
+		# such distinction is needed in some languages. Previously, the
+		# code used "Revert changes in" for both, but that can't work
+		# in languages where 'in' must be combined with word from
+		# rest of string (in different way for both cases of course).
+		#
+		# FIXME: Unfortunately, even that isn't enough in some languages
+		# as they have quite complex plural-form rules. Unfortunately,
+		# msgcat doesn't seem to support that kind of string
+		# translation.
+		#
+		if {$path_cnt == 1} {
+			set query [mc \
+				"Revert changes in file %s?" \
+				[short_path [lindex $path_list]] \
+				]
+		} else {
+			set query [mc \
+				"Revert changes in these %i files?" \
+				$path_cnt]
+		}
 
-	set reply [tk_dialog \
-		.confirm_revert \
-		"[appname] ([reponame])" \
-		"$query
+		set reply [tk_dialog \
+			.confirm_revert \
+			"[appname] ([reponame])" \
+			"$query
 
 [mc "Any unstaged changes will be permanently lost by the revert."]" \
-		question \
-		1 \
-		[mc "Do Nothing"] \
-		[mc "Revert Changes"] \
-		]
-	if {$reply == 1} {
-		checkout_index \
-			$txt \
+			question \
+			1 \
+			[mc "Do Nothing"] \
+			[mc "Revert Changes"] \
+			]
+
+		if {$reply == 1} {
+			checkout_index \
+				$txt \
+				$path_list \
+				[$after_chord add_note]
+		}
+	}
+
+	if {$untracked_cnt > 0} {
+		# Split question between singular and plural cases, because
+		# such distinction is needed in some languages.
+		#
+		# FIXME: Unfortunately, even that isn't enough in some languages
+		# as they have quite complex plural-form rules. Unfortunately,
+		# msgcat doesn't seem to support that kind of string
+		# translation.
+		#
+		if {$untracked_cnt == 1} {
+			set query [mc \
+				"Delete untracked file %s?" \
+				[short_path [lindex $untracked_list]] \
+				]
+		} else {
+			set query [mc \
+				"Delete these %i untracked files?" \
+				$untracked_cnt \
+				]
+		}
+
+		set reply [tk_dialog \
+			.confirm_revert \
+			"[appname] ([reponame])" \
+			"$query
+
+[mc "Files will be permanently deleted."]" \
+			question \
+			1 \
+			[mc "Do Nothing"] \
+			[mc "Delete Files"] \
+			]
+
+		if {$reply == 1} {
+			$after_chord eval { set should_reshow_diff 1 }
+
+			delete_files $untracked_list [$after_chord add_note]
+		}
+	}
+
+	# Activate the common note. If no other notes were created, this
+	# completes the chord. If other notes were created, then this common
+	# note prevents a race condition where the chord might complete early.
+	$after_common_note
+}
+
+# Delete all of the specified files, performing deletion in batches to allow the
+# UI to remain responsive and updated.
+proc delete_files {path_list after} {
+	# Enable progress bar status updates
+	$::main_status start [mc "Deleting"] [mc "files"]
+
+	set path_index 0
+	set deletion_errors [list]
+	set batch_size 50
+
+	delete_helper \
+		$path_list \
+		$path_index \
+		$deletion_errors \
+		$batch_size \
+		$after
+}
+
+# Helper function to delete a list of files in batches. Each call deletes one
+# batch of files, and then schedules a call for the next batch after any UI
+# messages have been processed.
+proc delete_helper {path_list path_index deletion_errors batch_size after} {
+	global file_states
+
+	set path_cnt [llength $path_list]
+
+	set batch_remaining $batch_size
+
+	while {$batch_remaining > 0} {
+		if {$path_index >= $path_cnt} { break }
+
+		set path [lindex $path_list $path_index]
+
+		set deletion_failed [catch {file delete -- $path} deletion_error]
+
+		if {$deletion_failed} {
+			lappend deletion_errors [list "$deletion_error"]
+		} else {
+			remove_empty_directories [file dirname $path]
+
+			# Don't assume the deletion worked. Remove the file from
+			# the UI, but only if it no longer exists.
+			if {![path_exists $path]} {
+				unset file_states($path)
+				display_file $path __
+			}
+		}
+
+		incr path_index 1
+		incr batch_remaining -1
+	}
+
+	# Update the progress bar to indicate that this batch has been
+	# completed. The update will be visible when this procedure returns
+	# and allows the UI thread to process messages.
+	$::main_status update $path_index $path_cnt
+
+	if {$path_index < $path_cnt} {
+		# The Tcler's Wiki lists this as the best practice for keeping
+		# a UI active and processing messages during a long-running
+		# operation.
+
+		after idle [list after 0 [list \
+			delete_helper \
 			$path_list \
-			[concat $after [list ui_ready]]
+			$path_index \
+			$deletion_errors \
+			$batch_size \
+			$after
+			]]
 	} else {
-		unlock_index
+		# Finish the status bar operation.
+		$::main_status stop
+
+		# Report error, if any, based on how many deletions failed.
+		set deletion_error_cnt [llength $deletion_errors]
+
+		if {($deletion_error_cnt > 0) && ($deletion_error_cnt <= [MAX_VERBOSE_FILES_IN_DELETION_ERROR])} {
+			set error_text "Encountered errors deleting files:\n"
+
+			foreach deletion_error $deletion_errors {
+				append error_text "* [lindex $deletion_error 0]\n"
+			}
+
+			error_popup $error_text
+		} elseif {$deletion_error_cnt == $path_cnt} {
+			error_popup [mc \
+				"None of the %d selected files could be deleted." \
+				$path_cnt \
+				]
+		} elseif {$deletion_error_cnt > 1} {
+			error_popup [mc \
+				"%d of the %d selected files could not be deleted." \
+				$deletion_error_cnt \
+				$path_cnt \
+				]
+		}
+
+		uplevel #0 $after
+	}
+}
+
+proc MAX_VERBOSE_FILES_IN_DELETION_ERROR {} { return 10; }
+
+# This function is from the TCL documentation:
+#
+#   https://wiki.tcl-lang.org/page/file+exists
+#
+# [file exists] returns false if the path does exist but is a symlink to a path
+# that doesn't exist. This proc returns true if the path exists, regardless of
+# whether it is a symlink and whether it is broken.
+proc path_exists {name} {
+	expr {![catch {file lstat $name finfo}]}
+}
+
+# Remove as many empty directories as we can starting at the specified path,
+# walking up the directory tree. If we encounter a directory that is not
+# empty, or if a directory deletion fails, then we stop the operation and
+# return to the caller. Even if this procedure fails to delete any
+# directories at all, it does not report failure.
+proc remove_empty_directories {directory_path} {
+	set parent_path [file dirname $directory_path]
+
+	while {$parent_path != $directory_path} {
+		set contents [glob -nocomplain -dir $directory_path *]
+
+		if {[llength $contents] > 0} { break }
+		if {[catch {file delete -- $directory_path}]} { break }
+
+		set directory_path $parent_path
+		set parent_path [file dirname $directory_path]
 	}
 }
 
-- 
gitgitgadget

Re: [PATCH v2 2/2] git-gui: revert untracked files by deleting them

[Pratyush Yadav]

Hi Jonathan,

Thanks for the re-roll. Some comments below. Apart from those comments, 
this looks close to good enough for merging :)

On 07/11/19 07:05AM, Jonathan Gilbert via GitGitGadget wrote:
> From: Jonathan Gilbert <JonathanG@iQmetrix.com>
> 
> Update the revert_helper procedure to also detect untracked files. If
> files are present, the user is asked if they want them deleted. Perform
> the deletion in batches, using new proc delete_files with helper
> delete_helper, to allow the UI to remain responsive. Coordinate the
> completion of multiple overlapping asynchronous operations using a new
> construct called a "chord". Migrate unlocking of the index out of
> _close_updateindex to a responsibility of the caller, to permit paths
> that don't directly unlock the index.
> 
> Signed-off-by: Jonathan Gilbert <JonathanG@iQmetrix.com>
> ---
>  lib/chord.tcl | 137 ++++++++++++++++++++++++
>  lib/index.tcl | 288 +++++++++++++++++++++++++++++++++++++++++++-------
>  2 files changed, 385 insertions(+), 40 deletions(-)
>  create mode 100644 lib/chord.tcl
> 
> diff --git a/lib/chord.tcl b/lib/chord.tcl
> new file mode 100644
> index 0000000000..2d13af14fc
> --- /dev/null
> +++ b/lib/chord.tcl
> @@ -0,0 +1,137 @@

The 'class' documentation [0] suggests adding a "package require TclOO". 
But TclOO ships by default with Tcl 8.6 and above. So, I'm not really 
sure if we need this.

> +# SimpleChord class:
> +#   Represents a procedure that conceptually has multiple entrypoints that must
> +#   all be called before the procedure executes. Each entrypoint is called a
> +#   "note". The chord is only "completed" when all the notes are "activated".
> +#
> +#   Constructor:
> +#     set chord [SimpleChord new {body}]
> +#       Creates a new chord object with the specified body script. The body
> +#       script is evaluated at most once, when a note is activated and the
> +#       chord has no other non-activated notes.
> +#
> +#   Methods:
> +#     $chord eval {script}
> +#       Runs the specified script in the same context (namespace) in which the
> +#       chord body will be evaluated. This can be used to set variable values
> +#       for the chord body to use.
> +#
> +#     set note [$chord add_note]
> +#       Adds a new note to the chord, an instance of ChordNote. Raises an
> +#       error if the chord is already completed, otherwise the chord is updated
> +#       so that the new note must also be activated before the body is
> +#       evaluated.
> +#
> +#     $chord notify_note_activation
> +#       For internal use only.
> +#
> +# ChordNote class:
> +#   Represents a note within a chord, providing a way to activate it. When the
> +#   final note of the chord is activated (this can be any note in the chord,
> +#   with all other notes already previously activated in any order), the chord's
> +#   body is evaluated.
> +#
> +#   Constructor:
> +#     Instances of ChordNote are created internally by calling add_note on
> +#     SimpleChord objects.
> +#
> +#   Methods:
> +#     [$note is_activated]
> +#       Returns true if this note has already been activated.
> +#
> +#     $note
> +#       Activates the note, if it has not already been activated, and completes
> +#       the chord if there are no other notes awaiting activation. Subsequent
> +#       calls will have no further effect.

Nice to see some good documentation!

One nitpick: would it make more sense to have the documentation for a 
method/constructor just above that method/constructor? This way, when 
someone updates the code some time later, they'll also hopefully 
remember to update the documentation. It is much more likely to be stale 
if all of it just stays on the top.

> +#
> +# Example:
> +#
> +#   # Turn off the UI while running a couple of async operations.
> +#   lock_ui
> +#
> +#   set chord [SimpleChord new {
> +#     unlock_ui
> +#     # Note: $notice here is not referenced in the calling scope
> +#     if {$notice} { info_popup $notice }
> +#   }
> +#
> +#   # Configure a note to keep the chord from completing until
> +#   # all operations have been initiated.
> +#   set common_note [$chord add_note]
> +#
> +#   # Pass notes as 'after' callbacks to other operations
> +#   async_operation $args [$chord add_note]
> +#   other_async_operation $args [$chord add_note]
> +#
> +#   # Communicate with the chord body
> +#   if {$condition} {
> +#     # This sets $notice in the same context that the chord body runs in.
> +#     $chord eval { set notice "Something interesting" }
> +#   }
> +#
> +#   # Activate the common note, making the chord eligible to complete
> +#   $common_note
> +#
> +# At this point, the chord will complete at some unknown point in the future.
> +# The common note might have been the first note activated, or the async
> +# operations might have completed synchronously and the common note is the
> +# last one, completing the chord before this code finishes, or anything in
> +# between. The purpose of the chord is to not have to worry about the order.
> +
> +oo::class create SimpleChord {

This comes from the TclOO package, right?

git-gui has its own object-oriented system (lib/class.tcl). It was 
written circa 2007. I suspect something like TclOO did not exist back 
then.

Why not use that? Does it have some limitations that TclOO does not 
have? I do not mind using the "official" OO system. I just want to know 
why exactly you made the choice.

We would end up mixing the two implementations/flavors in the same 
codebase, but as long as they don't interfere with each other and are 
cross compatible (which I think they are, but I haven't tested), I don't 
mind some "modernization" of the codebase. 

More importantly, TclOO ships as part of the core distribution with Tcl 
8.6, but as of now the minimum version required for git-gui is 8.4. So, 
I think we should bump the minimum version (8.6 released circa 2012, so 
most people should have caught up by now I hope).

> +	variable Notes
> +	variable Body
> +	variable IsCompleted

Nitpick: Please use snake_case, here and in other places.

> +
> +	constructor {body} {
> +		set Notes [list]
> +		set Body $body
> +		set IsCompleted 0
> +	}
> +
> +	method eval {script} {
> +		namespace eval [self] $script
> +	}
> +
> +	method add_note {} {
> +		if {$IsCompleted} { error "Cannot add a note to a completed chord" }
> +
> +		set note [ChordNote new [self]]
> +
> +		lappend Notes $note
> +
> +		return $note
> +	}
> +
> +	method notify_note_activation {} {

Since this method is for internal use only, can it be made "private"? 
Does the OO library support something like this?

> +		if {!$IsCompleted} {
> +			foreach note $Notes {
> +				if {![$note is_activated]} { return }
> +			}
> +
> +			set IsCompleted 1
> +
> +			namespace eval [self] $Body
> +			namespace delete [self]
> +		}
> +	}
> +}
> +
> +oo::class create ChordNote {
> +	variable Chord IsActivated
> +
> +	constructor {chord} {
> +		set Chord $chord
> +		set IsActivated 0
> +	}
> +
> +	method is_activated {} {
> +		return $IsActivated
> +	}
> +
> +	method unknown {} {

I'm a bit lost here. This method is named 'unknown', but searching for 
'unknown' in this patch just gives me two results: this line here, and 
then one in a comment at the start of the file.

From what I understand looking at the code, it some sort of a "default" 
method, and is called when you run just `$chord_note`. How exactly is 
this method designated to be the default?

Also, "unknown" makes little sense in this context. Can you rename it to 
something more meaningful? Maybe something like "activate_note"?

> +		if {!$IsActivated} {
> +			set IsActivated 1
> +			$Chord notify_note_activation
> +		}
> +	}
> +}

From what I understand, the "Note" object is effectively used as a 
count. There is no other state associated with it. When I first heard of 
your description of this abstraction, I assumed that a Note would also 
store a script to execute with it. So, when you "activate" a note, it 
would first execute the script, and then mark itself as "activated", and 
notify the chord. Would that abstraction make more sense?

I don't really mind keeping it this way, but I wonder if that design 
would make the abstraction easier to wrap your head around.

> diff --git a/lib/index.tcl b/lib/index.tcl
> index 28d4d2a54e..64046d6833 100644
> --- a/lib/index.tcl
> +++ b/lib/index.tcl
> @@ -7,7 +7,7 @@ proc _delete_indexlock {} {
>  	}
>  }
>  
> -proc _close_updateindex {fd after} {
> +proc _close_updateindex {fd} {
>  	global use_ttk NS
>  	fconfigure $fd -blocking 1
>  	if {[catch {close $fd} err]} {
> @@ -52,8 +52,6 @@ proc _close_updateindex {fd after} {
>  	}
>  
>  	$::main_status stop
> -	unlock_index
> -	uplevel #0 $after

There is a call to unlock_index in the body of the if statement above 
too. Do we want to remove that too, or should it be left alone?

But immediately after the unlocking of the index there, a call to 
`rescan` is made. `rescan` acquired the lock, so it would fail if we do 
not unlock the index there. Note that `rescan` itself is asynchronous. 

Since every call to `_close_updateindex` is followed by an index unlock, 
it would mean the index would be unlocked for the rescan while it is in 
progress (for all calls other than the one from `write_checkout_index`). 
What a mess!

That codepath seems to be taken when a major error happens, and we just 
resign to our fate and get a fresh start by doing a rescan and syncing 
the repo state. So it is quite likely whatever operation we were doing 
failed spectacularly.

Maybe the answer is to swallow the bitter pill and introduce a 
switch/boolean in `_close_updateindex` that controls whether the index 
is unlocked or not. We unlock it when the if statement is not taken, and 
keep the current codepath when it is. I call it a "bitter pill" because 
I'm usually not a huge fan of adding knobs like that in functions. Makes 
the function harder to reason about and makes it more bug prone.

If you can think of a better/cleaner way of working around this, 
suggestions are welcome!

>  }
>  
>  proc update_indexinfo {msg path_list after} {
> @@ -90,7 +88,9 @@ proc write_update_indexinfo {fd path_list total_cnt batch after} {
>  	global file_states current_diff_path
>  
>  	if {$update_index_cp >= $total_cnt} {
> -		_close_updateindex $fd $after
> +		_close_updateindex $fd
> +		unlock_index
> +		uplevel #0 $after
>  		return
>  	}
>  
> @@ -156,7 +156,9 @@ proc write_update_index {fd path_list total_cnt batch after} {
>  	global file_states current_diff_path
>  
>  	if {$update_index_cp >= $total_cnt} {
> -		_close_updateindex $fd $after
> +		_close_updateindex $fd
> +		unlock_index
> +		uplevel #0 $after
>  		return
>  	}
>  
> @@ -233,7 +235,8 @@ proc write_checkout_index {fd path_list total_cnt batch after} {
>  	global file_states current_diff_path
>  
>  	if {$update_index_cp >= $total_cnt} {
> -		_close_updateindex $fd $after
> +		_close_updateindex $fd $do_unlock_index $after
> +		uplevel #0 $after

_close_updateindex takes only one argument, and you pass it 3. 
$do_unlock_index does not seem to be defined anywhere. $after is 
evaluated just after this line, and _close_updateindex doesn't accept 
the argument anyway. I suspect this is a leftover from a different 
approach you tried before this one.

Also, unlike all the other places where _close_updateindex is used, this 
one does not make a call to unlock_index. Is that intended? IIUC, it 
should be intended, since this is the part which uses the "chord", but a 
confirmation would be nice.

>  		return
>  	}
>  
> @@ -393,61 +396,266 @@ proc revert_helper {txt paths} {
>  
>  	if {![lock_index begin-update]} return
>  
> +	# Common "after" functionality that waits until multiple asynchronous
> +	# operations are complete (by waiting for them to activate their notes
> +	# on the chord).

Nitpick: mention what the "multiple asynchronous operations" are exactly 
(i.e, they are the deletion and index checkout operations).

> +	set after_chord [SimpleChord new {
> +		unlock_index
> +		if {$should_reshow_diff} { reshow_diff }
> +		ui_ready
> +	}]
> +
> +	$after_chord eval { set should_reshow_diff 0 }
> +
> +	# We don't know how many notes we're going to create (it's dynamic based
> +	# on conditional paths below), so create a common note that will delay
> +	# the chord's completion until we activate it, and then activate it
> +	# after all the other notes have been created.
> +	set after_common_note [$after_chord add_note]
> +
>  	set path_list [list]
> +	set untracked_list [list]
>  	set after {}

'after' seems to be an unused variable. This line can be deleted.

>  	foreach path $paths {
>  		switch -glob -- [lindex $file_states($path) 0] {
>  		U? {continue}
> +		?O {
> +			lappend untracked_list $path
> +		}
>  		?M -
>  		?T -
>  		?D {
>  			lappend path_list $path
>  			if {$path eq $current_diff_path} {
> -				set after {reshow_diff;}
> +				$after_chord eval { set should_reshow_diff 1 }
>  			}
>  		}
>  		}
>  	}
>  
> +	set path_cnt [llength $path_list]
> +	set untracked_cnt [llength $untracked_list]
>  
> -	# Split question between singular and plural cases, because
> -	# such distinction is needed in some languages. Previously, the
> -	# code used "Revert changes in" for both, but that can't work
> -	# in languages where 'in' must be combined with word from
> -	# rest of string (in different way for both cases of course).
> -	#
> -	# FIXME: Unfortunately, even that isn't enough in some languages
> -	# as they have quite complex plural-form rules. Unfortunately,
> -	# msgcat doesn't seem to support that kind of string translation.
> -	#
> -	set n [llength $path_list]
> -	if {$n == 0} {
> -		unlock_index
> -		return
> -	} elseif {$n == 1} {
> -		set query [mc "Revert changes in file %s?" [short_path [lindex $path_list]]]
> -	} else {
> -		set query [mc "Revert changes in these %i files?" $n]
> -	}
> +	if {$path_cnt > 0} {
> +		# Split question between singular and plural cases, because
> +		# such distinction is needed in some languages. Previously, the
> +		# code used "Revert changes in" for both, but that can't work
> +		# in languages where 'in' must be combined with word from
> +		# rest of string (in different way for both cases of course).
> +		#
> +		# FIXME: Unfortunately, even that isn't enough in some languages
> +		# as they have quite complex plural-form rules. Unfortunately,
> +		# msgcat doesn't seem to support that kind of string
> +		# translation.
> +		#
> +		if {$path_cnt == 1} {
> +			set query [mc \
> +				"Revert changes in file %s?" \
> +				[short_path [lindex $path_list]] \
> +				]
> +		} else {
> +			set query [mc \
> +				"Revert changes in these %i files?" \
> +				$path_cnt]
> +		}
>  
> -	set reply [tk_dialog \
> -		.confirm_revert \
> -		"[appname] ([reponame])" \
> -		"$query
> +		set reply [tk_dialog \
> +			.confirm_revert \
> +			"[appname] ([reponame])" \
> +			"$query
>  
>  [mc "Any unstaged changes will be permanently lost by the revert."]" \
> -		question \
> -		1 \
> -		[mc "Do Nothing"] \
> -		[mc "Revert Changes"] \
> -		]
> -	if {$reply == 1} {
> -		checkout_index \
> -			$txt \
> +			question \
> +			1 \
> +			[mc "Do Nothing"] \
> +			[mc "Revert Changes"] \
> +			]
> +
> +		if {$reply == 1} {
> +			checkout_index \
> +				$txt \
> +				$path_list \
> +				[$after_chord add_note]
> +		}
> +	}
> +
> +	if {$untracked_cnt > 0} {
> +		# Split question between singular and plural cases, because
> +		# such distinction is needed in some languages.
> +		#
> +		# FIXME: Unfortunately, even that isn't enough in some languages
> +		# as they have quite complex plural-form rules. Unfortunately,
> +		# msgcat doesn't seem to support that kind of string
> +		# translation.
> +		#
> +		if {$untracked_cnt == 1} {
> +			set query [mc \
> +				"Delete untracked file %s?" \
> +				[short_path [lindex $untracked_list]] \
> +				]
> +		} else {
> +			set query [mc \
> +				"Delete these %i untracked files?" \
> +				$untracked_cnt \
> +				]
> +		}
> +
> +		set reply [tk_dialog \
> +			.confirm_revert \
> +			"[appname] ([reponame])" \
> +			"$query
> +
> +[mc "Files will be permanently deleted."]" \
> +			question \
> +			1 \
> +			[mc "Do Nothing"] \
> +			[mc "Delete Files"] \
> +			]
> +
> +		if {$reply == 1} {
> +			$after_chord eval { set should_reshow_diff 1 }
> +
> +			delete_files $untracked_list [$after_chord add_note]
> +		}
> +	}
> +
> +	# Activate the common note. If no other notes were created, this
> +	# completes the chord. If other notes were created, then this common
> +	# note prevents a race condition where the chord might complete early.
> +	$after_common_note
> +}
> +
> +# Delete all of the specified files, performing deletion in batches to allow the
> +# UI to remain responsive and updated.
> +proc delete_files {path_list after} {
> +	# Enable progress bar status updates
> +	$::main_status start [mc "Deleting"] [mc "files"]
> +
> +	set path_index 0
> +	set deletion_errors [list]
> +	set batch_size 50
> +
> +	delete_helper \
> +		$path_list \
> +		$path_index \
> +		$deletion_errors \
> +		$batch_size \
> +		$after
> +}
> +
> +# Helper function to delete a list of files in batches. Each call deletes one
> +# batch of files, and then schedules a call for the next batch after any UI
> +# messages have been processed.
> +proc delete_helper {path_list path_index deletion_errors batch_size after} {
> +	global file_states
> +
> +	set path_cnt [llength $path_list]
> +
> +	set batch_remaining $batch_size
> +
> +	while {$batch_remaining > 0} {
> +		if {$path_index >= $path_cnt} { break }
> +
> +		set path [lindex $path_list $path_index]
> +
> +		set deletion_failed [catch {file delete -- $path} deletion_error]
> +
> +		if {$deletion_failed} {
> +			lappend deletion_errors [list "$deletion_error"]
> +		} else {
> +			remove_empty_directories [file dirname $path]
> +
> +			# Don't assume the deletion worked. Remove the file from
> +			# the UI, but only if it no longer exists.
> +			if {![path_exists $path]} {
> +				unset file_states($path)
> +				display_file $path __
> +			}
> +		}
> +
> +		incr path_index 1
> +		incr batch_remaining -1
> +	}
> +
> +	# Update the progress bar to indicate that this batch has been
> +	# completed. The update will be visible when this procedure returns
> +	# and allows the UI thread to process messages.
> +	$::main_status update $path_index $path_cnt
> +
> +	if {$path_index < $path_cnt} {
> +		# The Tcler's Wiki lists this as the best practice for keeping
> +		# a UI active and processing messages during a long-running
> +		# operation.
> +
> +		after idle [list after 0 [list \
> +			delete_helper \
>  			$path_list \
> -			[concat $after [list ui_ready]]
> +			$path_index \
> +			$deletion_errors \
> +			$batch_size \
> +			$after
> +			]]
>  	} else {
> -		unlock_index
> +		# Finish the status bar operation.
> +		$::main_status stop
> +
> +		# Report error, if any, based on how many deletions failed.
> +		set deletion_error_cnt [llength $deletion_errors]
> +
> +		if {($deletion_error_cnt > 0) && ($deletion_error_cnt <= [MAX_VERBOSE_FILES_IN_DELETION_ERROR])} {

Nitpick: please split the line into two.

> +			set error_text "Encountered errors deleting files:\n"

Wrap the string in a `mc [...]` so it can be translated some time in the 
future.

> +
> +			foreach deletion_error $deletion_errors {
> +				append error_text "* [lindex $deletion_error 0]\n"
> +			}
> +
> +			error_popup $error_text
> +		} elseif {$deletion_error_cnt == $path_cnt} {
> +			error_popup [mc \
> +				"None of the %d selected files could be deleted." \
> +				$path_cnt \
> +				]
> +		} elseif {$deletion_error_cnt > 1} {
> +			error_popup [mc \
> +				"%d of the %d selected files could not be deleted." \
> +				$deletion_error_cnt \
> +				$path_cnt \
> +				]

Nice! In case someone in the future wants to have a config variable to 
change this limit, this makes it pretty easy to do so. 

> +		}
> +
> +		uplevel #0 $after
> +	}
> +}
> +
> +proc MAX_VERBOSE_FILES_IN_DELETION_ERROR {} { return 10; }

Why use a procedure, and not a global variable? My guess is to make it 
impossible for some code to change this value by mistake. Do I guess 
correctly?

> +
> +# This function is from the TCL documentation:
> +#
> +#   https://wiki.tcl-lang.org/page/file+exists
> +#
> +# [file exists] returns false if the path does exist but is a symlink to a path
> +# that doesn't exist. This proc returns true if the path exists, regardless of
> +# whether it is a symlink and whether it is broken.
> +proc path_exists {name} {
> +	expr {![catch {file lstat $name finfo}]}
> +}
> +
> +# Remove as many empty directories as we can starting at the specified path,
> +# walking up the directory tree. If we encounter a directory that is not
> +# empty, or if a directory deletion fails, then we stop the operation and
> +# return to the caller. Even if this procedure fails to delete any
> +# directories at all, it does not report failure.
> +proc remove_empty_directories {directory_path} {
> +	set parent_path [file dirname $directory_path]
> +
> +	while {$parent_path != $directory_path} {
> +		set contents [glob -nocomplain -dir $directory_path *]
> +
> +		if {[llength $contents] > 0} { break }
> +		if {[catch {file delete -- $directory_path}]} { break }
> +
> +		set directory_path $parent_path
> +		set parent_path [file dirname $directory_path]
>  	}
>  }

Wew! This took longer than I expected ;)

Tested on Linux. Works fine after fixing the extra arguments passed to 
`_close_updateindex`. Thanks.

[0] https://www.tcl.tk/man/tcl8.6/TclCmd/class.htm

-- 
Regards,
Pratyush Yadav

Re: [PATCH v2 2/2] git-gui: revert untracked files by deleting them

[Jonathan Gilbert]

On Mon, Nov 11, 2019 at 1:25 PM Pratyush Yadav me-at-yadavpratyush.com
|GitHub Public/Example Allow| <172q77k4bxwj0zt@sneakemail.com> wrote:
> On 07/11/19 07:05AM, Jonathan Gilbert via GitGitGadget wrote:
> > --- /dev/null
> > +++ b/lib/chord.tcl
> > @@ -0,0 +1,137 @@
>
> The 'class' documentation [0] suggests adding a "package require TclOO".
> But TclOO ships by default with Tcl 8.6 and above. So, I'm not really
> sure if we need this.

I'm not super familiar with it. I just checked what Tcl version I was
myself running, since it's only there because of the Git Gui
installation bundled with Git for Windows, and it was 8.6, so I
assumed it was fair game to use. It didn't occur to me that you could
already have an older version of Tcl installed and have Git Gui use
it. :-) So, if I'm understanding correctly, `TclOO` as a package could
potentially be used to allow TclOO to be used with 8.4, the minimum
supported version you mention below, and it just happened to work for
me in my testing without that because I have 8.6 installed but that's
technically newer than the supported baseline?

> Nice to see some good documentation!
>
> One nitpick: would it make more sense to have the documentation for a
> method/constructor just above that method/constructor? This way, when
> someone updates the code some time later, they'll also hopefully
> remember to update the documentation. It is much more likely to be stale
> if all of it just stays on the top.

Hmm, what do you think of both? I was thinking of the documentation as
a single self-contained block that someone could read to put together
an understanding of how the chord system fits together, and split out,
it wouldn't have that readability. What about a more abstract
description in a block at the top, and then more technically-detailed
& specific descriptions attached to each method?

> > +oo::class create SimpleChord {
>
> This comes from the TclOO package, right?
>
> git-gui has its own object-oriented system (lib/class.tcl). It was
> written circa 2007. I suspect something like TclOO did not exist back
> then.
>
> Why not use that? Does it have some limitations that TclOO does not
> have? I do not mind using the "official" OO system. I just want to know
> why exactly you made the choice.

Having limited experience with Tcl, I did a Google search for "tcl
object oriented" and ended up writing code using TclOO because that's
what came up. Do you think it makes sense to rework this to use
`class.tcl`, or perhaps instead the opposite: have a policy of using
the standard TclOO going forward, and let the rest of Git Gui
organically upgrade itself to some hypothetical point in the future
where class.tcl is no longer used by anything?

> More importantly, TclOO ships as part of the core distribution with Tcl
> 8.6, but as of now the minimum version required for git-gui is 8.4. So,
> I think we should bump the minimum version (8.6 released circa 2012, so
> most people should have caught up by now I hope).

If I understand correctly, you mentioned that TclOO was intrinsically
available to me because I was using Tcl 8.6, and that the manual
recommends `package require TclOO` -- does that package dependency
permit the use of TclOO on 8.4? If so, could that be a way to avoid
bumping the minimum version required? Simply in the interest of
keeping the scope of the change limited. If not, then bumping the
minimum required version to 8.6 from 2012 doesn't seem entirely
unreasonable either. :-)

> > +     variable Notes
> > +     variable Body
> > +     variable IsCompleted
>
> Nitpick: Please use snake_case, here and in other places.

Okay, yep -- I had copied the convention that I saw in TclOO examples,
conscious of the fact that there might be a standard specific to
object-oriented Tcl.

> > +     method notify_note_activation {} {
>
> Since this method is for internal use only, can it be made "private"?
> Does the OO library support something like this?

I don't think so, because it's called from outside the class. What
we'd be looking for is something like C++'s "friend" syntax. Tcl
doesn't seem to have this. Though, I just did some further Googling,
and saw a hint that it might be possible to bypass member security on
a case-by-case basis, so that the method is private but `ChordNote` is
able to call it anyway. I'll see if I can't figure this out. :-)

> > +     method unknown {} {
>
> I'm a bit lost here. This method is named 'unknown', but searching for
> 'unknown' in this patch just gives me two results: this line here, and
> then one in a comment at the start of the file.
>
> From what I understand looking at the code, it some sort of a "default"
> method, and is called when you run just `$chord_note`. How exactly is
> this method designated to be the default?
>
> Also, "unknown" makes little sense in this context. Can you rename it to
> something more meaningful? Maybe something like "activate_note"?

I think it's the fact that it is named `unknown` that makes it the
"default" method. I think this just needs documentary comments next to
it. The TclOO documentation says:

> obj unknown ?methodName? ?arg ...?
> This method is called when an attempt to invoke the method methodName on
> object obj fails. The arguments that the user supplied to the method are
> given as arg arguments. If methodName is absent, the object was invoked with
> no method name at all (or any other arguments).

It was based on that last sentence that I interpreted `unknown` as,
"This is a mechanism for making an object that can be called like a
method."

> > +             if {!$IsActivated} {
> > +                     set IsActivated 1
> > +                     $Chord notify_note_activation
> > +             }
> > +     }
> > +}
>
> From what I understand, the "Note" object is effectively used as a
> count. There is no other state associated with it. When I first heard of
> your description of this abstraction, I assumed that a Note would also
> store a script to execute with it. So, when you "activate" a note, it
> would first execute the script, and then mark itself as "activated", and
> notify the chord. Would that abstraction make more sense?
>
> I don't really mind keeping it this way, but I wonder if that design
> would make the abstraction easier to wrap your head around.

I learned about the concept of chords and notes from an experimental
language that Microsoft created many years back called "Polyphonic C#"
(which in turn got rolled into "Cw" (C-omega)), and in that
abstraction, the idea was that, well, as a baseline, for starters, we
have methods and each one, conceptually, has an entrypoint with a
certain set of parameters, and when you call that entrypoint, the
parameters are all set and the body runs. With a "chord", you have
more than one entrypoint attached to the same body -- the entrypoints
themselves don't have any logic associated with them individually.
Each note has its own parameter list, and when all the notes have been
called, the body is run with _all_ of those parameters.

I drew some ASCII art, don't know if it'll translate in the message,
but here goes :-)

Basic method (or, if you will, a "chord" with only one "note"):

           (caller)
              |
    void Add(int X, int Y)
              |
      { output(X + Y) }

A "chord" with two "notes":

        (caller)                (caller)
            |                       |
    void AddX(int X)         void AddY(int Y)
            |                       |
            `-----------.-----------'
                        |
                { output(X + Y) }

The specific details differ from what I've written here. In Polyphonic
C#, you don't have to instantiate a chord, you simply start calling
methods, and the runtime matches up complete sets dynamically. (Just
thinking through the implications of this, if the notes aren't all
called at exactly the same rate this obviously leads very easily to
bugs that chew up all memory on incomplete chords. :-P) Also,
Microsoft's language has parameters to each of the notes that are
_all_ passed to the body at once. My implementation here is a "simple"
chord, I didn't bother with arguments, as they aren't needed in this
usage :-) I also found it much simpler to think of implementing the
chord with the activations being explicit instead of implicit. So
instead of saying up front, "Here is my method body and here are its 3
entrypoints", with this implementation the chord is a dynamic object,
you say "Here is my method body" and get back a thing that you can
start tacking entrypoints onto.

But, a "note" in a SimpleChord isn't a counter, it's a latch. The
chord itself is acting sort of like a counter, in that all the notes
need to be activated, but because the notes are latches, activating a
note repeatedly has the same effect as activating it once. There's no
way for one note to interfere with other notes, which wouldn't be the
case if it literally were just a counter.

It seems to me that a chord where each note has a script of its own is
actually basically just a class with methods, I guess with a common
joined epilogue?:

        (caller)                (caller)
            |                       |
    void AddX(int X)         void AddY(int Y)
            |                       |
   { script for AddX }      {script for AddY }
            |                       |
            `-----------.-----------'
                        |
                { common tail?? }

The whole point is that the notes are conceptually different "headers"
into _the same_ body. When you call a note of a chord, it is because
you want the _chord_'s script to run, and the chord is acting as a
construct that says "okay, yes, I'll satisfy your request that I
execute, but you'll have to wait, because I'm going to satisfy _all_
your requests in one go".

> >       $::main_status stop
> > -     unlock_index
> > -     uplevel #0 $after
>
> There is a call to unlock_index in the body of the if statement above
> too. Do we want to remove that too, or should it be left alone?
>
> That codepath seems to be taken when a major error happens, and we just
> resign to our fate and get a fresh start by doing a rescan and syncing
> the repo state. So it is quite likely whatever operation we were doing
> failed spectacularly.
>
> Maybe the answer is to swallow the bitter pill and introduce a
> switch/boolean in `_close_updateindex` that controls whether the index
> is unlocked or not. We unlock it when the if statement is not taken, and
> keep the current codepath when it is. I call it a "bitter pill" because
> I'm usually not a huge fan of adding knobs like that in functions. Makes
> the function harder to reason about and makes it more bug prone.
>
> If you can think of a better/cleaner way of working around this,
> suggestions are welcome!

Hmm, so, yeah, the entire if statement only occurs if it can't close
the file descriptor. Is that something that actually happens? If so,
then it should perhaps be throwing an exception, because having
started a rescan is probably more than the caller bargained for. That
would prevent the callers from unlocking the index out from under the
rescan, and also cancel any other processing they might be doing that
is probably making bad assumptions with a rescan running.

> >       if {$update_index_cp >= $total_cnt} {
> > -             _close_updateindex $fd $after
> > +             _close_updateindex $fd $do_unlock_index $after
>
> _close_updateindex takes only one argument, and you pass it 3.
> $do_unlock_index does not seem to be defined anywhere. $after is
> evaluated just after this line, and _close_updateindex doesn't accept
> the argument anyway. I suspect this is a leftover from a different
> approach you tried before this one.

It is indeed, oops!

> Also, unlike all the other places where _close_updateindex is used, this
> one does not make a call to unlock_index. Is that intended? IIUC, it
> should be intended, since this is the part which uses the "chord", but a
> confirmation would be nice.

Intentional, yes. I'll see if there's a concise way to document this.

> > +     # Common "after" functionality that waits until multiple asynchronous
> > +     # operations are complete (by waiting for them to activate their notes
> > +     # on the chord).
>
> Nitpick: mention what the "multiple asynchronous operations" are exactly
> (i.e, they are the deletion and index checkout operations).

Okeydoke.

> >       set after {}
>
> 'after' seems to be an unused variable. This line can be deleted.

Good catch.

> > +             if {($deletion_error_cnt > 0) && ($deletion_error_cnt <= [MAX_VERBOSE_FILES_IN_DELETION_ERROR])} {
>
> Nitpick: please split the line into two.

Will do.

> > +                     set error_text "Encountered errors deleting files:\n"
>
> Wrap the string in a `mc [...]` so it can be translated some time in the
> future.

Ah, yes, I did that with most messages, this was an oversight.

> > +proc MAX_VERBOSE_FILES_IN_DELETION_ERROR {} { return 10; }
>
> Why use a procedure, and not a global variable? My guess is to make it
> impossible for some code to change this value by mistake. Do I guess
> correctly?

A variable is by definition not a constant. This is the pattern that
came up when I did a search for how one makes a constant in Tcl. ""\_(
``_/ )_/""

Making it a procedure means that if someone wants to put actual logic
behind it in the future, it's already being called as a proc.

> Wew! This took longer than I expected ;)
>
> Tested on Linux. Works fine after fixing the extra arguments passed to
> `_close_updateindex`. Thanks.

Yeah, I did run things as I was changing them to verify, and felt like
I covered everything, I'm surprised I didn't bump into that, obviously
I didn't cover everything after all. Perfect demonstration of why
developers should never be exclusively responsible for testing their
own code :-D

Let me know w.r.t. which OO framework to employ and what that means
for minimum required versions and/or package references.

Thanks very much,

Jonathan Gilbert

Re: [PATCH v2 2/2] git-gui: revert untracked files by deleting them

[Philip Oakley]

On 11/11/2019 21:55, Jonathan Gilbert wrote:
> Basic method (or, if you will, a "chord" with only one "note"):
>
>             (caller)
>                |
>      void Add(int X, int Y)
>                |
>        { output(X + Y) }
>
> A "chord" with two "notes":
>
>          (caller)                (caller)
>              |                       |
>      void AddX(int X)         void AddY(int Y)
>              |                       |
>              `-----------.-----------'
>                          |
>                  { output(X + Y) }
>
> The specific details differ from what I've written here. In Polyphonic
> C#, you don't have to instantiate a chord, you simply start calling
> methods, and the runtime matches up complete sets dynamically.
sounds like "Currying" a function but with the parameters taken in any 
order, though, in a sense, perhaps not generating intermediate functions...

Philip

Re: [PATCH v2 2/2] git-gui: revert untracked files by deleting them

[Jonathan Gilbert]

On Mon, Nov 11, 2019 at 4:59 PM Philip Oakley <philipoakley@iee.email> wrote:
> sounds like "Currying" a function but with the parameters taken in any
> order, though, in a sense, perhaps not generating intermediate functions...

It's like currying if you could pass g(x) = f(x, y) to one block of
code and h(y) = f(x, y) to another block of code, so that each of g
and h are each like curried versions of f that "bake in" one of the
arguments, without having to know which one will get called first. :-)

Jonathan Gilbert

Re: [PATCH v2 2/2] git-gui: revert untracked files by deleting them

[Philip Oakley]

On 12/11/2019 04:49, Jonathan Gilbert wrote:
> On Mon, Nov 11, 2019 at 4:59 PM Philip Oakley <philipoakley@iee.email> wrote:
>> sounds like "Currying" a function but with the parameters taken in any
>> order, though, in a sense, perhaps not generating intermediate functions...
> It's like currying if you could pass g(x) = f(x, y) to one block of
> code and h(y) = f(x, y) to another block of code, so that each of g
> and h are each like curried versions of f that "bake in" one of the
> arguments, without having to know which one will get called first. :-)
>
> Jonathan Gilbert
So that would be called "Chording"...
(Is there a 'proper' technical term for that approach?)
P.

Re: [PATCH v2 2/2] git-gui: revert untracked files by deleting them

[Jonathan Gilbert]

On Tue, Nov 12, 2019 at 4:45 AM Philip Oakley <philipoakley@iee.email> wrote:
> On 12/11/2019 04:49, Jonathan Gilbert wrote:
> > On Mon, Nov 11, 2019 at 4:59 PM Philip Oakley <philipoakley@iee.email> wrote:
> >> sounds like "Currying" a function but with the parameters taken in any
> >> order, though, in a sense, perhaps not generating intermediate functions...
> > It's like currying if you could pass g(x) = f(x, y) to one block of
> > code and h(y) = f(x, y) to another block of code, so that each of g
> > and h are each like curried versions of f that "bake in" one of the
> > arguments, without having to know which one will get called first. :-)
> >
> > Jonathan Gilbert
> So that would be called "Chording"...
> (Is there a 'proper' technical term for that approach?)

Not an entirely implausible term :-) The only other implementation
I've ever seen was Microsoft's "Polyphonic C#", which got rolled into
C-omega. I'm pretty sure, though, that it was never referred to as
something you _do to_ a function, but rather as a _different type_ of
function -- as in, the function hasn't been "chorded", it "is a
chord". Very little literature one way or the other though, and this
is the first actual, live use case for the structure I've encountered
in my years of programming :-)

Jonathan Gilbert

Re: [PATCH v2 2/2] git-gui: revert untracked files by deleting them

[Philip Oakley]

On 12/11/2019 16:29, Jonathan Gilbert wrote:
> On Tue, Nov 12, 2019 at 4:45 AM Philip Oakley <philipoakley@iee.email> wrote:
>> On 12/11/2019 04:49, Jonathan Gilbert wrote:
>>> On Mon, Nov 11, 2019 at 4:59 PM Philip Oakley <philipoakley@iee.email> wrote:
>>>> sounds like "Currying" a function but with the parameters taken in any
>>>> order, though, in a sense, perhaps not generating intermediate functions...
>>> It's like currying if you could pass g(x) = f(x, y) to one block of
>>> code and h(y) = f(x, y) to another block of code, so that each of g
>>> and h are each like curried versions of f that "bake in" one of the
>>> arguments, without having to know which one will get called first. :-)
>>>
>>> Jonathan Gilbert
>> So that would be called "Chording"...
>> (Is there a 'proper' technical term for that approach?)
> Not an entirely implausible term :-) The only other implementation
> I've ever seen was Microsoft's "Polyphonic C#", which got rolled into
> C-omega. I'm pretty sure, though, that it was never referred to as
> something you _do to_ a function, but rather as a _different type_ of
> function -- as in, the function hasn't been "chorded", it "is a
> chord". Very little literature one way or the other though, and this
> is the first actual, live use case for the structure I've encountered
> in my years of programming :-)
>
A little bit of late follow up ;-)

The basic ideas that are embedded in "chording" would appear to be the 
same as those used in Data Flow Diagrams and the older attempts at data 
flow based machines such as the Transputer and it's message passing, and 
out of order execution machines. See 
https://en.wikipedia.org/wiki/Dataflow_architecture etc.

It just looks like it's now moved to the compiler, or JIT (just-in-time) 
compilation, which appears to be the same thing with different branding!

Philip

Re: [PATCH v2 2/2] git-gui: revert untracked files by deleting them

[Pratyush Yadav]

Hi Jonathan,

On 11/11/19 03:55PM, Jonathan Gilbert wrote:
> On Mon, Nov 11, 2019 at 1:25 PM Pratyush Yadav me-at-yadavpratyush.com
> |GitHub Public/Example Allow| <172q77k4bxwj0zt@sneakemail.com> wrote:
> > On 07/11/19 07:05AM, Jonathan Gilbert via GitGitGadget wrote:
> > > --- /dev/null
> > > +++ b/lib/chord.tcl
> > > @@ -0,0 +1,137 @@
> >
> > The 'class' documentation [0] suggests adding a "package require TclOO".
> > But TclOO ships by default with Tcl 8.6 and above. So, I'm not really
> > sure if we need this.
> 
> I'm not super familiar with it. I just checked what Tcl version I was
> myself running, since it's only there because of the Git Gui
> installation bundled with Git for Windows, and it was 8.6, so I
> assumed it was fair game to use. It didn't occur to me that you could
> already have an older version of Tcl installed and have Git Gui use
> it. :-) So, if I'm understanding correctly, `TclOO` as a package could
> potentially be used to allow TclOO to be used with 8.4, the minimum
> supported version you mention below, and it just happened to work for
> me in my testing without that because I have 8.6 installed but that's
> technically newer than the supported baseline?
> 
> > Nice to see some good documentation!
> >
> > One nitpick: would it make more sense to have the documentation for a
> > method/constructor just above that method/constructor? This way, when
> > someone updates the code some time later, they'll also hopefully
> > remember to update the documentation. It is much more likely to be stale
> > if all of it just stays on the top.
> 
> Hmm, what do you think of both? I was thinking of the documentation as
> a single self-contained block that someone could read to put together
> an understanding of how the chord system fits together, and split out,
> it wouldn't have that readability. What about a more abstract
> description in a block at the top, and then more technically-detailed
> & specific descriptions attached to each method?

Since you put it this way, it does make sense to create some flow. I'm 
not sure if these relatively simple methods warrant specific detailed 
documentation.

So, if you can figure out a reasonable split, that'd be great. 
Otherwise, I guess we can just stick with this.
 
> > > +oo::class create SimpleChord {
> >
> > This comes from the TclOO package, right?
> >
> > git-gui has its own object-oriented system (lib/class.tcl). It was
> > written circa 2007. I suspect something like TclOO did not exist back
> > then.
> >
> > Why not use that? Does it have some limitations that TclOO does not
> > have? I do not mind using the "official" OO system. I just want to know
> > why exactly you made the choice.
> 
> Having limited experience with Tcl, I did a Google search for "tcl
> object oriented" and ended up writing code using TclOO because that's
> what came up. Do you think it makes sense to rework this to use
> `class.tcl`, or perhaps instead the opposite: have a policy of using
> the standard TclOO going forward, and let the rest of Git Gui
> organically upgrade itself to some hypothetical point in the future
> where class.tcl is no longer used by anything?

Replacing class.tcl would be a big effort, and seeing how things stand 
as of now in terms of active contributors, I don't think it would happen 
in the near future.

So the question really boils down to "do we want to mix these two 
flavors of OO frameworks?".

If TclOO gives us some benefit over our homegrown framework, or if our 
framework is in some way hard to use, then I would certainly side on 
just sticking with TclOO.

If not, it becomes a question of taste more of less. Which 
implementation do we like more, and which more people would be 
comfortable working with. And whether mixing the two is a good idea or 
not.

That being said, I am more inclined towards using our homegrown 
framework just for the sake of uniformity if nothing else.

So in the end I guess the answer is I dunno.
 
> > More importantly, TclOO ships as part of the core distribution with Tcl
> > 8.6, but as of now the minimum version required for git-gui is 8.4. So,
> > I think we should bump the minimum version (8.6 released circa 2012, so
> > most people should have caught up by now I hope).
> 
> If I understand correctly, you mentioned that TclOO was intrinsically
> available to me because I was using Tcl 8.6, and that the manual
> recommends `package require TclOO` -- does that package dependency
> permit the use of TclOO on 8.4? If so, could that be a way to avoid
> bumping the minimum version required? Simply in the interest of
> keeping the scope of the change limited. If not, then bumping the
> minimum required version to 8.6 from 2012 doesn't seem entirely
> unreasonable either. :-)

I looked around a bit, and it seems that TclOO would not work with 8.4 
[0]. So, a version bump is needed. Unless, of course, you decide to use 
the OO framework provided by class.tcl.

The version can be bumped by editing the line git-gui.sh:33.
 
> > > +     variable Notes
> > > +     variable Body
> > > +     variable IsCompleted
> >
> > Nitpick: Please use snake_case, here and in other places.
> 
> Okay, yep -- I had copied the convention that I saw in TclOO examples,
> conscious of the fact that there might be a standard specific to
> object-oriented Tcl.
> 
> > > +     method notify_note_activation {} {
> >
> > Since this method is for internal use only, can it be made "private"?
> > Does the OO library support something like this?
> 
> I don't think so, because it's called from outside the class. What
> we'd be looking for is something like C++'s "friend" syntax. Tcl
> doesn't seem to have this. Though, I just did some further Googling,
> and saw a hint that it might be possible to bypass member security on
> a case-by-case basis, so that the method is private but `ChordNote` is
> able to call it anyway. I'll see if I can't figure this out. :-)

I don't think too much complexity/hacking is warranted for something 
like this. If you can figure out a really simple way to do it, great! 
Otherwise, just keep it like it is.
 
> > > +     method unknown {} {
> >
> > I'm a bit lost here. This method is named 'unknown', but searching for
> > 'unknown' in this patch just gives me two results: this line here, and
> > then one in a comment at the start of the file.
> >
> > From what I understand looking at the code, it some sort of a "default"
> > method, and is called when you run just `$chord_note`. How exactly is
> > this method designated to be the default?
> >
> > Also, "unknown" makes little sense in this context. Can you rename it to
> > something more meaningful? Maybe something like "activate_note"?
> 
> I think it's the fact that it is named `unknown` that makes it the
> "default" method. I think this just needs documentary comments next to
> it. The TclOO documentation says:

Yes, a comment explaining it is the default would be nice.
 
> > obj unknown ?methodName? ?arg ...?
> > This method is called when an attempt to invoke the method methodName on
> > object obj fails. The arguments that the user supplied to the method are
> > given as arg arguments. If methodName is absent, the object was invoked with
> > no method name at all (or any other arguments).
> 
> It was based on that last sentence that I interpreted `unknown` as,
> "This is a mechanism for making an object that can be called like a
> method."

Looks like this method would also be called if someone misspelled a 
method name for this object. So say if someone by mistake writes 

  $note is_activate

this method would be called. This is a clear bug. So, add a check here 
to make sure 'methodName' is actually absent. And if it isn't, display 
an error. Displaying an error to the user on a programmer error can get 
annoying. But since we don't have something like assertions in git-gui 
yet, maybe that's the best way to get bugs noticed.
 
> > > +             if {!$IsActivated} {
> > > +                     set IsActivated 1
> > > +                     $Chord notify_note_activation
> > > +             }
> > > +     }
> > > +}
> >
> > From what I understand, the "Note" object is effectively used as a
> > count. There is no other state associated with it. When I first heard of
> > your description of this abstraction, I assumed that a Note would also
> > store a script to execute with it. So, when you "activate" a note, it
> > would first execute the script, and then mark itself as "activated", and
> > notify the chord. Would that abstraction make more sense?
> >
> > I don't really mind keeping it this way, but I wonder if that design
> > would make the abstraction easier to wrap your head around.
> 
> I learned about the concept of chords and notes from an experimental
> language that Microsoft created many years back called "Polyphonic C#"
> (which in turn got rolled into "Cw" (C-omega)), and in that
> abstraction, the idea was that, well, as a baseline, for starters, we
> have methods and each one, conceptually, has an entrypoint with a
> certain set of parameters, and when you call that entrypoint, the
> parameters are all set and the body runs. With a "chord", you have
> more than one entrypoint attached to the same body -- the entrypoints
> themselves don't have any logic associated with them individually.
> Each note has its own parameter list, and when all the notes have been
> called, the body is run with _all_ of those parameters.
> 
> I drew some ASCII art, don't know if it'll translate in the message,
> but here goes :-)
> 
> Basic method (or, if you will, a "chord" with only one "note"):
> 
>            (caller)
>               |
>     void Add(int X, int Y)
>               |
>       { output(X + Y) }
> 
> A "chord" with two "notes":
> 
>         (caller)                (caller)
>             |                       |
>     void AddX(int X)         void AddY(int Y)
>             |                       |
>             `-----------.-----------'
>                         |
>                 { output(X + Y) }
> 
> The specific details differ from what I've written here. In Polyphonic
> C#, you don't have to instantiate a chord, you simply start calling
> methods, and the runtime matches up complete sets dynamically. (Just
> thinking through the implications of this, if the notes aren't all
> called at exactly the same rate this obviously leads very easily to
> bugs that chew up all memory on incomplete chords. :-P) Also,
> Microsoft's language has parameters to each of the notes that are
> _all_ passed to the body at once. My implementation here is a "simple"
> chord, I didn't bother with arguments, as they aren't needed in this
> usage :-) I also found it much simpler to think of implementing the
> chord with the activations being explicit instead of implicit. So
> instead of saying up front, "Here is my method body and here are its 3
> entrypoints", with this implementation the chord is a dynamic object,
> you say "Here is my method body" and get back a thing that you can
> start tacking entrypoints onto.
> 
> But, a "note" in a SimpleChord isn't a counter, it's a latch. The
> chord itself is acting sort of like a counter, in that all the notes
> need to be activated, but because the notes are latches, activating a
> note repeatedly has the same effect as activating it once. There's no
> way for one note to interfere with other notes, which wouldn't be the
> case if it literally were just a counter.

Makes sense.
 
> It seems to me that a chord where each note has a script of its own is
> actually basically just a class with methods, I guess with a common
> joined epilogue?:
> 
>         (caller)                (caller)
>             |                       |
>     void AddX(int X)         void AddY(int Y)
>             |                       |
>    { script for AddX }      {script for AddY }
>             |                       |
>             `-----------.-----------'
>                         |
>                 { common tail?? }

Thanks for explaining.

I had a slightly different mental model of the abstraction. The figure 
here is what I had in mind, with the exception being that the two 
functions that the two callers call are independent of each other.

To put it in more detail, what I was thinking of was that you'd create a 
bunch of scripts that had to be evaluated separately, independent of 
each other. Each script is associated with a note. Activating a note 
runs that script. And when all the notes are activated, the common tail 
is executed.

As far as I see, the use of the chord in the patch has just two 
independent operations that need to run a common tail once both are 
complete.

That's not to say it has to be done this way. Your way works just as 
well, just in a slightly different way :)
 
> The whole point is that the notes are conceptually different "headers"
> into _the same_ body. When you call a note of a chord, it is because
> you want the _chord_'s script to run, and the chord is acting as a
> construct that says "okay, yes, I'll satisfy your request that I
> execute, but you'll have to wait, because I'm going to satisfy _all_
> your requests in one go".
> 
> > >       $::main_status stop
> > > -     unlock_index
> > > -     uplevel #0 $after
> >
> > There is a call to unlock_index in the body of the if statement above
> > too. Do we want to remove that too, or should it be left alone?
> >
> > That codepath seems to be taken when a major error happens, and we just
> > resign to our fate and get a fresh start by doing a rescan and syncing
> > the repo state. So it is quite likely whatever operation we were doing
> > failed spectacularly.
> >
> > Maybe the answer is to swallow the bitter pill and introduce a
> > switch/boolean in `_close_updateindex` that controls whether the index
> > is unlocked or not. We unlock it when the if statement is not taken, and
> > keep the current codepath when it is. I call it a "bitter pill" because
> > I'm usually not a huge fan of adding knobs like that in functions. Makes
> > the function harder to reason about and makes it more bug prone.
> >
> > If you can think of a better/cleaner way of working around this,
> > suggestions are welcome!
> 
> Hmm, so, yeah, the entire if statement only occurs if it can't close
> the file descriptor. Is that something that actually happens? If so,
> then it should perhaps be throwing an exception, because having
> started a rescan is probably more than the caller bargained for. That
> would prevent the callers from unlocking the index out from under the
> rescan, and also cancel any other processing they might be doing that
> is probably making bad assumptions with a rescan running.

This seems like defensive programming. It is accounting for something 
_really bad_ happening.

If closing the file descriptor fails, it means the buffer was not 
flushed properly for some reason. Whatever operations we thought we did 
were potentially not completed. So, we just discard all 
assumptions/state, and get a fresh start by doing a rescan. This was 
introduced in d4e890e5 ("git-gui: Make sure we get errors from 
git-update-index", 23-10-2007). The commit message says:

    I'm seeing a lot of silent failures from git-update-index on
    Windows and this is leaving the index.lock file intact, which
    means users are later unable to perform additional operations.

    When the index is locked behind our back and we are unable to
    use it we may need to allow the user to delete the index lock
    and try again.  However our UI state is probably not currect
    as we have assumed that some changes were applied but none of
    them actually did.  A rescan is the easiest (in code anyway)
    solution to correct our UI to show what the index really has
    (or doesn't have).

Since this is a _really_ old commit, I'm not sure if the problem still 
exists today though.

So, this recovery code has to go somewhere. Yes, a rescan is certainly 
more than what the caller wanted, but it is better than working on an 
inconsistent in-memory state of the repo.

The question then becomes where the best place to do so is. This seems 
like a good one if we can get our locking requirements to work with it 
properly.

The glaring problem is that we don't want the rescan to run while the 
deletion task is still running because they will interfere with each 
other. Also, deletion expects the index to be locked, so the rescan and 
deletion should be mutually exclusive.

One quick hack I can think of is to throw an error from this function, 
and let the caller handle it. Then, in the callers that don't have the 
deletion task to worry about, they just call the rescan (to be more 
specific, the body of the if statement - moved to its own function). The 
callers that do have to worry about the deletion somehow schedule it 
after the deletion process finished. Or, they somehow cancel the 
deletion operation, and then run the rescan.

Waiting till the deletion is over can probably be done by polling the 
lock in an `after idle...`.

This is what I can think of at first glance. Maybe I'm missing a better 
and cleaner way?
 
> > >       if {$update_index_cp >= $total_cnt} {
> > > -             _close_updateindex $fd $after
> > > +             _close_updateindex $fd $do_unlock_index $after
> >
> > _close_updateindex takes only one argument, and you pass it 3.
> > $do_unlock_index does not seem to be defined anywhere. $after is
> > evaluated just after this line, and _close_updateindex doesn't accept
> > the argument anyway. I suspect this is a leftover from a different
> > approach you tried before this one.
> 
> It is indeed, oops!
> 
> > Also, unlike all the other places where _close_updateindex is used, this
> > one does not make a call to unlock_index. Is that intended? IIUC, it
> > should be intended, since this is the part which uses the "chord", but a
> > confirmation would be nice.
> 
> Intentional, yes. I'll see if there's a concise way to document this.
> 
> > > +     # Common "after" functionality that waits until multiple asynchronous
> > > +     # operations are complete (by waiting for them to activate their notes
> > > +     # on the chord).
> >
> > Nitpick: mention what the "multiple asynchronous operations" are exactly
> > (i.e, they are the deletion and index checkout operations).
> 
> Okeydoke.
> 
> > >       set after {}
> >
> > 'after' seems to be an unused variable. This line can be deleted.
> 
> Good catch.
> 
> > > +             if {($deletion_error_cnt > 0) && ($deletion_error_cnt <= [MAX_VERBOSE_FILES_IN_DELETION_ERROR])} {
> >
> > Nitpick: please split the line into two.
> 
> Will do.
> 
> > > +                     set error_text "Encountered errors deleting files:\n"
> >
> > Wrap the string in a `mc [...]` so it can be translated some time in the
> > future.
> 
> Ah, yes, I did that with most messages, this was an oversight.
> 
> > > +proc MAX_VERBOSE_FILES_IN_DELETION_ERROR {} { return 10; }
> >
> > Why use a procedure, and not a global variable? My guess is to make it
> > impossible for some code to change this value by mistake. Do I guess
> > correctly?
> 
> A variable is by definition not a constant. This is the pattern that
> came up when I did a search for how one makes a constant in Tcl. ""\_(
> ``_/ )_/""
> 
> Making it a procedure means that if someone wants to put actual logic
> behind it in the future, it's already being called as a proc.

Makes sense.
 
> > Wew! This took longer than I expected ;)
> >
> > Tested on Linux. Works fine after fixing the extra arguments passed to
> > `_close_updateindex`. Thanks.
> 
> Yeah, I did run things as I was changing them to verify, and felt like
> I covered everything, I'm surprised I didn't bump into that, obviously
> I didn't cover everything after all. Perfect demonstration of why
> developers should never be exclusively responsible for testing their
> own code :-D
> 
> Let me know w.r.t. which OO framework to employ and what that means
> for minimum required versions and/or package references.
> 
> Thanks very much,
> 
> Jonathan Gilbert

[0] https://wiki.tcl-lang.org/page/MeTOO

-- 
Regards,
Pratyush Yadav

Re: [PATCH v2 0/2] git-gui: revert untracked files by deleting them

[Pratyush Yadav]

On 07/11/19 07:05AM, Jonathan Gilbert via GitGitGadget wrote:
> My development environment sometimes makes automatic changes that I don't
> want to keep. In some cases, this involves new files being added that I
> don't want to commit or keep (but I also don't want to outright .gitignore 
> forever). I have typically had to explicitly delete those files externally
> to Git Gui, which is a context switch to a manual operation, and I want to
> be able to just select those newly-created untracked files in the UI and
> "revert" them into oblivion.
> 
> This change updates the revert_helper proc to check for untracked files as
> well as changes, and then changes to be reverted and untracked files are
> handled by independent blocks of code. The user is prompted independently
> for untracked files, since the underlying action is fundamentally different
> (rm -f). If after deleting untracked files, the directory containing them
> becomes empty, then the directory is removed as well. A new proc 
> delete_files takes care of actually deleting the files, using the Tcler's
> Wiki recommended approach for keeping the UI responsive.
> 
> Since the checkout_index and delete_files calls are both asynchronous and
> could potentially complete in any order, a "chord" is used to coordinate
> unlocking the index and returning the UI to a usable state only after both
> operations are complete.
> 
> This is the third revision of this change, which differs from the second
> version in the following ways:
> 
>  * A new construct called a "chord" is used to coordinate the completion of
>    multiple asynchronous operations that can be kicked off by revert_helper.
>    A chord is, conceptually, a procedure with multiple entrypoints whose
>    body only executes once all entrypoints have been activated. The 
>    chord.tcl file includes comprehensive documentation of how to use the
>    chord classes.
>    
>    
>  * Since we might not yet be ready to unlock the index when checkout_index 
>    returns, the _close_updateindex proc where it was ultimately unlocking
>    the index has been modified so that unlocking the index is the
>    responsibility of the caller. Since the $after functionality ran after 
>    unlock_index, that is also hoisted out. Nothing in _close_updateindex 
>    appears to be asynchronous, so the caller can simply make the calls
>    itself upon its return.

The cover letter is so much more descriptive than the commit message. It 
would be nice to have all this context and commentary in the commit 
message. Of course, you'd remove the "personal workflow" bit and some 
other stuff, but most of this can be copied verbatim.

Also, like I mentioned in the review of your second patch, 
`_close_updateindex` _does_ have an asynchronous component 
unfortunately.
    
>    
>  * lexists has been renamed to path_exists.
>    
>    
>  * Up to 10 deletion errors are now shown simultaneously. I also confirmed
>    that Tcl's file delete code will always return a nicely-formatted error
>    including the filename, and changed the message so that it isn't also 
>    injecting the filename.

-- 
Regards,
Pratyush Yadav

[PATCH v3 0/2] git-gui: revert untracked files by deleting them

[Jonathan Gilbert via GitGitGadget]

My development environment sometimes makes automatic changes that I don't
want to keep. In some cases, this involves new files being added that I
don't want to commit or keep (but I also don't want to outright .gitignore 
forever). I have typically had to explicitly delete those files externally
to Git Gui, which is a context switch to a manual operation, and I want to
be able to just select those newly-created untracked files in the UI and
"revert" them into oblivion.

This change updates the revert_helper proc to check for untracked files as
well as changes, and then changes to be reverted and untracked files are
handled by independent blocks of code. The user is prompted independently
for untracked files, since the underlying action is fundamentally different
(rm -f). If after deleting untracked files, the directory containing them
becomes empty, then the directory is removed as well. A new proc 
delete_files takes care of actually deleting the files, using the Tcler's
Wiki recommended approach for keeping the UI responsive.

Since the checkout_index and delete_files calls are both asynchronous and
could potentially complete in any order, a "chord" is used to coordinate
unlocking the index and returning the UI to a usable state only after both
operations are complete.

The _close_updateindex proc contains error handling (added in d4e890e5) that
has the potential to interact badly with unlock_index running at the
completion of an async operation. I have refactored the procedure into
separate procs _close_updateindex and rescan_on_error, and the original
functionality is captured with _close_updateindex_rescan_on_error. Call
sites have been updated appropriately, and checkout_index has been reworked
to take a functor that captures any errors that occur in a caller-defined
way. revert_helper uses this to supply a lambda function that stashes the
error within the chord's body namespace, so that it can call rescan_on_error 
when the chord is completed, which might be substantially after 
checkout_index encounters its error. If a rescan is called for, it is done
once the deletion is complete.

This is the fourth revision of this change, which differs from the third
version in the following ways:

 * Merged some of the wording from the cover letter into the commit message.
   
   
 * The Tcl/Tk dependency is updated to 8.6.
   
   
 * The chord.tcl documentation has been reworked, moving the mechanistic
   class/member documentation next to the declarations, and including a more
   "human-readable" holistic explanation at the top.
   
   
 * Class variables defined within chord.tcl have snake_case names. When I
   made this switch, I saw one possible reason why the convention from the
   Tcl documentation was different: it's quite common to have a parameter to
   the constructor with the same name as a class variable, and if the names
   are literally identical then they conflict in the namespace (e.g. set
   body $body).
   
   
 * Removed unnecessary variable from revert_helper in index.tcl, added
   comments and split long line per feedback.
   
   
 * _close_updateindex's error handling is split out to new proc 
   rescan_on_error, and _close_updateindex_rescan_on_error calls 
   rescan_on_error if it catches an error from _close_updateindex. Most call
   sites are updated to call the wrapper function, but the split is crucial
   for error handling within revert_helper.
   
   
 * checkout_index uses the _close_updateindex without the error handler, and
   instead takes a functor from the caller that allows the caller to do
   whatever it wants with any errors that occur (but without abnormally
   terminating the execution of checkout_index the way throwing an error
   would).
   
   
 * revert_helper is where the most meaningful change is. The $after_chord 
   body now checks for a stashed error, and if there is one, it calls 
   rescan_on_error. I create a lambda function $capture_error that takes
   whatever error message is passed to it and stashes it in $after_chord's
   namespace. Then, this is passed to checkout_index. The result is that if
   an error happens closing the index, the error message is passed back up,
   and then the checkout note is activated, but the $after_chord body
   doesn't execute until the deletion note is also activated, delaying the
   rescan until after the deletion is complete too.
   
   

On Mon, Nov 11, 2019 at 1:25 PM Pratyush Yadav me@yadavpratyush.com
[me@yadavpratyush.com] wrote:

> The 'class' documentation [0] suggests adding a "package require TclOO". But
TclOO ships by default with Tcl 8.6 and above. So, I'm not really sure if we
need this.


I couldn't find any evidence that it is required in my testing.

On Tue, Nov 12, 2019 at 1:35 PM Pratyush Yadav me@yadavpratyush.com
[me@yadavpratyush.com] wrote:

> > > > +oo::class create SimpleChord {


This comes from the TclOO package, right?

git-gui has its own object-oriented system (lib/class.tcl). It was written
circa 2007. I suspect something like TclOO did not exist back then.

Why not use that? Does it have some limitations that TclOO does not have? I
do not mind using the "official" OO system. I just want to know why exactly
you made the choice.


Having limited experience with Tcl, I did a Google search for "tcl object
oriented" and ended up writing code using TclOO because that's what came up.
Do you think it makes sense to rework this to useclass.tcl, or perhaps
instead the opposite: have a policy of using the standard TclOO going
forward, and let the rest of Git Gui organically upgrade itself to some
hypothetical point in the future where class.tcl is no longer used by
anything?


Replacing class.tcl would be a big effort, and seeing how things stand as of
now in terms of active contributors, I don't think it would happen in the
near future.

So the question really boils down to "do we want to mix these two flavors of
OO frameworks?".

If TclOO gives us some benefit over our homegrown framework, or if our
framework is in some way hard to use, then I would certainly side on just
sticking with TclOO.


It looks like the "treat an object as a method" functionality that the 
unknown method provides is not easily duplicated with class.tcl. It would be
possible to just replace it with a named method, but the code using it
wouldn't look as nice. Also, not that it matters in this instance, but
purely as a matter of principle, from what I've read, it seems that TclOO is
significantly supported by native code in the runtime and has much better
performance and far less overhead than all pre-8.6 OO solutions. This
suggests that a long-term goal of eliminating class.tcl might not be a bad
idea. I haven't seen any way that having chord.tcl use TclOO could interfere
with other, unrelated things using class.tcl.

> > > >  * method notify_note_activation {} {


Since this method is for internal use only, can it be made "private"? Does
the OO library support something like this?


I don't think so, because it's called from outside the class. What we'd be
looking for is something like C++'s "friend" syntax. Tcl doesn't seem to
have this. Though, I just did some further Googling, and saw a hint that it
might be possible to bypass member security on a case-by-case basis, so that
the method is private but ChordNote is able to call it anyway. I'll see if I
can't figure this out. :-)


I don't think too much complexity/hacking is warranted for something like
this. If you can figure out a really simple way to do it, great! Otherwise,
just keep it like it is.


It seems that there isn't any way in TclOO to get into a class without it
having a public "door", whether it's the method itself, or some "accessor"
method that returns its [my] functor. You can choose to unexport a method,
but once you do that, there doesn't appear to exist any way at all to
override this for just one call site.

> > "This is a mechanism for making an object that can be called like a method."


Looks like this method would also be called if someone misspelled a method
name for this object. So say if someone by mistake writes

 $note is_activate

this method would be called. This is a clear bug. So, add a check here to
make sure 'methodName' is actually absent. And if it isn't, display an
error. Displaying an error to the user on a programmer error can get
annoying. But since we don't have something like assertions in git-gui yet,
maybe that's the best way to get bugs noticed.


I did some testing and discovered that I was mistaken, if unknown has no
parameters then it cannot receive calls to unknown method names, these
generate errors. As written, it is only capable of processing calls against
the object itself.

> > Hmm, so, yeah, the entire if statement only occurs if it can't close the
file descriptor. Is that something that actually happens? If so, then it
should perhaps be throwing an exception, because having started a rescan is
probably more than the caller bargained for. That would prevent the callers
from unlocking the index out from under the rescan, and also cancel any
other processing they might be doing that is probably making bad assumptions
with a rescan running.


This seems like defensive programming. It is accounting for somethingreally
bad happening.


[..]

> So, this recovery code has to go somewhere. Yes, a rescan is certainly more
than what the caller wanted, but it is better than working on an
inconsistent in-memory state of the repo.

The question then becomes where the best place to do so is. This seems like
a good one if we can get our locking requirements to work with it properly.>
The glaring problem is that we don't want the rescan to run while the
deletion task is still running because they will interfere with each other.
Also, deletion expects the index to be locked, so the rescan and deletion
should be mutually exclusive.


I came up with a fairly concise way to defer the rescan until all async
operations are completed, by splitting the error handling out into a
separate method and then making this flow call that method from the
$after_chord body.

Jonathan Gilbert (2):
  git-gui: consolidate naming conventions
  git-gui: revert untracked files by deleting them

 git-gui.sh    |   4 +-
 lib/chord.tcl | 160 ++++++++++++++++
 lib/index.tcl | 500 +++++++++++++++++++++++++++++++++++++-------------
 3 files changed, 538 insertions(+), 126 deletions(-)
 create mode 100644 lib/chord.tcl


base-commit: b524f6b399c77b40c8bf2b6217585fde4731472a
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-436%2Flogiclrd%2Fgit-gui-revert-untracked-v3
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-436/logiclrd/git-gui-revert-untracked-v3
Pull-Request: https://github.com/gitgitgadget/git/pull/436

Range-diff vs v2:

 1:  da1704c56e = 1:  da1704c56e git-gui: consolidate naming conventions
 2:  9469beb599 ! 2:  dc12c1668d git-gui: revert untracked files by deleting them
     @@ -2,66 +2,72 @@
      
          git-gui: revert untracked files by deleting them
      
     -    Update the revert_helper procedure to also detect untracked files. If
     -    files are present, the user is asked if they want them deleted. Perform
     -    the deletion in batches, using new proc delete_files with helper
     -    delete_helper, to allow the UI to remain responsive. Coordinate the
     -    completion of multiple overlapping asynchronous operations using a new
     -    construct called a "chord". Migrate unlocking of the index out of
     -    _close_updateindex to a responsibility of the caller, to permit paths
     -    that don't directly unlock the index.
     +    Update the revert_helper proc to check for untracked files as well as
     +    changes, and then handle changes to be reverted and untracked files with
     +    independent blocks of code. Prompt the user independently for untracked
     +    files, since the underlying action is fundamentally different (rm -f).
     +    If after deleting untracked files, the directory containing them becomes
     +    empty, then remove the directory as well. Migrate unlocking of the index
     +    out of _close_updateindex to a responsibility of the caller, to permit
     +    paths that don't directly unlock the index, and refactor the error
     +    handling added in d4e890e5 so that callers can make flow control
     +    decisions in the event of errors.
     +
     +    A new proc delete_files takes care of actually deleting the files in
     +    batches, using the Tcler's Wiki recommended approach for keeping the UI
     +    responsive.
     +
     +    Since the checkout_index and delete_files calls are both asynchronous
     +    and could potentially complete in any order, a "chord" is used to
     +    coordinate unlocking the index and returning the UI to a usable state
     +    only after both operations are complete. The `SimpleChord` class,
     +    based on TclOO (Tcl/Tk 8.6), is added in this commit.
      
          Signed-off-by: Jonathan Gilbert <JonathanG@iQmetrix.com>
      
     + diff --git a/git-gui.sh b/git-gui.sh
     + --- a/git-gui.sh
     + +++ b/git-gui.sh
     +@@
     + ##
     + ## Tcl/Tk sanity check
     + 
     +-if {[catch {package require Tcl 8.4} err]
     +- || [catch {package require Tk  8.4} err]
     ++if {[catch {package require Tcl 8.6} err]
     ++ || [catch {package require Tk  8.6} err]
     + } {
     + 	catch {wm withdraw .}
     + 	tk_messageBox \
     +
       diff --git a/lib/chord.tcl b/lib/chord.tcl
       new file mode 100644
       --- /dev/null
       +++ b/lib/chord.tcl
      @@
     -+# SimpleChord class:
     -+#   Represents a procedure that conceptually has multiple entrypoints that must
     -+#   all be called before the procedure executes. Each entrypoint is called a
     -+#   "note". The chord is only "completed" when all the notes are "activated".
     -+#
     -+#   Constructor:
     -+#     set chord [SimpleChord new {body}]
     -+#       Creates a new chord object with the specified body script. The body
     -+#       script is evaluated at most once, when a note is activated and the
     -+#       chord has no other non-activated notes.
     -+#
     -+#   Methods:
     -+#     $chord eval {script}
     -+#       Runs the specified script in the same context (namespace) in which the
     -+#       chord body will be evaluated. This can be used to set variable values
     -+#       for the chord body to use.
     -+#
     -+#     set note [$chord add_note]
     -+#       Adds a new note to the chord, an instance of ChordNote. Raises an
     -+#       error if the chord is already completed, otherwise the chord is updated
     -+#       so that the new note must also be activated before the body is
     -+#       evaluated.
     -+#
     -+#     $chord notify_note_activation
     -+#       For internal use only.
     -+#
     -+# ChordNote class:
     -+#   Represents a note within a chord, providing a way to activate it. When the
     -+#   final note of the chord is activated (this can be any note in the chord,
     -+#   with all other notes already previously activated in any order), the chord's
     -+#   body is evaluated.
     ++# Simple Chord for Tcl
      +#
     -+#   Constructor:
     -+#     Instances of ChordNote are created internally by calling add_note on
     -+#     SimpleChord objects.
     ++# A "chord" is a method with more than one entrypoint and only one body, such
     ++# that the body runs only once all the entrypoints have been called by
     ++# different asynchronous tasks. In this implementation, the chord is defined
     ++# dynamically for each invocation. A SimpleChord object is created, supplying
     ++# body script to be run when the chord is completed, and then one or more notes
     ++# are added to the chord. Each note can be called like a proc, and returns
     ++# immediately if the chord isn't yet complete. When the last remaining note is
     ++# called, the body runs before the note returns.
      +#
     -+#   Methods:
     -+#     [$note is_activated]
     -+#       Returns true if this note has already been activated.
     ++# The SimpleChord class has a constructor that takes the body script, and a
     ++# method add_note that returns a note object. Since the body script does not
     ++# run in the context of the procedure that defined it, a mechanism is provided
     ++# for injecting variables into the chord for use by the body script. The
     ++# activation of a note is idempotent; multiple calls have the same effect as
     ++# a simple call.
      +#
     -+#     $note
     -+#       Activates the note, if it has not already been activated, and completes
     -+#       the chord if there are no other notes awaiting activation. Subsequent
     -+#       calls will have no further effect.
     ++# If you are invoking asynchronous operations with chord notes as completion
     ++# callbacks, and there is a possibility that earlier operations could complete
     ++# before later ones are started, it is a good practice to create a "common"
     ++# note on the chord that prevents it from being complete until you're certain
     ++# you've added all the notes you need.
      +#
      +# Example:
      +#
     @@ -97,61 +103,105 @@
      +# last one, completing the chord before this code finishes, or anything in
      +# between. The purpose of the chord is to not have to worry about the order.
      +
     ++# SimpleChord class:
     ++#   Represents a procedure that conceptually has multiple entrypoints that must
     ++#   all be called before the procedure executes. Each entrypoint is called a
     ++#   "note". The chord is only "completed" when all the notes are "activated".
      +oo::class create SimpleChord {
     -+	variable Notes
     -+	variable Body
     -+	variable IsCompleted
     ++	variable notes body is_completed
      +
     ++	# Constructor:
     ++	#   set chord [SimpleChord new {body}]
     ++	#     Creates a new chord object with the specified body script. The
     ++	#     body script is evaluated at most once, when a note is activated
     ++	#     and the chord has no other non-activated notes.
      +	constructor {body} {
     -+		set Notes [list]
     -+		set Body $body
     -+		set IsCompleted 0
     ++		set notes [list]
     ++		my eval [list set body $body]
     ++		set is_completed 0
      +	}
      +
     ++	# Method:
     ++	#   $chord eval {script}
     ++	#     Runs the specified script in the same context (namespace) in which
     ++	#     the chord body will be evaluated. This can be used to set variable
     ++	#     values for the chord body to use.
      +	method eval {script} {
      +		namespace eval [self] $script
      +	}
      +
     ++	# Method:
     ++	#   set note [$chord add_note]
     ++	#     Adds a new note to the chord, an instance of ChordNote. Raises an
     ++	#     error if the chord is already completed, otherwise the chord is
     ++	#     updated so that the new note must also be activated before the
     ++	#     body is evaluated.
      +	method add_note {} {
     -+		if {$IsCompleted} { error "Cannot add a note to a completed chord" }
     ++		if {$is_completed} { error "Cannot add a note to a completed chord" }
      +
      +		set note [ChordNote new [self]]
      +
     -+		lappend Notes $note
     ++		lappend notes $note
      +
      +		return $note
      +	}
      +
     ++	# This method is for internal use only and is intentionally undocumented.
      +	method notify_note_activation {} {
     -+		if {!$IsCompleted} {
     -+			foreach note $Notes {
     ++		if {!$is_completed} {
     ++			foreach note $notes {
      +				if {![$note is_activated]} { return }
      +			}
      +
     -+			set IsCompleted 1
     ++			set is_completed 1
      +
     -+			namespace eval [self] $Body
     ++			namespace eval [self] $body
      +			namespace delete [self]
      +		}
      +	}
      +}
      +
     ++# ChordNote class:
     ++#   Represents a note within a chord, providing a way to activate it. When the
     ++#   final note of the chord is activated (this can be any note in the chord,
     ++#   with all other notes already previously activated in any order), the chord's
     ++#   body is evaluated.
      +oo::class create ChordNote {
     -+	variable Chord IsActivated
     ++	variable chord is_activated
      +
     ++	# Constructor:
     ++	#   Instances of ChordNote are created internally by calling add_note on
     ++	#   SimpleChord objects.
      +	constructor {chord} {
     -+		set Chord $chord
     -+		set IsActivated 0
     ++		my eval set chord $chord
     ++		set is_activated 0
      +	}
      +
     ++	# Method:
     ++	#   [$note is_activated]
     ++	#     Returns true if this note has already been activated.
      +	method is_activated {} {
     -+		return $IsActivated
     ++		return $is_activated
      +	}
      +
     ++	# Method:
     ++	#   $note
     ++	#     Activates the note, if it has not already been activated, and
     ++	#     completes the chord if there are no other notes awaiting
     ++	#     activation. Subsequent calls will have no further effect.
     ++	#
     ++	# NB: In TclOO, if an object is invoked like a method without supplying
     ++	#     any method name, then this internal method `unknown` is what
     ++	#     actually runs (with no parameters). It is used in the ChordNote
     ++	#     class for the purpose of allowing the note object to be called as
     ++	#     a function (see example above). (The `unknown` method can also be
     ++	#     used to support dynamic dispatch, but must take parameters to
     ++	#     identify the "unknown" method to be invoked. In this form, this
     ++	#     proc serves only to make instances behave directly like methods.)
      +	method unknown {} {
     -+		if {!$IsActivated} {
     -+			set IsActivated 1
     -+			$Chord notify_note_activation
     ++		if {!$is_activated} {
     ++			set is_activated 1
     ++			$chord notify_note_activation
      +		}
      +	}
      +}
     @@ -164,16 +214,103 @@
       }
       
      -proc _close_updateindex {fd after} {
     +-	global use_ttk NS
     ++# Returns true if the operation succeeded, false if a rescan has been initiated.
     ++proc _close_updateindex_rescan_on_error {fd} {
     ++	if {![catch {_close_updateindex $fd} err]} {
     ++		return true
     ++	} else {
     ++		rescan_on_error $err
     ++		return false
     ++	}
     ++}
     ++
      +proc _close_updateindex {fd} {
     - 	global use_ttk NS
       	fconfigure $fd -blocking 1
     - 	if {[catch {close $fd} err]} {
     -@@
     - 	}
     +-	if {[catch {close $fd} err]} {
     +-		set w .indexfried
     +-		Dialog $w
     +-		wm withdraw $w
     +-		wm title $w [strcat "[appname] ([reponame]): " [mc "Index Error"]]
     +-		wm geometry $w "+[winfo rootx .]+[winfo rooty .]"
     +-		set s [mc "Updating the Git index failed.  A rescan will be automatically started to resynchronize git-gui."]
     +-		text $w.msg -yscrollcommand [list $w.vs set] \
     +-			-width [string length $s] -relief flat \
     +-			-borderwidth 0 -highlightthickness 0 \
     +-			-background [get_bg_color $w]
     +-		$w.msg tag configure bold -font font_uibold -justify center
     +-		${NS}::scrollbar $w.vs -command [list $w.msg yview]
     +-		$w.msg insert end $s bold \n\n$err {}
     +-		$w.msg configure -state disabled
     +-
     +-		${NS}::button $w.continue \
     +-			-text [mc "Continue"] \
     +-			-command [list destroy $w]
     +-		${NS}::button $w.unlock \
     +-			-text [mc "Unlock Index"] \
     +-			-command "destroy $w; _delete_indexlock"
     +-		grid $w.msg - $w.vs -sticky news
     +-		grid $w.unlock $w.continue - -sticky se -padx 2 -pady 2
     +-		grid columnconfigure $w 0 -weight 1
     +-		grid rowconfigure $w 0 -weight 1
     +-
     +-		wm protocol $w WM_DELETE_WINDOW update
     +-		bind $w.continue <Visibility> "
     +-			grab $w
     +-			focus %W
     +-		"
     +-		wm deiconify $w
     +-		tkwait window $w
     ++	close $fd
     ++	$::main_status stop
     ++}
     + 
     +-		$::main_status stop
     +-		unlock_index
     +-		rescan $after 0
     +-		return
     +-	}
     ++proc rescan_on_error {err} {
     ++	global use_ttk NS
     ++
     ++	set w .indexfried
     ++	Dialog $w
     ++	wm withdraw $w
     ++	wm title $w [strcat "[appname] ([reponame]): " [mc "Index Error"]]
     ++	wm geometry $w "+[winfo rootx .]+[winfo rooty .]"
     ++	set s [mc "Updating the Git index failed.  A rescan will be automatically started to resynchronize git-gui."]
     ++	text $w.msg -yscrollcommand [list $w.vs set] \
     ++		-width [string length $s] -relief flat \
     ++		-borderwidth 0 -highlightthickness 0 \
     ++		-background [get_bg_color $w]
     ++	$w.msg tag configure bold -font font_uibold -justify center
     ++	${NS}::scrollbar $w.vs -command [list $w.msg yview]
     ++	$w.msg insert end $s bold \n\n$err {}
     ++	$w.msg configure -state disabled
     ++
     ++	${NS}::button $w.continue \
     ++		-text [mc "Continue"] \
     ++		-command [list destroy $w]
     ++	${NS}::button $w.unlock \
     ++		-text [mc "Unlock Index"] \
     ++		-command "destroy $w; _delete_indexlock"
     ++	grid $w.msg - $w.vs -sticky news
     ++	grid $w.unlock $w.continue - -sticky se -padx 2 -pady 2
     ++	grid columnconfigure $w 0 -weight 1
     ++	grid rowconfigure $w 0 -weight 1
     ++
     ++	wm protocol $w WM_DELETE_WINDOW update
     ++	bind $w.continue <Visibility> "
     ++		grab $w
     ++		focus %W
     ++	"
     ++	wm deiconify $w
     ++	tkwait window $w
       
       	$::main_status stop
     --	unlock_index
     + 	unlock_index
      -	uplevel #0 $after
     ++	rescan ui_ready 0
       }
       
       proc update_indexinfo {msg path_list after} {
     @@ -182,8 +319,10 @@
       
       	if {$update_index_cp >= $total_cnt} {
      -		_close_updateindex $fd $after
     -+		_close_updateindex $fd
     -+		unlock_index
     ++		if {[_close_updateindex_rescan_on_error $fd]} {
     ++			unlock_index
     ++		}
     ++
      +		uplevel #0 $after
       		return
       	}
     @@ -193,37 +332,86 @@
       
       	if {$update_index_cp >= $total_cnt} {
      -		_close_updateindex $fd $after
     -+		_close_updateindex $fd
     -+		unlock_index
     ++		if {[_close_updateindex_rescan_on_error $fd]} {
     ++			unlock_index
     ++		}
     ++
      +		uplevel #0 $after
       		return
       	}
       
      @@
     + 	$::main_status update $update_index_cp $total_cnt
     + }
     + 
     +-proc checkout_index {msg path_list after} {
     ++proc checkout_index {msg path_list after capture_error} {
     + 	global update_index_cp
     + 
     + 	if {![lock_index update]} return
     +@@
     + 		$total_cnt \
     + 		$batch \
     + 		$after \
     ++		$capture_error \
     + 		]
     + }
     + 
     +-proc write_checkout_index {fd path_list total_cnt batch after} {
     ++proc write_checkout_index {fd path_list total_cnt batch after capture_error} {
     + 	global update_index_cp
       	global file_states current_diff_path
       
       	if {$update_index_cp >= $total_cnt} {
      -		_close_updateindex $fd $after
     -+		_close_updateindex $fd $do_unlock_index $after
     ++		if {[catch {_close_updateindex $fd} err]} {
     ++			uplevel #0 $capture_error [list $err]
     ++		}
     ++
      +		uplevel #0 $after
     ++
       		return
       	}
       
      @@
     + 	add_helper [mc "Adding all changed files"] $paths
     + }
     + 
     ++# Copied from TclLib package "lambda".
     ++proc lambda {arguments body args} {
     ++	return [list ::apply [list $arguments $body] {*}$args]
     ++}
     ++
     + proc revert_helper {txt paths} {
     + 	global file_states current_diff_path
       
       	if {![lock_index begin-update]} return
       
      +	# Common "after" functionality that waits until multiple asynchronous
      +	# operations are complete (by waiting for them to activate their notes
      +	# on the chord).
     ++	#
     ++	# The asynchronous operations are each indicated below by a comment
     ++	# before the code block that starts the async operation.
      +	set after_chord [SimpleChord new {
      +		unlock_index
     -+		if {$should_reshow_diff} { reshow_diff }
     -+		ui_ready
     ++		if {[string trim $err] != ""} {
     ++			rescan_on_error $err
     ++		} else {
     ++			if {$should_reshow_diff} { reshow_diff }
     ++			ui_ready
     ++		}
      +	}]
      +
      +	$after_chord eval { set should_reshow_diff 0 }
      +
     ++	# This function captures an error for processing when after_chord is
     ++	# completed. (The chord is curried into the lambda function.)
     ++	set capture_error [lambda \
     ++		{chord error} \
     ++		{ $chord eval [list set err $error] } \
     ++		$after_chord]
     ++
      +	# We don't know how many notes we're going to create (it's dynamic based
      +	# on conditional paths below), so create a common note that will delay
      +	# the chord's completion until we activate it, and then activate it
     @@ -231,8 +419,9 @@
      +	set after_common_note [$after_chord add_note]
      +
       	set path_list [list]
     +-	set after {}
      +	set untracked_list [list]
     - 	set after {}
     ++
       	foreach path $paths {
       		switch -glob -- [lindex $file_states($path) 0] {
       		U? {continue}
     @@ -253,26 +442,9 @@
       
      +	set path_cnt [llength $path_list]
      +	set untracked_cnt [llength $untracked_list]
     - 
     --	# Split question between singular and plural cases, because
     --	# such distinction is needed in some languages. Previously, the
     --	# code used "Revert changes in" for both, but that can't work
     --	# in languages where 'in' must be combined with word from
     --	# rest of string (in different way for both cases of course).
     --	#
     --	# FIXME: Unfortunately, even that isn't enough in some languages
     --	# as they have quite complex plural-form rules. Unfortunately,
     --	# msgcat doesn't seem to support that kind of string translation.
     --	#
     --	set n [llength $path_list]
     --	if {$n == 0} {
     --		unlock_index
     --		return
     --	} elseif {$n == 1} {
     --		set query [mc "Revert changes in file %s?" [short_path [lindex $path_list]]]
     --	} else {
     --		set query [mc "Revert changes in these %i files?" $n]
     --	}
     ++
     ++	# Asynchronous operation: revert changes by checking them out afresh
     ++	# from the index.
      +	if {$path_cnt > 0} {
      +		# Split question between singular and plural cases, because
      +		# such distinction is needed in some languages. Previously, the
     @@ -295,25 +467,31 @@
      +				"Revert changes in these %i files?" \
      +				$path_cnt]
      +		}
     - 
     --	set reply [tk_dialog \
     --		.confirm_revert \
     --		"[appname] ([reponame])" \
     --		"$query
     ++
      +		set reply [tk_dialog \
      +			.confirm_revert \
      +			"[appname] ([reponame])" \
      +			"$query
       
     - [mc "Any unstaged changes will be permanently lost by the revert."]" \
     --		question \
     --		1 \
     --		[mc "Do Nothing"] \
     --		[mc "Revert Changes"] \
     --		]
     --	if {$reply == 1} {
     --		checkout_index \
     --			$txt \
     +-	# Split question between singular and plural cases, because
     +-	# such distinction is needed in some languages. Previously, the
     +-	# code used "Revert changes in" for both, but that can't work
     +-	# in languages where 'in' must be combined with word from
     +-	# rest of string (in different way for both cases of course).
     +-	#
     +-	# FIXME: Unfortunately, even that isn't enough in some languages
     +-	# as they have quite complex plural-form rules. Unfortunately,
     +-	# msgcat doesn't seem to support that kind of string translation.
     +-	#
     +-	set n [llength $path_list]
     +-	if {$n == 0} {
     +-		unlock_index
     +-		return
     +-	} elseif {$n == 1} {
     +-		set query [mc "Revert changes in file %s?" [short_path [lindex $path_list]]]
     +-	} else {
     +-		set query [mc "Revert changes in these %i files?" $n]
     ++[mc "Any unstaged changes will be permanently lost by the revert."]" \
      +			question \
      +			1 \
      +			[mc "Do Nothing"] \
     @@ -324,10 +502,16 @@
      +			checkout_index \
      +				$txt \
      +				$path_list \
     -+				[$after_chord add_note]
     ++				[$after_chord add_note] \
     ++				$capture_error
      +		}
     -+	}
     -+
     + 	}
     + 
     +-	set reply [tk_dialog \
     +-		.confirm_revert \
     +-		"[appname] ([reponame])" \
     +-		"$query
     ++	# Asynchronous operation: Deletion of untracked files.
      +	if {$untracked_cnt > 0} {
      +		# Split question between singular and plural cases, because
      +		# such distinction is needed in some languages.
     @@ -348,7 +532,16 @@
      +				$untracked_cnt \
      +				]
      +		}
     -+
     + 
     +-[mc "Any unstaged changes will be permanently lost by the revert."]" \
     +-		question \
     +-		1 \
     +-		[mc "Do Nothing"] \
     +-		[mc "Revert Changes"] \
     +-		]
     +-	if {$reply == 1} {
     +-		checkout_index \
     +-			$txt \
      +		set reply [tk_dialog \
      +			.confirm_revert \
      +			"[appname] ([reponame])" \
     @@ -453,8 +646,9 @@
      +		# Report error, if any, based on how many deletions failed.
      +		set deletion_error_cnt [llength $deletion_errors]
      +
     -+		if {($deletion_error_cnt > 0) && ($deletion_error_cnt <= [MAX_VERBOSE_FILES_IN_DELETION_ERROR])} {
     -+			set error_text "Encountered errors deleting files:\n"
     ++		if {($deletion_error_cnt > 0)
     ++		 && ($deletion_error_cnt <= [MAX_VERBOSE_FILES_IN_DELETION_ERROR])} {
     ++			set error_text [mc "Encountered errors deleting files:\n"]
      +
      +			foreach deletion_error $deletion_errors {
      +				append error_text "* [lindex $deletion_error 0]\n"

-- 
gitgitgadget

[PATCH v3 1/2] git-gui: consolidate naming conventions

[Jonathan Gilbert via GitGitGadget]

From: Jonathan Gilbert <JonathanG@iQmetrix.com>

A few variables in this file use camelCase, while the overall standard
is snake_case. A consistent naming scheme will improve readability of
future changes. To avoid mixing naming changes with semantic changes,
this commit contains only naming changes.

Signed-off-by: Jonathan Gilbert <JonathanG@iQmetrix.com>
---
 lib/index.tcl | 92 +++++++++++++++++++++++++--------------------------
 1 file changed, 46 insertions(+), 46 deletions(-)

diff --git a/lib/index.tcl b/lib/index.tcl
index e07b7a3762..28d4d2a54e 100644
--- a/lib/index.tcl
+++ b/lib/index.tcl
@@ -56,15 +56,15 @@ proc _close_updateindex {fd after} {
 	uplevel #0 $after
 }
 
-proc update_indexinfo {msg pathList after} {
+proc update_indexinfo {msg path_list after} {
 	global update_index_cp
 
 	if {![lock_index update]} return
 
 	set update_index_cp 0
-	set pathList [lsort $pathList]
-	set totalCnt [llength $pathList]
-	set batch [expr {int($totalCnt * .01) + 1}]
+	set path_list [lsort $path_list]
+	set total_cnt [llength $path_list]
+	set batch [expr {int($total_cnt * .01) + 1}]
 	if {$batch > 25} {set batch 25}
 
 	$::main_status start $msg [mc "files"]
@@ -78,26 +78,26 @@ proc update_indexinfo {msg pathList after} {
 	fileevent $fd writable [list \
 		write_update_indexinfo \
 		$fd \
-		$pathList \
-		$totalCnt \
+		$path_list \
+		$total_cnt \
 		$batch \
 		$after \
 		]
 }
 
-proc write_update_indexinfo {fd pathList totalCnt batch after} {
+proc write_update_indexinfo {fd path_list total_cnt batch after} {
 	global update_index_cp
 	global file_states current_diff_path
 
-	if {$update_index_cp >= $totalCnt} {
+	if {$update_index_cp >= $total_cnt} {
 		_close_updateindex $fd $after
 		return
 	}
 
 	for {set i $batch} \
-		{$update_index_cp < $totalCnt && $i > 0} \
+		{$update_index_cp < $total_cnt && $i > 0} \
 		{incr i -1} {
-		set path [lindex $pathList $update_index_cp]
+		set path [lindex $path_list $update_index_cp]
 		incr update_index_cp
 
 		set s $file_states($path)
@@ -119,18 +119,18 @@ proc write_update_indexinfo {fd pathList totalCnt batch after} {
 		display_file $path $new
 	}
 
-	$::main_status update $update_index_cp $totalCnt
+	$::main_status update $update_index_cp $total_cnt
 }
 
-proc update_index {msg pathList after} {
+proc update_index {msg path_list after} {
 	global update_index_cp
 
 	if {![lock_index update]} return
 
 	set update_index_cp 0
-	set pathList [lsort $pathList]
-	set totalCnt [llength $pathList]
-	set batch [expr {int($totalCnt * .01) + 1}]
+	set path_list [lsort $path_list]
+	set total_cnt [llength $path_list]
+	set batch [expr {int($total_cnt * .01) + 1}]
 	if {$batch > 25} {set batch 25}
 
 	$::main_status start $msg [mc "files"]
@@ -144,26 +144,26 @@ proc update_index {msg pathList after} {
 	fileevent $fd writable [list \
 		write_update_index \
 		$fd \
-		$pathList \
-		$totalCnt \
+		$path_list \
+		$total_cnt \
 		$batch \
 		$after \
 		]
 }
 
-proc write_update_index {fd pathList totalCnt batch after} {
+proc write_update_index {fd path_list total_cnt batch after} {
 	global update_index_cp
 	global file_states current_diff_path
 
-	if {$update_index_cp >= $totalCnt} {
+	if {$update_index_cp >= $total_cnt} {
 		_close_updateindex $fd $after
 		return
 	}
 
 	for {set i $batch} \
-		{$update_index_cp < $totalCnt && $i > 0} \
+		{$update_index_cp < $total_cnt && $i > 0} \
 		{incr i -1} {
-		set path [lindex $pathList $update_index_cp]
+		set path [lindex $path_list $update_index_cp]
 		incr update_index_cp
 
 		switch -glob -- [lindex $file_states($path) 0] {
@@ -190,18 +190,18 @@ proc write_update_index {fd pathList totalCnt batch after} {
 		display_file $path $new
 	}
 
-	$::main_status update $update_index_cp $totalCnt
+	$::main_status update $update_index_cp $total_cnt
 }
 
-proc checkout_index {msg pathList after} {
+proc checkout_index {msg path_list after} {
 	global update_index_cp
 
 	if {![lock_index update]} return
 
 	set update_index_cp 0
-	set pathList [lsort $pathList]
-	set totalCnt [llength $pathList]
-	set batch [expr {int($totalCnt * .01) + 1}]
+	set path_list [lsort $path_list]
+	set total_cnt [llength $path_list]
+	set batch [expr {int($total_cnt * .01) + 1}]
 	if {$batch > 25} {set batch 25}
 
 	$::main_status start $msg [mc "files"]
@@ -221,26 +221,26 @@ proc checkout_index {msg pathList after} {
 	fileevent $fd writable [list \
 		write_checkout_index \
 		$fd \
-		$pathList \
-		$totalCnt \
+		$path_list \
+		$total_cnt \
 		$batch \
 		$after \
 		]
 }
 
-proc write_checkout_index {fd pathList totalCnt batch after} {
+proc write_checkout_index {fd path_list total_cnt batch after} {
 	global update_index_cp
 	global file_states current_diff_path
 
-	if {$update_index_cp >= $totalCnt} {
+	if {$update_index_cp >= $total_cnt} {
 		_close_updateindex $fd $after
 		return
 	}
 
 	for {set i $batch} \
-		{$update_index_cp < $totalCnt && $i > 0} \
+		{$update_index_cp < $total_cnt && $i > 0} \
 		{incr i -1} {
-		set path [lindex $pathList $update_index_cp]
+		set path [lindex $path_list $update_index_cp]
 		incr update_index_cp
 		switch -glob -- [lindex $file_states($path) 0] {
 		U? {continue}
@@ -253,7 +253,7 @@ proc write_checkout_index {fd pathList totalCnt batch after} {
 		}
 	}
 
-	$::main_status update $update_index_cp $totalCnt
+	$::main_status update $update_index_cp $total_cnt
 }
 
 proc unstage_helper {txt paths} {
@@ -261,7 +261,7 @@ proc unstage_helper {txt paths} {
 
 	if {![lock_index begin-update]} return
 
-	set pathList [list]
+	set path_list [list]
 	set after {}
 	foreach path $paths {
 		switch -glob -- [lindex $file_states($path) 0] {
@@ -269,19 +269,19 @@ proc unstage_helper {txt paths} {
 		M? -
 		T? -
 		D? {
-			lappend pathList $path
+			lappend path_list $path
 			if {$path eq $current_diff_path} {
 				set after {reshow_diff;}
 			}
 		}
 		}
 	}
-	if {$pathList eq {}} {
+	if {$path_list eq {}} {
 		unlock_index
 	} else {
 		update_indexinfo \
 			$txt \
-			$pathList \
+			$path_list \
 			[concat $after [list ui_ready]]
 	}
 }
@@ -305,7 +305,7 @@ proc add_helper {txt paths} {
 
 	if {![lock_index begin-update]} return
 
-	set pathList [list]
+	set path_list [list]
 	set after {}
 	foreach path $paths {
 		switch -glob -- [lindex $file_states($path) 0] {
@@ -321,19 +321,19 @@ proc add_helper {txt paths} {
 		?M -
 		?D -
 		?T {
-			lappend pathList $path
+			lappend path_list $path
 			if {$path eq $current_diff_path} {
 				set after {reshow_diff;}
 			}
 		}
 		}
 	}
-	if {$pathList eq {}} {
+	if {$path_list eq {}} {
 		unlock_index
 	} else {
 		update_index \
 			$txt \
-			$pathList \
+			$path_list \
 			[concat $after {ui_status [mc "Ready to commit."]}]
 	}
 }
@@ -393,7 +393,7 @@ proc revert_helper {txt paths} {
 
 	if {![lock_index begin-update]} return
 
-	set pathList [list]
+	set path_list [list]
 	set after {}
 	foreach path $paths {
 		switch -glob -- [lindex $file_states($path) 0] {
@@ -401,7 +401,7 @@ proc revert_helper {txt paths} {
 		?M -
 		?T -
 		?D {
-			lappend pathList $path
+			lappend path_list $path
 			if {$path eq $current_diff_path} {
 				set after {reshow_diff;}
 			}
@@ -420,12 +420,12 @@ proc revert_helper {txt paths} {
 	# as they have quite complex plural-form rules. Unfortunately,
 	# msgcat doesn't seem to support that kind of string translation.
 	#
-	set n [llength $pathList]
+	set n [llength $path_list]
 	if {$n == 0} {
 		unlock_index
 		return
 	} elseif {$n == 1} {
-		set query [mc "Revert changes in file %s?" [short_path [lindex $pathList]]]
+		set query [mc "Revert changes in file %s?" [short_path [lindex $path_list]]]
 	} else {
 		set query [mc "Revert changes in these %i files?" $n]
 	}
@@ -444,7 +444,7 @@ proc revert_helper {txt paths} {
 	if {$reply == 1} {
 		checkout_index \
 			$txt \
-			$pathList \
+			$path_list \
 			[concat $after [list ui_ready]]
 	} else {
 		unlock_index
-- 
gitgitgadget

[PATCH v3 2/2] git-gui: revert untracked files by deleting them

[Jonathan Gilbert via GitGitGadget]

From: Jonathan Gilbert <JonathanG@iQmetrix.com>

Update the revert_helper proc to check for untracked files as well as
changes, and then handle changes to be reverted and untracked files with
independent blocks of code. Prompt the user independently for untracked
files, since the underlying action is fundamentally different (rm -f).
If after deleting untracked files, the directory containing them becomes
empty, then remove the directory as well. Migrate unlocking of the index
out of _close_updateindex to a responsibility of the caller, to permit
paths that don't directly unlock the index, and refactor the error
handling added in d4e890e5 so that callers can make flow control
decisions in the event of errors.

A new proc delete_files takes care of actually deleting the files in
batches, using the Tcler's Wiki recommended approach for keeping the UI
responsive.

Since the checkout_index and delete_files calls are both asynchronous
and could potentially complete in any order, a "chord" is used to
coordinate unlocking the index and returning the UI to a usable state
only after both operations are complete. The `SimpleChord` class,
based on TclOO (Tcl/Tk 8.6), is added in this commit.

Signed-off-by: Jonathan Gilbert <JonathanG@iQmetrix.com>
---
 git-gui.sh    |   4 +-
 lib/chord.tcl | 160 +++++++++++++++++++
 lib/index.tcl | 416 ++++++++++++++++++++++++++++++++++++++++----------
 3 files changed, 496 insertions(+), 84 deletions(-)
 create mode 100644 lib/chord.tcl

diff --git a/git-gui.sh b/git-gui.sh
index 0d21f5688b..dd6f3a3592 100755
--- a/git-gui.sh
+++ b/git-gui.sh
@@ -30,8 +30,8 @@ along with this program; if not, see <http://www.gnu.org/licenses/>.}]
 ##
 ## Tcl/Tk sanity check
 
-if {[catch {package require Tcl 8.4} err]
- || [catch {package require Tk  8.4} err]
+if {[catch {package require Tcl 8.6} err]
+ || [catch {package require Tk  8.6} err]
 } {
 	catch {wm withdraw .}
 	tk_messageBox \
diff --git a/lib/chord.tcl b/lib/chord.tcl
new file mode 100644
index 0000000000..275a6cd4a1
--- /dev/null
+++ b/lib/chord.tcl
@@ -0,0 +1,160 @@
+# Simple Chord for Tcl
+#
+# A "chord" is a method with more than one entrypoint and only one body, such
+# that the body runs only once all the entrypoints have been called by
+# different asynchronous tasks. In this implementation, the chord is defined
+# dynamically for each invocation. A SimpleChord object is created, supplying
+# body script to be run when the chord is completed, and then one or more notes
+# are added to the chord. Each note can be called like a proc, and returns
+# immediately if the chord isn't yet complete. When the last remaining note is
+# called, the body runs before the note returns.
+#
+# The SimpleChord class has a constructor that takes the body script, and a
+# method add_note that returns a note object. Since the body script does not
+# run in the context of the procedure that defined it, a mechanism is provided
+# for injecting variables into the chord for use by the body script. The
+# activation of a note is idempotent; multiple calls have the same effect as
+# a simple call.
+#
+# If you are invoking asynchronous operations with chord notes as completion
+# callbacks, and there is a possibility that earlier operations could complete
+# before later ones are started, it is a good practice to create a "common"
+# note on the chord that prevents it from being complete until you're certain
+# you've added all the notes you need.
+#
+# Example:
+#
+#   # Turn off the UI while running a couple of async operations.
+#   lock_ui
+#
+#   set chord [SimpleChord new {
+#     unlock_ui
+#     # Note: $notice here is not referenced in the calling scope
+#     if {$notice} { info_popup $notice }
+#   }
+#
+#   # Configure a note to keep the chord from completing until
+#   # all operations have been initiated.
+#   set common_note [$chord add_note]
+#
+#   # Pass notes as 'after' callbacks to other operations
+#   async_operation $args [$chord add_note]
+#   other_async_operation $args [$chord add_note]
+#
+#   # Communicate with the chord body
+#   if {$condition} {
+#     # This sets $notice in the same context that the chord body runs in.
+#     $chord eval { set notice "Something interesting" }
+#   }
+#
+#   # Activate the common note, making the chord eligible to complete
+#   $common_note
+#
+# At this point, the chord will complete at some unknown point in the future.
+# The common note might have been the first note activated, or the async
+# operations might have completed synchronously and the common note is the
+# last one, completing the chord before this code finishes, or anything in
+# between. The purpose of the chord is to not have to worry about the order.
+
+# SimpleChord class:
+#   Represents a procedure that conceptually has multiple entrypoints that must
+#   all be called before the procedure executes. Each entrypoint is called a
+#   "note". The chord is only "completed" when all the notes are "activated".
+oo::class create SimpleChord {
+	variable notes body is_completed
+
+	# Constructor:
+	#   set chord [SimpleChord new {body}]
+	#     Creates a new chord object with the specified body script. The
+	#     body script is evaluated at most once, when a note is activated
+	#     and the chord has no other non-activated notes.
+	constructor {body} {
+		set notes [list]
+		my eval [list set body $body]
+		set is_completed 0
+	}
+
+	# Method:
+	#   $chord eval {script}
+	#     Runs the specified script in the same context (namespace) in which
+	#     the chord body will be evaluated. This can be used to set variable
+	#     values for the chord body to use.
+	method eval {script} {
+		namespace eval [self] $script
+	}
+
+	# Method:
+	#   set note [$chord add_note]
+	#     Adds a new note to the chord, an instance of ChordNote. Raises an
+	#     error if the chord is already completed, otherwise the chord is
+	#     updated so that the new note must also be activated before the
+	#     body is evaluated.
+	method add_note {} {
+		if {$is_completed} { error "Cannot add a note to a completed chord" }
+
+		set note [ChordNote new [self]]
+
+		lappend notes $note
+
+		return $note
+	}
+
+	# This method is for internal use only and is intentionally undocumented.
+	method notify_note_activation {} {
+		if {!$is_completed} {
+			foreach note $notes {
+				if {![$note is_activated]} { return }
+			}
+
+			set is_completed 1
+
+			namespace eval [self] $body
+			namespace delete [self]
+		}
+	}
+}
+
+# ChordNote class:
+#   Represents a note within a chord, providing a way to activate it. When the
+#   final note of the chord is activated (this can be any note in the chord,
+#   with all other notes already previously activated in any order), the chord's
+#   body is evaluated.
+oo::class create ChordNote {
+	variable chord is_activated
+
+	# Constructor:
+	#   Instances of ChordNote are created internally by calling add_note on
+	#   SimpleChord objects.
+	constructor {chord} {
+		my eval set chord $chord
+		set is_activated 0
+	}
+
+	# Method:
+	#   [$note is_activated]
+	#     Returns true if this note has already been activated.
+	method is_activated {} {
+		return $is_activated
+	}
+
+	# Method:
+	#   $note
+	#     Activates the note, if it has not already been activated, and
+	#     completes the chord if there are no other notes awaiting
+	#     activation. Subsequent calls will have no further effect.
+	#
+	# NB: In TclOO, if an object is invoked like a method without supplying
+	#     any method name, then this internal method `unknown` is what
+	#     actually runs (with no parameters). It is used in the ChordNote
+	#     class for the purpose of allowing the note object to be called as
+	#     a function (see example above). (The `unknown` method can also be
+	#     used to support dynamic dispatch, but must take parameters to
+	#     identify the "unknown" method to be invoked. In this form, this
+	#     proc serves only to make instances behave directly like methods.)
+	method unknown {} {
+		if {!$is_activated} {
+			set is_activated 1
+			$chord notify_note_activation
+		}
+	}
+}
diff --git a/lib/index.tcl b/lib/index.tcl
index 28d4d2a54e..3ac08281c2 100644
--- a/lib/index.tcl
+++ b/lib/index.tcl
@@ -7,53 +7,62 @@ proc _delete_indexlock {} {
 	}
 }
 
-proc _close_updateindex {fd after} {
-	global use_ttk NS
+# Returns true if the operation succeeded, false if a rescan has been initiated.
+proc _close_updateindex_rescan_on_error {fd} {
+	if {![catch {_close_updateindex $fd} err]} {
+		return true
+	} else {
+		rescan_on_error $err
+		return false
+	}
+}
+
+proc _close_updateindex {fd} {
 	fconfigure $fd -blocking 1
-	if {[catch {close $fd} err]} {
-		set w .indexfried
-		Dialog $w
-		wm withdraw $w
-		wm title $w [strcat "[appname] ([reponame]): " [mc "Index Error"]]
-		wm geometry $w "+[winfo rootx .]+[winfo rooty .]"
-		set s [mc "Updating the Git index failed.  A rescan will be automatically started to resynchronize git-gui."]
-		text $w.msg -yscrollcommand [list $w.vs set] \
-			-width [string length $s] -relief flat \
-			-borderwidth 0 -highlightthickness 0 \
-			-background [get_bg_color $w]
-		$w.msg tag configure bold -font font_uibold -justify center
-		${NS}::scrollbar $w.vs -command [list $w.msg yview]
-		$w.msg insert end $s bold \n\n$err {}
-		$w.msg configure -state disabled
-
-		${NS}::button $w.continue \
-			-text [mc "Continue"] \
-			-command [list destroy $w]
-		${NS}::button $w.unlock \
-			-text [mc "Unlock Index"] \
-			-command "destroy $w; _delete_indexlock"
-		grid $w.msg - $w.vs -sticky news
-		grid $w.unlock $w.continue - -sticky se -padx 2 -pady 2
-		grid columnconfigure $w 0 -weight 1
-		grid rowconfigure $w 0 -weight 1
-
-		wm protocol $w WM_DELETE_WINDOW update
-		bind $w.continue <Visibility> "
-			grab $w
-			focus %W
-		"
-		wm deiconify $w
-		tkwait window $w
+	close $fd
+	$::main_status stop
+}
 
-		$::main_status stop
-		unlock_index
-		rescan $after 0
-		return
-	}
+proc rescan_on_error {err} {
+	global use_ttk NS
+
+	set w .indexfried
+	Dialog $w
+	wm withdraw $w
+	wm title $w [strcat "[appname] ([reponame]): " [mc "Index Error"]]
+	wm geometry $w "+[winfo rootx .]+[winfo rooty .]"
+	set s [mc "Updating the Git index failed.  A rescan will be automatically started to resynchronize git-gui."]
+	text $w.msg -yscrollcommand [list $w.vs set] \
+		-width [string length $s] -relief flat \
+		-borderwidth 0 -highlightthickness 0 \
+		-background [get_bg_color $w]
+	$w.msg tag configure bold -font font_uibold -justify center
+	${NS}::scrollbar $w.vs -command [list $w.msg yview]
+	$w.msg insert end $s bold \n\n$err {}
+	$w.msg configure -state disabled
+
+	${NS}::button $w.continue \
+		-text [mc "Continue"] \
+		-command [list destroy $w]
+	${NS}::button $w.unlock \
+		-text [mc "Unlock Index"] \
+		-command "destroy $w; _delete_indexlock"
+	grid $w.msg - $w.vs -sticky news
+	grid $w.unlock $w.continue - -sticky se -padx 2 -pady 2
+	grid columnconfigure $w 0 -weight 1
+	grid rowconfigure $w 0 -weight 1
+
+	wm protocol $w WM_DELETE_WINDOW update
+	bind $w.continue <Visibility> "
+		grab $w
+		focus %W
+	"
+	wm deiconify $w
+	tkwait window $w
 
 	$::main_status stop
 	unlock_index
-	uplevel #0 $after
+	rescan ui_ready 0
 }
 
 proc update_indexinfo {msg path_list after} {
@@ -90,7 +99,11 @@ proc write_update_indexinfo {fd path_list total_cnt batch after} {
 	global file_states current_diff_path
 
 	if {$update_index_cp >= $total_cnt} {
-		_close_updateindex $fd $after
+		if {[_close_updateindex_rescan_on_error $fd]} {
+			unlock_index
+		}
+
+		uplevel #0 $after
 		return
 	}
 
@@ -156,7 +169,11 @@ proc write_update_index {fd path_list total_cnt batch after} {
 	global file_states current_diff_path
 
 	if {$update_index_cp >= $total_cnt} {
-		_close_updateindex $fd $after
+		if {[_close_updateindex_rescan_on_error $fd]} {
+			unlock_index
+		}
+
+		uplevel #0 $after
 		return
 	}
 
@@ -193,7 +210,7 @@ proc write_update_index {fd path_list total_cnt batch after} {
 	$::main_status update $update_index_cp $total_cnt
 }
 
-proc checkout_index {msg path_list after} {
+proc checkout_index {msg path_list after capture_error} {
 	global update_index_cp
 
 	if {![lock_index update]} return
@@ -225,15 +242,21 @@ proc checkout_index {msg path_list after} {
 		$total_cnt \
 		$batch \
 		$after \
+		$capture_error \
 		]
 }
 
-proc write_checkout_index {fd path_list total_cnt batch after} {
+proc write_checkout_index {fd path_list total_cnt batch after capture_error} {
 	global update_index_cp
 	global file_states current_diff_path
 
 	if {$update_index_cp >= $total_cnt} {
-		_close_updateindex $fd $after
+		if {[catch {_close_updateindex $fd} err]} {
+			uplevel #0 $capture_error [list $err]
+		}
+
+		uplevel #0 $after
+
 		return
 	}
 
@@ -388,66 +411,295 @@ proc do_add_all {} {
 	add_helper [mc "Adding all changed files"] $paths
 }
 
+# Copied from TclLib package "lambda".
+proc lambda {arguments body args} {
+	return [list ::apply [list $arguments $body] {*}$args]
+}
+
 proc revert_helper {txt paths} {
 	global file_states current_diff_path
 
 	if {![lock_index begin-update]} return
 
+	# Common "after" functionality that waits until multiple asynchronous
+	# operations are complete (by waiting for them to activate their notes
+	# on the chord).
+	#
+	# The asynchronous operations are each indicated below by a comment
+	# before the code block that starts the async operation.
+	set after_chord [SimpleChord new {
+		unlock_index
+		if {[string trim $err] != ""} {
+			rescan_on_error $err
+		} else {
+			if {$should_reshow_diff} { reshow_diff }
+			ui_ready
+		}
+	}]
+
+	$after_chord eval { set should_reshow_diff 0 }
+
+	# This function captures an error for processing when after_chord is
+	# completed. (The chord is curried into the lambda function.)
+	set capture_error [lambda \
+		{chord error} \
+		{ $chord eval [list set err $error] } \
+		$after_chord]
+
+	# We don't know how many notes we're going to create (it's dynamic based
+	# on conditional paths below), so create a common note that will delay
+	# the chord's completion until we activate it, and then activate it
+	# after all the other notes have been created.
+	set after_common_note [$after_chord add_note]
+
 	set path_list [list]
-	set after {}
+	set untracked_list [list]
+
 	foreach path $paths {
 		switch -glob -- [lindex $file_states($path) 0] {
 		U? {continue}
+		?O {
+			lappend untracked_list $path
+		}
 		?M -
 		?T -
 		?D {
 			lappend path_list $path
 			if {$path eq $current_diff_path} {
-				set after {reshow_diff;}
+				$after_chord eval { set should_reshow_diff 1 }
 			}
 		}
 		}
 	}
 
+	set path_cnt [llength $path_list]
+	set untracked_cnt [llength $untracked_list]
+
+	# Asynchronous operation: revert changes by checking them out afresh
+	# from the index.
+	if {$path_cnt > 0} {
+		# Split question between singular and plural cases, because
+		# such distinction is needed in some languages. Previously, the
+		# code used "Revert changes in" for both, but that can't work
+		# in languages where 'in' must be combined with word from
+		# rest of string (in different way for both cases of course).
+		#
+		# FIXME: Unfortunately, even that isn't enough in some languages
+		# as they have quite complex plural-form rules. Unfortunately,
+		# msgcat doesn't seem to support that kind of string
+		# translation.
+		#
+		if {$path_cnt == 1} {
+			set query [mc \
+				"Revert changes in file %s?" \
+				[short_path [lindex $path_list]] \
+				]
+		} else {
+			set query [mc \
+				"Revert changes in these %i files?" \
+				$path_cnt]
+		}
+
+		set reply [tk_dialog \
+			.confirm_revert \
+			"[appname] ([reponame])" \
+			"$query
 
-	# Split question between singular and plural cases, because
-	# such distinction is needed in some languages. Previously, the
-	# code used "Revert changes in" for both, but that can't work
-	# in languages where 'in' must be combined with word from
-	# rest of string (in different way for both cases of course).
-	#
-	# FIXME: Unfortunately, even that isn't enough in some languages
-	# as they have quite complex plural-form rules. Unfortunately,
-	# msgcat doesn't seem to support that kind of string translation.
-	#
-	set n [llength $path_list]
-	if {$n == 0} {
-		unlock_index
-		return
-	} elseif {$n == 1} {
-		set query [mc "Revert changes in file %s?" [short_path [lindex $path_list]]]
-	} else {
-		set query [mc "Revert changes in these %i files?" $n]
+[mc "Any unstaged changes will be permanently lost by the revert."]" \
+			question \
+			1 \
+			[mc "Do Nothing"] \
+			[mc "Revert Changes"] \
+			]
+
+		if {$reply == 1} {
+			checkout_index \
+				$txt \
+				$path_list \
+				[$after_chord add_note] \
+				$capture_error
+		}
 	}
 
-	set reply [tk_dialog \
-		.confirm_revert \
-		"[appname] ([reponame])" \
-		"$query
+	# Asynchronous operation: Deletion of untracked files.
+	if {$untracked_cnt > 0} {
+		# Split question between singular and plural cases, because
+		# such distinction is needed in some languages.
+		#
+		# FIXME: Unfortunately, even that isn't enough in some languages
+		# as they have quite complex plural-form rules. Unfortunately,
+		# msgcat doesn't seem to support that kind of string
+		# translation.
+		#
+		if {$untracked_cnt == 1} {
+			set query [mc \
+				"Delete untracked file %s?" \
+				[short_path [lindex $untracked_list]] \
+				]
+		} else {
+			set query [mc \
+				"Delete these %i untracked files?" \
+				$untracked_cnt \
+				]
+		}
 
-[mc "Any unstaged changes will be permanently lost by the revert."]" \
-		question \
-		1 \
-		[mc "Do Nothing"] \
-		[mc "Revert Changes"] \
-		]
-	if {$reply == 1} {
-		checkout_index \
-			$txt \
+		set reply [tk_dialog \
+			.confirm_revert \
+			"[appname] ([reponame])" \
+			"$query
+
+[mc "Files will be permanently deleted."]" \
+			question \
+			1 \
+			[mc "Do Nothing"] \
+			[mc "Delete Files"] \
+			]
+
+		if {$reply == 1} {
+			$after_chord eval { set should_reshow_diff 1 }
+
+			delete_files $untracked_list [$after_chord add_note]
+		}
+	}
+
+	# Activate the common note. If no other notes were created, this
+	# completes the chord. If other notes were created, then this common
+	# note prevents a race condition where the chord might complete early.
+	$after_common_note
+}
+
+# Delete all of the specified files, performing deletion in batches to allow the
+# UI to remain responsive and updated.
+proc delete_files {path_list after} {
+	# Enable progress bar status updates
+	$::main_status start [mc "Deleting"] [mc "files"]
+
+	set path_index 0
+	set deletion_errors [list]
+	set batch_size 50
+
+	delete_helper \
+		$path_list \
+		$path_index \
+		$deletion_errors \
+		$batch_size \
+		$after
+}
+
+# Helper function to delete a list of files in batches. Each call deletes one
+# batch of files, and then schedules a call for the next batch after any UI
+# messages have been processed.
+proc delete_helper {path_list path_index deletion_errors batch_size after} {
+	global file_states
+
+	set path_cnt [llength $path_list]
+
+	set batch_remaining $batch_size
+
+	while {$batch_remaining > 0} {
+		if {$path_index >= $path_cnt} { break }
+
+		set path [lindex $path_list $path_index]
+
+		set deletion_failed [catch {file delete -- $path} deletion_error]
+
+		if {$deletion_failed} {
+			lappend deletion_errors [list "$deletion_error"]
+		} else {
+			remove_empty_directories [file dirname $path]
+
+			# Don't assume the deletion worked. Remove the file from
+			# the UI, but only if it no longer exists.
+			if {![path_exists $path]} {
+				unset file_states($path)
+				display_file $path __
+			}
+		}
+
+		incr path_index 1
+		incr batch_remaining -1
+	}
+
+	# Update the progress bar to indicate that this batch has been
+	# completed. The update will be visible when this procedure returns
+	# and allows the UI thread to process messages.
+	$::main_status update $path_index $path_cnt
+
+	if {$path_index < $path_cnt} {
+		# The Tcler's Wiki lists this as the best practice for keeping
+		# a UI active and processing messages during a long-running
+		# operation.
+
+		after idle [list after 0 [list \
+			delete_helper \
 			$path_list \
-			[concat $after [list ui_ready]]
+			$path_index \
+			$deletion_errors \
+			$batch_size \
+			$after
+			]]
 	} else {
-		unlock_index
+		# Finish the status bar operation.
+		$::main_status stop
+
+		# Report error, if any, based on how many deletions failed.
+		set deletion_error_cnt [llength $deletion_errors]
+
+		if {($deletion_error_cnt > 0)
+		 && ($deletion_error_cnt <= [MAX_VERBOSE_FILES_IN_DELETION_ERROR])} {
+			set error_text [mc "Encountered errors deleting files:\n"]
+
+			foreach deletion_error $deletion_errors {
+				append error_text "* [lindex $deletion_error 0]\n"
+			}
+
+			error_popup $error_text
+		} elseif {$deletion_error_cnt == $path_cnt} {
+			error_popup [mc \
+				"None of the %d selected files could be deleted." \
+				$path_cnt \
+				]
+		} elseif {$deletion_error_cnt > 1} {
+			error_popup [mc \
+				"%d of the %d selected files could not be deleted." \
+				$deletion_error_cnt \
+				$path_cnt \
+				]
+		}
+
+		uplevel #0 $after
+	}
+}
+
+proc MAX_VERBOSE_FILES_IN_DELETION_ERROR {} { return 10; }
+
+# This function is from the TCL documentation:
+#
+#   https://wiki.tcl-lang.org/page/file+exists
+#
+# [file exists] returns false if the path does exist but is a symlink to a path
+# that doesn't exist. This proc returns true if the path exists, regardless of
+# whether it is a symlink and whether it is broken.
+proc path_exists {name} {
+	expr {![catch {file lstat $name finfo}]}
+}
+
+# Remove as many empty directories as we can starting at the specified path,
+# walking up the directory tree. If we encounter a directory that is not
+# empty, or if a directory deletion fails, then we stop the operation and
+# return to the caller. Even if this procedure fails to delete any
+# directories at all, it does not report failure.
+proc remove_empty_directories {directory_path} {
+	set parent_path [file dirname $directory_path]
+
+	while {$parent_path != $directory_path} {
+		set contents [glob -nocomplain -dir $directory_path *]
+
+		if {[llength $contents] > 0} { break }
+		if {[catch {file delete -- $directory_path}]} { break }
+
+		set directory_path $parent_path
+		set parent_path [file dirname $directory_path]
 	}
 }
 
-- 
gitgitgadget

Re: [PATCH v3 2/2] git-gui: revert untracked files by deleting them

[Pratyush Yadav]

Hi Jonathan,

Thanks for the re-roll.

[I removed some parts of the diff to make the reply easier to read. I am 
implicitly OK with the removed parts.]

On 13/11/19 09:56AM, Jonathan Gilbert via GitGitGadget wrote:
> From: Jonathan Gilbert <JonathanG@iQmetrix.com>
> 
> Update the revert_helper proc to check for untracked files as well as
> changes, and then handle changes to be reverted and untracked files with
> independent blocks of code. Prompt the user independently for untracked
> files, since the underlying action is fundamentally different (rm -f).
> If after deleting untracked files, the directory containing them becomes
> empty, then remove the directory as well. Migrate unlocking of the index
> out of _close_updateindex to a responsibility of the caller, to permit
> paths that don't directly unlock the index, and refactor the error
> handling added in d4e890e5 so that callers can make flow control
> decisions in the event of errors.
> 
> A new proc delete_files takes care of actually deleting the files in
> batches, using the Tcler's Wiki recommended approach for keeping the UI
> responsive.
> 
> Since the checkout_index and delete_files calls are both asynchronous
> and could potentially complete in any order, a "chord" is used to
> coordinate unlocking the index and returning the UI to a usable state
> only after both operations are complete. The `SimpleChord` class,
> based on TclOO (Tcl/Tk 8.6), is added in this commit.

Looks much better!
 
> Signed-off-by: Jonathan Gilbert <JonathanG@iQmetrix.com>
> ---
>  git-gui.sh    |   4 +-
>  lib/chord.tcl | 160 +++++++++++++++++++
>  lib/index.tcl | 416 ++++++++++++++++++++++++++++++++++++++++----------
>  3 files changed, 496 insertions(+), 84 deletions(-)
>  create mode 100644 lib/chord.tcl
> 
> diff --git a/lib/index.tcl b/lib/index.tcl
> index 28d4d2a54e..3ac08281c2 100644
> --- a/lib/index.tcl
> +++ b/lib/index.tcl
> @@ -7,53 +7,62 @@ proc _delete_indexlock {} {
>  	}
>  }
>  
> -proc _close_updateindex {fd after} {
> -	global use_ttk NS
> +# Returns true if the operation succeeded, false if a rescan has been initiated.
> +proc _close_updateindex_rescan_on_error {fd} {
> +	if {![catch {_close_updateindex $fd} err]} {
> +		return true
> +	} else {
> +		rescan_on_error $err
> +		return false
> +	}
> +}
> +
> +proc _close_updateindex {fd} {
>  	fconfigure $fd -blocking 1
> -	if {[catch {close $fd} err]} {
> -		set w .indexfried
> -		Dialog $w
> -		wm withdraw $w
> -		wm title $w [strcat "[appname] ([reponame]): " [mc "Index Error"]]
> -		wm geometry $w "+[winfo rootx .]+[winfo rooty .]"
> -		set s [mc "Updating the Git index failed.  A rescan will be automatically started to resynchronize git-gui."]
> -		text $w.msg -yscrollcommand [list $w.vs set] \
> -			-width [string length $s] -relief flat \
> -			-borderwidth 0 -highlightthickness 0 \
> -			-background [get_bg_color $w]
> -		$w.msg tag configure bold -font font_uibold -justify center
> -		${NS}::scrollbar $w.vs -command [list $w.msg yview]
> -		$w.msg insert end $s bold \n\n$err {}
> -		$w.msg configure -state disabled
> -
> -		${NS}::button $w.continue \
> -			-text [mc "Continue"] \
> -			-command [list destroy $w]
> -		${NS}::button $w.unlock \
> -			-text [mc "Unlock Index"] \
> -			-command "destroy $w; _delete_indexlock"
> -		grid $w.msg - $w.vs -sticky news
> -		grid $w.unlock $w.continue - -sticky se -padx 2 -pady 2
> -		grid columnconfigure $w 0 -weight 1
> -		grid rowconfigure $w 0 -weight 1
> -
> -		wm protocol $w WM_DELETE_WINDOW update
> -		bind $w.continue <Visibility> "
> -			grab $w
> -			focus %W
> -		"
> -		wm deiconify $w
> -		tkwait window $w
> +	close $fd
> +	$::main_status stop

I didn't spot this earlier. Will this call to 'stop' interfere with the 
'start' in 'delete_files'?

> +}
>  
> -		$::main_status stop
> -		unlock_index
> -		rescan $after 0
> -		return
> -	}
> +proc rescan_on_error {err} {
> +	global use_ttk NS
> +
> +	set w .indexfried
> +	Dialog $w
> +	wm withdraw $w
> +	wm title $w [strcat "[appname] ([reponame]): " [mc "Index Error"]]
> +	wm geometry $w "+[winfo rootx .]+[winfo rooty .]"
> +	set s [mc "Updating the Git index failed.  A rescan will be automatically started to resynchronize git-gui."]
> +	text $w.msg -yscrollcommand [list $w.vs set] \
> +		-width [string length $s] -relief flat \
> +		-borderwidth 0 -highlightthickness 0 \
> +		-background [get_bg_color $w]
> +	$w.msg tag configure bold -font font_uibold -justify center
> +	${NS}::scrollbar $w.vs -command [list $w.msg yview]
> +	$w.msg insert end $s bold \n\n$err {}
> +	$w.msg configure -state disabled
> +
> +	${NS}::button $w.continue \
> +		-text [mc "Continue"] \
> +		-command [list destroy $w]
> +	${NS}::button $w.unlock \
> +		-text [mc "Unlock Index"] \
> +		-command "destroy $w; _delete_indexlock"
> +	grid $w.msg - $w.vs -sticky news
> +	grid $w.unlock $w.continue - -sticky se -padx 2 -pady 2
> +	grid columnconfigure $w 0 -weight 1
> +	grid rowconfigure $w 0 -weight 1
> +
> +	wm protocol $w WM_DELETE_WINDOW update
> +	bind $w.continue <Visibility> "
> +		grab $w
> +		focus %W
> +	"
> +	wm deiconify $w
> +	tkwait window $w
>  
>  	$::main_status stop

Same question here.

>  	unlock_index
> -	uplevel #0 $after
> +	rescan ui_ready 0
>  }
>  
>  proc update_indexinfo {msg path_list after} {
> @@ -90,7 +99,11 @@ proc write_update_indexinfo {fd path_list total_cnt batch after} {
>  	global file_states current_diff_path
>  
>  	if {$update_index_cp >= $total_cnt} {
> -		_close_updateindex $fd $after
> +		if {[_close_updateindex_rescan_on_error $fd]} {
> +			unlock_index
> +		}
> +
> +		uplevel #0 $after

This changes when $after is called. If you pass it to 'rescan', it runs 
_after_ the rescan is finished. Now it runs "in parallel" with it. Are 
you sure that is the intended behaviour? Should we just stick to passing 
$after to rescan on failure?

>  		return
>  	}
>  
> @@ -156,7 +169,11 @@ proc write_update_index {fd path_list total_cnt batch after} {
>  	global file_states current_diff_path
>  
>  	if {$update_index_cp >= $total_cnt} {
> -		_close_updateindex $fd $after
> +		if {[_close_updateindex_rescan_on_error $fd]} {
> +			unlock_index
> +		}
> +
> +		uplevel #0 $after

While we're here, how about just moving this entire thing to 
'_close_updateindex_rescan_on_error', since the only two consumers of 
the function do the _exact_ same thing?

This would also allow us to pass $after to 'rescan'. It would also 
hopefully make the code a bit easier to follow because you can clearly 
see that we only unlock the index when there is no error.

Even better, unlock the index unconditionally in 
'_close_updateindex_rescan_on_error', and remove the 'unlock_index' call 
from 'rescan_on_error'. I generally prefer to keep locking/unlocking 
paths as simple as possible.

>  		return
>  	}
>  
> @@ -193,7 +210,7 @@ proc write_update_index {fd path_list total_cnt batch after} {
>  	$::main_status update $update_index_cp $total_cnt
>  }
>  
> -proc checkout_index {msg path_list after} {
> +proc checkout_index {msg path_list after capture_error} {
>  	global update_index_cp
>  
>  	if {![lock_index update]} return
> @@ -225,15 +242,21 @@ proc checkout_index {msg path_list after} {
>  		$total_cnt \
>  		$batch \
>  		$after \
> +		$capture_error \
>  		]
>  }
>  
> -proc write_checkout_index {fd path_list total_cnt batch after} {
> +proc write_checkout_index {fd path_list total_cnt batch after capture_error} {
>  	global update_index_cp
>  	global file_states current_diff_path
>  
>  	if {$update_index_cp >= $total_cnt} {
> -		_close_updateindex $fd $after
> +		if {[catch {_close_updateindex $fd} err]} {
> +			uplevel #0 $capture_error [list $err]
> +		}
> +
> +		uplevel #0 $after
> +

Nitpick: Please explicitly mention why we _don't_ want to unlock the 
index here.

There are two function very similar to this one: 'write_update_index' 
and 'write_update_indexinfo'. This subtle but important difference is 
very easy to gloss over.

>  		return
>  	}
>  

This patch is almost ready to be merged. Looking forward to the 
(hopefully) final iteration of this topic :)

-- 
Regards,
Pratyush Yadav

Re: [PATCH v3 2/2] git-gui: revert untracked files by deleting them

[Jonathan Gilbert]

On Sat, Nov 16, 2019 at 9:11 AM Pratyush Yadav me-at-yadavpratyush.com
|GitHub Public/Example Allow| <172q77k4bxwj0zt@sneakemail.com> wrote:
> > -             grid $w.msg - $w.vs -sticky news
> > -             grid $w.unlock $w.continue - -sticky se -padx 2 -pady 2
> > -             grid columnconfigure $w 0 -weight 1
> > -             grid rowconfigure $w 0 -weight 1
> > -
> > -             wm protocol $w WM_DELETE_WINDOW update
> > -             bind $w.continue <Visibility> "
> > -                     grab $w
> > -                     focus %W
> > -             "
> > -             wm deiconify $w
> > -             tkwait window $w
> > +     close $fd
> > +     $::main_status stop
>
> I didn't spot this earlier. Will this call to 'stop' interfere with the
> 'start' in 'delete_files'?

Hmm, I think this actually highlights a larger issue. Both
`write_checkout_index` and `delete_helper` display their progress in
the status bar, so if the user elects to do a check-out, and then
while it is still in progress asynchronously, elects to delete files,
they'll fight over who gets to set the status. If I'm understanding
correctly, this won't actually interfere with correct operation, but
of course it won't look very nice.

If they overlap in this manner, _then_ multiple calls to `stop` could
be made, though it does appear that `stop` is idempotent. The Tk
documentation states that `destroy` doesn't return any error if you
point it at a window that doesn't exist.

`start` is explicitly idempotent, only creating a new canvas if it
doesn't already have one.

I'll see what I can come up with for letting operations more cleanly
share the status bar.

> >       if {$update_index_cp >= $total_cnt} {
> > -             _close_updateindex $fd $after
> > +             if {[_close_updateindex_rescan_on_error $fd]} {
> > +                     unlock_index
> > +             }
> > +
> > +             uplevel #0 $after
>
> This changes when $after is called. If you pass it to 'rescan', it runs
> _after_ the rescan is finished. Now it runs "in parallel" with it. Are
> you sure that is the intended behaviour? Should we just stick to passing
> $after to rescan on failure?
>
> [..]
>
> While we're here, how about just moving this entire thing to
> '_close_updateindex_rescan_on_error', since the only two consumers of
> the function do the _exact_ same thing?
>
> This would also allow us to pass $after to 'rescan'. It would also
> hopefully make the code a bit easier to follow because you can clearly
> see that we only unlock the index when there is no error.
>
> Even better, unlock the index unconditionally in
> '_close_updateindex_rescan_on_error', and remove the 'unlock_index' call
> from 'rescan_on_error'. I generally prefer to keep locking/unlocking
> paths as simple as possible.

Hmm, yeah, this makes sense. Pass it `$after`, and then if it calls
`rescan`, it can hand it off, and `rescan` also (I'm assuming?)
implicitly unlocks the index. If it doesn't need to call `rescan`,
then `_close_updateindex_rescan_on_error` itself unlocks the index
_and_ invokes `$after`.

> >       if {$update_index_cp >= $total_cnt} {
> > -             _close_updateindex $fd $after
> > +             if {[catch {_close_updateindex $fd} err]} {
> > +                     uplevel #0 $capture_error [list $err]
> > +             }
> > +
> > +             uplevel #0 $after
> > +
>
> Nitpick: Please explicitly mention why we _don't_ want to unlock the
> index here.
>
> There are two function very similar to this one: 'write_update_index'
> and 'write_update_indexinfo'. This subtle but important difference is
> very easy to gloss over.

Hmm, so, this suggests a rename of
`_close_updateindex_rescan_on_error`, because (with the previous
proposal) it implicitly includes unlocking the index, whereas
`_close_updateindex` does not.

Thanks,

Jonathan Gilbert

[PATCH v4 0/2] git-gui: revert untracked files by deleting them

[Jonathan Gilbert via GitGitGadget]

My development environment sometimes makes automatic changes that I don't
want to keep. In some cases, this involves new files being added that I
don't want to commit or keep (but I also don't want to outright .gitignore 
forever). I have typically had to explicitly delete those files externally
to Git Gui, which is a context switch to a manual operation, and I want to
be able to just select those newly-created untracked files in the UI and
"revert" them into oblivion.

This change updates the revert_helper proc to check for untracked files as
well as changes, and then changes to be reverted and untracked files are
handled by independent blocks of code. The user is prompted independently
for untracked files, since the underlying action is fundamentally different
(rm -f). If after deleting untracked files, the directory containing them
becomes empty, then the directory is removed as well. A new proc 
delete_files takes care of actually deleting the files, using the Tcler's
Wiki recommended approach for keeping the UI responsive.

Since the checkout_index and delete_files calls are both asynchronous and
could potentially complete in any order, a "chord" is used to coordinate
unlocking the index and returning the UI to a usable state only after both
operations are complete.

Since the checkout_index and delete_files calls are both asynchronous and
overlap, they clash in wanting to update the status bar. To address this,
the status bar is reworked so that when an operation wants to display
ongoing updates/progress, it explicitly starts an "operation", which is
tracked by its own object, and the status bar handles multiple concurrent
operations by merging their progress and concatenating their text.

The _close_updateindex proc contains error handling (added in d4e890e5) that
has the potential to interact badly with unlock_index running at the
completion of an async operation. I have refactored the procedure into
separate procs _close_updateindex and rescan_on_error, and the original
functionality is captured with _close_updateindex_rescan_on_error. Call
sites have been updated appropriately, and checkout_index has been reworked
to take a functor that captures any errors that occur in a caller-defined
way. revert_helper uses this to supply a lambda function that stashes the
error within the chord's body namespace, so that it can call rescan_on_error 
when the chord is completed, which might be substantially after 
checkout_index encounters its error. If a rescan is called for, it is done
once the deletion is complete.

This is the fifth revision of this change, which differs from the fourth
version in the following ways:

 * The status_bar.tcl code has been reworked so that tracking an operation
   with updates and progress is now done in instances of a separate 
   status_bar_operation class. main_status start returns an operation
   instead of directly setting the state on the main progress bar, and then
   you send all your updates to the operation. This model allows the main
   progress bar to support multiple ongoing operations, in which case their
   progress data is merged: The status text is concatenated (separated by
   '/'), and the progress is combined mathematically into a single progress
   bar.
   
   
 * All call sites that used to directly send updates to main_status have
   been updated to use the new model.
   
   
 * The initialization code in git-gui.sh (which I'm assuming translates
   somehow to git-gui.tcl in the installation?) now explicitly clears the
   "Initializing..." status bar text, since the new status bar model won't
   do this automatically when operations are performed.
   
   
 * rescan_on_error makes a call to a special status bar function to stop and
   unhook all ongoing operations, on the assumption that the rescan is
   superseding any and all ongoing operations. Of course, if the operations
   are still actually running, errors will result, but this seemed the
   clearest mapping from the previous revision's $::main_status stop call
   inside the rescan code.
   
   
 * _close_updateindex_rescan_on_error has been renamed to 
   close_and_unlock_updateindex_rescan_on_error, and once again takes $after
   . As indicated by the name change, it also encapsulates the unlocking of
   the index, so that is removed from the call sites.
   
   
 * rescan_on_error takes $after as well, in case 
   close_and_unlock_updateindex_rescan_on_error needs to call it.
   
   
 * The after_chord body in revert_helper only calls unlock_index if it
   doesn't call rescan_on_error.
   
   

git remote add logiclrd https://github.com/logiclrd/git.git
git fetch logiclrd git-gui-revert-untracked revision4
git diff dc12c16..23d4f5d

Jonathan Gilbert (2):
  git-gui: consolidate naming conventions
  git-gui: revert untracked files by deleting them

 git-gui.sh          |   7 +-
 lib/checkout_op.tcl |  15 +-
 lib/chord.tcl       | 160 ++++++++++++++
 lib/index.tcl       | 517 +++++++++++++++++++++++++++++++++-----------
 lib/merge.tcl       |  14 +-
 lib/status_bar.tcl  | 221 +++++++++++++++++--
 6 files changed, 771 insertions(+), 163 deletions(-)
 create mode 100644 lib/chord.tcl


base-commit: b524f6b399c77b40c8bf2b6217585fde4731472a
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-436%2Flogiclrd%2Fgit-gui-revert-untracked-v4
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-436/logiclrd/git-gui-revert-untracked-v4
Pull-Request: https://github.com/gitgitgadget/git/pull/436

Range-diff vs v3:

 1:  da1704c56e = 1:  da1704c56e git-gui: consolidate naming conventions
 2:  dc12c1668d ! 2:  23d4f5d829 git-gui: revert untracked files by deleting them
     @@ -11,7 +11,8 @@
          out of _close_updateindex to a responsibility of the caller, to permit
          paths that don't directly unlock the index, and refactor the error
          handling added in d4e890e5 so that callers can make flow control
     -    decisions in the event of errors.
     +    decisions in the event of errors. Rework status_bar to explicitly handle
     +    multiple overlapping operations, and update all call sites.
      
          A new proc delete_files takes care of actually deleting the files in
          batches, using the Tcler's Wiki recommended approach for keeping the UI
     @@ -23,6 +24,14 @@
          only after both operations are complete. The `SimpleChord` class,
          based on TclOO (Tcl/Tk 8.6), is added in this commit.
      
     +    Since the checkout_index and delete_files calls are both asynchronous
     +    and overlap, they clash in wanting to update the status bar. This commit
     +    reworks the status bar so that when an operation wants to display
     +    ongoing updates/progress, it explicitly starts an "operation", which is
     +    tracked by its own object, and the status bar handles multiple
     +    concurrent operations by merging their progress and concatenating their
     +    text.
     +
          Signed-off-by: Jonathan Gilbert <JonathanG@iQmetrix.com>
      
       diff --git a/git-gui.sh b/git-gui.sh
     @@ -39,6 +48,73 @@
       } {
       	catch {wm withdraw .}
       	tk_messageBox \
     +@@
     + 	do_explore
     + }
     + 
     ++# Clear "Initializing..." status
     ++after idle {after 500 {$main_status show ""}}
     ++
     + # Local variables:
     + # mode: tcl
     + # indent-tabs-mode: t
     +
     + diff --git a/lib/checkout_op.tcl b/lib/checkout_op.tcl
     + --- a/lib/checkout_op.tcl
     + +++ b/lib/checkout_op.tcl
     +@@
     + 	global HEAD
     + 
     + 	set readtree_d {}
     +-	$::main_status start \
     ++	set status_bar_operation [$::main_status start \
     + 		[mc "Updating working directory to '%s'..." [_name $this]] \
     +-		[mc "files checked out"]
     ++		[mc "files checked out"]]
     + 
     + 	set fd [git_read --stderr read-tree \
     + 		-m \
     +@@
     + 		$new_hash \
     + 		]
     + 	fconfigure $fd -blocking 0 -translation binary
     +-	fileevent $fd readable [cb _readtree_wait $fd]
     ++	fileevent $fd readable [cb _readtree_wait $fd $status_bar_operation]
     + }
     + 
     +-method _readtree_wait {fd} {
     ++method _readtree_wait {fd status_bar_operation} {
     + 	global current_branch
     + 
     + 	set buf [read $fd]
     +-	$::main_status update_meter $buf
     ++	$status_bar_operation update_meter $buf
     + 	append readtree_d $buf
     + 
     + 	fconfigure $fd -blocking 1
     + 	if {![eof $fd]} {
     + 		fconfigure $fd -blocking 0
     ++		$status_bar_operation stop
     + 		return
     + 	}
     + 
     + 	if {[catch {close $fd}]} {
     + 		set err $readtree_d
     + 		regsub {^fatal: } $err {} err
     +-		$::main_status stop [mc "Aborted checkout of '%s' (file level merging is required)." [_name $this]]
     ++		$status_bar_operation stop [mc "Aborted checkout of '%s' (file level merging is required)." [_name $this]]
     + 		warn_popup [strcat [mc "File level merge required."] "
     + 
     + $err
     +@@
     + 		return
     + 	}
     + 
     +-	$::main_status stop
     ++	$status_bar_operation stop
     + 	_after_readtree $this
     + }
     + 
      
       diff --git a/lib/chord.tcl b/lib/chord.tcl
       new file mode 100644
     @@ -215,18 +291,7 @@
       
      -proc _close_updateindex {fd after} {
      -	global use_ttk NS
     -+# Returns true if the operation succeeded, false if a rescan has been initiated.
     -+proc _close_updateindex_rescan_on_error {fd} {
     -+	if {![catch {_close_updateindex $fd} err]} {
     -+		return true
     -+	} else {
     -+		rescan_on_error $err
     -+		return false
     -+	}
     -+}
     -+
     -+proc _close_updateindex {fd} {
     - 	fconfigure $fd -blocking 1
     +-	fconfigure $fd -blocking 1
      -	if {[catch {close $fd} err]} {
      -		set w .indexfried
      -		Dialog $w
     @@ -261,16 +326,29 @@
      -		"
      -		wm deiconify $w
      -		tkwait window $w
     -+	close $fd
     -+	$::main_status stop
     -+}
     - 
     +-
      -		$::main_status stop
     --		unlock_index
     ++# Returns true if the operation succeeded, false if a rescan has been initiated.
     ++proc close_and_unlock_updateindex_rescan_on_error {fd after} {
     ++	if {![catch {_close_updateindex $fd} err]} {
     + 		unlock_index
      -		rescan $after 0
      -		return
     --	}
     -+proc rescan_on_error {err} {
     ++		uplevel #0 $after
     ++		return 1
     ++	} else {
     ++		rescan_on_error $err $after
     ++		return 0
     + 	}
     ++}
     + 
     +-	$::main_status stop
     ++proc _close_updateindex {fd} {
     ++	fconfigure $fd -blocking 1
     ++	close $fd
     ++}
     ++
     ++proc rescan_on_error {err {after {}}} {
      +	global use_ttk NS
      +
      +	set w .indexfried
     @@ -306,42 +384,91 @@
      +	"
      +	wm deiconify $w
      +	tkwait window $w
     - 
     - 	$::main_status stop
     ++
     ++	$::main_status stop_all
       	unlock_index
      -	uplevel #0 $after
     -+	rescan ui_ready 0
     ++	rescan [concat $after [list ui_ready]] 0
       }
       
       proc update_indexinfo {msg path_list after} {
      @@
     + 	set batch [expr {int($total_cnt * .01) + 1}]
     + 	if {$batch > 25} {set batch 25}
     + 
     +-	$::main_status start $msg [mc "files"]
     ++	set status_bar_operation [$::main_status start $msg [mc "files"]]
     + 	set fd [git_write update-index -z --index-info]
     + 	fconfigure $fd \
     + 		-blocking 0 \
     +@@
     + 		$path_list \
     + 		$total_cnt \
     + 		$batch \
     ++		$status_bar_operation \
     + 		$after \
     + 		]
     + }
     + 
     +-proc write_update_indexinfo {fd path_list total_cnt batch after} {
     ++proc write_update_indexinfo {fd path_list total_cnt batch status_bar_operation \
     ++	after} {
     + 	global update_index_cp
       	global file_states current_diff_path
       
       	if {$update_index_cp >= $total_cnt} {
      -		_close_updateindex $fd $after
     -+		if {[_close_updateindex_rescan_on_error $fd]} {
     -+			unlock_index
     -+		}
     -+
     -+		uplevel #0 $after
     ++		$status_bar_operation stop
     ++		close_and_unlock_updateindex_rescan_on_error $fd $after
       		return
       	}
       
      @@
     + 		display_file $path $new
     + 	}
     + 
     +-	$::main_status update $update_index_cp $total_cnt
     ++	$status_bar_operation update $update_index_cp $total_cnt
     + }
     + 
     + proc update_index {msg path_list after} {
     +@@
     + 	set batch [expr {int($total_cnt * .01) + 1}]
     + 	if {$batch > 25} {set batch 25}
     + 
     +-	$::main_status start $msg [mc "files"]
     ++	set status_bar_operation [$::main_status start $msg [mc "files"]]
     + 	set fd [git_write update-index --add --remove -z --stdin]
     + 	fconfigure $fd \
     + 		-blocking 0 \
     +@@
     + 		$path_list \
     + 		$total_cnt \
     + 		$batch \
     ++		$status_bar_operation \
     + 		$after \
     + 		]
     + }
     + 
     +-proc write_update_index {fd path_list total_cnt batch after} {
     ++proc write_update_index {fd path_list total_cnt batch status_bar_operation \
     ++	after} {
     + 	global update_index_cp
       	global file_states current_diff_path
       
       	if {$update_index_cp >= $total_cnt} {
      -		_close_updateindex $fd $after
     -+		if {[_close_updateindex_rescan_on_error $fd]} {
     -+			unlock_index
     -+		}
     -+
     -+		uplevel #0 $after
     ++		$status_bar_operation stop
     ++		close_and_unlock_updateindex_rescan_on_error $fd $after
       		return
       	}
       
      @@
     - 	$::main_status update $update_index_cp $total_cnt
     + 		display_file $path $new
     + 	}
     + 
     +-	$::main_status update $update_index_cp $total_cnt
     ++	$status_bar_operation update $update_index_cp $total_cnt
       }
       
      -proc checkout_index {msg path_list after} {
     @@ -350,20 +477,34 @@
       
       	if {![lock_index update]} return
      @@
     + 	set batch [expr {int($total_cnt * .01) + 1}]
     + 	if {$batch > 25} {set batch 25}
     + 
     +-	$::main_status start $msg [mc "files"]
     ++	set status_bar_operation [$::main_status start $msg [mc "files"]]
     + 	set fd [git_write checkout-index \
     + 		--index \
     + 		--quiet \
     +@@
     + 		$path_list \
       		$total_cnt \
       		$batch \
     ++		$status_bar_operation \
       		$after \
      +		$capture_error \
       		]
       }
       
      -proc write_checkout_index {fd path_list total_cnt batch after} {
     -+proc write_checkout_index {fd path_list total_cnt batch after capture_error} {
     ++proc write_checkout_index {fd path_list total_cnt batch status_bar_operation \
     ++	after capture_error} {
       	global update_index_cp
       	global file_states current_diff_path
       
       	if {$update_index_cp >= $total_cnt} {
      -		_close_updateindex $fd $after
     ++		$status_bar_operation stop
     ++
      +		if {[catch {_close_updateindex $fd} err]} {
      +			uplevel #0 $capture_error [list $err]
      +		}
     @@ -373,6 +514,15 @@
       		return
       	}
       
     +@@
     + 		}
     + 	}
     + 
     +-	$::main_status update $update_index_cp $total_cnt
     ++	$status_bar_operation update $update_index_cp $total_cnt
     + }
     + 
     + proc unstage_helper {txt paths} {
      @@
       	add_helper [mc "Adding all changed files"] $paths
       }
     @@ -394,10 +544,10 @@
      +	# The asynchronous operations are each indicated below by a comment
      +	# before the code block that starts the async operation.
      +	set after_chord [SimpleChord new {
     -+		unlock_index
      +		if {[string trim $err] != ""} {
      +			rescan_on_error $err
      +		} else {
     ++			unlock_index
      +			if {$should_reshow_diff} { reshow_diff }
      +			ui_ready
      +		}
     @@ -467,11 +617,6 @@
      +				"Revert changes in these %i files?" \
      +				$path_cnt]
      +		}
     -+
     -+		set reply [tk_dialog \
     -+			.confirm_revert \
     -+			"[appname] ([reponame])" \
     -+			"$query
       
      -	# Split question between singular and plural cases, because
      -	# such distinction is needed in some languages. Previously, the
     @@ -491,6 +636,11 @@
      -		set query [mc "Revert changes in file %s?" [short_path [lindex $path_list]]]
      -	} else {
      -		set query [mc "Revert changes in these %i files?" $n]
     ++		set reply [tk_dialog \
     ++			.confirm_revert \
     ++			"[appname] ([reponame])" \
     ++			"$query
     ++
      +[mc "Any unstaged changes will be permanently lost by the revert."]" \
      +			question \
      +			1 \
     @@ -571,7 +721,10 @@
      +# UI to remain responsive and updated.
      +proc delete_files {path_list after} {
      +	# Enable progress bar status updates
     -+	$::main_status start [mc "Deleting"] [mc "files"]
     ++	set status_bar_operation [$::main_status \
     ++		start \
     ++		[mc "Deleting"] \
     ++		[mc "files"]]
      +
      +	set path_index 0
      +	set deletion_errors [list]
     @@ -582,13 +735,15 @@
      +		$path_index \
      +		$deletion_errors \
      +		$batch_size \
     ++		$status_bar_operation \
      +		$after
      +}
      +
      +# Helper function to delete a list of files in batches. Each call deletes one
      +# batch of files, and then schedules a call for the next batch after any UI
      +# messages have been processed.
     -+proc delete_helper {path_list path_index deletion_errors batch_size after} {
     ++proc delete_helper {path_list path_index deletion_errors batch_size \
     ++	status_bar_operation after} {
      +	global file_states
      +
      +	set path_cnt [llength $path_list]
     @@ -622,7 +777,7 @@
      +	# Update the progress bar to indicate that this batch has been
      +	# completed. The update will be visible when this procedure returns
      +	# and allows the UI thread to process messages.
     -+	$::main_status update $path_index $path_cnt
     ++	$status_bar_operation update $path_index $path_cnt
      +
      +	if {$path_index < $path_cnt} {
      +		# The Tcler's Wiki lists this as the best practice for keeping
     @@ -636,12 +791,13 @@
      +			$path_index \
      +			$deletion_errors \
      +			$batch_size \
     ++			$status_bar_operation \
      +			$after
      +			]]
       	} else {
      -		unlock_index
      +		# Finish the status bar operation.
     -+		$::main_status stop
     ++		$status_bar_operation stop
      +
      +		# Report error, if any, based on how many deletions failed.
      +		set deletion_error_cnt [llength $deletion_errors]
     @@ -704,3 +860,348 @@
       	}
       }
       
     +
     + diff --git a/lib/merge.tcl b/lib/merge.tcl
     + --- a/lib/merge.tcl
     + +++ b/lib/merge.tcl
     +@@
     + 	if {[ask_popup $op_question] eq {yes}} {
     + 		set fd [git_read --stderr read-tree --reset -u -v HEAD]
     + 		fconfigure $fd -blocking 0 -translation binary
     +-		fileevent $fd readable [namespace code [list _reset_wait $fd]]
     +-		$::main_status start [mc "Aborting"] [mc "files reset"]
     ++		set status_bar_operation [$::main_status \
     ++			start \
     ++			[mc "Aborting"] \
     ++			[mc "files reset"]
     ++		fileevent $fd readable [namespace code [list \
     ++			_reset_wait $fd $status_bar_operation]]
     + 	} else {
     + 		unlock_index
     + 	}
     + }
     + 
     +-proc _reset_wait {fd} {
     ++proc _reset_wait {fd status_bar_operation} {
     + 	global ui_comm
     + 
     +-	$::main_status update_meter [read $fd]
     ++	$status_bar_operation update_meter [read $fd]
     + 
     + 	fconfigure $fd -blocking 1
     + 	if {[eof $fd]} {
     + 		set fail [catch {close $fd} err]
     +-		$::main_status stop
     + 		unlock_index
     ++		$status_bar_operation stop
     + 
     + 		$ui_comm delete 0.0 end
     + 		$ui_comm edit modified false
     +
     + diff --git a/lib/status_bar.tcl b/lib/status_bar.tcl
     + --- a/lib/status_bar.tcl
     + +++ b/lib/status_bar.tcl
     +@@
     + # git-gui status bar mega-widget
     + # Copyright (C) 2007 Shawn Pearce
     + 
     ++# The status_bar class manages the entire status bar. It is possible for
     ++# multiple overlapping asynchronous operations to want to display status
     ++# simultaneously. Each one receives a status_bar_operation when it calls the
     ++# start method, and the status bar combines all active operations into the
     ++# line of text it displays. Most of the time, there will be at most one
     ++# ongoing operation.
     ++#
     ++# Note that the entire status bar can be either in single-line or two-line
     ++# mode, depending on the constructor. Multiple active operations are only
     ++# supported for single-line status bars.
     ++
     + class status_bar {
     + 
     ++field allow_multiple ; # configured at construction
     ++
     + field w         ; # our own window path
     + field w_l       ; # text widget we draw messages into
     + field w_c       ; # canvas we draw a progress bar into
     + field c_pack    ; # script to pack the canvas with
     +-field status  {}; # single line of text we show
     +-field prefix  {}; # text we format into status
     +-field units   {}; # unit of progress
     +-field meter   {}; # current core git progress meter (if active)
     ++
     ++field baseline_text   ; # text to show if there are no operations
     ++field status_bar_text ; # combined text for all operations
     ++
     ++field operations ; # list of current ongoing operations
     ++
     ++# The status bar can display a progress bar, updated when consumers call the
     ++# update method on their status_bar_operation. When there are multiple
     ++# operations, the status bar shows the combined status of all operations.
     ++#
     ++# When an overlapping operation completes, the progress bar is going to
     ++# abruptly have one fewer operation in the calculation, causing a discontinuity.
     ++# Therefore, whenever an operation completes, if it is not the last operation,
     ++# this counter is increased, and the progress bar is calculated as though there
     ++# were still another operation at 100%. When the last operation completes, this
     ++# is reset to 0.
     ++field completed_operation_count
     + 
     + constructor new {path} {
     + 	global use_ttk NS
     +@@
     + 	set w_l $w.l
     + 	set w_c $w.c
     + 
     ++	# Standard single-line status bar: Permit overlapping operations
     ++	set allow_multiple 1
     ++
     ++	set baseline_text ""
     ++	set operations [list]
     ++	set completed_operation_count 0
     ++
     + 	${NS}::frame $w
     + 	if {!$use_ttk} {
     + 		$w configure -borderwidth 1 -relief sunken
     + 	}
     + 	${NS}::label $w_l \
     +-		-textvariable @status \
     ++		-textvariable @status_bar_text \
     + 		-anchor w \
     + 		-justify left
     + 	pack $w_l -side left
     +@@
     + 	set w_l $w.l
     + 	set w_c $w.c
     + 
     ++	# Two-line status bar: Only one ongoing operation permitted.
     ++	set allow_multiple 0
     ++
     ++	set baseline_text ""
     ++	set operations [list]
     ++
     + 	${NS}::frame $w
     + 	${NS}::label $w_l \
     +-		-textvariable @status \
     ++		-textvariable @status_bar_text \
     + 		-anchor w \
     + 		-justify left
     + 	pack $w_l -anchor w -fill x
     +@@
     + 	return $this
     + }
     + 
     +-method start {msg uds} {
     ++method ensure_canvas {} {
     + 	if {[winfo exists $w_c]} {
     + 		$w_c coords bar 0 0 0 20
     + 	} else {
     +@@
     + 		$w_c create rectangle 0 0 0 20 -tags bar -fill navy
     + 		eval $c_pack
     + 	}
     ++}
     ++
     ++method show {msg {test {}}} {
     ++	if {$test eq {} || $status eq $test} {
     ++		$this ensure_canvas
     ++		set baseline_text $msg
     ++		$this refresh
     ++	}
     ++}
     ++
     ++method start {msg uds} {
     ++	set baseline_text ""
     ++
     ++	if {!$allow_multiple && [llength $operations]} {
     ++		return [lindex $operations 0]
     ++	}
     ++
     ++	$this ensure_canvas
     ++
     ++	set operation [status_bar_operation::new $this $msg $uds]
     ++
     ++	lappend operations $operation
     ++
     ++	$this refresh
     ++
     ++	return $operation
     ++}
     ++
     ++method refresh {} {
     ++	set new_text ""
     ++
     ++	set total [expr $completed_operation_count * 100]
     ++	set have $total
     ++
     ++	foreach operation $operations {
     ++		if {$new_text != ""} {
     ++			append new_text " / "
     ++		}
     ++
     ++		append new_text [$operation get_status]
     ++
     ++		set total [expr $total + 100]
     ++		set have [expr $have + [$operation get_progress]]
     ++	}
     ++
     ++	if {$new_text == ""} {
     ++		set new_text $baseline_text
     ++	}
     ++
     ++	set status_bar_text $new_text
     ++
     ++	set pixel_width 0
     ++	if {$have > 0} {
     ++		set pixel_width [expr {[winfo width $w_c] * $have / $total}]
     ++	}
     ++
     ++	$w_c coords bar 0 0 $pixel_width 20
     ++}
     ++
     ++method stop {operation stop_msg} {
     ++	set idx [lsearch $operations $operation]
     ++
     ++	if {$idx >= 0} {
     ++		set operations [lreplace $operations $idx $idx]
     ++		set completed_operation_count [expr \
     ++			$completed_operation_count + 1]
     ++
     ++		if {[llength operations] == 0} {
     ++			set completed_operation_count 0
     ++
     ++			destroy $w_c
     ++			if {$stop_msg ne {}} {
     ++				set baseline_text $stop_msg
     ++			}
     ++		}
     ++
     ++		$this refresh
     ++	}
     ++}
     ++
     ++method stop_all {{stop_msg {}}} {
     ++	set operations_copy $operations
     ++	set operations [list] # This makes the operation's call to stop a no-op.
     ++
     ++	foreach $operation operations_copy {
     ++		$operation stop
     ++	}
     ++
     ++	if {$stop_msg ne {}} {
     ++		set baseline_text $stop_msg
     ++	}
     ++
     ++	$this refresh
     ++}
     ++
     ++method _delete {current} {
     ++	if {$current eq $w} {
     ++		delete_this
     ++	}
     ++}
     ++
     ++}
     ++
     ++# The status_bar_operation class tracks a single consumer's ongoing status bar
     ++# activity, with the context that there are a few situations where multiple
     ++# overlapping asynchronous operations might want to display status information
     ++# simultaneously. Instances of status_bar_operation are created by calling
     ++# start on the status_bar, and when the caller is done with its stauts bar
     ++# operation, it calls stop on the operation.
     ++
     ++class status_bar_operation {
     ++
     ++field status_bar; # reference back to the status_bar that owns this object
     ++
     ++field is_active;
     ++
     ++field status   {}; # single line of text we show
     ++field progress {}; # current progress (0 to 100)
     ++field prefix   {}; # text we format into status
     ++field units    {}; # unit of progress
     ++field meter    {}; # current core git progress meter (if active)
     ++
     ++constructor new {owner msg uds} {
     ++	set status_bar $owner
     + 
     + 	set status $msg
     ++	set progress 0
     + 	set prefix $msg
     + 	set units  $uds
     + 	set meter  {}
     ++
     ++	set is_active 1
     ++
     ++	return $this
     + }
     + 
     ++method get_is_active {} { return $is_active }
     ++method get_status {} { return $status }
     ++method get_progress {} { return $progress }
     ++
     + method update {have total} {
     +-	set pdone 0
     +-	set cdone 0
     ++	if {!$is_active} { return }
     ++
     ++	set progress 0
     ++
     + 	if {$total > 0} {
     +-		set pdone [expr {100 * $have / $total}]
     +-		set cdone [expr {[winfo width $w_c] * $have / $total}]
     ++		set progress [expr {100 * $have / $total}]
     + 	}
     + 
     + 	set prec [string length [format %i $total]]
     ++
     + 	set status [mc "%s ... %*i of %*i %s (%3i%%)" \
     + 		$prefix \
     + 		$prec $have \
     + 		$prec $total \
     +-		$units $pdone]
     +-	$w_c coords bar 0 0 $cdone 20
     ++		$units $progress]
     ++
     ++	$status_bar refresh
     + }
     + 
     + method update_meter {buf} {
     ++	if {!$is_active} { return }
     ++
     + 	append meter $buf
     + 	set r [string last "\r" $meter]
     + 	if {$r == -1} {
     +@@
     + 	}
     + }
     + 
     +-method stop {{msg {}}} {
     +-	destroy $w_c
     +-	if {$msg ne {}} {
     +-		set status $msg
     ++method stop {{stop_msg {}}} {
     ++	if {$is_active} {
     ++		set is_active 0
     ++		$status_bar stop $this $stop_msg
     + 	}
     + }
     + 
     + method show {msg {test {}}} {
     ++	if {!$is_active} { return }
     ++
     + 	if {$test eq {} || $status eq $test} {
     + 		set status $msg
     ++		$status_bar refresh
     + 	}
     + }
     + 
     +-method _delete {current} {
     +-	if {$current eq $w} {
     +-		delete_this
     +-	}
     ++method _delete {} {
     ++	stop
     ++	delete_this
     + }
     + 
     + }

-- 
gitgitgadget

[PATCH v4 1/2] git-gui: consolidate naming conventions

[Jonathan Gilbert via GitGitGadget]

From: Jonathan Gilbert <JonathanG@iQmetrix.com>

A few variables in this file use camelCase, while the overall standard
is snake_case. A consistent naming scheme will improve readability of
future changes. To avoid mixing naming changes with semantic changes,
this commit contains only naming changes.

Signed-off-by: Jonathan Gilbert <JonathanG@iQmetrix.com>
---
 lib/index.tcl | 92 +++++++++++++++++++++++++--------------------------
 1 file changed, 46 insertions(+), 46 deletions(-)

diff --git a/lib/index.tcl b/lib/index.tcl
index e07b7a3762..28d4d2a54e 100644
--- a/lib/index.tcl
+++ b/lib/index.tcl
@@ -56,15 +56,15 @@ proc _close_updateindex {fd after} {
 	uplevel #0 $after
 }
 
-proc update_indexinfo {msg pathList after} {
+proc update_indexinfo {msg path_list after} {
 	global update_index_cp
 
 	if {![lock_index update]} return
 
 	set update_index_cp 0
-	set pathList [lsort $pathList]
-	set totalCnt [llength $pathList]
-	set batch [expr {int($totalCnt * .01) + 1}]
+	set path_list [lsort $path_list]
+	set total_cnt [llength $path_list]
+	set batch [expr {int($total_cnt * .01) + 1}]
 	if {$batch > 25} {set batch 25}
 
 	$::main_status start $msg [mc "files"]
@@ -78,26 +78,26 @@ proc update_indexinfo {msg pathList after} {
 	fileevent $fd writable [list \
 		write_update_indexinfo \
 		$fd \
-		$pathList \
-		$totalCnt \
+		$path_list \
+		$total_cnt \
 		$batch \
 		$after \
 		]
 }
 
-proc write_update_indexinfo {fd pathList totalCnt batch after} {
+proc write_update_indexinfo {fd path_list total_cnt batch after} {
 	global update_index_cp
 	global file_states current_diff_path
 
-	if {$update_index_cp >= $totalCnt} {
+	if {$update_index_cp >= $total_cnt} {
 		_close_updateindex $fd $after
 		return
 	}
 
 	for {set i $batch} \
-		{$update_index_cp < $totalCnt && $i > 0} \
+		{$update_index_cp < $total_cnt && $i > 0} \
 		{incr i -1} {
-		set path [lindex $pathList $update_index_cp]
+		set path [lindex $path_list $update_index_cp]
 		incr update_index_cp
 
 		set s $file_states($path)
@@ -119,18 +119,18 @@ proc write_update_indexinfo {fd pathList totalCnt batch after} {
 		display_file $path $new
 	}
 
-	$::main_status update $update_index_cp $totalCnt
+	$::main_status update $update_index_cp $total_cnt
 }
 
-proc update_index {msg pathList after} {
+proc update_index {msg path_list after} {
 	global update_index_cp
 
 	if {![lock_index update]} return
 
 	set update_index_cp 0
-	set pathList [lsort $pathList]
-	set totalCnt [llength $pathList]
-	set batch [expr {int($totalCnt * .01) + 1}]
+	set path_list [lsort $path_list]
+	set total_cnt [llength $path_list]
+	set batch [expr {int($total_cnt * .01) + 1}]
 	if {$batch > 25} {set batch 25}
 
 	$::main_status start $msg [mc "files"]
@@ -144,26 +144,26 @@ proc update_index {msg pathList after} {
 	fileevent $fd writable [list \
 		write_update_index \
 		$fd \
-		$pathList \
-		$totalCnt \
+		$path_list \
+		$total_cnt \
 		$batch \
 		$after \
 		]
 }
 
-proc write_update_index {fd pathList totalCnt batch after} {
+proc write_update_index {fd path_list total_cnt batch after} {
 	global update_index_cp
 	global file_states current_diff_path
 
-	if {$update_index_cp >= $totalCnt} {
+	if {$update_index_cp >= $total_cnt} {
 		_close_updateindex $fd $after
 		return
 	}
 
 	for {set i $batch} \
-		{$update_index_cp < $totalCnt && $i > 0} \
+		{$update_index_cp < $total_cnt && $i > 0} \
 		{incr i -1} {
-		set path [lindex $pathList $update_index_cp]
+		set path [lindex $path_list $update_index_cp]
 		incr update_index_cp
 
 		switch -glob -- [lindex $file_states($path) 0] {
@@ -190,18 +190,18 @@ proc write_update_index {fd pathList totalCnt batch after} {
 		display_file $path $new
 	}
 
-	$::main_status update $update_index_cp $totalCnt
+	$::main_status update $update_index_cp $total_cnt
 }
 
-proc checkout_index {msg pathList after} {
+proc checkout_index {msg path_list after} {
 	global update_index_cp
 
 	if {![lock_index update]} return
 
 	set update_index_cp 0
-	set pathList [lsort $pathList]
-	set totalCnt [llength $pathList]
-	set batch [expr {int($totalCnt * .01) + 1}]
+	set path_list [lsort $path_list]
+	set total_cnt [llength $path_list]
+	set batch [expr {int($total_cnt * .01) + 1}]
 	if {$batch > 25} {set batch 25}
 
 	$::main_status start $msg [mc "files"]
@@ -221,26 +221,26 @@ proc checkout_index {msg pathList after} {
 	fileevent $fd writable [list \
 		write_checkout_index \
 		$fd \
-		$pathList \
-		$totalCnt \
+		$path_list \
+		$total_cnt \
 		$batch \
 		$after \
 		]
 }
 
-proc write_checkout_index {fd pathList totalCnt batch after} {
+proc write_checkout_index {fd path_list total_cnt batch after} {
 	global update_index_cp
 	global file_states current_diff_path
 
-	if {$update_index_cp >= $totalCnt} {
+	if {$update_index_cp >= $total_cnt} {
 		_close_updateindex $fd $after
 		return
 	}
 
 	for {set i $batch} \
-		{$update_index_cp < $totalCnt && $i > 0} \
+		{$update_index_cp < $total_cnt && $i > 0} \
 		{incr i -1} {
-		set path [lindex $pathList $update_index_cp]
+		set path [lindex $path_list $update_index_cp]
 		incr update_index_cp
 		switch -glob -- [lindex $file_states($path) 0] {
 		U? {continue}
@@ -253,7 +253,7 @@ proc write_checkout_index {fd pathList totalCnt batch after} {
 		}
 	}
 
-	$::main_status update $update_index_cp $totalCnt
+	$::main_status update $update_index_cp $total_cnt
 }
 
 proc unstage_helper {txt paths} {
@@ -261,7 +261,7 @@ proc unstage_helper {txt paths} {
 
 	if {![lock_index begin-update]} return
 
-	set pathList [list]
+	set path_list [list]
 	set after {}
 	foreach path $paths {
 		switch -glob -- [lindex $file_states($path) 0] {
@@ -269,19 +269,19 @@ proc unstage_helper {txt paths} {
 		M? -
 		T? -
 		D? {
-			lappend pathList $path
+			lappend path_list $path
 			if {$path eq $current_diff_path} {
 				set after {reshow_diff;}
 			}
 		}
 		}
 	}
-	if {$pathList eq {}} {
+	if {$path_list eq {}} {
 		unlock_index
 	} else {
 		update_indexinfo \
 			$txt \
-			$pathList \
+			$path_list \
 			[concat $after [list ui_ready]]
 	}
 }
@@ -305,7 +305,7 @@ proc add_helper {txt paths} {
 
 	if {![lock_index begin-update]} return
 
-	set pathList [list]
+	set path_list [list]
 	set after {}
 	foreach path $paths {
 		switch -glob -- [lindex $file_states($path) 0] {
@@ -321,19 +321,19 @@ proc add_helper {txt paths} {
 		?M -
 		?D -
 		?T {
-			lappend pathList $path
+			lappend path_list $path
 			if {$path eq $current_diff_path} {
 				set after {reshow_diff;}
 			}
 		}
 		}
 	}
-	if {$pathList eq {}} {
+	if {$path_list eq {}} {
 		unlock_index
 	} else {
 		update_index \
 			$txt \
-			$pathList \
+			$path_list \
 			[concat $after {ui_status [mc "Ready to commit."]}]
 	}
 }
@@ -393,7 +393,7 @@ proc revert_helper {txt paths} {
 
 	if {![lock_index begin-update]} return
 
-	set pathList [list]
+	set path_list [list]
 	set after {}
 	foreach path $paths {
 		switch -glob -- [lindex $file_states($path) 0] {
@@ -401,7 +401,7 @@ proc revert_helper {txt paths} {
 		?M -
 		?T -
 		?D {
-			lappend pathList $path
+			lappend path_list $path
 			if {$path eq $current_diff_path} {
 				set after {reshow_diff;}
 			}
@@ -420,12 +420,12 @@ proc revert_helper {txt paths} {
 	# as they have quite complex plural-form rules. Unfortunately,
 	# msgcat doesn't seem to support that kind of string translation.
 	#
-	set n [llength $pathList]
+	set n [llength $path_list]
 	if {$n == 0} {
 		unlock_index
 		return
 	} elseif {$n == 1} {
-		set query [mc "Revert changes in file %s?" [short_path [lindex $pathList]]]
+		set query [mc "Revert changes in file %s?" [short_path [lindex $path_list]]]
 	} else {
 		set query [mc "Revert changes in these %i files?" $n]
 	}
@@ -444,7 +444,7 @@ proc revert_helper {txt paths} {
 	if {$reply == 1} {
 		checkout_index \
 			$txt \
-			$pathList \
+			$path_list \
 			[concat $after [list ui_ready]]
 	} else {
 		unlock_index
-- 
gitgitgadget

[PATCH v4 2/2] git-gui: revert untracked files by deleting them

[Jonathan Gilbert via GitGitGadget]

From: Jonathan Gilbert <JonathanG@iQmetrix.com>

Update the revert_helper proc to check for untracked files as well as
changes, and then handle changes to be reverted and untracked files with
independent blocks of code. Prompt the user independently for untracked
files, since the underlying action is fundamentally different (rm -f).
If after deleting untracked files, the directory containing them becomes
empty, then remove the directory as well. Migrate unlocking of the index
out of _close_updateindex to a responsibility of the caller, to permit
paths that don't directly unlock the index, and refactor the error
handling added in d4e890e5 so that callers can make flow control
decisions in the event of errors. Rework status_bar to explicitly handle
multiple overlapping operations, and update all call sites.

A new proc delete_files takes care of actually deleting the files in
batches, using the Tcler's Wiki recommended approach for keeping the UI
responsive.

Since the checkout_index and delete_files calls are both asynchronous
and could potentially complete in any order, a "chord" is used to
coordinate unlocking the index and returning the UI to a usable state
only after both operations are complete. The `SimpleChord` class,
based on TclOO (Tcl/Tk 8.6), is added in this commit.

Since the checkout_index and delete_files calls are both asynchronous
and overlap, they clash in wanting to update the status bar. This commit
reworks the status bar so that when an operation wants to display
ongoing updates/progress, it explicitly starts an "operation", which is
tracked by its own object, and the status bar handles multiple
concurrent operations by merging their progress and concatenating their
text.

Signed-off-by: Jonathan Gilbert <JonathanG@iQmetrix.com>
---
 git-gui.sh          |   7 +-
 lib/checkout_op.tcl |  15 +-
 lib/chord.tcl       | 160 ++++++++++++++++
 lib/index.tcl       | 443 +++++++++++++++++++++++++++++++++++---------
 lib/merge.tcl       |  14 +-
 lib/status_bar.tcl  | 221 +++++++++++++++++++---
 6 files changed, 734 insertions(+), 126 deletions(-)
 create mode 100644 lib/chord.tcl

diff --git a/git-gui.sh b/git-gui.sh
index 0d21f5688b..dc4ac577ac 100755
--- a/git-gui.sh
+++ b/git-gui.sh
@@ -30,8 +30,8 @@ along with this program; if not, see <http://www.gnu.org/licenses/>.}]
 ##
 ## Tcl/Tk sanity check
 
-if {[catch {package require Tcl 8.4} err]
- || [catch {package require Tk  8.4} err]
+if {[catch {package require Tcl 8.6} err]
+ || [catch {package require Tk  8.6} err]
 } {
 	catch {wm withdraw .}
 	tk_messageBox \
@@ -4159,6 +4159,9 @@ if {$picked && [is_config_true gui.autoexplore]} {
 	do_explore
 }
 
+# Clear "Initializing..." status
+after idle {after 500 {$main_status show ""}}
+
 # Local variables:
 # mode: tcl
 # indent-tabs-mode: t
diff --git a/lib/checkout_op.tcl b/lib/checkout_op.tcl
index a5228297db..21ea768d80 100644
--- a/lib/checkout_op.tcl
+++ b/lib/checkout_op.tcl
@@ -341,9 +341,9 @@ method _readtree {} {
 	global HEAD
 
 	set readtree_d {}
-	$::main_status start \
+	set status_bar_operation [$::main_status start \
 		[mc "Updating working directory to '%s'..." [_name $this]] \
-		[mc "files checked out"]
+		[mc "files checked out"]]
 
 	set fd [git_read --stderr read-tree \
 		-m \
@@ -354,26 +354,27 @@ method _readtree {} {
 		$new_hash \
 		]
 	fconfigure $fd -blocking 0 -translation binary
-	fileevent $fd readable [cb _readtree_wait $fd]
+	fileevent $fd readable [cb _readtree_wait $fd $status_bar_operation]
 }
 
-method _readtree_wait {fd} {
+method _readtree_wait {fd status_bar_operation} {
 	global current_branch
 
 	set buf [read $fd]
-	$::main_status update_meter $buf
+	$status_bar_operation update_meter $buf
 	append readtree_d $buf
 
 	fconfigure $fd -blocking 1
 	if {![eof $fd]} {
 		fconfigure $fd -blocking 0
+		$status_bar_operation stop
 		return
 	}
 
 	if {[catch {close $fd}]} {
 		set err $readtree_d
 		regsub {^fatal: } $err {} err
-		$::main_status stop [mc "Aborted checkout of '%s' (file level merging is required)." [_name $this]]
+		$status_bar_operation stop [mc "Aborted checkout of '%s' (file level merging is required)." [_name $this]]
 		warn_popup [strcat [mc "File level merge required."] "
 
 $err
@@ -384,7 +385,7 @@ $err
 		return
 	}
 
-	$::main_status stop
+	$status_bar_operation stop
 	_after_readtree $this
 }
 
diff --git a/lib/chord.tcl b/lib/chord.tcl
new file mode 100644
index 0000000000..275a6cd4a1
--- /dev/null
+++ b/lib/chord.tcl
@@ -0,0 +1,160 @@
+# Simple Chord for Tcl
+#
+# A "chord" is a method with more than one entrypoint and only one body, such
+# that the body runs only once all the entrypoints have been called by
+# different asynchronous tasks. In this implementation, the chord is defined
+# dynamically for each invocation. A SimpleChord object is created, supplying
+# body script to be run when the chord is completed, and then one or more notes
+# are added to the chord. Each note can be called like a proc, and returns
+# immediately if the chord isn't yet complete. When the last remaining note is
+# called, the body runs before the note returns.
+#
+# The SimpleChord class has a constructor that takes the body script, and a
+# method add_note that returns a note object. Since the body script does not
+# run in the context of the procedure that defined it, a mechanism is provided
+# for injecting variables into the chord for use by the body script. The
+# activation of a note is idempotent; multiple calls have the same effect as
+# a simple call.
+#
+# If you are invoking asynchronous operations with chord notes as completion
+# callbacks, and there is a possibility that earlier operations could complete
+# before later ones are started, it is a good practice to create a "common"
+# note on the chord that prevents it from being complete until you're certain
+# you've added all the notes you need.
+#
+# Example:
+#
+#   # Turn off the UI while running a couple of async operations.
+#   lock_ui
+#
+#   set chord [SimpleChord new {
+#     unlock_ui
+#     # Note: $notice here is not referenced in the calling scope
+#     if {$notice} { info_popup $notice }
+#   }
+#
+#   # Configure a note to keep the chord from completing until
+#   # all operations have been initiated.
+#   set common_note [$chord add_note]
+#
+#   # Pass notes as 'after' callbacks to other operations
+#   async_operation $args [$chord add_note]
+#   other_async_operation $args [$chord add_note]
+#
+#   # Communicate with the chord body
+#   if {$condition} {
+#     # This sets $notice in the same context that the chord body runs in.
+#     $chord eval { set notice "Something interesting" }
+#   }
+#
+#   # Activate the common note, making the chord eligible to complete
+#   $common_note
+#
+# At this point, the chord will complete at some unknown point in the future.
+# The common note might have been the first note activated, or the async
+# operations might have completed synchronously and the common note is the
+# last one, completing the chord before this code finishes, or anything in
+# between. The purpose of the chord is to not have to worry about the order.
+
+# SimpleChord class:
+#   Represents a procedure that conceptually has multiple entrypoints that must
+#   all be called before the procedure executes. Each entrypoint is called a
+#   "note". The chord is only "completed" when all the notes are "activated".
+oo::class create SimpleChord {
+	variable notes body is_completed
+
+	# Constructor:
+	#   set chord [SimpleChord new {body}]
+	#     Creates a new chord object with the specified body script. The
+	#     body script is evaluated at most once, when a note is activated
+	#     and the chord has no other non-activated notes.
+	constructor {body} {
+		set notes [list]
+		my eval [list set body $body]
+		set is_completed 0
+	}
+
+	# Method:
+	#   $chord eval {script}
+	#     Runs the specified script in the same context (namespace) in which
+	#     the chord body will be evaluated. This can be used to set variable
+	#     values for the chord body to use.
+	method eval {script} {
+		namespace eval [self] $script
+	}
+
+	# Method:
+	#   set note [$chord add_note]
+	#     Adds a new note to the chord, an instance of ChordNote. Raises an
+	#     error if the chord is already completed, otherwise the chord is
+	#     updated so that the new note must also be activated before the
+	#     body is evaluated.
+	method add_note {} {
+		if {$is_completed} { error "Cannot add a note to a completed chord" }
+
+		set note [ChordNote new [self]]
+
+		lappend notes $note
+
+		return $note
+	}
+
+	# This method is for internal use only and is intentionally undocumented.
+	method notify_note_activation {} {
+		if {!$is_completed} {
+			foreach note $notes {
+				if {![$note is_activated]} { return }
+			}
+
+			set is_completed 1
+
+			namespace eval [self] $body
+			namespace delete [self]
+		}
+	}
+}
+
+# ChordNote class:
+#   Represents a note within a chord, providing a way to activate it. When the
+#   final note of the chord is activated (this can be any note in the chord,
+#   with all other notes already previously activated in any order), the chord's
+#   body is evaluated.
+oo::class create ChordNote {
+	variable chord is_activated
+
+	# Constructor:
+	#   Instances of ChordNote are created internally by calling add_note on
+	#   SimpleChord objects.
+	constructor {chord} {
+		my eval set chord $chord
+		set is_activated 0
+	}
+
+	# Method:
+	#   [$note is_activated]
+	#     Returns true if this note has already been activated.
+	method is_activated {} {
+		return $is_activated
+	}
+
+	# Method:
+	#   $note
+	#     Activates the note, if it has not already been activated, and
+	#     completes the chord if there are no other notes awaiting
+	#     activation. Subsequent calls will have no further effect.
+	#
+	# NB: In TclOO, if an object is invoked like a method without supplying
+	#     any method name, then this internal method `unknown` is what
+	#     actually runs (with no parameters). It is used in the ChordNote
+	#     class for the purpose of allowing the note object to be called as
+	#     a function (see example above). (The `unknown` method can also be
+	#     used to support dynamic dispatch, but must take parameters to
+	#     identify the "unknown" method to be invoked. In this form, this
+	#     proc serves only to make instances behave directly like methods.)
+	method unknown {} {
+		if {!$is_activated} {
+			set is_activated 1
+			$chord notify_note_activation
+		}
+	}
+}
diff --git a/lib/index.tcl b/lib/index.tcl
index 28d4d2a54e..8d7590241e 100644
--- a/lib/index.tcl
+++ b/lib/index.tcl
@@ -7,53 +7,63 @@ proc _delete_indexlock {} {
 	}
 }
 
-proc _close_updateindex {fd after} {
-	global use_ttk NS
-	fconfigure $fd -blocking 1
-	if {[catch {close $fd} err]} {
-		set w .indexfried
-		Dialog $w
-		wm withdraw $w
-		wm title $w [strcat "[appname] ([reponame]): " [mc "Index Error"]]
-		wm geometry $w "+[winfo rootx .]+[winfo rooty .]"
-		set s [mc "Updating the Git index failed.  A rescan will be automatically started to resynchronize git-gui."]
-		text $w.msg -yscrollcommand [list $w.vs set] \
-			-width [string length $s] -relief flat \
-			-borderwidth 0 -highlightthickness 0 \
-			-background [get_bg_color $w]
-		$w.msg tag configure bold -font font_uibold -justify center
-		${NS}::scrollbar $w.vs -command [list $w.msg yview]
-		$w.msg insert end $s bold \n\n$err {}
-		$w.msg configure -state disabled
-
-		${NS}::button $w.continue \
-			-text [mc "Continue"] \
-			-command [list destroy $w]
-		${NS}::button $w.unlock \
-			-text [mc "Unlock Index"] \
-			-command "destroy $w; _delete_indexlock"
-		grid $w.msg - $w.vs -sticky news
-		grid $w.unlock $w.continue - -sticky se -padx 2 -pady 2
-		grid columnconfigure $w 0 -weight 1
-		grid rowconfigure $w 0 -weight 1
-
-		wm protocol $w WM_DELETE_WINDOW update
-		bind $w.continue <Visibility> "
-			grab $w
-			focus %W
-		"
-		wm deiconify $w
-		tkwait window $w
-
-		$::main_status stop
+# Returns true if the operation succeeded, false if a rescan has been initiated.
+proc close_and_unlock_updateindex_rescan_on_error {fd after} {
+	if {![catch {_close_updateindex $fd} err]} {
 		unlock_index
-		rescan $after 0
-		return
+		uplevel #0 $after
+		return 1
+	} else {
+		rescan_on_error $err $after
+		return 0
 	}
+}
 
-	$::main_status stop
+proc _close_updateindex {fd} {
+	fconfigure $fd -blocking 1
+	close $fd
+}
+
+proc rescan_on_error {err {after {}}} {
+	global use_ttk NS
+
+	set w .indexfried
+	Dialog $w
+	wm withdraw $w
+	wm title $w [strcat "[appname] ([reponame]): " [mc "Index Error"]]
+	wm geometry $w "+[winfo rootx .]+[winfo rooty .]"
+	set s [mc "Updating the Git index failed.  A rescan will be automatically started to resynchronize git-gui."]
+	text $w.msg -yscrollcommand [list $w.vs set] \
+		-width [string length $s] -relief flat \
+		-borderwidth 0 -highlightthickness 0 \
+		-background [get_bg_color $w]
+	$w.msg tag configure bold -font font_uibold -justify center
+	${NS}::scrollbar $w.vs -command [list $w.msg yview]
+	$w.msg insert end $s bold \n\n$err {}
+	$w.msg configure -state disabled
+
+	${NS}::button $w.continue \
+		-text [mc "Continue"] \
+		-command [list destroy $w]
+	${NS}::button $w.unlock \
+		-text [mc "Unlock Index"] \
+		-command "destroy $w; _delete_indexlock"
+	grid $w.msg - $w.vs -sticky news
+	grid $w.unlock $w.continue - -sticky se -padx 2 -pady 2
+	grid columnconfigure $w 0 -weight 1
+	grid rowconfigure $w 0 -weight 1
+
+	wm protocol $w WM_DELETE_WINDOW update
+	bind $w.continue <Visibility> "
+		grab $w
+		focus %W
+	"
+	wm deiconify $w
+	tkwait window $w
+
+	$::main_status stop_all
 	unlock_index
-	uplevel #0 $after
+	rescan [concat $after [list ui_ready]] 0
 }
 
 proc update_indexinfo {msg path_list after} {
@@ -67,7 +77,7 @@ proc update_indexinfo {msg path_list after} {
 	set batch [expr {int($total_cnt * .01) + 1}]
 	if {$batch > 25} {set batch 25}
 
-	$::main_status start $msg [mc "files"]
+	set status_bar_operation [$::main_status start $msg [mc "files"]]
 	set fd [git_write update-index -z --index-info]
 	fconfigure $fd \
 		-blocking 0 \
@@ -81,16 +91,19 @@ proc update_indexinfo {msg path_list after} {
 		$path_list \
 		$total_cnt \
 		$batch \
+		$status_bar_operation \
 		$after \
 		]
 }
 
-proc write_update_indexinfo {fd path_list total_cnt batch after} {
+proc write_update_indexinfo {fd path_list total_cnt batch status_bar_operation \
+	after} {
 	global update_index_cp
 	global file_states current_diff_path
 
 	if {$update_index_cp >= $total_cnt} {
-		_close_updateindex $fd $after
+		$status_bar_operation stop
+		close_and_unlock_updateindex_rescan_on_error $fd $after
 		return
 	}
 
@@ -119,7 +132,7 @@ proc write_update_indexinfo {fd path_list total_cnt batch after} {
 		display_file $path $new
 	}
 
-	$::main_status update $update_index_cp $total_cnt
+	$status_bar_operation update $update_index_cp $total_cnt
 }
 
 proc update_index {msg path_list after} {
@@ -133,7 +146,7 @@ proc update_index {msg path_list after} {
 	set batch [expr {int($total_cnt * .01) + 1}]
 	if {$batch > 25} {set batch 25}
 
-	$::main_status start $msg [mc "files"]
+	set status_bar_operation [$::main_status start $msg [mc "files"]]
 	set fd [git_write update-index --add --remove -z --stdin]
 	fconfigure $fd \
 		-blocking 0 \
@@ -147,16 +160,19 @@ proc update_index {msg path_list after} {
 		$path_list \
 		$total_cnt \
 		$batch \
+		$status_bar_operation \
 		$after \
 		]
 }
 
-proc write_update_index {fd path_list total_cnt batch after} {
+proc write_update_index {fd path_list total_cnt batch status_bar_operation \
+	after} {
 	global update_index_cp
 	global file_states current_diff_path
 
 	if {$update_index_cp >= $total_cnt} {
-		_close_updateindex $fd $after
+		$status_bar_operation stop
+		close_and_unlock_updateindex_rescan_on_error $fd $after
 		return
 	}
 
@@ -190,10 +206,10 @@ proc write_update_index {fd path_list total_cnt batch after} {
 		display_file $path $new
 	}
 
-	$::main_status update $update_index_cp $total_cnt
+	$status_bar_operation update $update_index_cp $total_cnt
 }
 
-proc checkout_index {msg path_list after} {
+proc checkout_index {msg path_list after capture_error} {
 	global update_index_cp
 
 	if {![lock_index update]} return
@@ -204,7 +220,7 @@ proc checkout_index {msg path_list after} {
 	set batch [expr {int($total_cnt * .01) + 1}]
 	if {$batch > 25} {set batch 25}
 
-	$::main_status start $msg [mc "files"]
+	set status_bar_operation [$::main_status start $msg [mc "files"]]
 	set fd [git_write checkout-index \
 		--index \
 		--quiet \
@@ -224,16 +240,26 @@ proc checkout_index {msg path_list after} {
 		$path_list \
 		$total_cnt \
 		$batch \
+		$status_bar_operation \
 		$after \
+		$capture_error \
 		]
 }
 
-proc write_checkout_index {fd path_list total_cnt batch after} {
+proc write_checkout_index {fd path_list total_cnt batch status_bar_operation \
+	after capture_error} {
 	global update_index_cp
 	global file_states current_diff_path
 
 	if {$update_index_cp >= $total_cnt} {
-		_close_updateindex $fd $after
+		$status_bar_operation stop
+
+		if {[catch {_close_updateindex $fd} err]} {
+			uplevel #0 $capture_error [list $err]
+		}
+
+		uplevel #0 $after
+
 		return
 	}
 
@@ -253,7 +279,7 @@ proc write_checkout_index {fd path_list total_cnt batch after} {
 		}
 	}
 
-	$::main_status update $update_index_cp $total_cnt
+	$status_bar_operation update $update_index_cp $total_cnt
 }
 
 proc unstage_helper {txt paths} {
@@ -388,66 +414,301 @@ proc do_add_all {} {
 	add_helper [mc "Adding all changed files"] $paths
 }
 
+# Copied from TclLib package "lambda".
+proc lambda {arguments body args} {
+	return [list ::apply [list $arguments $body] {*}$args]
+}
+
 proc revert_helper {txt paths} {
 	global file_states current_diff_path
 
 	if {![lock_index begin-update]} return
 
+	# Common "after" functionality that waits until multiple asynchronous
+	# operations are complete (by waiting for them to activate their notes
+	# on the chord).
+	#
+	# The asynchronous operations are each indicated below by a comment
+	# before the code block that starts the async operation.
+	set after_chord [SimpleChord new {
+		if {[string trim $err] != ""} {
+			rescan_on_error $err
+		} else {
+			unlock_index
+			if {$should_reshow_diff} { reshow_diff }
+			ui_ready
+		}
+	}]
+
+	$after_chord eval { set should_reshow_diff 0 }
+
+	# This function captures an error for processing when after_chord is
+	# completed. (The chord is curried into the lambda function.)
+	set capture_error [lambda \
+		{chord error} \
+		{ $chord eval [list set err $error] } \
+		$after_chord]
+
+	# We don't know how many notes we're going to create (it's dynamic based
+	# on conditional paths below), so create a common note that will delay
+	# the chord's completion until we activate it, and then activate it
+	# after all the other notes have been created.
+	set after_common_note [$after_chord add_note]
+
 	set path_list [list]
-	set after {}
+	set untracked_list [list]
+
 	foreach path $paths {
 		switch -glob -- [lindex $file_states($path) 0] {
 		U? {continue}
+		?O {
+			lappend untracked_list $path
+		}
 		?M -
 		?T -
 		?D {
 			lappend path_list $path
 			if {$path eq $current_diff_path} {
-				set after {reshow_diff;}
+				$after_chord eval { set should_reshow_diff 1 }
 			}
 		}
 		}
 	}
 
+	set path_cnt [llength $path_list]
+	set untracked_cnt [llength $untracked_list]
+
+	# Asynchronous operation: revert changes by checking them out afresh
+	# from the index.
+	if {$path_cnt > 0} {
+		# Split question between singular and plural cases, because
+		# such distinction is needed in some languages. Previously, the
+		# code used "Revert changes in" for both, but that can't work
+		# in languages where 'in' must be combined with word from
+		# rest of string (in different way for both cases of course).
+		#
+		# FIXME: Unfortunately, even that isn't enough in some languages
+		# as they have quite complex plural-form rules. Unfortunately,
+		# msgcat doesn't seem to support that kind of string
+		# translation.
+		#
+		if {$path_cnt == 1} {
+			set query [mc \
+				"Revert changes in file %s?" \
+				[short_path [lindex $path_list]] \
+				]
+		} else {
+			set query [mc \
+				"Revert changes in these %i files?" \
+				$path_cnt]
+		}
 
-	# Split question between singular and plural cases, because
-	# such distinction is needed in some languages. Previously, the
-	# code used "Revert changes in" for both, but that can't work
-	# in languages where 'in' must be combined with word from
-	# rest of string (in different way for both cases of course).
-	#
-	# FIXME: Unfortunately, even that isn't enough in some languages
-	# as they have quite complex plural-form rules. Unfortunately,
-	# msgcat doesn't seem to support that kind of string translation.
-	#
-	set n [llength $path_list]
-	if {$n == 0} {
-		unlock_index
-		return
-	} elseif {$n == 1} {
-		set query [mc "Revert changes in file %s?" [short_path [lindex $path_list]]]
-	} else {
-		set query [mc "Revert changes in these %i files?" $n]
+		set reply [tk_dialog \
+			.confirm_revert \
+			"[appname] ([reponame])" \
+			"$query
+
+[mc "Any unstaged changes will be permanently lost by the revert."]" \
+			question \
+			1 \
+			[mc "Do Nothing"] \
+			[mc "Revert Changes"] \
+			]
+
+		if {$reply == 1} {
+			checkout_index \
+				$txt \
+				$path_list \
+				[$after_chord add_note] \
+				$capture_error
+		}
 	}
 
-	set reply [tk_dialog \
-		.confirm_revert \
-		"[appname] ([reponame])" \
-		"$query
+	# Asynchronous operation: Deletion of untracked files.
+	if {$untracked_cnt > 0} {
+		# Split question between singular and plural cases, because
+		# such distinction is needed in some languages.
+		#
+		# FIXME: Unfortunately, even that isn't enough in some languages
+		# as they have quite complex plural-form rules. Unfortunately,
+		# msgcat doesn't seem to support that kind of string
+		# translation.
+		#
+		if {$untracked_cnt == 1} {
+			set query [mc \
+				"Delete untracked file %s?" \
+				[short_path [lindex $untracked_list]] \
+				]
+		} else {
+			set query [mc \
+				"Delete these %i untracked files?" \
+				$untracked_cnt \
+				]
+		}
 
-[mc "Any unstaged changes will be permanently lost by the revert."]" \
-		question \
-		1 \
-		[mc "Do Nothing"] \
-		[mc "Revert Changes"] \
-		]
-	if {$reply == 1} {
-		checkout_index \
-			$txt \
+		set reply [tk_dialog \
+			.confirm_revert \
+			"[appname] ([reponame])" \
+			"$query
+
+[mc "Files will be permanently deleted."]" \
+			question \
+			1 \
+			[mc "Do Nothing"] \
+			[mc "Delete Files"] \
+			]
+
+		if {$reply == 1} {
+			$after_chord eval { set should_reshow_diff 1 }
+
+			delete_files $untracked_list [$after_chord add_note]
+		}
+	}
+
+	# Activate the common note. If no other notes were created, this
+	# completes the chord. If other notes were created, then this common
+	# note prevents a race condition where the chord might complete early.
+	$after_common_note
+}
+
+# Delete all of the specified files, performing deletion in batches to allow the
+# UI to remain responsive and updated.
+proc delete_files {path_list after} {
+	# Enable progress bar status updates
+	set status_bar_operation [$::main_status \
+		start \
+		[mc "Deleting"] \
+		[mc "files"]]
+
+	set path_index 0
+	set deletion_errors [list]
+	set batch_size 50
+
+	delete_helper \
+		$path_list \
+		$path_index \
+		$deletion_errors \
+		$batch_size \
+		$status_bar_operation \
+		$after
+}
+
+# Helper function to delete a list of files in batches. Each call deletes one
+# batch of files, and then schedules a call for the next batch after any UI
+# messages have been processed.
+proc delete_helper {path_list path_index deletion_errors batch_size \
+	status_bar_operation after} {
+	global file_states
+
+	set path_cnt [llength $path_list]
+
+	set batch_remaining $batch_size
+
+	while {$batch_remaining > 0} {
+		if {$path_index >= $path_cnt} { break }
+
+		set path [lindex $path_list $path_index]
+
+		set deletion_failed [catch {file delete -- $path} deletion_error]
+
+		if {$deletion_failed} {
+			lappend deletion_errors [list "$deletion_error"]
+		} else {
+			remove_empty_directories [file dirname $path]
+
+			# Don't assume the deletion worked. Remove the file from
+			# the UI, but only if it no longer exists.
+			if {![path_exists $path]} {
+				unset file_states($path)
+				display_file $path __
+			}
+		}
+
+		incr path_index 1
+		incr batch_remaining -1
+	}
+
+	# Update the progress bar to indicate that this batch has been
+	# completed. The update will be visible when this procedure returns
+	# and allows the UI thread to process messages.
+	$status_bar_operation update $path_index $path_cnt
+
+	if {$path_index < $path_cnt} {
+		# The Tcler's Wiki lists this as the best practice for keeping
+		# a UI active and processing messages during a long-running
+		# operation.
+
+		after idle [list after 0 [list \
+			delete_helper \
 			$path_list \
-			[concat $after [list ui_ready]]
+			$path_index \
+			$deletion_errors \
+			$batch_size \
+			$status_bar_operation \
+			$after
+			]]
 	} else {
-		unlock_index
+		# Finish the status bar operation.
+		$status_bar_operation stop
+
+		# Report error, if any, based on how many deletions failed.
+		set deletion_error_cnt [llength $deletion_errors]
+
+		if {($deletion_error_cnt > 0)
+		 && ($deletion_error_cnt <= [MAX_VERBOSE_FILES_IN_DELETION_ERROR])} {
+			set error_text [mc "Encountered errors deleting files:\n"]
+
+			foreach deletion_error $deletion_errors {
+				append error_text "* [lindex $deletion_error 0]\n"
+			}
+
+			error_popup $error_text
+		} elseif {$deletion_error_cnt == $path_cnt} {
+			error_popup [mc \
+				"None of the %d selected files could be deleted." \
+				$path_cnt \
+				]
+		} elseif {$deletion_error_cnt > 1} {
+			error_popup [mc \
+				"%d of the %d selected files could not be deleted." \
+				$deletion_error_cnt \
+				$path_cnt \
+				]
+		}
+
+		uplevel #0 $after
+	}
+}
+
+proc MAX_VERBOSE_FILES_IN_DELETION_ERROR {} { return 10; }
+
+# This function is from the TCL documentation:
+#
+#   https://wiki.tcl-lang.org/page/file+exists
+#
+# [file exists] returns false if the path does exist but is a symlink to a path
+# that doesn't exist. This proc returns true if the path exists, regardless of
+# whether it is a symlink and whether it is broken.
+proc path_exists {name} {
+	expr {![catch {file lstat $name finfo}]}
+}
+
+# Remove as many empty directories as we can starting at the specified path,
+# walking up the directory tree. If we encounter a directory that is not
+# empty, or if a directory deletion fails, then we stop the operation and
+# return to the caller. Even if this procedure fails to delete any
+# directories at all, it does not report failure.
+proc remove_empty_directories {directory_path} {
+	set parent_path [file dirname $directory_path]
+
+	while {$parent_path != $directory_path} {
+		set contents [glob -nocomplain -dir $directory_path *]
+
+		if {[llength $contents] > 0} { break }
+		if {[catch {file delete -- $directory_path}]} { break }
+
+		set directory_path $parent_path
+		set parent_path [file dirname $directory_path]
 	}
 }
 
diff --git a/lib/merge.tcl b/lib/merge.tcl
index 9f253db5b3..8df8ffae55 100644
--- a/lib/merge.tcl
+++ b/lib/merge.tcl
@@ -241,23 +241,27 @@ Continue with resetting the current changes?"]
 	if {[ask_popup $op_question] eq {yes}} {
 		set fd [git_read --stderr read-tree --reset -u -v HEAD]
 		fconfigure $fd -blocking 0 -translation binary
-		fileevent $fd readable [namespace code [list _reset_wait $fd]]
-		$::main_status start [mc "Aborting"] [mc "files reset"]
+		set status_bar_operation [$::main_status \
+			start \
+			[mc "Aborting"] \
+			[mc "files reset"]
+		fileevent $fd readable [namespace code [list \
+			_reset_wait $fd $status_bar_operation]]
 	} else {
 		unlock_index
 	}
 }
 
-proc _reset_wait {fd} {
+proc _reset_wait {fd status_bar_operation} {
 	global ui_comm
 
-	$::main_status update_meter [read $fd]
+	$status_bar_operation update_meter [read $fd]
 
 	fconfigure $fd -blocking 1
 	if {[eof $fd]} {
 		set fail [catch {close $fd} err]
-		$::main_status stop
 		unlock_index
+		$status_bar_operation stop
 
 		$ui_comm delete 0.0 end
 		$ui_comm edit modified false
diff --git a/lib/status_bar.tcl b/lib/status_bar.tcl
index 02111a1742..6a73988b23 100644
--- a/lib/status_bar.tcl
+++ b/lib/status_bar.tcl
@@ -1,16 +1,42 @@
 # git-gui status bar mega-widget
 # Copyright (C) 2007 Shawn Pearce
 
+# The status_bar class manages the entire status bar. It is possible for
+# multiple overlapping asynchronous operations to want to display status
+# simultaneously. Each one receives a status_bar_operation when it calls the
+# start method, and the status bar combines all active operations into the
+# line of text it displays. Most of the time, there will be at most one
+# ongoing operation.
+#
+# Note that the entire status bar can be either in single-line or two-line
+# mode, depending on the constructor. Multiple active operations are only
+# supported for single-line status bars.
+
 class status_bar {
 
+field allow_multiple ; # configured at construction
+
 field w         ; # our own window path
 field w_l       ; # text widget we draw messages into
 field w_c       ; # canvas we draw a progress bar into
 field c_pack    ; # script to pack the canvas with
-field status  {}; # single line of text we show
-field prefix  {}; # text we format into status
-field units   {}; # unit of progress
-field meter   {}; # current core git progress meter (if active)
+
+field baseline_text   ; # text to show if there are no operations
+field status_bar_text ; # combined text for all operations
+
+field operations ; # list of current ongoing operations
+
+# The status bar can display a progress bar, updated when consumers call the
+# update method on their status_bar_operation. When there are multiple
+# operations, the status bar shows the combined status of all operations.
+#
+# When an overlapping operation completes, the progress bar is going to
+# abruptly have one fewer operation in the calculation, causing a discontinuity.
+# Therefore, whenever an operation completes, if it is not the last operation,
+# this counter is increased, and the progress bar is calculated as though there
+# were still another operation at 100%. When the last operation completes, this
+# is reset to 0.
+field completed_operation_count
 
 constructor new {path} {
 	global use_ttk NS
@@ -18,12 +44,19 @@ constructor new {path} {
 	set w_l $w.l
 	set w_c $w.c
 
+	# Standard single-line status bar: Permit overlapping operations
+	set allow_multiple 1
+
+	set baseline_text ""
+	set operations [list]
+	set completed_operation_count 0
+
 	${NS}::frame $w
 	if {!$use_ttk} {
 		$w configure -borderwidth 1 -relief sunken
 	}
 	${NS}::label $w_l \
-		-textvariable @status \
+		-textvariable @status_bar_text \
 		-anchor w \
 		-justify left
 	pack $w_l -side left
@@ -44,9 +77,15 @@ constructor two_line {path} {
 	set w_l $w.l
 	set w_c $w.c
 
+	# Two-line status bar: Only one ongoing operation permitted.
+	set allow_multiple 0
+
+	set baseline_text ""
+	set operations [list]
+
 	${NS}::frame $w
 	${NS}::label $w_l \
-		-textvariable @status \
+		-textvariable @status_bar_text \
 		-anchor w \
 		-justify left
 	pack $w_l -anchor w -fill x
@@ -56,7 +95,7 @@ constructor two_line {path} {
 	return $this
 }
 
-method start {msg uds} {
+method ensure_canvas {} {
 	if {[winfo exists $w_c]} {
 		$w_c coords bar 0 0 0 20
 	} else {
@@ -68,31 +107,169 @@ method start {msg uds} {
 		$w_c create rectangle 0 0 0 20 -tags bar -fill navy
 		eval $c_pack
 	}
+}
+
+method show {msg {test {}}} {
+	if {$test eq {} || $status eq $test} {
+		$this ensure_canvas
+		set baseline_text $msg
+		$this refresh
+	}
+}
+
+method start {msg uds} {
+	set baseline_text ""
+
+	if {!$allow_multiple && [llength $operations]} {
+		return [lindex $operations 0]
+	}
+
+	$this ensure_canvas
+
+	set operation [status_bar_operation::new $this $msg $uds]
+
+	lappend operations $operation
+
+	$this refresh
+
+	return $operation
+}
+
+method refresh {} {
+	set new_text ""
+
+	set total [expr $completed_operation_count * 100]
+	set have $total
+
+	foreach operation $operations {
+		if {$new_text != ""} {
+			append new_text " / "
+		}
+
+		append new_text [$operation get_status]
+
+		set total [expr $total + 100]
+		set have [expr $have + [$operation get_progress]]
+	}
+
+	if {$new_text == ""} {
+		set new_text $baseline_text
+	}
+
+	set status_bar_text $new_text
+
+	set pixel_width 0
+	if {$have > 0} {
+		set pixel_width [expr {[winfo width $w_c] * $have / $total}]
+	}
+
+	$w_c coords bar 0 0 $pixel_width 20
+}
+
+method stop {operation stop_msg} {
+	set idx [lsearch $operations $operation]
+
+	if {$idx >= 0} {
+		set operations [lreplace $operations $idx $idx]
+		set completed_operation_count [expr \
+			$completed_operation_count + 1]
+
+		if {[llength operations] == 0} {
+			set completed_operation_count 0
+
+			destroy $w_c
+			if {$stop_msg ne {}} {
+				set baseline_text $stop_msg
+			}
+		}
+
+		$this refresh
+	}
+}
+
+method stop_all {{stop_msg {}}} {
+	set operations_copy $operations
+	set operations [list] # This makes the operation's call to stop a no-op.
+
+	foreach $operation operations_copy {
+		$operation stop
+	}
+
+	if {$stop_msg ne {}} {
+		set baseline_text $stop_msg
+	}
+
+	$this refresh
+}
+
+method _delete {current} {
+	if {$current eq $w} {
+		delete_this
+	}
+}
+
+}
+
+# The status_bar_operation class tracks a single consumer's ongoing status bar
+# activity, with the context that there are a few situations where multiple
+# overlapping asynchronous operations might want to display status information
+# simultaneously. Instances of status_bar_operation are created by calling
+# start on the status_bar, and when the caller is done with its stauts bar
+# operation, it calls stop on the operation.
+
+class status_bar_operation {
+
+field status_bar; # reference back to the status_bar that owns this object
+
+field is_active;
+
+field status   {}; # single line of text we show
+field progress {}; # current progress (0 to 100)
+field prefix   {}; # text we format into status
+field units    {}; # unit of progress
+field meter    {}; # current core git progress meter (if active)
+
+constructor new {owner msg uds} {
+	set status_bar $owner
 
 	set status $msg
+	set progress 0
 	set prefix $msg
 	set units  $uds
 	set meter  {}
+
+	set is_active 1
+
+	return $this
 }
 
+method get_is_active {} { return $is_active }
+method get_status {} { return $status }
+method get_progress {} { return $progress }
+
 method update {have total} {
-	set pdone 0
-	set cdone 0
+	if {!$is_active} { return }
+
+	set progress 0
+
 	if {$total > 0} {
-		set pdone [expr {100 * $have / $total}]
-		set cdone [expr {[winfo width $w_c] * $have / $total}]
+		set progress [expr {100 * $have / $total}]
 	}
 
 	set prec [string length [format %i $total]]
+
 	set status [mc "%s ... %*i of %*i %s (%3i%%)" \
 		$prefix \
 		$prec $have \
 		$prec $total \
-		$units $pdone]
-	$w_c coords bar 0 0 $cdone 20
+		$units $progress]
+
+	$status_bar refresh
 }
 
 method update_meter {buf} {
+	if {!$is_active} { return }
+
 	append meter $buf
 	set r [string last "\r" $meter]
 	if {$r == -1} {
@@ -109,23 +286,25 @@ method update_meter {buf} {
 	}
 }
 
-method stop {{msg {}}} {
-	destroy $w_c
-	if {$msg ne {}} {
-		set status $msg
+method stop {{stop_msg {}}} {
+	if {$is_active} {
+		set is_active 0
+		$status_bar stop $this $stop_msg
 	}
 }
 
 method show {msg {test {}}} {
+	if {!$is_active} { return }
+
 	if {$test eq {} || $status eq $test} {
 		set status $msg
+		$status_bar refresh
 	}
 }
 
-method _delete {current} {
-	if {$current eq $w} {
-		delete_this
-	}
+method _delete {} {
+	stop
+	delete_this
 }
 
 }
-- 
gitgitgadget

Re: [PATCH v4 2/2] git-gui: revert untracked files by deleting them

[Pratyush Yadav]

Hi Jonathan,

Thanks for the re-roll. Sorry for taking so long to review. I couldn't 
find too much free time past few days.

On 17/11/19 06:56AM, Jonathan Gilbert via GitGitGadget wrote:
> From: Jonathan Gilbert <JonathanG@iQmetrix.com>
> 
> Update the revert_helper proc to check for untracked files as well as
> changes, and then handle changes to be reverted and untracked files with
> independent blocks of code. Prompt the user independently for untracked
> files, since the underlying action is fundamentally different (rm -f).
> If after deleting untracked files, the directory containing them becomes
> empty, then remove the directory as well. Migrate unlocking of the index
> out of _close_updateindex to a responsibility of the caller, to permit
> paths that don't directly unlock the index, and refactor the error
> handling added in d4e890e5 so that callers can make flow control
> decisions in the event of errors. Rework status_bar to explicitly handle
> multiple overlapping operations, and update all call sites.
> 
> A new proc delete_files takes care of actually deleting the files in
> batches, using the Tcler's Wiki recommended approach for keeping the UI
> responsive.
> 
> Since the checkout_index and delete_files calls are both asynchronous
> and could potentially complete in any order, a "chord" is used to
> coordinate unlocking the index and returning the UI to a usable state
> only after both operations are complete. The `SimpleChord` class,
> based on TclOO (Tcl/Tk 8.6), is added in this commit.
> 
> Since the checkout_index and delete_files calls are both asynchronous
> and overlap, they clash in wanting to update the status bar. This commit
> reworks the status bar so that when an operation wants to display
> ongoing updates/progress, it explicitly starts an "operation", which is
> tracked by its own object, and the status bar handles multiple
> concurrent operations by merging their progress and concatenating their
> text.

The status bar is a major change, so I think it should be in a separate 
commit. That would make it easier to debug it when bisecting, and to 
revert it in case we discover a bug later.

Unfortunately, this change breaks things. The users of 'status_bar' that 
aren't updated don't work. As an example, if I run 'git gui blame 
git-gui.sh' with your patch applied, I get the following error:

  invalid command name "::status_bar::update"
  invalid command name "::status_bar::update"
      while executing
  "::status_bar::update ::status_bar::__o1::__d 5 4169"
      ("eval" body line 1)
      invoked from within
  "eval [list ::status_bar::$name ::status_bar::__o1::__d] $args"
      (procedure "::status_bar::__o1::__d" line 1)
      invoked from within
  "$status update $blame_lines [set ${__this}::total_lines]"
      (procedure "blame::_read_blame" line 184)
      invoked from within
  "blame::_read_blame ::blame::__o1::__d file7 .file_pane.out.asimple_t ::blame::__o1::asim_data"

This error is raised because of lib/blame.tcl:812, and causes blame to 
not annotate lines properly, which is the entire reason to use blame.

Another caller that would probably break is 'lib/choose_repository.tcl'. 
These are the only two broken callsites I can spot after some quick 
looking around.

Are there any other backward-compatibility breaking changes to 
status_bar? I have a feeling that this changeset is already getting a 
bit too large in scope. Maybe we should figure out a simpler compromise 
instead of making a huge re-work like this.

If the existing callsites can be updated without much trouble, then its 
fine. Otherwise, maybe reducing the scope of this change would be a 
better idea.

Either way, please split the status bar refactor in a separate commit 
such that the entire system still works properly (so this means the 
commit would include updating the existing callsites).
 
> Signed-off-by: Jonathan Gilbert <JonathanG@iQmetrix.com>
> ---
>  git-gui.sh          |   7 +-
>  lib/checkout_op.tcl |  15 +-
>  lib/chord.tcl       | 160 ++++++++++++++++
>  lib/index.tcl       | 443 +++++++++++++++++++++++++++++++++++---------
>  lib/merge.tcl       |  14 +-
>  lib/status_bar.tcl  | 221 +++++++++++++++++++---
>  6 files changed, 734 insertions(+), 126 deletions(-)
>  create mode 100644 lib/chord.tcl
> 
> diff --git a/git-gui.sh b/git-gui.sh
> index 0d21f5688b..dc4ac577ac 100755
> --- a/git-gui.sh
> +++ b/git-gui.sh
> @@ -30,8 +30,8 @@ along with this program; if not, see <http://www.gnu.org/licenses/>.}]
>  ##
>  ## Tcl/Tk sanity check
>  
> -if {[catch {package require Tcl 8.4} err]
> - || [catch {package require Tk  8.4} err]
> +if {[catch {package require Tcl 8.6} err]
> + || [catch {package require Tk  8.6} err]
>  } {
>  	catch {wm withdraw .}
>  	tk_messageBox \
> @@ -4159,6 +4159,9 @@ if {$picked && [is_config_true gui.autoexplore]} {
>  	do_explore
>  }
>  
> +# Clear "Initializing..." status
> +after idle {after 500 {$main_status show ""}}

Why put this in an 'after idle'? What's wrong with just 'after 500'? 
This is not an expensive operation so we shouldn't really require the 
application to be idle to run it.

> +
>  # Local variables:
>  # mode: tcl
>  # indent-tabs-mode: t
> diff --git a/lib/checkout_op.tcl b/lib/checkout_op.tcl
> index a5228297db..21ea768d80 100644
> --- a/lib/checkout_op.tcl
> +++ b/lib/checkout_op.tcl
> @@ -341,9 +341,9 @@ method _readtree {} {
>  	global HEAD
>  
>  	set readtree_d {}
> -	$::main_status start \
> +	set status_bar_operation [$::main_status start \
>  		[mc "Updating working directory to '%s'..." [_name $this]] \
> -		[mc "files checked out"]
> +		[mc "files checked out"]]
>  
>  	set fd [git_read --stderr read-tree \
>  		-m \
> @@ -354,26 +354,27 @@ method _readtree {} {
>  		$new_hash \
>  		]
>  	fconfigure $fd -blocking 0 -translation binary
> -	fileevent $fd readable [cb _readtree_wait $fd]
> +	fileevent $fd readable [cb _readtree_wait $fd $status_bar_operation]
>  }
>  
> -method _readtree_wait {fd} {
> +method _readtree_wait {fd status_bar_operation} {
>  	global current_branch
>  
>  	set buf [read $fd]
> -	$::main_status update_meter $buf
> +	$status_bar_operation update_meter $buf
>  	append readtree_d $buf
>  
>  	fconfigure $fd -blocking 1
>  	if {![eof $fd]} {
>  		fconfigure $fd -blocking 0
> +		$status_bar_operation stop
>  		return
>  	}
>  
>  	if {[catch {close $fd}]} {
>  		set err $readtree_d
>  		regsub {^fatal: } $err {} err
> -		$::main_status stop [mc "Aborted checkout of '%s' (file level merging is required)." [_name $this]]
> +		$status_bar_operation stop [mc "Aborted checkout of '%s' (file level merging is required)." [_name $this]]
>  		warn_popup [strcat [mc "File level merge required."] "
>  
>  $err
> @@ -384,7 +385,7 @@ $err
>  		return
>  	}
>  
> -	$::main_status stop
> +	$status_bar_operation stop
>  	_after_readtree $this
>  }
>  
> diff --git a/lib/index.tcl b/lib/index.tcl
> index 28d4d2a54e..8d7590241e 100644
> --- a/lib/index.tcl
> +++ b/lib/index.tcl
> @@ -7,53 +7,63 @@ proc _delete_indexlock {} {
>  	}
>  }
>  
> -proc _close_updateindex {fd after} {
> -	global use_ttk NS
> -	fconfigure $fd -blocking 1
> -	if {[catch {close $fd} err]} {
> -		set w .indexfried
> -		Dialog $w
> -		wm withdraw $w
> -		wm title $w [strcat "[appname] ([reponame]): " [mc "Index Error"]]
> -		wm geometry $w "+[winfo rootx .]+[winfo rooty .]"
> -		set s [mc "Updating the Git index failed.  A rescan will be automatically started to resynchronize git-gui."]
> -		text $w.msg -yscrollcommand [list $w.vs set] \
> -			-width [string length $s] -relief flat \
> -			-borderwidth 0 -highlightthickness 0 \
> -			-background [get_bg_color $w]
> -		$w.msg tag configure bold -font font_uibold -justify center
> -		${NS}::scrollbar $w.vs -command [list $w.msg yview]
> -		$w.msg insert end $s bold \n\n$err {}
> -		$w.msg configure -state disabled
> -
> -		${NS}::button $w.continue \
> -			-text [mc "Continue"] \
> -			-command [list destroy $w]
> -		${NS}::button $w.unlock \
> -			-text [mc "Unlock Index"] \
> -			-command "destroy $w; _delete_indexlock"
> -		grid $w.msg - $w.vs -sticky news
> -		grid $w.unlock $w.continue - -sticky se -padx 2 -pady 2
> -		grid columnconfigure $w 0 -weight 1
> -		grid rowconfigure $w 0 -weight 1
> -
> -		wm protocol $w WM_DELETE_WINDOW update
> -		bind $w.continue <Visibility> "
> -			grab $w
> -			focus %W
> -		"
> -		wm deiconify $w
> -		tkwait window $w
> -
> -		$::main_status stop
> +# Returns true if the operation succeeded, false if a rescan has been initiated.
> +proc close_and_unlock_updateindex_rescan_on_error {fd after} {

Nitpick: That name is a bit too unwieldy. Maybe something a bit more 
concise like 'close_and_unlock_index' (I'm not great at naming things. 
Maybe you can figure out something better)? Let the readers figure out 
what happens on error.

> +	if {![catch {_close_updateindex $fd} err]} {
>  		unlock_index
> -		rescan $after 0
> -		return
> +		uplevel #0 $after
> +		return 1
> +	} else {
> +		rescan_on_error $err $after
> +		return 0

Neither of the two callers use the return value. Are these really 
needed?

>  	}
> +}
>  
> -	$::main_status stop
> +proc _close_updateindex {fd} {
> +	fconfigure $fd -blocking 1
> +	close $fd
> +}
> +
> +proc rescan_on_error {err {after {}}} {
> +	global use_ttk NS
> +
> +	set w .indexfried
> +	Dialog $w
> +	wm withdraw $w
> +	wm title $w [strcat "[appname] ([reponame]): " [mc "Index Error"]]
> +	wm geometry $w "+[winfo rootx .]+[winfo rooty .]"
> +	set s [mc "Updating the Git index failed.  A rescan will be automatically started to resynchronize git-gui."]
> +	text $w.msg -yscrollcommand [list $w.vs set] \
> +		-width [string length $s] -relief flat \
> +		-borderwidth 0 -highlightthickness 0 \
> +		-background [get_bg_color $w]
> +	$w.msg tag configure bold -font font_uibold -justify center
> +	${NS}::scrollbar $w.vs -command [list $w.msg yview]
> +	$w.msg insert end $s bold \n\n$err {}
> +	$w.msg configure -state disabled
> +
> +	${NS}::button $w.continue \
> +		-text [mc "Continue"] \
> +		-command [list destroy $w]
> +	${NS}::button $w.unlock \
> +		-text [mc "Unlock Index"] \
> +		-command "destroy $w; _delete_indexlock"
> +	grid $w.msg - $w.vs -sticky news
> +	grid $w.unlock $w.continue - -sticky se -padx 2 -pady 2
> +	grid columnconfigure $w 0 -weight 1
> +	grid rowconfigure $w 0 -weight 1
> +
> +	wm protocol $w WM_DELETE_WINDOW update
> +	bind $w.continue <Visibility> "
> +		grab $w
> +		focus %W
> +	"
> +	wm deiconify $w
> +	tkwait window $w
> +
> +	$::main_status stop_all
>  	unlock_index
> -	uplevel #0 $after
> +	rescan [concat $after [list ui_ready]] 0
>  }
>  
>  proc update_indexinfo {msg path_list after} {
> @@ -67,7 +77,7 @@ proc update_indexinfo {msg path_list after} {
>  	set batch [expr {int($total_cnt * .01) + 1}]
>  	if {$batch > 25} {set batch 25}
>  
> -	$::main_status start $msg [mc "files"]
> +	set status_bar_operation [$::main_status start $msg [mc "files"]]
>  	set fd [git_write update-index -z --index-info]
>  	fconfigure $fd \
>  		-blocking 0 \
> @@ -81,16 +91,19 @@ proc update_indexinfo {msg path_list after} {
>  		$path_list \
>  		$total_cnt \
>  		$batch \
> +		$status_bar_operation \
>  		$after \
>  		]
>  }
>  
> -proc write_update_indexinfo {fd path_list total_cnt batch after} {
> +proc write_update_indexinfo {fd path_list total_cnt batch status_bar_operation \
> +	after} {
>  	global update_index_cp
>  	global file_states current_diff_path
>  
>  	if {$update_index_cp >= $total_cnt} {
> -		_close_updateindex $fd $after
> +		$status_bar_operation stop
> +		close_and_unlock_updateindex_rescan_on_error $fd $after
>  		return
>  	}
>  
> @@ -119,7 +132,7 @@ proc write_update_indexinfo {fd path_list total_cnt batch after} {
>  		display_file $path $new
>  	}
>  
> -	$::main_status update $update_index_cp $total_cnt
> +	$status_bar_operation update $update_index_cp $total_cnt
>  }
>  
>  proc update_index {msg path_list after} {
> @@ -133,7 +146,7 @@ proc update_index {msg path_list after} {
>  	set batch [expr {int($total_cnt * .01) + 1}]
>  	if {$batch > 25} {set batch 25}
>  
> -	$::main_status start $msg [mc "files"]
> +	set status_bar_operation [$::main_status start $msg [mc "files"]]
>  	set fd [git_write update-index --add --remove -z --stdin]
>  	fconfigure $fd \
>  		-blocking 0 \
> @@ -147,16 +160,19 @@ proc update_index {msg path_list after} {
>  		$path_list \
>  		$total_cnt \
>  		$batch \
> +		$status_bar_operation \
>  		$after \
>  		]
>  }
>  
> -proc write_update_index {fd path_list total_cnt batch after} {
> +proc write_update_index {fd path_list total_cnt batch status_bar_operation \
> +	after} {
>  	global update_index_cp
>  	global file_states current_diff_path
>  
>  	if {$update_index_cp >= $total_cnt} {
> -		_close_updateindex $fd $after
> +		$status_bar_operation stop
> +		close_and_unlock_updateindex_rescan_on_error $fd $after
>  		return
>  	}
>  
> @@ -190,10 +206,10 @@ proc write_update_index {fd path_list total_cnt batch after} {
>  		display_file $path $new
>  	}
>  
> -	$::main_status update $update_index_cp $total_cnt
> +	$status_bar_operation update $update_index_cp $total_cnt
>  }
>  
> -proc checkout_index {msg path_list after} {
> +proc checkout_index {msg path_list after capture_error} {
>  	global update_index_cp
>  
>  	if {![lock_index update]} return
> @@ -204,7 +220,7 @@ proc checkout_index {msg path_list after} {
>  	set batch [expr {int($total_cnt * .01) + 1}]
>  	if {$batch > 25} {set batch 25}
>  
> -	$::main_status start $msg [mc "files"]
> +	set status_bar_operation [$::main_status start $msg [mc "files"]]
>  	set fd [git_write checkout-index \
>  		--index \
>  		--quiet \
> @@ -224,16 +240,26 @@ proc checkout_index {msg path_list after} {
>  		$path_list \
>  		$total_cnt \
>  		$batch \
> +		$status_bar_operation \
>  		$after \
> +		$capture_error \
>  		]
>  }
>  
> -proc write_checkout_index {fd path_list total_cnt batch after} {
> +proc write_checkout_index {fd path_list total_cnt batch status_bar_operation \
> +	after capture_error} {
>  	global update_index_cp
>  	global file_states current_diff_path
>  
>  	if {$update_index_cp >= $total_cnt} {
> -		_close_updateindex $fd $after
> +		$status_bar_operation stop
> +
> +		if {[catch {_close_updateindex $fd} err]} {

Nitpick: Please mention exactly why we don't use 
'close_and_unlock_updateindex_rescan_on_error' (or whatever its new name 
would be) here. This function is very similar to 'write_update_index' 
and 'write_checkout_index', so this subtle difference is not very easily 
apparent.

> +			uplevel #0 $capture_error [list $err]
> +		}
> +
> +		uplevel #0 $after
> +
>  		return
>  	}
>  
> diff --git a/lib/status_bar.tcl b/lib/status_bar.tcl
> index 02111a1742..6a73988b23 100644
> --- a/lib/status_bar.tcl
> +++ b/lib/status_bar.tcl
> @@ -1,16 +1,42 @@
>  # git-gui status bar mega-widget
>  # Copyright (C) 2007 Shawn Pearce
>  
> +# The status_bar class manages the entire status bar. It is possible for
> +# multiple overlapping asynchronous operations to want to display status
> +# simultaneously. Each one receives a status_bar_operation when it calls the
> +# start method, and the status bar combines all active operations into the
> +# line of text it displays. Most of the time, there will be at most one
> +# ongoing operation.
> +#
> +# Note that the entire status bar can be either in single-line or two-line
> +# mode, depending on the constructor. Multiple active operations are only
> +# supported for single-line status bars.
> +
>  class status_bar {
>  
> +field allow_multiple ; # configured at construction
> +
>  field w         ; # our own window path
>  field w_l       ; # text widget we draw messages into
>  field w_c       ; # canvas we draw a progress bar into
>  field c_pack    ; # script to pack the canvas with
> -field status  {}; # single line of text we show

The field 'status' is removed, but the procedure 'show' still uses it. 
The if condition needs to be refactored.

> -field prefix  {}; # text we format into status
> -field units   {}; # unit of progress
> -field meter   {}; # current core git progress meter (if active)
> +
> +field baseline_text   ; # text to show if there are no operations
> +field status_bar_text ; # combined text for all operations
> +
> +field operations ; # list of current ongoing operations
> +
> +# The status bar can display a progress bar, updated when consumers call the
> +# update method on their status_bar_operation. When there are multiple
> +# operations, the status bar shows the combined status of all operations.
> +#
> +# When an overlapping operation completes, the progress bar is going to
> +# abruptly have one fewer operation in the calculation, causing a discontinuity.
> +# Therefore, whenever an operation completes, if it is not the last operation,
> +# this counter is increased, and the progress bar is calculated as though there
> +# were still another operation at 100%. When the last operation completes, this
> +# is reset to 0.
> +field completed_operation_count
>  
>  constructor new {path} {
>  	global use_ttk NS
> @@ -18,12 +44,19 @@ constructor new {path} {
>  	set w_l $w.l
>  	set w_c $w.c
>  
> +	# Standard single-line status bar: Permit overlapping operations
> +	set allow_multiple 1
> +
> +	set baseline_text ""
> +	set operations [list]
> +	set completed_operation_count 0
> +
>  	${NS}::frame $w
>  	if {!$use_ttk} {
>  		$w configure -borderwidth 1 -relief sunken
>  	}
>  	${NS}::label $w_l \
> -		-textvariable @status \
> +		-textvariable @status_bar_text \
>  		-anchor w \
>  		-justify left
>  	pack $w_l -side left
> @@ -44,9 +77,15 @@ constructor two_line {path} {
>  	set w_l $w.l
>  	set w_c $w.c
>  
> +	# Two-line status bar: Only one ongoing operation permitted.
> +	set allow_multiple 0
> +
> +	set baseline_text ""
> +	set operations [list]
> +
>  	${NS}::frame $w
>  	${NS}::label $w_l \
> -		-textvariable @status \
> +		-textvariable @status_bar_text \
>  		-anchor w \
>  		-justify left
>  	pack $w_l -anchor w -fill x
> @@ -56,7 +95,7 @@ constructor two_line {path} {
>  	return $this
>  }
>  
> -method start {msg uds} {
> +method ensure_canvas {} {
>  	if {[winfo exists $w_c]} {
>  		$w_c coords bar 0 0 0 20
>  	} else {
> @@ -68,31 +107,169 @@ method start {msg uds} {
>  		$w_c create rectangle 0 0 0 20 -tags bar -fill navy
>  		eval $c_pack
>  	}
> +}
> +
> +method show {msg {test {}}} {
> +	if {$test eq {} || $status eq $test} {
> +		$this ensure_canvas
> +		set baseline_text $msg
> +		$this refresh
> +	}
> +}
> +
> +method start {msg uds} {
> +	set baseline_text ""
> +
> +	if {!$allow_multiple && [llength $operations]} {

This silently ignores multiple 'start's on a status bar that doesn't 
allow it, correct?

> +		return [lindex $operations 0]
> +	}
> +
> +	$this ensure_canvas
> +
> +	set operation [status_bar_operation::new $this $msg $uds]
> +
> +	lappend operations $operation
> +
> +	$this refresh
> +
> +	return $operation
> +}
> +
> +method refresh {} {
> +	set new_text ""
> +
> +	set total [expr $completed_operation_count * 100]
> +	set have $total
> +
> +	foreach operation $operations {
> +		if {$new_text != ""} {
> +			append new_text " / "
> +		}
> +
> +		append new_text [$operation get_status]
> +
> +		set total [expr $total + 100]
> +		set have [expr $have + [$operation get_progress]]
> +	}
> +
> +	if {$new_text == ""} {
> +		set new_text $baseline_text
> +	}
> +
> +	set status_bar_text $new_text
> +
> +	set pixel_width 0
> +	if {$have > 0} {
> +		set pixel_width [expr {[winfo width $w_c] * $have / $total}]
> +	}
> +
> +	$w_c coords bar 0 0 $pixel_width 20
> +}
> +
> +method stop {operation stop_msg} {
> +	set idx [lsearch $operations $operation]
> +
> +	if {$idx >= 0} {
> +		set operations [lreplace $operations $idx $idx]
> +		set completed_operation_count [expr \
> +			$completed_operation_count + 1]
> +
> +		if {[llength operations] == 0} {
> +			set completed_operation_count 0
> +
> +			destroy $w_c
> +			if {$stop_msg ne {}} {
> +				set baseline_text $stop_msg
> +			}
> +		}
> +
> +		$this refresh
> +	}
> +}
> +
> +method stop_all {{stop_msg {}}} {
> +	set operations_copy $operations
> +	set operations [list] # This makes the operation's call to stop a no-op.
> +
> +	foreach $operation operations_copy {
> +		$operation stop
> +	}
> +
> +	if {$stop_msg ne {}} {
> +		set baseline_text $stop_msg
> +	}
> +
> +	$this refresh
> +}
> +
> +method _delete {current} {
> +	if {$current eq $w} {
> +		delete_this
> +	}
> +}
> +
> +}
> +
> +# The status_bar_operation class tracks a single consumer's ongoing status bar
> +# activity, with the context that there are a few situations where multiple
> +# overlapping asynchronous operations might want to display status information
> +# simultaneously. Instances of status_bar_operation are created by calling
> +# start on the status_bar, and when the caller is done with its stauts bar
> +# operation, it calls stop on the operation.
> +
> +class status_bar_operation {
> +
> +field status_bar; # reference back to the status_bar that owns this object
> +
> +field is_active;
> +
> +field status   {}; # single line of text we show
> +field progress {}; # current progress (0 to 100)
> +field prefix   {}; # text we format into status
> +field units    {}; # unit of progress
> +field meter    {}; # current core git progress meter (if active)
> +
> +constructor new {owner msg uds} {
> +	set status_bar $owner
>  
>  	set status $msg
> +	set progress 0
>  	set prefix $msg
>  	set units  $uds
>  	set meter  {}
> +
> +	set is_active 1
> +
> +	return $this
>  }
>  
> +method get_is_active {} { return $is_active }
> +method get_status {} { return $status }
> +method get_progress {} { return $progress }
> +
>  method update {have total} {
> -	set pdone 0
> -	set cdone 0
> +	if {!$is_active} { return }
> +
> +	set progress 0
> +
>  	if {$total > 0} {
> -		set pdone [expr {100 * $have / $total}]
> -		set cdone [expr {[winfo width $w_c] * $have / $total}]
> +		set progress [expr {100 * $have / $total}]
>  	}
>  
>  	set prec [string length [format %i $total]]
> +
>  	set status [mc "%s ... %*i of %*i %s (%3i%%)" \
>  		$prefix \
>  		$prec $have \
>  		$prec $total \
> -		$units $pdone]
> -	$w_c coords bar 0 0 $cdone 20
> +		$units $progress]
> +
> +	$status_bar refresh
>  }
>  
>  method update_meter {buf} {
> +	if {!$is_active} { return }
> +
>  	append meter $buf
>  	set r [string last "\r" $meter]
>  	if {$r == -1} {
> @@ -109,23 +286,25 @@ method update_meter {buf} {
>  	}
>  }
>  
> -method stop {{msg {}}} {
> -	destroy $w_c
> -	if {$msg ne {}} {
> -		set status $msg
> +method stop {{stop_msg {}}} {
> +	if {$is_active} {
> +		set is_active 0
> +		$status_bar stop $this $stop_msg
>  	}
>  }
>  
>  method show {msg {test {}}} {
> +	if {!$is_active} { return }
> +
>  	if {$test eq {} || $status eq $test} {
>  		set status $msg
> +		$status_bar refresh
>  	}
>  }
>  
> -method _delete {current} {
> -	if {$current eq $w} {
> -		delete_this
> -	}
> +method _delete {} {
> +	stop
> +	delete_this
>  }
>  
>  }

One quick question: the consumers of status_bar who don't run multiple 
operations in parallel would still continue working exactly the same 
(after refactoring them to use 'status_bar_operation'), right?

Works fine on some quick testing, though I haven't done anything too 
thorough. Thanks.

-- 
Regards,
Pratyush Yadav

Re: [PATCH v4 0/2] git-gui: revert untracked files by deleting them

[Pratyush Yadav]

On 17/11/19 06:56AM, Jonathan Gilbert via GitGitGadget wrote:
>  * The initialization code in git-gui.sh (which I'm assuming 
>  translates
>    somehow to git-gui.tcl in the installation?) now explicitly clears the

Well, the design is a bit strange. git-gui.sh happens to be _both_ a 
shell script and a Tcl script. When you run './git-gui.sh', it is 
executed as a shell script. That shell script then executes itself via 
'wish' (which is the Tcl/Tk windowing shell), and Tcl ignores the first 
"line" (it is actually the lines 3-10, but they all have an escaped 
newline so it is effectively a single line).

It has been like since the very first revision of git-gui. I wonder why 
the original author went with this instead of just doing something like:

  #!/usr/bin/env wish

which seems to work just fine on my quick testing, but that is another 
topic entirely ;)

>    "Initializing..." status bar text, since the new status bar model won't
>    do this automatically when operations are performed.

PS: I am in the process of reviewing the latest revision of the patch 
series. But I have been short on free time recently so it might take me 
a couple more days.

-- 
Regards,
Pratyush Yadav

Re: [PATCH v4 0/2] git-gui: revert untracked files by deleting them

[Jonathan Gilbert]

On Tue, Nov 19, 2019 at 9:22 AM Pratyush Yadav me-at-yadavpratyush.com
|GitHub Public/Example Allow| <172q77k4bxwj0zt@sneakemail.com> wrote:
> On 17/11/19 06:56AM, Jonathan Gilbert via GitGitGadget wrote:
> >  * The initialization code in git-gui.sh (which I'm assuming
> >     translates somehow to git-gui.tcl in the installation?)
>
> Well, the design is a bit strange. git-gui.sh happens to be _both_ a
> shell script and a Tcl script.

Ah, I see -- I had managed to convince myself that they were different
files, but never actually diffed them. In my installation, I have a
file "C:\Program Files\Git\mingw64\libexec\git-core\git-gui.tcl" and
that _is_ the same file as git-gui.sh in the repository. So maybe it's
Windows-specific, maybe not, I'm not sure, but at some point it gets
renamed from git-gui.sh to git-gui.tcl. I incorrectly assumed that the
.tcl file didn't have all the facets of the .sh file. :-P

Thanks,

Jonathan Gilbert

[PATCH v5 0/3] git-gui: revert untracked files by deleting them

[Jonathan Gilbert via GitGitGadget]

My development environment sometimes makes automatic changes that I don't
want to keep. In some cases, this involves new files being added that I
don't want to commit or keep (but I also don't want to outright .gitignore 
forever). I have typically had to explicitly delete those files externally
to Git Gui, which is a context switch to a manual operation, and I want to
be able to just select those newly-created untracked files in the UI and
"revert" them into oblivion.

This change updates the revert_helper proc to check for untracked files as
well as changes, and then changes to be reverted and untracked files are
handled by independent blocks of code. The user is prompted independently
for untracked files, since the underlying action is fundamentally different
(rm -f). If after deleting untracked files, the directory containing them
becomes empty, then the directory is removed as well. A new proc 
delete_files takes care of actually deleting the files, using the Tcler's
Wiki recommended approach for keeping the UI responsive.

Since the checkout_index and delete_files calls are both asynchronous and
could potentially complete in any order, a "chord" is used to coordinate
unlocking the index and returning the UI to a usable state only after both
operations are complete.

Since the checkout_index and delete_files calls are both asynchronous and
overlap, they clash in wanting to update the status bar. To address this,
the status bar is reworked so that when an operation wants to display
ongoing updates/progress, it explicitly starts an "operation", which is
tracked by its own object, and the status bar handles multiple concurrent
operations by merging their progress and concatenating their text. This is
captured in a separate commit, since it touches a variety of files.

The _close_updateindex proc contains error handling (added in d4e890e5) that
has the potential to interact badly with unlock_index running at the
completion of an async operation. I have refactored the procedure into
separate procs _close_updateindex and rescan_on_error. Call sites that
exercised the combined functionality also unlocked the index, so a combined
proc close_and_unlock_index calls _close_updateindex and then either 
rescan_on_error or unlock_index as appropriate. Call sites have been updated
appropriately.

The revert_helper proc, with its overlapping operations, is an example of a
call site that does not combine the close and unlock/rescan operations. The 
checkout_index proc has been reworked to only call _close_updateindex, and
to call a functor supplied by the caller to captures any errors that occur. 
revert_helper uses this to supply a lambda function that stashes the error
within the chord's body namespace, so that it can then separately call 
rescan_on_error when the chord is completed (or unlock_index, if no error
was captured), which might be substantially after checkout_index encounters
its error. If it turns out that a rescan is called for, it is done once the
deletion is complete.

This is the sixth revision of this change, which differs from the fifth
version in the following ways:

 * The status_bar.tcl changes have been isolated into a separate commit.
   
   
 * A method in status_bar.tcl that apparently had never been hit had some
   simple bugs in it that have been corrected.
   
   
 * The show methods on the classes in status_bar.tcl no longer have a test 
   parameter, as nothing was using that feature that I could see.
   
   
 * The refresh method in status_bar.tcl now only tries to update the
   progress bar widget if it actually exists.
   
   
 * blame.tcl had been missed when searching for code using the status bar,
   this has been addressed.
   
   
 * rescan_on_error takes $after as well, in case 
   close_and_unlock_updateindex_rescan_on_error needs to call it.
   
   
 * close_and_unlock_updateindex_rescan_on_error has been renamed to simply 
   close_and_unlock_index.
   
   

On Sun, Nov 24, 2019 at 7:09 AM Pratyush Yadav wrote:

> Unfortunately, this change breaks things. The users of 'status_bar' that
aren't updated don't work. As an example, if I run 'git gui blame
git-gui.sh' with your patch applied, I get the following error:

 invalid command name "::status_bar::update"


I thought I'd found all places that used the status bar, but apparently
overlooked blame.tcl. This has been addressed. My apologies!

choose_repository.tcl was addressed already in the previous commit.

> Either way, please split the status bar refactor in a separate commit such
that the entire system still works properly (so this means the commit would
include updating the existing callsites).


Done. In doing so and testing it independently, I actually found paths that
weren't being hit with the full set of changes and fixed a few bugs. In
particular, stop_all was completely broken :-P I thought I had exercised it
before and I hadn't.

> > +# Clear "Initializing..." status +after idle {after 500 {$main_status show
""}}


Why put this in an 'after idle'? What's wrong with just 'after 500'? This is
not an expensive operation so we shouldn't really require the application to
be idle to run it.


My thinking was to make it clear the status bar 500 milliseconds after the
queue empties. It's quite possible that my understanding of what it means
for the queue to have emptied means that this isn't a terribly meaningful
thing to do. I was wanting it to continue saying "Initializing..." until,
heuristically, it is done initializing, including any queued up operations.
I guess if anything waits on I/O, then the queue may to go idle even though
it's still busy doing things. So, a straight-up after 500 { } would make
more sense? I've changed it to this, can make further changes if they are
called for.

> > +# Returns true if the operation succeeded, false if a rescan has been
initiated. +proc close_and_unlock_updateindex_rescan_on_error {fd after} {


Nitpick: That name is a bit too unwieldy. Maybe something a bit more concise
like 'close_and_unlock_index' (I'm not great at naming things. Maybe you can
figure out something better)? Let the readers figure out what happens on
error.


Good point. The thinking that had been going on in my head is that 
close_and_unlock_updateindex_rescan_on_error was combining two operations
that most but not all paths would do together, and then the paths that
needed them separated would call close_and_unlock in one place and 
rescan_on_error in another. The previous "cover letter" actually explicitly
described this, referring to proc names that actually weren't current any
more by the time the code was submitted. Upon closer review, at this point,
the place that calls rescan_on_error independently is not making a separate
call to something like close_and_unlock, it's just calling 
_close_updateindex directly, and the unlock is occurring in the chord body.

> >  * if {![catch {_close_updateindex $fd} err]} {    unlock_index
   
   
 * rescan $after 0
 * return
 * uplevel #0 $after
 * return 1
 * } else {
 * rescan_on_error $err $after
 * return 0


Neither of the two callers use the return value. Are these really needed?


I'm pretty sure there was an iteration of the code where at least one path
checked, but since nothing checks it now, I've removed the return value.

> > +proc write_checkout_index {fd path_list total_cnt batch
status_bar_operation \

 * after capture_error} { global update_index_cp global file_states
   current_diff_path
   
   if {$update_index_cp >= $total_cnt} {
   
   
 * _close_updateindex $fd $after
   
   
 * $status_bar_operation stop
   
   
 * 
 * if {[catch {_close_updateindex $fd} err]} {
   
   


Nitpick: Please mention exactly why we don't use
'close_and_unlock_updateindex_rescan_on_error' (or whatever its new name
would be) here. This function is very similar to 'write_update_index' and
'write_checkout_index', so this subtle difference is not very easily
apparent.


Done.

> > -field status {}; # single line of text we show


The field 'status' is removed, but the procedure 'show' still uses it. The
if condition needs to be refactored.


As far as I can tell, this feature of show to only change the status if the
test matches isn't actually used by any call sites. I've removed it. If this
was in error, then I'll reintroduce it correctly. I think, generally
speaking, supporting overlapping operations resolves the problem that this
would have originally resolved, which is that something else has updated the
status since it was previously set and the caller doesn't want to clear
somebody else's more up-to-date status text.

> >  * if {!$allow_multiple && [llength $operations]} {


This silently ignores multiple 'start's on a status bar that doesn't allow
it, correct?


It does, yes. The only status bar that doesn't allow multiple operations is
the two-line one created by choose_repository.

A caller that did this erroneously would get the same operation reference
both times, which would mean that (presumably) it got stopped multiple times
--- but stop on a status bar operation is idempotent, so this shouldn't
actually result in any errors.

> One quick question: the consumers of status_bar who don't run multiple
operations in parallel would still continue working exactly the same (after
refactoring them to use 'status_bar_operation'), right?


This is the expectation, yes, and is what I have observed in my testing. :-)

git remote add logiclrd https://github.com/logiclrd/git.git
git fetch logiclrd git-gui-revert-untracked revision5
git diff 23d4f5d..d0d6593b42

Jonathan Gilbert (3):
  git-gui: consolidate naming conventions
  git-gui: update status bar to track operations
  git-gui: revert untracked files by deleting them

 git-gui.sh          |  11 +-
 lib/blame.tcl       |  22 +-
 lib/checkout_op.tcl |  15 +-
 lib/chord.tcl       | 160 ++++++++++++++
 lib/index.tcl       | 523 +++++++++++++++++++++++++++++++++-----------
 lib/merge.tcl       |  14 +-
 lib/status_bar.tcl  | 228 ++++++++++++++++---
 7 files changed, 797 insertions(+), 176 deletions(-)
 create mode 100644 lib/chord.tcl


base-commit: b524f6b399c77b40c8bf2b6217585fde4731472a
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-436%2Flogiclrd%2Fgit-gui-revert-untracked-v5
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-436/logiclrd/git-gui-revert-untracked-v5
Pull-Request: https://github.com/gitgitgadget/git/pull/436

Range-diff vs v4:

 1:  da1704c56e = 1:  da1704c56e git-gui: consolidate naming conventions
 -:  ---------- > 2:  aa05a78d28 git-gui: update status bar to track operations
 2:  23d4f5d829 ! 3:  d0d6593b42 git-gui: revert untracked files by deleting them
     @@ -11,8 +11,8 @@
          out of _close_updateindex to a responsibility of the caller, to permit
          paths that don't directly unlock the index, and refactor the error
          handling added in d4e890e5 so that callers can make flow control
     -    decisions in the event of errors. Rework status_bar to explicitly handle
     -    multiple overlapping operations, and update all call sites.
     +    decisions in the event of errors. Update Tcl/Tk dependency from 8.4 to
     +    8.6 in git-gui.sh.
      
          A new proc delete_files takes care of actually deleting the files in
          batches, using the Tcler's Wiki recommended approach for keeping the UI
     @@ -24,14 +24,6 @@
          only after both operations are complete. The `SimpleChord` class,
          based on TclOO (Tcl/Tk 8.6), is added in this commit.
      
     -    Since the checkout_index and delete_files calls are both asynchronous
     -    and overlap, they clash in wanting to update the status bar. This commit
     -    reworks the status bar so that when an operation wants to display
     -    ongoing updates/progress, it explicitly starts an "operation", which is
     -    tracked by its own object, and the status bar handles multiple
     -    concurrent operations by merging their progress and concatenating their
     -    text.
     -
          Signed-off-by: Jonathan Gilbert <JonathanG@iQmetrix.com>
      
       diff --git a/git-gui.sh b/git-gui.sh
     @@ -48,73 +40,6 @@
       } {
       	catch {wm withdraw .}
       	tk_messageBox \
     -@@
     - 	do_explore
     - }
     - 
     -+# Clear "Initializing..." status
     -+after idle {after 500 {$main_status show ""}}
     -+
     - # Local variables:
     - # mode: tcl
     - # indent-tabs-mode: t
     -
     - diff --git a/lib/checkout_op.tcl b/lib/checkout_op.tcl
     - --- a/lib/checkout_op.tcl
     - +++ b/lib/checkout_op.tcl
     -@@
     - 	global HEAD
     - 
     - 	set readtree_d {}
     --	$::main_status start \
     -+	set status_bar_operation [$::main_status start \
     - 		[mc "Updating working directory to '%s'..." [_name $this]] \
     --		[mc "files checked out"]
     -+		[mc "files checked out"]]
     - 
     - 	set fd [git_read --stderr read-tree \
     - 		-m \
     -@@
     - 		$new_hash \
     - 		]
     - 	fconfigure $fd -blocking 0 -translation binary
     --	fileevent $fd readable [cb _readtree_wait $fd]
     -+	fileevent $fd readable [cb _readtree_wait $fd $status_bar_operation]
     - }
     - 
     --method _readtree_wait {fd} {
     -+method _readtree_wait {fd status_bar_operation} {
     - 	global current_branch
     - 
     - 	set buf [read $fd]
     --	$::main_status update_meter $buf
     -+	$status_bar_operation update_meter $buf
     - 	append readtree_d $buf
     - 
     - 	fconfigure $fd -blocking 1
     - 	if {![eof $fd]} {
     - 		fconfigure $fd -blocking 0
     -+		$status_bar_operation stop
     - 		return
     - 	}
     - 
     - 	if {[catch {close $fd}]} {
     - 		set err $readtree_d
     - 		regsub {^fatal: } $err {} err
     --		$::main_status stop [mc "Aborted checkout of '%s' (file level merging is required)." [_name $this]]
     -+		$status_bar_operation stop [mc "Aborted checkout of '%s' (file level merging is required)." [_name $this]]
     - 		warn_popup [strcat [mc "File level merge required."] "
     - 
     - $err
     -@@
     - 		return
     - 	}
     - 
     --	$::main_status stop
     -+	$status_bar_operation stop
     - 	_after_readtree $this
     - }
     - 
      
       diff --git a/lib/chord.tcl b/lib/chord.tcl
       new file mode 100644
     @@ -327,22 +252,18 @@
      -		wm deiconify $w
      -		tkwait window $w
      -
     --		$::main_status stop
     -+# Returns true if the operation succeeded, false if a rescan has been initiated.
     -+proc close_and_unlock_updateindex_rescan_on_error {fd after} {
     +-		$::main_status stop_all
     ++proc close_and_unlock_index {fd after} {
      +	if {![catch {_close_updateindex $fd} err]} {
       		unlock_index
      -		rescan $after 0
      -		return
      +		uplevel #0 $after
     -+		return 1
      +	} else {
      +		rescan_on_error $err $after
     -+		return 0
       	}
      +}
     - 
     --	$::main_status stop
     ++
      +proc _close_updateindex {fd} {
      +	fconfigure $fd -blocking 1
      +	close $fd
     @@ -384,8 +305,8 @@
      +	"
      +	wm deiconify $w
      +	tkwait window $w
     -+
     -+	$::main_status stop_all
     + 
     + 	$::main_status stop_all
       	unlock_index
      -	uplevel #0 $after
      +	rescan [concat $after [list ui_ready]] 0
     @@ -393,82 +314,25 @@
       
       proc update_indexinfo {msg path_list after} {
      @@
     - 	set batch [expr {int($total_cnt * .01) + 1}]
     - 	if {$batch > 25} {set batch 25}
     - 
     --	$::main_status start $msg [mc "files"]
     -+	set status_bar_operation [$::main_status start $msg [mc "files"]]
     - 	set fd [git_write update-index -z --index-info]
     - 	fconfigure $fd \
     - 		-blocking 0 \
     -@@
     - 		$path_list \
     - 		$total_cnt \
     - 		$batch \
     -+		$status_bar_operation \
     - 		$after \
     - 		]
     - }
     - 
     --proc write_update_indexinfo {fd path_list total_cnt batch after} {
     -+proc write_update_indexinfo {fd path_list total_cnt batch status_bar_operation \
     -+	after} {
     - 	global update_index_cp
     - 	global file_states current_diff_path
       
       	if {$update_index_cp >= $total_cnt} {
     + 		$status_bar_operation stop
      -		_close_updateindex $fd $after
     -+		$status_bar_operation stop
     -+		close_and_unlock_updateindex_rescan_on_error $fd $after
     ++		close_and_unlock_index $fd $after
       		return
       	}
       
      @@
     - 		display_file $path $new
     - 	}
     - 
     --	$::main_status update $update_index_cp $total_cnt
     -+	$status_bar_operation update $update_index_cp $total_cnt
     - }
     - 
     - proc update_index {msg path_list after} {
     -@@
     - 	set batch [expr {int($total_cnt * .01) + 1}]
     - 	if {$batch > 25} {set batch 25}
     - 
     --	$::main_status start $msg [mc "files"]
     -+	set status_bar_operation [$::main_status start $msg [mc "files"]]
     - 	set fd [git_write update-index --add --remove -z --stdin]
     - 	fconfigure $fd \
     - 		-blocking 0 \
     -@@
     - 		$path_list \
     - 		$total_cnt \
     - 		$batch \
     -+		$status_bar_operation \
     - 		$after \
     - 		]
     - }
     - 
     --proc write_update_index {fd path_list total_cnt batch after} {
     -+proc write_update_index {fd path_list total_cnt batch status_bar_operation \
     -+	after} {
     - 	global update_index_cp
     - 	global file_states current_diff_path
       
       	if {$update_index_cp >= $total_cnt} {
     + 		$status_bar_operation stop
      -		_close_updateindex $fd $after
     -+		$status_bar_operation stop
     -+		close_and_unlock_updateindex_rescan_on_error $fd $after
     ++		close_and_unlock_index $fd $after
       		return
       	}
       
      @@
     - 		display_file $path $new
     - 	}
     - 
     --	$::main_status update $update_index_cp $total_cnt
     -+	$status_bar_operation update $update_index_cp $total_cnt
     + 	$status_bar_operation update $update_index_cp $total_cnt
       }
       
      -proc checkout_index {msg path_list after} {
     @@ -477,33 +341,31 @@
       
       	if {![lock_index update]} return
      @@
     - 	set batch [expr {int($total_cnt * .01) + 1}]
     - 	if {$batch > 25} {set batch 25}
     - 
     --	$::main_status start $msg [mc "files"]
     -+	set status_bar_operation [$::main_status start $msg [mc "files"]]
     - 	set fd [git_write checkout-index \
     - 		--index \
     - 		--quiet \
     -@@
     - 		$path_list \
     - 		$total_cnt \
       		$batch \
     -+		$status_bar_operation \
     + 		$status_bar_operation \
       		$after \
      +		$capture_error \
       		]
       }
       
     --proc write_checkout_index {fd path_list total_cnt batch after} {
     -+proc write_checkout_index {fd path_list total_cnt batch status_bar_operation \
     + proc write_checkout_index {fd path_list total_cnt batch status_bar_operation \
     +-	after} {
      +	after capture_error} {
       	global update_index_cp
       	global file_states current_diff_path
       
       	if {$update_index_cp >= $total_cnt} {
     + 		$status_bar_operation stop
      -		_close_updateindex $fd $after
     -+		$status_bar_operation stop
     ++
     ++		# We do not unlock the index directly here because this
     ++		# operation expects to potentially run in parallel with file
     ++		# deletions scheduled by revert_helper. We're done with the
     ++		# update index, so we close it, but actually unlocking the index
     ++		# and dealing with potential errors is deferred to the chord
     ++		# body that runs when all async operations are completed.
     ++		#
     ++		# (See after_chord in revert_helper.)
      +
      +		if {[catch {_close_updateindex $fd} err]} {
      +			uplevel #0 $capture_error [list $err]
     @@ -514,15 +376,6 @@
       		return
       	}
       
     -@@
     - 		}
     - 	}
     - 
     --	$::main_status update $update_index_cp $total_cnt
     -+	$status_bar_operation update $update_index_cp $total_cnt
     - }
     - 
     - proc unstage_helper {txt paths} {
      @@
       	add_helper [mc "Adding all changed files"] $paths
       }
     @@ -860,348 +713,3 @@
       	}
       }
       
     -
     - diff --git a/lib/merge.tcl b/lib/merge.tcl
     - --- a/lib/merge.tcl
     - +++ b/lib/merge.tcl
     -@@
     - 	if {[ask_popup $op_question] eq {yes}} {
     - 		set fd [git_read --stderr read-tree --reset -u -v HEAD]
     - 		fconfigure $fd -blocking 0 -translation binary
     --		fileevent $fd readable [namespace code [list _reset_wait $fd]]
     --		$::main_status start [mc "Aborting"] [mc "files reset"]
     -+		set status_bar_operation [$::main_status \
     -+			start \
     -+			[mc "Aborting"] \
     -+			[mc "files reset"]
     -+		fileevent $fd readable [namespace code [list \
     -+			_reset_wait $fd $status_bar_operation]]
     - 	} else {
     - 		unlock_index
     - 	}
     - }
     - 
     --proc _reset_wait {fd} {
     -+proc _reset_wait {fd status_bar_operation} {
     - 	global ui_comm
     - 
     --	$::main_status update_meter [read $fd]
     -+	$status_bar_operation update_meter [read $fd]
     - 
     - 	fconfigure $fd -blocking 1
     - 	if {[eof $fd]} {
     - 		set fail [catch {close $fd} err]
     --		$::main_status stop
     - 		unlock_index
     -+		$status_bar_operation stop
     - 
     - 		$ui_comm delete 0.0 end
     - 		$ui_comm edit modified false
     -
     - diff --git a/lib/status_bar.tcl b/lib/status_bar.tcl
     - --- a/lib/status_bar.tcl
     - +++ b/lib/status_bar.tcl
     -@@
     - # git-gui status bar mega-widget
     - # Copyright (C) 2007 Shawn Pearce
     - 
     -+# The status_bar class manages the entire status bar. It is possible for
     -+# multiple overlapping asynchronous operations to want to display status
     -+# simultaneously. Each one receives a status_bar_operation when it calls the
     -+# start method, and the status bar combines all active operations into the
     -+# line of text it displays. Most of the time, there will be at most one
     -+# ongoing operation.
     -+#
     -+# Note that the entire status bar can be either in single-line or two-line
     -+# mode, depending on the constructor. Multiple active operations are only
     -+# supported for single-line status bars.
     -+
     - class status_bar {
     - 
     -+field allow_multiple ; # configured at construction
     -+
     - field w         ; # our own window path
     - field w_l       ; # text widget we draw messages into
     - field w_c       ; # canvas we draw a progress bar into
     - field c_pack    ; # script to pack the canvas with
     --field status  {}; # single line of text we show
     --field prefix  {}; # text we format into status
     --field units   {}; # unit of progress
     --field meter   {}; # current core git progress meter (if active)
     -+
     -+field baseline_text   ; # text to show if there are no operations
     -+field status_bar_text ; # combined text for all operations
     -+
     -+field operations ; # list of current ongoing operations
     -+
     -+# The status bar can display a progress bar, updated when consumers call the
     -+# update method on their status_bar_operation. When there are multiple
     -+# operations, the status bar shows the combined status of all operations.
     -+#
     -+# When an overlapping operation completes, the progress bar is going to
     -+# abruptly have one fewer operation in the calculation, causing a discontinuity.
     -+# Therefore, whenever an operation completes, if it is not the last operation,
     -+# this counter is increased, and the progress bar is calculated as though there
     -+# were still another operation at 100%. When the last operation completes, this
     -+# is reset to 0.
     -+field completed_operation_count
     - 
     - constructor new {path} {
     - 	global use_ttk NS
     -@@
     - 	set w_l $w.l
     - 	set w_c $w.c
     - 
     -+	# Standard single-line status bar: Permit overlapping operations
     -+	set allow_multiple 1
     -+
     -+	set baseline_text ""
     -+	set operations [list]
     -+	set completed_operation_count 0
     -+
     - 	${NS}::frame $w
     - 	if {!$use_ttk} {
     - 		$w configure -borderwidth 1 -relief sunken
     - 	}
     - 	${NS}::label $w_l \
     --		-textvariable @status \
     -+		-textvariable @status_bar_text \
     - 		-anchor w \
     - 		-justify left
     - 	pack $w_l -side left
     -@@
     - 	set w_l $w.l
     - 	set w_c $w.c
     - 
     -+	# Two-line status bar: Only one ongoing operation permitted.
     -+	set allow_multiple 0
     -+
     -+	set baseline_text ""
     -+	set operations [list]
     -+
     - 	${NS}::frame $w
     - 	${NS}::label $w_l \
     --		-textvariable @status \
     -+		-textvariable @status_bar_text \
     - 		-anchor w \
     - 		-justify left
     - 	pack $w_l -anchor w -fill x
     -@@
     - 	return $this
     - }
     - 
     --method start {msg uds} {
     -+method ensure_canvas {} {
     - 	if {[winfo exists $w_c]} {
     - 		$w_c coords bar 0 0 0 20
     - 	} else {
     -@@
     - 		$w_c create rectangle 0 0 0 20 -tags bar -fill navy
     - 		eval $c_pack
     - 	}
     -+}
     -+
     -+method show {msg {test {}}} {
     -+	if {$test eq {} || $status eq $test} {
     -+		$this ensure_canvas
     -+		set baseline_text $msg
     -+		$this refresh
     -+	}
     -+}
     -+
     -+method start {msg uds} {
     -+	set baseline_text ""
     -+
     -+	if {!$allow_multiple && [llength $operations]} {
     -+		return [lindex $operations 0]
     -+	}
     -+
     -+	$this ensure_canvas
     -+
     -+	set operation [status_bar_operation::new $this $msg $uds]
     -+
     -+	lappend operations $operation
     -+
     -+	$this refresh
     -+
     -+	return $operation
     -+}
     -+
     -+method refresh {} {
     -+	set new_text ""
     -+
     -+	set total [expr $completed_operation_count * 100]
     -+	set have $total
     -+
     -+	foreach operation $operations {
     -+		if {$new_text != ""} {
     -+			append new_text " / "
     -+		}
     -+
     -+		append new_text [$operation get_status]
     -+
     -+		set total [expr $total + 100]
     -+		set have [expr $have + [$operation get_progress]]
     -+	}
     -+
     -+	if {$new_text == ""} {
     -+		set new_text $baseline_text
     -+	}
     -+
     -+	set status_bar_text $new_text
     -+
     -+	set pixel_width 0
     -+	if {$have > 0} {
     -+		set pixel_width [expr {[winfo width $w_c] * $have / $total}]
     -+	}
     -+
     -+	$w_c coords bar 0 0 $pixel_width 20
     -+}
     -+
     -+method stop {operation stop_msg} {
     -+	set idx [lsearch $operations $operation]
     -+
     -+	if {$idx >= 0} {
     -+		set operations [lreplace $operations $idx $idx]
     -+		set completed_operation_count [expr \
     -+			$completed_operation_count + 1]
     -+
     -+		if {[llength operations] == 0} {
     -+			set completed_operation_count 0
     -+
     -+			destroy $w_c
     -+			if {$stop_msg ne {}} {
     -+				set baseline_text $stop_msg
     -+			}
     -+		}
     -+
     -+		$this refresh
     -+	}
     -+}
     -+
     -+method stop_all {{stop_msg {}}} {
     -+	set operations_copy $operations
     -+	set operations [list] # This makes the operation's call to stop a no-op.
     -+
     -+	foreach $operation operations_copy {
     -+		$operation stop
     -+	}
     -+
     -+	if {$stop_msg ne {}} {
     -+		set baseline_text $stop_msg
     -+	}
     -+
     -+	$this refresh
     -+}
     -+
     -+method _delete {current} {
     -+	if {$current eq $w} {
     -+		delete_this
     -+	}
     -+}
     -+
     -+}
     -+
     -+# The status_bar_operation class tracks a single consumer's ongoing status bar
     -+# activity, with the context that there are a few situations where multiple
     -+# overlapping asynchronous operations might want to display status information
     -+# simultaneously. Instances of status_bar_operation are created by calling
     -+# start on the status_bar, and when the caller is done with its stauts bar
     -+# operation, it calls stop on the operation.
     -+
     -+class status_bar_operation {
     -+
     -+field status_bar; # reference back to the status_bar that owns this object
     -+
     -+field is_active;
     -+
     -+field status   {}; # single line of text we show
     -+field progress {}; # current progress (0 to 100)
     -+field prefix   {}; # text we format into status
     -+field units    {}; # unit of progress
     -+field meter    {}; # current core git progress meter (if active)
     -+
     -+constructor new {owner msg uds} {
     -+	set status_bar $owner
     - 
     - 	set status $msg
     -+	set progress 0
     - 	set prefix $msg
     - 	set units  $uds
     - 	set meter  {}
     -+
     -+	set is_active 1
     -+
     -+	return $this
     - }
     - 
     -+method get_is_active {} { return $is_active }
     -+method get_status {} { return $status }
     -+method get_progress {} { return $progress }
     -+
     - method update {have total} {
     --	set pdone 0
     --	set cdone 0
     -+	if {!$is_active} { return }
     -+
     -+	set progress 0
     -+
     - 	if {$total > 0} {
     --		set pdone [expr {100 * $have / $total}]
     --		set cdone [expr {[winfo width $w_c] * $have / $total}]
     -+		set progress [expr {100 * $have / $total}]
     - 	}
     - 
     - 	set prec [string length [format %i $total]]
     -+
     - 	set status [mc "%s ... %*i of %*i %s (%3i%%)" \
     - 		$prefix \
     - 		$prec $have \
     - 		$prec $total \
     --		$units $pdone]
     --	$w_c coords bar 0 0 $cdone 20
     -+		$units $progress]
     -+
     -+	$status_bar refresh
     - }
     - 
     - method update_meter {buf} {
     -+	if {!$is_active} { return }
     -+
     - 	append meter $buf
     - 	set r [string last "\r" $meter]
     - 	if {$r == -1} {
     -@@
     - 	}
     - }
     - 
     --method stop {{msg {}}} {
     --	destroy $w_c
     --	if {$msg ne {}} {
     --		set status $msg
     -+method stop {{stop_msg {}}} {
     -+	if {$is_active} {
     -+		set is_active 0
     -+		$status_bar stop $this $stop_msg
     - 	}
     - }
     - 
     - method show {msg {test {}}} {
     -+	if {!$is_active} { return }
     -+
     - 	if {$test eq {} || $status eq $test} {
     - 		set status $msg
     -+		$status_bar refresh
     - 	}
     - }
     - 
     --method _delete {current} {
     --	if {$current eq $w} {
     --		delete_this
     --	}
     -+method _delete {} {
     -+	stop
     -+	delete_this
     - }
     - 
     - }

-- 
gitgitgadget

[PATCH v5 1/3] git-gui: consolidate naming conventions

[Jonathan Gilbert via GitGitGadget]

From: Jonathan Gilbert <JonathanG@iQmetrix.com>

A few variables in this file use camelCase, while the overall standard
is snake_case. A consistent naming scheme will improve readability of
future changes. To avoid mixing naming changes with semantic changes,
this commit contains only naming changes.

Signed-off-by: Jonathan Gilbert <JonathanG@iQmetrix.com>
---
 lib/index.tcl | 92 +++++++++++++++++++++++++--------------------------
 1 file changed, 46 insertions(+), 46 deletions(-)

diff --git a/lib/index.tcl b/lib/index.tcl
index e07b7a3762..28d4d2a54e 100644
--- a/lib/index.tcl
+++ b/lib/index.tcl
@@ -56,15 +56,15 @@ proc _close_updateindex {fd after} {
 	uplevel #0 $after
 }
 
-proc update_indexinfo {msg pathList after} {
+proc update_indexinfo {msg path_list after} {
 	global update_index_cp
 
 	if {![lock_index update]} return
 
 	set update_index_cp 0
-	set pathList [lsort $pathList]
-	set totalCnt [llength $pathList]
-	set batch [expr {int($totalCnt * .01) + 1}]
+	set path_list [lsort $path_list]
+	set total_cnt [llength $path_list]
+	set batch [expr {int($total_cnt * .01) + 1}]
 	if {$batch > 25} {set batch 25}
 
 	$::main_status start $msg [mc "files"]
@@ -78,26 +78,26 @@ proc update_indexinfo {msg pathList after} {
 	fileevent $fd writable [list \
 		write_update_indexinfo \
 		$fd \
-		$pathList \
-		$totalCnt \
+		$path_list \
+		$total_cnt \
 		$batch \
 		$after \
 		]
 }
 
-proc write_update_indexinfo {fd pathList totalCnt batch after} {
+proc write_update_indexinfo {fd path_list total_cnt batch after} {
 	global update_index_cp
 	global file_states current_diff_path
 
-	if {$update_index_cp >= $totalCnt} {
+	if {$update_index_cp >= $total_cnt} {
 		_close_updateindex $fd $after
 		return
 	}
 
 	for {set i $batch} \
-		{$update_index_cp < $totalCnt && $i > 0} \
+		{$update_index_cp < $total_cnt && $i > 0} \
 		{incr i -1} {
-		set path [lindex $pathList $update_index_cp]
+		set path [lindex $path_list $update_index_cp]
 		incr update_index_cp
 
 		set s $file_states($path)
@@ -119,18 +119,18 @@ proc write_update_indexinfo {fd pathList totalCnt batch after} {
 		display_file $path $new
 	}
 
-	$::main_status update $update_index_cp $totalCnt
+	$::main_status update $update_index_cp $total_cnt
 }
 
-proc update_index {msg pathList after} {
+proc update_index {msg path_list after} {
 	global update_index_cp
 
 	if {![lock_index update]} return
 
 	set update_index_cp 0
-	set pathList [lsort $pathList]
-	set totalCnt [llength $pathList]
-	set batch [expr {int($totalCnt * .01) + 1}]
+	set path_list [lsort $path_list]
+	set total_cnt [llength $path_list]
+	set batch [expr {int($total_cnt * .01) + 1}]
 	if {$batch > 25} {set batch 25}
 
 	$::main_status start $msg [mc "files"]
@@ -144,26 +144,26 @@ proc update_index {msg pathList after} {
 	fileevent $fd writable [list \
 		write_update_index \
 		$fd \
-		$pathList \
-		$totalCnt \
+		$path_list \
+		$total_cnt \
 		$batch \
 		$after \
 		]
 }
 
-proc write_update_index {fd pathList totalCnt batch after} {
+proc write_update_index {fd path_list total_cnt batch after} {
 	global update_index_cp
 	global file_states current_diff_path
 
-	if {$update_index_cp >= $totalCnt} {
+	if {$update_index_cp >= $total_cnt} {
 		_close_updateindex $fd $after
 		return
 	}
 
 	for {set i $batch} \
-		{$update_index_cp < $totalCnt && $i > 0} \
+		{$update_index_cp < $total_cnt && $i > 0} \
 		{incr i -1} {
-		set path [lindex $pathList $update_index_cp]
+		set path [lindex $path_list $update_index_cp]
 		incr update_index_cp
 
 		switch -glob -- [lindex $file_states($path) 0] {
@@ -190,18 +190,18 @@ proc write_update_index {fd pathList totalCnt batch after} {
 		display_file $path $new
 	}
 
-	$::main_status update $update_index_cp $totalCnt
+	$::main_status update $update_index_cp $total_cnt
 }
 
-proc checkout_index {msg pathList after} {
+proc checkout_index {msg path_list after} {
 	global update_index_cp
 
 	if {![lock_index update]} return
 
 	set update_index_cp 0
-	set pathList [lsort $pathList]
-	set totalCnt [llength $pathList]
-	set batch [expr {int($totalCnt * .01) + 1}]
+	set path_list [lsort $path_list]
+	set total_cnt [llength $path_list]
+	set batch [expr {int($total_cnt * .01) + 1}]
 	if {$batch > 25} {set batch 25}
 
 	$::main_status start $msg [mc "files"]
@@ -221,26 +221,26 @@ proc checkout_index {msg pathList after} {
 	fileevent $fd writable [list \
 		write_checkout_index \
 		$fd \
-		$pathList \
-		$totalCnt \
+		$path_list \
+		$total_cnt \
 		$batch \
 		$after \
 		]
 }
 
-proc write_checkout_index {fd pathList totalCnt batch after} {
+proc write_checkout_index {fd path_list total_cnt batch after} {
 	global update_index_cp
 	global file_states current_diff_path
 
-	if {$update_index_cp >= $totalCnt} {
+	if {$update_index_cp >= $total_cnt} {
 		_close_updateindex $fd $after
 		return
 	}
 
 	for {set i $batch} \
-		{$update_index_cp < $totalCnt && $i > 0} \
+		{$update_index_cp < $total_cnt && $i > 0} \
 		{incr i -1} {
-		set path [lindex $pathList $update_index_cp]
+		set path [lindex $path_list $update_index_cp]
 		incr update_index_cp
 		switch -glob -- [lindex $file_states($path) 0] {
 		U? {continue}
@@ -253,7 +253,7 @@ proc write_checkout_index {fd pathList totalCnt batch after} {
 		}
 	}
 
-	$::main_status update $update_index_cp $totalCnt
+	$::main_status update $update_index_cp $total_cnt
 }
 
 proc unstage_helper {txt paths} {
@@ -261,7 +261,7 @@ proc unstage_helper {txt paths} {
 
 	if {![lock_index begin-update]} return
 
-	set pathList [list]
+	set path_list [list]
 	set after {}
 	foreach path $paths {
 		switch -glob -- [lindex $file_states($path) 0] {
@@ -269,19 +269,19 @@ proc unstage_helper {txt paths} {
 		M? -
 		T? -
 		D? {
-			lappend pathList $path
+			lappend path_list $path
 			if {$path eq $current_diff_path} {
 				set after {reshow_diff;}
 			}
 		}
 		}
 	}
-	if {$pathList eq {}} {
+	if {$path_list eq {}} {
 		unlock_index
 	} else {
 		update_indexinfo \
 			$txt \
-			$pathList \
+			$path_list \
 			[concat $after [list ui_ready]]
 	}
 }
@@ -305,7 +305,7 @@ proc add_helper {txt paths} {
 
 	if {![lock_index begin-update]} return
 
-	set pathList [list]
+	set path_list [list]
 	set after {}
 	foreach path $paths {
 		switch -glob -- [lindex $file_states($path) 0] {
@@ -321,19 +321,19 @@ proc add_helper {txt paths} {
 		?M -
 		?D -
 		?T {
-			lappend pathList $path
+			lappend path_list $path
 			if {$path eq $current_diff_path} {
 				set after {reshow_diff;}
 			}
 		}
 		}
 	}
-	if {$pathList eq {}} {
+	if {$path_list eq {}} {
 		unlock_index
 	} else {
 		update_index \
 			$txt \
-			$pathList \
+			$path_list \
 			[concat $after {ui_status [mc "Ready to commit."]}]
 	}
 }
@@ -393,7 +393,7 @@ proc revert_helper {txt paths} {
 
 	if {![lock_index begin-update]} return
 
-	set pathList [list]
+	set path_list [list]
 	set after {}
 	foreach path $paths {
 		switch -glob -- [lindex $file_states($path) 0] {
@@ -401,7 +401,7 @@ proc revert_helper {txt paths} {
 		?M -
 		?T -
 		?D {
-			lappend pathList $path
+			lappend path_list $path
 			if {$path eq $current_diff_path} {
 				set after {reshow_diff;}
 			}
@@ -420,12 +420,12 @@ proc revert_helper {txt paths} {
 	# as they have quite complex plural-form rules. Unfortunately,
 	# msgcat doesn't seem to support that kind of string translation.
 	#
-	set n [llength $pathList]
+	set n [llength $path_list]
 	if {$n == 0} {
 		unlock_index
 		return
 	} elseif {$n == 1} {
-		set query [mc "Revert changes in file %s?" [short_path [lindex $pathList]]]
+		set query [mc "Revert changes in file %s?" [short_path [lindex $path_list]]]
 	} else {
 		set query [mc "Revert changes in these %i files?" $n]
 	}
@@ -444,7 +444,7 @@ proc revert_helper {txt paths} {
 	if {$reply == 1} {
 		checkout_index \
 			$txt \
-			$pathList \
+			$path_list \
 			[concat $after [list ui_ready]]
 	} else {
 		unlock_index
-- 
gitgitgadget

[PATCH v5 2/3] git-gui: update status bar to track operations

[Jonathan Gilbert via GitGitGadget]

From: Jonathan Gilbert <JonathanG@iQmetrix.com>

Update the status bar to track updates as individual "operations" that
can overlap. Update all call sites to interact with the new status bar
mechanism. Update initialization to explicitly clear status text,
since otherwise it may persist across future operations.

Signed-off-by: Jonathan Gilbert <JonathanG@iQmetrix.com>
---
 git-gui.sh          |   7 +-
 lib/blame.tcl       |  22 +++--
 lib/checkout_op.tcl |  15 +--
 lib/index.tcl       |  31 +++---
 lib/merge.tcl       |  14 ++-
 lib/status_bar.tcl  | 228 +++++++++++++++++++++++++++++++++++++++-----
 6 files changed, 260 insertions(+), 57 deletions(-)

diff --git a/git-gui.sh b/git-gui.sh
index 0d21f5688b..db02e399e7 100755
--- a/git-gui.sh
+++ b/git-gui.sh
@@ -1797,10 +1797,10 @@ proc ui_status {msg} {
 	}
 }
 
-proc ui_ready {{test {}}} {
+proc ui_ready {} {
 	global main_status
 	if {[info exists main_status]} {
-		$main_status show [mc "Ready."] $test
+		$main_status show [mc "Ready."]
 	}
 }
 
@@ -4159,6 +4159,9 @@ if {$picked && [is_config_true gui.autoexplore]} {
 	do_explore
 }
 
+# Clear "Initializing..." status
+after 500 {$main_status show ""}
+
 # Local variables:
 # mode: tcl
 # indent-tabs-mode: t
diff --git a/lib/blame.tcl b/lib/blame.tcl
index a1aeb8b96e..888f98bab2 100644
--- a/lib/blame.tcl
+++ b/lib/blame.tcl
@@ -24,6 +24,7 @@ field w_cviewer  ; # pane showing commit message
 field finder     ; # find mini-dialog frame
 field gotoline   ; # line goto mini-dialog frame
 field status     ; # status mega-widget instance
+field status_operation ; # status operation
 field old_height ; # last known height of $w.file_pane
 
 
@@ -274,6 +275,7 @@ constructor new {i_commit i_path i_jump} {
 	pack $w_cviewer -expand 1 -fill both
 
 	set status [::status_bar::new $w.status]
+	set status_operation {}
 
 	menu $w.ctxm -tearoff 0
 	$w.ctxm add command \
@@ -602,16 +604,21 @@ method _exec_blame {cur_w cur_d options cur_s} {
 	} else {
 		lappend options $commit
 	}
+
+	# We may recurse in from another call to _exec_blame and already have
+	# a status operation.
+	if {$status_operation == {}} {
+		set status_operation [$status start \
+			$cur_s \
+			[mc "lines annotated"]]
+	}
+
 	lappend options -- $path
 	set fd [eval git_read --nice blame $options]
 	fconfigure $fd -blocking 0 -translation lf -encoding utf-8
 	fileevent $fd readable [cb _read_blame $fd $cur_w $cur_d]
 	set current_fd $fd
 	set blame_lines 0
-
-	$status start \
-		$cur_s \
-		[mc "lines annotated"]
 }
 
 method _read_blame {fd cur_w cur_d} {
@@ -806,10 +813,11 @@ method _read_blame {fd cur_w cur_d} {
 				[mc "Loading original location annotations..."]
 		} else {
 			set current_fd {}
-			$status stop [mc "Annotation complete."]
+			$status_operation stop [mc "Annotation complete."]
+			set status_operation {}
 		}
 	} else {
-		$status update $blame_lines $total_lines
+		$status_operation update $blame_lines $total_lines
 	}
 } ifdeleted { catch {close $fd} }
 
@@ -1124,7 +1132,7 @@ method _blameparent {} {
 			set diffcmd [list diff-tree --unified=0 $cparent $cmit -- $new_path]
 		}
 		if {[catch {set fd [eval git_read $diffcmd]} err]} {
-			$status stop [mc "Unable to display parent"]
+			$status_operation stop [mc "Unable to display parent"]
 			error_popup [strcat [mc "Error loading diff:"] "\n\n$err"]
 			return
 		}
diff --git a/lib/checkout_op.tcl b/lib/checkout_op.tcl
index a5228297db..21ea768d80 100644
--- a/lib/checkout_op.tcl
+++ b/lib/checkout_op.tcl
@@ -341,9 +341,9 @@ method _readtree {} {
 	global HEAD
 
 	set readtree_d {}
-	$::main_status start \
+	set status_bar_operation [$::main_status start \
 		[mc "Updating working directory to '%s'..." [_name $this]] \
-		[mc "files checked out"]
+		[mc "files checked out"]]
 
 	set fd [git_read --stderr read-tree \
 		-m \
@@ -354,26 +354,27 @@ method _readtree {} {
 		$new_hash \
 		]
 	fconfigure $fd -blocking 0 -translation binary
-	fileevent $fd readable [cb _readtree_wait $fd]
+	fileevent $fd readable [cb _readtree_wait $fd $status_bar_operation]
 }
 
-method _readtree_wait {fd} {
+method _readtree_wait {fd status_bar_operation} {
 	global current_branch
 
 	set buf [read $fd]
-	$::main_status update_meter $buf
+	$status_bar_operation update_meter $buf
 	append readtree_d $buf
 
 	fconfigure $fd -blocking 1
 	if {![eof $fd]} {
 		fconfigure $fd -blocking 0
+		$status_bar_operation stop
 		return
 	}
 
 	if {[catch {close $fd}]} {
 		set err $readtree_d
 		regsub {^fatal: } $err {} err
-		$::main_status stop [mc "Aborted checkout of '%s' (file level merging is required)." [_name $this]]
+		$status_bar_operation stop [mc "Aborted checkout of '%s' (file level merging is required)." [_name $this]]
 		warn_popup [strcat [mc "File level merge required."] "
 
 $err
@@ -384,7 +385,7 @@ $err
 		return
 	}
 
-	$::main_status stop
+	$status_bar_operation stop
 	_after_readtree $this
 }
 
diff --git a/lib/index.tcl b/lib/index.tcl
index 28d4d2a54e..62f4773ef4 100644
--- a/lib/index.tcl
+++ b/lib/index.tcl
@@ -45,13 +45,13 @@ proc _close_updateindex {fd after} {
 		wm deiconify $w
 		tkwait window $w
 
-		$::main_status stop
+		$::main_status stop_all
 		unlock_index
 		rescan $after 0
 		return
 	}
 
-	$::main_status stop
+	$::main_status stop_all
 	unlock_index
 	uplevel #0 $after
 }
@@ -67,7 +67,7 @@ proc update_indexinfo {msg path_list after} {
 	set batch [expr {int($total_cnt * .01) + 1}]
 	if {$batch > 25} {set batch 25}
 
-	$::main_status start $msg [mc "files"]
+	set status_bar_operation [$::main_status start $msg [mc "files"]]
 	set fd [git_write update-index -z --index-info]
 	fconfigure $fd \
 		-blocking 0 \
@@ -81,15 +81,18 @@ proc update_indexinfo {msg path_list after} {
 		$path_list \
 		$total_cnt \
 		$batch \
+		$status_bar_operation \
 		$after \
 		]
 }
 
-proc write_update_indexinfo {fd path_list total_cnt batch after} {
+proc write_update_indexinfo {fd path_list total_cnt batch status_bar_operation \
+	after} {
 	global update_index_cp
 	global file_states current_diff_path
 
 	if {$update_index_cp >= $total_cnt} {
+		$status_bar_operation stop
 		_close_updateindex $fd $after
 		return
 	}
@@ -119,7 +122,7 @@ proc write_update_indexinfo {fd path_list total_cnt batch after} {
 		display_file $path $new
 	}
 
-	$::main_status update $update_index_cp $total_cnt
+	$status_bar_operation update $update_index_cp $total_cnt
 }
 
 proc update_index {msg path_list after} {
@@ -133,7 +136,7 @@ proc update_index {msg path_list after} {
 	set batch [expr {int($total_cnt * .01) + 1}]
 	if {$batch > 25} {set batch 25}
 
-	$::main_status start $msg [mc "files"]
+	set status_bar_operation [$::main_status start $msg [mc "files"]]
 	set fd [git_write update-index --add --remove -z --stdin]
 	fconfigure $fd \
 		-blocking 0 \
@@ -147,15 +150,18 @@ proc update_index {msg path_list after} {
 		$path_list \
 		$total_cnt \
 		$batch \
+		$status_bar_operation \
 		$after \
 		]
 }
 
-proc write_update_index {fd path_list total_cnt batch after} {
+proc write_update_index {fd path_list total_cnt batch status_bar_operation \
+	after} {
 	global update_index_cp
 	global file_states current_diff_path
 
 	if {$update_index_cp >= $total_cnt} {
+		$status_bar_operation stop
 		_close_updateindex $fd $after
 		return
 	}
@@ -190,7 +196,7 @@ proc write_update_index {fd path_list total_cnt batch after} {
 		display_file $path $new
 	}
 
-	$::main_status update $update_index_cp $total_cnt
+	$status_bar_operation update $update_index_cp $total_cnt
 }
 
 proc checkout_index {msg path_list after} {
@@ -204,7 +210,7 @@ proc checkout_index {msg path_list after} {
 	set batch [expr {int($total_cnt * .01) + 1}]
 	if {$batch > 25} {set batch 25}
 
-	$::main_status start $msg [mc "files"]
+	set status_bar_operation [$::main_status start $msg [mc "files"]]
 	set fd [git_write checkout-index \
 		--index \
 		--quiet \
@@ -224,15 +230,18 @@ proc checkout_index {msg path_list after} {
 		$path_list \
 		$total_cnt \
 		$batch \
+		$status_bar_operation \
 		$after \
 		]
 }
 
-proc write_checkout_index {fd path_list total_cnt batch after} {
+proc write_checkout_index {fd path_list total_cnt batch status_bar_operation \
+	after} {
 	global update_index_cp
 	global file_states current_diff_path
 
 	if {$update_index_cp >= $total_cnt} {
+		$status_bar_operation stop
 		_close_updateindex $fd $after
 		return
 	}
@@ -253,7 +262,7 @@ proc write_checkout_index {fd path_list total_cnt batch after} {
 		}
 	}
 
-	$::main_status update $update_index_cp $total_cnt
+	$status_bar_operation update $update_index_cp $total_cnt
 }
 
 proc unstage_helper {txt paths} {
diff --git a/lib/merge.tcl b/lib/merge.tcl
index 9f253db5b3..8df8ffae55 100644
--- a/lib/merge.tcl
+++ b/lib/merge.tcl
@@ -241,23 +241,27 @@ Continue with resetting the current changes?"]
 	if {[ask_popup $op_question] eq {yes}} {
 		set fd [git_read --stderr read-tree --reset -u -v HEAD]
 		fconfigure $fd -blocking 0 -translation binary
-		fileevent $fd readable [namespace code [list _reset_wait $fd]]
-		$::main_status start [mc "Aborting"] [mc "files reset"]
+		set status_bar_operation [$::main_status \
+			start \
+			[mc "Aborting"] \
+			[mc "files reset"]
+		fileevent $fd readable [namespace code [list \
+			_reset_wait $fd $status_bar_operation]]
 	} else {
 		unlock_index
 	}
 }
 
-proc _reset_wait {fd} {
+proc _reset_wait {fd status_bar_operation} {
 	global ui_comm
 
-	$::main_status update_meter [read $fd]
+	$status_bar_operation update_meter [read $fd]
 
 	fconfigure $fd -blocking 1
 	if {[eof $fd]} {
 		set fail [catch {close $fd} err]
-		$::main_status stop
 		unlock_index
+		$status_bar_operation stop
 
 		$ui_comm delete 0.0 end
 		$ui_comm edit modified false
diff --git a/lib/status_bar.tcl b/lib/status_bar.tcl
index 02111a1742..c4bff98856 100644
--- a/lib/status_bar.tcl
+++ b/lib/status_bar.tcl
@@ -1,16 +1,42 @@
 # git-gui status bar mega-widget
 # Copyright (C) 2007 Shawn Pearce
 
+# The status_bar class manages the entire status bar. It is possible for
+# multiple overlapping asynchronous operations to want to display status
+# simultaneously. Each one receives a status_bar_operation when it calls the
+# start method, and the status bar combines all active operations into the
+# line of text it displays. Most of the time, there will be at most one
+# ongoing operation.
+#
+# Note that the entire status bar can be either in single-line or two-line
+# mode, depending on the constructor. Multiple active operations are only
+# supported for single-line status bars.
+
 class status_bar {
 
+field allow_multiple ; # configured at construction
+
 field w         ; # our own window path
 field w_l       ; # text widget we draw messages into
 field w_c       ; # canvas we draw a progress bar into
 field c_pack    ; # script to pack the canvas with
-field status  {}; # single line of text we show
-field prefix  {}; # text we format into status
-field units   {}; # unit of progress
-field meter   {}; # current core git progress meter (if active)
+
+field baseline_text   ; # text to show if there are no operations
+field status_bar_text ; # combined text for all operations
+
+field operations ; # list of current ongoing operations
+
+# The status bar can display a progress bar, updated when consumers call the
+# update method on their status_bar_operation. When there are multiple
+# operations, the status bar shows the combined status of all operations.
+#
+# When an overlapping operation completes, the progress bar is going to
+# abruptly have one fewer operation in the calculation, causing a discontinuity.
+# Therefore, whenever an operation completes, if it is not the last operation,
+# this counter is increased, and the progress bar is calculated as though there
+# were still another operation at 100%. When the last operation completes, this
+# is reset to 0.
+field completed_operation_count
 
 constructor new {path} {
 	global use_ttk NS
@@ -18,12 +44,19 @@ constructor new {path} {
 	set w_l $w.l
 	set w_c $w.c
 
+	# Standard single-line status bar: Permit overlapping operations
+	set allow_multiple 1
+
+	set baseline_text ""
+	set operations [list]
+	set completed_operation_count 0
+
 	${NS}::frame $w
 	if {!$use_ttk} {
 		$w configure -borderwidth 1 -relief sunken
 	}
 	${NS}::label $w_l \
-		-textvariable @status \
+		-textvariable @status_bar_text \
 		-anchor w \
 		-justify left
 	pack $w_l -side left
@@ -44,9 +77,15 @@ constructor two_line {path} {
 	set w_l $w.l
 	set w_c $w.c
 
+	# Two-line status bar: Only one ongoing operation permitted.
+	set allow_multiple 0
+
+	set baseline_text ""
+	set operations [list]
+
 	${NS}::frame $w
 	${NS}::label $w_l \
-		-textvariable @status \
+		-textvariable @status_bar_text \
 		-anchor w \
 		-justify left
 	pack $w_l -anchor w -fill x
@@ -56,7 +95,7 @@ constructor two_line {path} {
 	return $this
 }
 
-method start {msg uds} {
+method ensure_canvas {} {
 	if {[winfo exists $w_c]} {
 		$w_c coords bar 0 0 0 20
 	} else {
@@ -68,31 +107,170 @@ method start {msg uds} {
 		$w_c create rectangle 0 0 0 20 -tags bar -fill navy
 		eval $c_pack
 	}
+}
+
+method show {msg} {
+	$this ensure_canvas
+	set baseline_text $msg
+	$this refresh
+}
+
+method start {msg uds} {
+	set baseline_text ""
+
+	if {!$allow_multiple && [llength $operations]} {
+		return [lindex $operations 0]
+	}
+
+	$this ensure_canvas
+
+	set operation [status_bar_operation::new $this $msg $uds]
+
+	lappend operations $operation
+
+	$this refresh
+
+	return $operation
+}
+
+method refresh {} {
+	set new_text ""
+
+	set total [expr $completed_operation_count * 100]
+	set have $total
+
+	foreach operation $operations {
+		if {$new_text != ""} {
+			append new_text " / "
+		}
+
+		append new_text [$operation get_status]
+
+		set total [expr $total + 100]
+		set have [expr $have + [$operation get_progress]]
+	}
+
+	if {$new_text == ""} {
+		set new_text $baseline_text
+	}
+
+	set status_bar_text $new_text
+
+	if {[winfo exists $w_c]} {
+		set pixel_width 0
+		if {$have > 0} {
+			set pixel_width [expr {[winfo width $w_c] * $have / $total}]
+		}
+
+		$w_c coords bar 0 0 $pixel_width 20
+	}
+}
+
+method stop {operation stop_msg} {
+	set idx [lsearch $operations $operation]
+
+	if {$idx >= 0} {
+		set operations [lreplace $operations $idx $idx]
+		set completed_operation_count [expr \
+			$completed_operation_count + 1]
+
+		if {[llength $operations] == 0} {
+			set completed_operation_count 0
+
+			destroy $w_c
+			if {$stop_msg ne {}} {
+				set baseline_text $stop_msg
+			}
+		}
+
+		$this refresh
+	}
+}
+
+method stop_all {{stop_msg {}}} {
+	# This makes the operation's call to stop a no-op.
+	set operations_copy $operations
+	set operations [list]
+
+	foreach operation $operations_copy {
+		$operation stop
+	}
+
+	if {$stop_msg ne {}} {
+		set baseline_text $stop_msg
+	}
+
+	$this refresh
+}
+
+method _delete {current} {
+	if {$current eq $w} {
+		delete_this
+	}
+}
+
+}
+
+# The status_bar_operation class tracks a single consumer's ongoing status bar
+# activity, with the context that there are a few situations where multiple
+# overlapping asynchronous operations might want to display status information
+# simultaneously. Instances of status_bar_operation are created by calling
+# start on the status_bar, and when the caller is done with its stauts bar
+# operation, it calls stop on the operation.
+
+class status_bar_operation {
+
+field status_bar; # reference back to the status_bar that owns this object
+
+field is_active;
+
+field status   {}; # single line of text we show
+field progress {}; # current progress (0 to 100)
+field prefix   {}; # text we format into status
+field units    {}; # unit of progress
+field meter    {}; # current core git progress meter (if active)
+
+constructor new {owner msg uds} {
+	set status_bar $owner
 
 	set status $msg
+	set progress 0
 	set prefix $msg
 	set units  $uds
 	set meter  {}
+
+	set is_active 1
+
+	return $this
 }
 
+method get_is_active {} { return $is_active }
+method get_status {} { return $status }
+method get_progress {} { return $progress }
+
 method update {have total} {
-	set pdone 0
-	set cdone 0
+	if {!$is_active} { return }
+
+	set progress 0
+
 	if {$total > 0} {
-		set pdone [expr {100 * $have / $total}]
-		set cdone [expr {[winfo width $w_c] * $have / $total}]
+		set progress [expr {100 * $have / $total}]
 	}
 
 	set prec [string length [format %i $total]]
+
 	set status [mc "%s ... %*i of %*i %s (%3i%%)" \
 		$prefix \
 		$prec $have \
 		$prec $total \
-		$units $pdone]
-	$w_c coords bar 0 0 $cdone 20
+		$units $progress]
+
+	$status_bar refresh
 }
 
 method update_meter {buf} {
+	if {!$is_active} { return }
+
 	append meter $buf
 	set r [string last "\r" $meter]
 	if {$r == -1} {
@@ -109,23 +287,23 @@ method update_meter {buf} {
 	}
 }
 
-method stop {{msg {}}} {
-	destroy $w_c
-	if {$msg ne {}} {
-		set status $msg
+method stop {{stop_msg {}}} {
+	if {$is_active} {
+		set is_active 0
+		$status_bar stop $this $stop_msg
 	}
 }
 
-method show {msg {test {}}} {
-	if {$test eq {} || $status eq $test} {
-		set status $msg
-	}
+method show {msg} {
+	if {!$is_active} { return }
+
+	set status $msg
+	$status_bar refresh
 }
 
-method _delete {current} {
-	if {$current eq $w} {
-		delete_this
-	}
+method _delete {} {
+	stop
+	delete_this
 }
 
 }
-- 
gitgitgadget

Re: [PATCH v5 2/3] git-gui: update status bar to track operations

[Pratyush Yadav]

Hi Jonathan,

Thanks for the re-roll.

On 24/11/19 08:37PM, Jonathan Gilbert via GitGitGadget wrote:
> From: Jonathan Gilbert <JonathanG@iQmetrix.com>
> 
> Update the status bar to track updates as individual "operations" that
> can overlap. Update all call sites to interact with the new status bar
> mechanism. Update initialization to explicitly clear status text,
> since otherwise it may persist across future operations.
> 
> Signed-off-by: Jonathan Gilbert <JonathanG@iQmetrix.com>
> ---
>  git-gui.sh          |   7 +-
>  lib/blame.tcl       |  22 +++--
>  lib/checkout_op.tcl |  15 +--
>  lib/index.tcl       |  31 +++---
>  lib/merge.tcl       |  14 ++-
>  lib/status_bar.tcl  | 228 +++++++++++++++++++++++++++++++++++++++-----
>  6 files changed, 260 insertions(+), 57 deletions(-)
> 
> diff --git a/git-gui.sh b/git-gui.sh
> index 0d21f5688b..db02e399e7 100755
> --- a/git-gui.sh
> +++ b/git-gui.sh
> @@ -1797,10 +1797,10 @@ proc ui_status {msg} {
>  	}
>  }
>  
> -proc ui_ready {{test {}}} {
> +proc ui_ready {} {

This is not quite correct. There is one user of 'ui_ready' that uses 
'test'. It is in git-gui.sh:2211. It is used when starting gitk. This 
change breaks that call. 10 seconds after opening gitk via the 
"Visualise master's history" option, I get the following error:

  wrong # args: should be "ui_ready"
      while executing
  "ui_ready $starting_gitk_msg"
      ("after" script)
 
The code that calls it (git-gui.sh:2211) looks like:

  ui_status $::starting_gitk_msg
  after 10000 {
  	ui_ready $starting_gitk_msg
  }

I am not quite sure why this is done though. It was introduced in 
e210e67 (git-gui: Corrected keyboard bindings on Windows, improved state 
management., 2006-11-06) [0], but the commit message doesn't really 
explain why (probably because it is a small part of a larger change, 
though it doesn't really fit in with the topic of the change). I can't 
find a mailing list thread about the commit so I don't think we'll ever 
know for sure.

From looking at it, my guess is that it was added because gitk took a 
long time to start up (maybe it still does, but for me its almost 
instant). And so, this message was shown for 10 seconds, and then 
cleared because by then it probably would have started. But to avoid 
over-writing some other message, 'test' was used to make sure only the 
message intended to be cleared is cleared.

I'm not sure if this heuristic/hack is really needed, and that we need 
to keep the "Starting gitk..." message around for 10 seconds. The way I 
see it, it doesn't add too much value unless gitk takes a long time to 
start up on other platforms or repos. In that case an indication of 
"we're working on starting gitk" would be nice. Otherwise, I don't mind 
seeing this go. And even then, I think it is gitk's responsibility to 
give some sort of indication to the user that it is booting up, and not 
ours.

So, I vote for just getting rid of this hack.

>  	global main_status
>  	if {[info exists main_status]} {
> -		$main_status show [mc "Ready."] $test
> +		$main_status show [mc "Ready."]
>  	}
>  }
>  
> @@ -4159,6 +4159,9 @@ if {$picked && [is_config_true gui.autoexplore]} {
>  	do_explore
>  }
>  
> +# Clear "Initializing..." status
> +after 500 {$main_status show ""}
> +
>  # Local variables:
>  # mode: tcl
>  # indent-tabs-mode: t
> diff --git a/lib/blame.tcl b/lib/blame.tcl
> index a1aeb8b96e..888f98bab2 100644
> --- a/lib/blame.tcl
> +++ b/lib/blame.tcl
> @@ -24,6 +24,7 @@ field w_cviewer  ; # pane showing commit message
>  field finder     ; # find mini-dialog frame
>  field gotoline   ; # line goto mini-dialog frame
>  field status     ; # status mega-widget instance
> +field status_operation ; # status operation

Nitpick: The comment doesn't give any information the field name doesn't 
already give. Either remove it or replace it with something more 
descriptive.

>  field old_height ; # last known height of $w.file_pane
>  
>  
> @@ -274,6 +275,7 @@ constructor new {i_commit i_path i_jump} {
>  	pack $w_cviewer -expand 1 -fill both
>  
>  	set status [::status_bar::new $w.status]
> +	set status_operation {}
>  
>  	menu $w.ctxm -tearoff 0
>  	$w.ctxm add command \
> @@ -602,16 +604,21 @@ method _exec_blame {cur_w cur_d options cur_s} {
>  	} else {
>  		lappend options $commit
>  	}
> +
> +	# We may recurse in from another call to _exec_blame and already have
> +	# a status operation.

Thanks for being thorough enough to spot this :)

> +	if {$status_operation == {}} {
> +		set status_operation [$status start \
> +			$cur_s \
> +			[mc "lines annotated"]]

The call to this method from '_read_blame' specifies a different $cur_s. 
So shouldn't we be destroying $status_operation (after stopping it), and 
creating a new one?

> +	}
> +
>  	lappend options -- $path
>  	set fd [eval git_read --nice blame $options]
>  	fconfigure $fd -blocking 0 -translation lf -encoding utf-8
>  	fileevent $fd readable [cb _read_blame $fd $cur_w $cur_d]
>  	set current_fd $fd
>  	set blame_lines 0
> -
> -	$status start \
> -		$cur_s \
> -		[mc "lines annotated"]
>  }
>  
>  method _read_blame {fd cur_w cur_d} {

You did not update 'lib/choose_repository.tcl'. It still uses the old 
version of the status bar. Other than that, the rest of the patch looks 
good. Thanks.

[0]:
  Curiously, if I do 'git log -L 2208,+5:git-gui.sh' to find the origins 
  of the line, it leads me to the commit 25476c6. And looking at the 
  commit, it does indeed appear to be the origin of the line since the 
  line is in the post-image, and not the pre-image. But I accidentally 
  noticed the line in a parent of that commit. Looking further, it turns 
  out the line originated in e210e67. Probably a bug in some really old 
  versions of git. Interesting nonetheless.

-- 
Regards,
Pratyush Yadav

Re: [PATCH v5 2/3] git-gui: update status bar to track operations

[Jonathan Gilbert]

On Wed, Nov 27, 2019 at 3:59 PM Pratyush Yadav me-at-yadavpratyush.com
|GitHub Public/Example Allow| <172q77k4bxwj0zt@sneakemail.com> wrote:
> On 24/11/19 08:37PM, Jonathan Gilbert via GitGitGadget wrote:
> > -proc ui_ready {{test {}}} {
> > +proc ui_ready {} {
>
> This is not quite correct. There is one user of 'ui_ready' that uses
> 'test'. It is in git-gui.sh:2211. It is used when starting gitk. This
> change breaks that call. 10 seconds after opening gitk via the
> "Visualise master's history" option, I get the following error:
>
>   wrong # args: should be "ui_ready"
>       while executing
>   "ui_ready $starting_gitk_msg"
>       ("after" script)
[..]
> I'm not sure if this heuristic/hack is really needed, and that we need
> to keep the "Starting gitk..." message around for 10 seconds.
[..]
> So, I vote for just getting rid of this hack.

Oh geeze, I can't believe I missed this. This looks like it ought to
be relatively straightforward to port to the new operations, though,
which is a more isolated approach (keeping this change's fingers where
they belong), and then the operation provides segregation that means
it can just be ended after X seconds without caring what anything else
might be doing with the status bar. We can independently figure out if
we want to restructure that part. Given that computers are faster now
and that the status bar could end up doing something else in the
meantime (well let's be realistic, probably not, but who knows :-) ),
I'd vote for reducing the time the message is shown from 10 seconds
to, I dunno, 3 or 4 seconds.

One other thing I note is that both `do_gitk` and `do_git_gui` use
`$starting_gitk_msg`, which means that when `do_git_gui` is invoked to
launch a Git Gui child process for a submodule, it will be setting the
status bar text to say that it is launching Gitk.

Speaking of things that are out of scope for this PR, I did notice
this in the code:

> # -- Always start git gui through whatever we were loaded with.  This
> #    lets us bypass using shell process on Windows systems.
> #
> set exe [list [_which git]]

As far as I can tell, there's virtually no connection between the
comment and what the code is actually doing. I haven't yet figured out
what exactly it is or where it comes from, but on my Windows systems,
`git-gui` is actually an EXE file `git-gui.exe`, and I _think_ what it
is doing is running `wish.exe`, which I'm guessing has something to do
with hosting a Tcl interpreter with Win32 support for Tk GUI.

I'm not sure whether the code is doing the right thing here or not,
but I'm pretty sure what it's _not_ doing is figuring out how the
current `git-gui` process was started/is being hosted. :-P

> >  field finder     ; # find mini-dialog frame
> >  field gotoline   ; # line goto mini-dialog frame
> >  field status     ; # status mega-widget instance
> > +field status_operation ; # status operation
>
> Nitpick: The comment doesn't give any information the field name doesn't
> already give. Either remove it or replace it with something more
> descriptive.

Hmm, okay. I didn't want something that felt wildly imbalanced with
respect to the other lines, but you're right that this particular line
is literally just repeating the variable name. :-P

> > +     if {$status_operation == {}} {
> > +             set status_operation [$status start \
> > +                     $cur_s \
> > +                     [mc "lines annotated"]]
>
> The call to this method from '_read_blame' specifies a different $cur_s.
> So shouldn't we be destroying $status_operation (after stopping it), and
> creating a new one?

We can change the text by calling `$status_operation show`.

> >  method _read_blame {fd cur_w cur_d} {
>
> You did not update 'lib/choose_repository.tcl'. It still uses the old
> version of the status bar. Other than that, the rest of the patch looks
> good. Thanks.

Ugh, I can't believe I overlooked this. I was aware of the file using
the status bar, because it's the one place that uses the `two_line`
constructor, but then I forgot to actually make it create and use the
(single concurrent) operation that a `two_line`-er is allowed.

The code in there seems to overload the purpose of the `o_cons`
variable, so that sometimes it is pointing at a status bar and
sometimes it is pointing at whatever `console::embed` returns. I will
change this.

This code also depends heavily on `update` to keep the UI active,
which as I understand it is problematic because it could potentially
result in re-entrance since the user can interact with the UI in the
middle of the operation. I will not make any attempt to change this,
though. :-)

> [0]:
>   Curiously, if I do 'git log -L 2208,+5:git-gui.sh' to find the origins
>   of the line, it leads me to the commit 25476c6. And looking at the
>   commit, it does indeed appear to be the origin of the line since the
>   line is in the post-image, and not the pre-image. But I accidentally
>   noticed the line in a parent of that commit. Looking further, it turns
>   out the line originated in e210e67. Probably a bug in some really old
>   versions of git. Interesting nonetheless.

In e210e67, I see this:

set starting_gitk_msg {Please wait... Starting gitk...}
proc do_gitk {} {
        global tcl_platform ui_status_value starting_gitk_msg

        set ui_status_value $starting_gitk_msg
        after 5000 {
                if {$ui_status_value == $starting_gitk_msg} {
                        set ui_status_value {Ready.}
                }
        }
        ...

In 043f7011, all string comparisons were changed from ==/!= to eq/ne.
The commit message explains that when you use == and !=, Tcl will
attempt to convert either side to numeric if one of the two sides
looks like a numeric. Guess I should review my commit for this error
:-P

-                if {$ui_status_value == $starting_gitk_msg} {
+                if {$ui_status_value eq $starting_gitk_msg} {

In 699d5601 "Refactor our ui_status_value update technique", this became:

set starting_gitk_msg [mc "Starting gitk... please wait..."]
...
        global ... starting_gitk_msg
...
        ui_status $starting_gitk_msg
        after 10000 {
                ui_ready $starting_gitk_msg
        }

Finally it became this in 02efd48f, apparently an unrelated
refactoring removed the global variable declaration:

set starting_gitk_msg [mc "Starting gitk... please wait..."]
...
        ui_status $::starting_gitk_msg
        after 10000 {
                ui_ready $starting_gitk_msg
        }

I gathered this information using Git Gui's blame function, which I
guess is a good demonstration that my latest blame.tcl revision
corrects the problems in the earlier submission :-D

Next revision coming soon.

Jonathan Gilbert

[PATCH v5 3/3] git-gui: revert untracked files by deleting them

[Jonathan Gilbert via GitGitGadget]

From: Jonathan Gilbert <JonathanG@iQmetrix.com>

Update the revert_helper proc to check for untracked files as well as
changes, and then handle changes to be reverted and untracked files with
independent blocks of code. Prompt the user independently for untracked
files, since the underlying action is fundamentally different (rm -f).
If after deleting untracked files, the directory containing them becomes
empty, then remove the directory as well. Migrate unlocking of the index
out of _close_updateindex to a responsibility of the caller, to permit
paths that don't directly unlock the index, and refactor the error
handling added in d4e890e5 so that callers can make flow control
decisions in the event of errors. Update Tcl/Tk dependency from 8.4 to
8.6 in git-gui.sh.

A new proc delete_files takes care of actually deleting the files in
batches, using the Tcler's Wiki recommended approach for keeping the UI
responsive.

Since the checkout_index and delete_files calls are both asynchronous
and could potentially complete in any order, a "chord" is used to
coordinate unlocking the index and returning the UI to a usable state
only after both operations are complete. The `SimpleChord` class,
based on TclOO (Tcl/Tk 8.6), is added in this commit.

Signed-off-by: Jonathan Gilbert <JonathanG@iQmetrix.com>
---
 git-gui.sh    |   4 +-
 lib/chord.tcl | 160 +++++++++++++++++++
 lib/index.tcl | 422 ++++++++++++++++++++++++++++++++++++++++----------
 3 files changed, 502 insertions(+), 84 deletions(-)
 create mode 100644 lib/chord.tcl

diff --git a/git-gui.sh b/git-gui.sh
index db02e399e7..ad87703b2d 100755
--- a/git-gui.sh
+++ b/git-gui.sh
@@ -30,8 +30,8 @@ along with this program; if not, see <http://www.gnu.org/licenses/>.}]
 ##
 ## Tcl/Tk sanity check
 
-if {[catch {package require Tcl 8.4} err]
- || [catch {package require Tk  8.4} err]
+if {[catch {package require Tcl 8.6} err]
+ || [catch {package require Tk  8.6} err]
 } {
 	catch {wm withdraw .}
 	tk_messageBox \
diff --git a/lib/chord.tcl b/lib/chord.tcl
new file mode 100644
index 0000000000..275a6cd4a1
--- /dev/null
+++ b/lib/chord.tcl
@@ -0,0 +1,160 @@
+# Simple Chord for Tcl
+#
+# A "chord" is a method with more than one entrypoint and only one body, such
+# that the body runs only once all the entrypoints have been called by
+# different asynchronous tasks. In this implementation, the chord is defined
+# dynamically for each invocation. A SimpleChord object is created, supplying
+# body script to be run when the chord is completed, and then one or more notes
+# are added to the chord. Each note can be called like a proc, and returns
+# immediately if the chord isn't yet complete. When the last remaining note is
+# called, the body runs before the note returns.
+#
+# The SimpleChord class has a constructor that takes the body script, and a
+# method add_note that returns a note object. Since the body script does not
+# run in the context of the procedure that defined it, a mechanism is provided
+# for injecting variables into the chord for use by the body script. The
+# activation of a note is idempotent; multiple calls have the same effect as
+# a simple call.
+#
+# If you are invoking asynchronous operations with chord notes as completion
+# callbacks, and there is a possibility that earlier operations could complete
+# before later ones are started, it is a good practice to create a "common"
+# note on the chord that prevents it from being complete until you're certain
+# you've added all the notes you need.
+#
+# Example:
+#
+#   # Turn off the UI while running a couple of async operations.
+#   lock_ui
+#
+#   set chord [SimpleChord new {
+#     unlock_ui
+#     # Note: $notice here is not referenced in the calling scope
+#     if {$notice} { info_popup $notice }
+#   }
+#
+#   # Configure a note to keep the chord from completing until
+#   # all operations have been initiated.
+#   set common_note [$chord add_note]
+#
+#   # Pass notes as 'after' callbacks to other operations
+#   async_operation $args [$chord add_note]
+#   other_async_operation $args [$chord add_note]
+#
+#   # Communicate with the chord body
+#   if {$condition} {
+#     # This sets $notice in the same context that the chord body runs in.
+#     $chord eval { set notice "Something interesting" }
+#   }
+#
+#   # Activate the common note, making the chord eligible to complete
+#   $common_note
+#
+# At this point, the chord will complete at some unknown point in the future.
+# The common note might have been the first note activated, or the async
+# operations might have completed synchronously and the common note is the
+# last one, completing the chord before this code finishes, or anything in
+# between. The purpose of the chord is to not have to worry about the order.
+
+# SimpleChord class:
+#   Represents a procedure that conceptually has multiple entrypoints that must
+#   all be called before the procedure executes. Each entrypoint is called a
+#   "note". The chord is only "completed" when all the notes are "activated".
+oo::class create SimpleChord {
+	variable notes body is_completed
+
+	# Constructor:
+	#   set chord [SimpleChord new {body}]
+	#     Creates a new chord object with the specified body script. The
+	#     body script is evaluated at most once, when a note is activated
+	#     and the chord has no other non-activated notes.
+	constructor {body} {
+		set notes [list]
+		my eval [list set body $body]
+		set is_completed 0
+	}
+
+	# Method:
+	#   $chord eval {script}
+	#     Runs the specified script in the same context (namespace) in which
+	#     the chord body will be evaluated. This can be used to set variable
+	#     values for the chord body to use.
+	method eval {script} {
+		namespace eval [self] $script
+	}
+
+	# Method:
+	#   set note [$chord add_note]
+	#     Adds a new note to the chord, an instance of ChordNote. Raises an
+	#     error if the chord is already completed, otherwise the chord is
+	#     updated so that the new note must also be activated before the
+	#     body is evaluated.
+	method add_note {} {
+		if {$is_completed} { error "Cannot add a note to a completed chord" }
+
+		set note [ChordNote new [self]]
+
+		lappend notes $note
+
+		return $note
+	}
+
+	# This method is for internal use only and is intentionally undocumented.
+	method notify_note_activation {} {
+		if {!$is_completed} {
+			foreach note $notes {
+				if {![$note is_activated]} { return }
+			}
+
+			set is_completed 1
+
+			namespace eval [self] $body
+			namespace delete [self]
+		}
+	}
+}
+
+# ChordNote class:
+#   Represents a note within a chord, providing a way to activate it. When the
+#   final note of the chord is activated (this can be any note in the chord,
+#   with all other notes already previously activated in any order), the chord's
+#   body is evaluated.
+oo::class create ChordNote {
+	variable chord is_activated
+
+	# Constructor:
+	#   Instances of ChordNote are created internally by calling add_note on
+	#   SimpleChord objects.
+	constructor {chord} {
+		my eval set chord $chord
+		set is_activated 0
+	}
+
+	# Method:
+	#   [$note is_activated]
+	#     Returns true if this note has already been activated.
+	method is_activated {} {
+		return $is_activated
+	}
+
+	# Method:
+	#   $note
+	#     Activates the note, if it has not already been activated, and
+	#     completes the chord if there are no other notes awaiting
+	#     activation. Subsequent calls will have no further effect.
+	#
+	# NB: In TclOO, if an object is invoked like a method without supplying
+	#     any method name, then this internal method `unknown` is what
+	#     actually runs (with no parameters). It is used in the ChordNote
+	#     class for the purpose of allowing the note object to be called as
+	#     a function (see example above). (The `unknown` method can also be
+	#     used to support dynamic dispatch, but must take parameters to
+	#     identify the "unknown" method to be invoked. In this form, this
+	#     proc serves only to make instances behave directly like methods.)
+	method unknown {} {
+		if {!$is_activated} {
+			set is_activated 1
+			$chord notify_note_activation
+		}
+	}
+}
diff --git a/lib/index.tcl b/lib/index.tcl
index 62f4773ef4..1254145634 100644
--- a/lib/index.tcl
+++ b/lib/index.tcl
@@ -7,53 +7,60 @@ proc _delete_indexlock {} {
 	}
 }
 
-proc _close_updateindex {fd after} {
-	global use_ttk NS
-	fconfigure $fd -blocking 1
-	if {[catch {close $fd} err]} {
-		set w .indexfried
-		Dialog $w
-		wm withdraw $w
-		wm title $w [strcat "[appname] ([reponame]): " [mc "Index Error"]]
-		wm geometry $w "+[winfo rootx .]+[winfo rooty .]"
-		set s [mc "Updating the Git index failed.  A rescan will be automatically started to resynchronize git-gui."]
-		text $w.msg -yscrollcommand [list $w.vs set] \
-			-width [string length $s] -relief flat \
-			-borderwidth 0 -highlightthickness 0 \
-			-background [get_bg_color $w]
-		$w.msg tag configure bold -font font_uibold -justify center
-		${NS}::scrollbar $w.vs -command [list $w.msg yview]
-		$w.msg insert end $s bold \n\n$err {}
-		$w.msg configure -state disabled
-
-		${NS}::button $w.continue \
-			-text [mc "Continue"] \
-			-command [list destroy $w]
-		${NS}::button $w.unlock \
-			-text [mc "Unlock Index"] \
-			-command "destroy $w; _delete_indexlock"
-		grid $w.msg - $w.vs -sticky news
-		grid $w.unlock $w.continue - -sticky se -padx 2 -pady 2
-		grid columnconfigure $w 0 -weight 1
-		grid rowconfigure $w 0 -weight 1
-
-		wm protocol $w WM_DELETE_WINDOW update
-		bind $w.continue <Visibility> "
-			grab $w
-			focus %W
-		"
-		wm deiconify $w
-		tkwait window $w
-
-		$::main_status stop_all
+proc close_and_unlock_index {fd after} {
+	if {![catch {_close_updateindex $fd} err]} {
 		unlock_index
-		rescan $after 0
-		return
+		uplevel #0 $after
+	} else {
+		rescan_on_error $err $after
 	}
+}
+
+proc _close_updateindex {fd} {
+	fconfigure $fd -blocking 1
+	close $fd
+}
+
+proc rescan_on_error {err {after {}}} {
+	global use_ttk NS
+
+	set w .indexfried
+	Dialog $w
+	wm withdraw $w
+	wm title $w [strcat "[appname] ([reponame]): " [mc "Index Error"]]
+	wm geometry $w "+[winfo rootx .]+[winfo rooty .]"
+	set s [mc "Updating the Git index failed.  A rescan will be automatically started to resynchronize git-gui."]
+	text $w.msg -yscrollcommand [list $w.vs set] \
+		-width [string length $s] -relief flat \
+		-borderwidth 0 -highlightthickness 0 \
+		-background [get_bg_color $w]
+	$w.msg tag configure bold -font font_uibold -justify center
+	${NS}::scrollbar $w.vs -command [list $w.msg yview]
+	$w.msg insert end $s bold \n\n$err {}
+	$w.msg configure -state disabled
+
+	${NS}::button $w.continue \
+		-text [mc "Continue"] \
+		-command [list destroy $w]
+	${NS}::button $w.unlock \
+		-text [mc "Unlock Index"] \
+		-command "destroy $w; _delete_indexlock"
+	grid $w.msg - $w.vs -sticky news
+	grid $w.unlock $w.continue - -sticky se -padx 2 -pady 2
+	grid columnconfigure $w 0 -weight 1
+	grid rowconfigure $w 0 -weight 1
+
+	wm protocol $w WM_DELETE_WINDOW update
+	bind $w.continue <Visibility> "
+		grab $w
+		focus %W
+	"
+	wm deiconify $w
+	tkwait window $w
 
 	$::main_status stop_all
 	unlock_index
-	uplevel #0 $after
+	rescan [concat $after [list ui_ready]] 0
 }
 
 proc update_indexinfo {msg path_list after} {
@@ -93,7 +100,7 @@ proc write_update_indexinfo {fd path_list total_cnt batch status_bar_operation \
 
 	if {$update_index_cp >= $total_cnt} {
 		$status_bar_operation stop
-		_close_updateindex $fd $after
+		close_and_unlock_index $fd $after
 		return
 	}
 
@@ -162,7 +169,7 @@ proc write_update_index {fd path_list total_cnt batch status_bar_operation \
 
 	if {$update_index_cp >= $total_cnt} {
 		$status_bar_operation stop
-		_close_updateindex $fd $after
+		close_and_unlock_index $fd $after
 		return
 	}
 
@@ -199,7 +206,7 @@ proc write_update_index {fd path_list total_cnt batch status_bar_operation \
 	$status_bar_operation update $update_index_cp $total_cnt
 }
 
-proc checkout_index {msg path_list after} {
+proc checkout_index {msg path_list after capture_error} {
 	global update_index_cp
 
 	if {![lock_index update]} return
@@ -232,17 +239,33 @@ proc checkout_index {msg path_list after} {
 		$batch \
 		$status_bar_operation \
 		$after \
+		$capture_error \
 		]
 }
 
 proc write_checkout_index {fd path_list total_cnt batch status_bar_operation \
-	after} {
+	after capture_error} {
 	global update_index_cp
 	global file_states current_diff_path
 
 	if {$update_index_cp >= $total_cnt} {
 		$status_bar_operation stop
-		_close_updateindex $fd $after
+
+		# We do not unlock the index directly here because this
+		# operation expects to potentially run in parallel with file
+		# deletions scheduled by revert_helper. We're done with the
+		# update index, so we close it, but actually unlocking the index
+		# and dealing with potential errors is deferred to the chord
+		# body that runs when all async operations are completed.
+		#
+		# (See after_chord in revert_helper.)
+
+		if {[catch {_close_updateindex $fd} err]} {
+			uplevel #0 $capture_error [list $err]
+		}
+
+		uplevel #0 $after
+
 		return
 	}
 
@@ -397,66 +420,301 @@ proc do_add_all {} {
 	add_helper [mc "Adding all changed files"] $paths
 }
 
+# Copied from TclLib package "lambda".
+proc lambda {arguments body args} {
+	return [list ::apply [list $arguments $body] {*}$args]
+}
+
 proc revert_helper {txt paths} {
 	global file_states current_diff_path
 
 	if {![lock_index begin-update]} return
 
+	# Common "after" functionality that waits until multiple asynchronous
+	# operations are complete (by waiting for them to activate their notes
+	# on the chord).
+	#
+	# The asynchronous operations are each indicated below by a comment
+	# before the code block that starts the async operation.
+	set after_chord [SimpleChord new {
+		if {[string trim $err] != ""} {
+			rescan_on_error $err
+		} else {
+			unlock_index
+			if {$should_reshow_diff} { reshow_diff }
+			ui_ready
+		}
+	}]
+
+	$after_chord eval { set should_reshow_diff 0 }
+
+	# This function captures an error for processing when after_chord is
+	# completed. (The chord is curried into the lambda function.)
+	set capture_error [lambda \
+		{chord error} \
+		{ $chord eval [list set err $error] } \
+		$after_chord]
+
+	# We don't know how many notes we're going to create (it's dynamic based
+	# on conditional paths below), so create a common note that will delay
+	# the chord's completion until we activate it, and then activate it
+	# after all the other notes have been created.
+	set after_common_note [$after_chord add_note]
+
 	set path_list [list]
-	set after {}
+	set untracked_list [list]
+
 	foreach path $paths {
 		switch -glob -- [lindex $file_states($path) 0] {
 		U? {continue}
+		?O {
+			lappend untracked_list $path
+		}
 		?M -
 		?T -
 		?D {
 			lappend path_list $path
 			if {$path eq $current_diff_path} {
-				set after {reshow_diff;}
+				$after_chord eval { set should_reshow_diff 1 }
 			}
 		}
 		}
 	}
 
+	set path_cnt [llength $path_list]
+	set untracked_cnt [llength $untracked_list]
+
+	# Asynchronous operation: revert changes by checking them out afresh
+	# from the index.
+	if {$path_cnt > 0} {
+		# Split question between singular and plural cases, because
+		# such distinction is needed in some languages. Previously, the
+		# code used "Revert changes in" for both, but that can't work
+		# in languages where 'in' must be combined with word from
+		# rest of string (in different way for both cases of course).
+		#
+		# FIXME: Unfortunately, even that isn't enough in some languages
+		# as they have quite complex plural-form rules. Unfortunately,
+		# msgcat doesn't seem to support that kind of string
+		# translation.
+		#
+		if {$path_cnt == 1} {
+			set query [mc \
+				"Revert changes in file %s?" \
+				[short_path [lindex $path_list]] \
+				]
+		} else {
+			set query [mc \
+				"Revert changes in these %i files?" \
+				$path_cnt]
+		}
 
-	# Split question between singular and plural cases, because
-	# such distinction is needed in some languages. Previously, the
-	# code used "Revert changes in" for both, but that can't work
-	# in languages where 'in' must be combined with word from
-	# rest of string (in different way for both cases of course).
-	#
-	# FIXME: Unfortunately, even that isn't enough in some languages
-	# as they have quite complex plural-form rules. Unfortunately,
-	# msgcat doesn't seem to support that kind of string translation.
-	#
-	set n [llength $path_list]
-	if {$n == 0} {
-		unlock_index
-		return
-	} elseif {$n == 1} {
-		set query [mc "Revert changes in file %s?" [short_path [lindex $path_list]]]
-	} else {
-		set query [mc "Revert changes in these %i files?" $n]
+		set reply [tk_dialog \
+			.confirm_revert \
+			"[appname] ([reponame])" \
+			"$query
+
+[mc "Any unstaged changes will be permanently lost by the revert."]" \
+			question \
+			1 \
+			[mc "Do Nothing"] \
+			[mc "Revert Changes"] \
+			]
+
+		if {$reply == 1} {
+			checkout_index \
+				$txt \
+				$path_list \
+				[$after_chord add_note] \
+				$capture_error
+		}
 	}
 
-	set reply [tk_dialog \
-		.confirm_revert \
-		"[appname] ([reponame])" \
-		"$query
+	# Asynchronous operation: Deletion of untracked files.
+	if {$untracked_cnt > 0} {
+		# Split question between singular and plural cases, because
+		# such distinction is needed in some languages.
+		#
+		# FIXME: Unfortunately, even that isn't enough in some languages
+		# as they have quite complex plural-form rules. Unfortunately,
+		# msgcat doesn't seem to support that kind of string
+		# translation.
+		#
+		if {$untracked_cnt == 1} {
+			set query [mc \
+				"Delete untracked file %s?" \
+				[short_path [lindex $untracked_list]] \
+				]
+		} else {
+			set query [mc \
+				"Delete these %i untracked files?" \
+				$untracked_cnt \
+				]
+		}
 
-[mc "Any unstaged changes will be permanently lost by the revert."]" \
-		question \
-		1 \
-		[mc "Do Nothing"] \
-		[mc "Revert Changes"] \
-		]
-	if {$reply == 1} {
-		checkout_index \
-			$txt \
+		set reply [tk_dialog \
+			.confirm_revert \
+			"[appname] ([reponame])" \
+			"$query
+
+[mc "Files will be permanently deleted."]" \
+			question \
+			1 \
+			[mc "Do Nothing"] \
+			[mc "Delete Files"] \
+			]
+
+		if {$reply == 1} {
+			$after_chord eval { set should_reshow_diff 1 }
+
+			delete_files $untracked_list [$after_chord add_note]
+		}
+	}
+
+	# Activate the common note. If no other notes were created, this
+	# completes the chord. If other notes were created, then this common
+	# note prevents a race condition where the chord might complete early.
+	$after_common_note
+}
+
+# Delete all of the specified files, performing deletion in batches to allow the
+# UI to remain responsive and updated.
+proc delete_files {path_list after} {
+	# Enable progress bar status updates
+	set status_bar_operation [$::main_status \
+		start \
+		[mc "Deleting"] \
+		[mc "files"]]
+
+	set path_index 0
+	set deletion_errors [list]
+	set batch_size 50
+
+	delete_helper \
+		$path_list \
+		$path_index \
+		$deletion_errors \
+		$batch_size \
+		$status_bar_operation \
+		$after
+}
+
+# Helper function to delete a list of files in batches. Each call deletes one
+# batch of files, and then schedules a call for the next batch after any UI
+# messages have been processed.
+proc delete_helper {path_list path_index deletion_errors batch_size \
+	status_bar_operation after} {
+	global file_states
+
+	set path_cnt [llength $path_list]
+
+	set batch_remaining $batch_size
+
+	while {$batch_remaining > 0} {
+		if {$path_index >= $path_cnt} { break }
+
+		set path [lindex $path_list $path_index]
+
+		set deletion_failed [catch {file delete -- $path} deletion_error]
+
+		if {$deletion_failed} {
+			lappend deletion_errors [list "$deletion_error"]
+		} else {
+			remove_empty_directories [file dirname $path]
+
+			# Don't assume the deletion worked. Remove the file from
+			# the UI, but only if it no longer exists.
+			if {![path_exists $path]} {
+				unset file_states($path)
+				display_file $path __
+			}
+		}
+
+		incr path_index 1
+		incr batch_remaining -1
+	}
+
+	# Update the progress bar to indicate that this batch has been
+	# completed. The update will be visible when this procedure returns
+	# and allows the UI thread to process messages.
+	$status_bar_operation update $path_index $path_cnt
+
+	if {$path_index < $path_cnt} {
+		# The Tcler's Wiki lists this as the best practice for keeping
+		# a UI active and processing messages during a long-running
+		# operation.
+
+		after idle [list after 0 [list \
+			delete_helper \
 			$path_list \
-			[concat $after [list ui_ready]]
+			$path_index \
+			$deletion_errors \
+			$batch_size \
+			$status_bar_operation \
+			$after
+			]]
 	} else {
-		unlock_index
+		# Finish the status bar operation.
+		$status_bar_operation stop
+
+		# Report error, if any, based on how many deletions failed.
+		set deletion_error_cnt [llength $deletion_errors]
+
+		if {($deletion_error_cnt > 0)
+		 && ($deletion_error_cnt <= [MAX_VERBOSE_FILES_IN_DELETION_ERROR])} {
+			set error_text [mc "Encountered errors deleting files:\n"]
+
+			foreach deletion_error $deletion_errors {
+				append error_text "* [lindex $deletion_error 0]\n"
+			}
+
+			error_popup $error_text
+		} elseif {$deletion_error_cnt == $path_cnt} {
+			error_popup [mc \
+				"None of the %d selected files could be deleted." \
+				$path_cnt \
+				]
+		} elseif {$deletion_error_cnt > 1} {
+			error_popup [mc \
+				"%d of the %d selected files could not be deleted." \
+				$deletion_error_cnt \
+				$path_cnt \
+				]
+		}
+
+		uplevel #0 $after
+	}
+}
+
+proc MAX_VERBOSE_FILES_IN_DELETION_ERROR {} { return 10; }
+
+# This function is from the TCL documentation:
+#
+#   https://wiki.tcl-lang.org/page/file+exists
+#
+# [file exists] returns false if the path does exist but is a symlink to a path
+# that doesn't exist. This proc returns true if the path exists, regardless of
+# whether it is a symlink and whether it is broken.
+proc path_exists {name} {
+	expr {![catch {file lstat $name finfo}]}
+}
+
+# Remove as many empty directories as we can starting at the specified path,
+# walking up the directory tree. If we encounter a directory that is not
+# empty, or if a directory deletion fails, then we stop the operation and
+# return to the caller. Even if this procedure fails to delete any
+# directories at all, it does not report failure.
+proc remove_empty_directories {directory_path} {
+	set parent_path [file dirname $directory_path]
+
+	while {$parent_path != $directory_path} {
+		set contents [glob -nocomplain -dir $directory_path *]
+
+		if {[llength $contents] > 0} { break }
+		if {[catch {file delete -- $directory_path}]} { break }
+
+		set directory_path $parent_path
+		set parent_path [file dirname $directory_path]
 	}
 }
 
-- 
gitgitgadget

Re: [PATCH v5 3/3] git-gui: revert untracked files by deleting them

[Pratyush Yadav]

Hi Jonathan,

On 24/11/19 08:37PM, Jonathan Gilbert via GitGitGadget wrote:
> From: Jonathan Gilbert <JonathanG@iQmetrix.com>
> 
> Update the revert_helper proc to check for untracked files as well as
> changes, and then handle changes to be reverted and untracked files with
> independent blocks of code. Prompt the user independently for untracked
> files, since the underlying action is fundamentally different (rm -f).
> If after deleting untracked files, the directory containing them becomes
> empty, then remove the directory as well. Migrate unlocking of the index
> out of _close_updateindex to a responsibility of the caller, to permit
> paths that don't directly unlock the index, and refactor the error
> handling added in d4e890e5 so that callers can make flow control
> decisions in the event of errors. Update Tcl/Tk dependency from 8.4 to
> 8.6 in git-gui.sh.
> 
> A new proc delete_files takes care of actually deleting the files in
> batches, using the Tcler's Wiki recommended approach for keeping the UI
> responsive.
> 
> Since the checkout_index and delete_files calls are both asynchronous
> and could potentially complete in any order, a "chord" is used to
> coordinate unlocking the index and returning the UI to a usable state
> only after both operations are complete. The `SimpleChord` class,
> based on TclOO (Tcl/Tk 8.6), is added in this commit.
> 
> Signed-off-by: Jonathan Gilbert <JonathanG@iQmetrix.com>
> ---
>  git-gui.sh    |   4 +-
>  lib/chord.tcl | 160 +++++++++++++++++++
>  lib/index.tcl | 422 ++++++++++++++++++++++++++++++++++++++++----------
>  3 files changed, 502 insertions(+), 84 deletions(-)
>  create mode 100644 lib/chord.tcl

From what I can tell, this re-roll of the patch only has minor changes 
all of which look good. Thanks.

-- 
Regards,
Pratyush Yadav

[PATCH v6 0/3] git-gui: revert untracked files by deleting them

[Jonathan Gilbert via GitGitGadget]

My development environment sometimes makes automatic changes that I don't
want to keep. In some cases, this involves new files being added that I
don't want to commit or keep (but I also don't want to outright .gitignore 
forever). I have typically had to explicitly delete those files externally
to Git Gui, which is a context switch to a manual operation, and I want to
be able to just select those newly-created untracked files in the UI and
"revert" them into oblivion.

This change updates the revert_helper proc to check for untracked files as
well as changes, and then changes to be reverted and untracked files are
handled by independent blocks of code. The user is prompted independently
for untracked files, since the underlying action is fundamentally different
(rm -f). If after deleting untracked files, the directory containing them
becomes empty, then the directory is removed as well. A new proc 
delete_files takes care of actually deleting the files, using the Tcler's
Wiki recommended approach for keeping the UI responsive.

Since the checkout_index and delete_files calls are both asynchronous and
could potentially complete in any order, a "chord" is used to coordinate
unlocking the index and returning the UI to a usable state only after both
operations are complete.

Since the checkout_index and delete_files calls are both asynchronous and
overlap, they clash in wanting to update the status bar. To address this,
the status bar is reworked so that when an operation wants to display
ongoing updates/progress, it explicitly starts an "operation", which is
tracked by its own object, and the status bar handles multiple concurrent
operations by merging their progress and concatenating their text. This is
captured in a separate commit, since it touches a variety of files.

The _close_updateindex proc contains error handling (added in d4e890e5) that
has the potential to interact badly with unlock_index running at the
completion of an async operation. I have refactored the procedure into
separate procs _close_updateindex and rescan_on_error. Call sites that
exercised the combined functionality also unlocked the index, so a combined
proc close_and_unlock_index calls _close_updateindex and then either 
rescan_on_error or unlock_index as appropriate. Call sites have been updated
appropriately.

The revert_helper proc, with its overlapping operations, is an example of a
call site that does not combine the close and unlock/rescan operations. The 
checkout_index proc has been reworked to only call _close_updateindex, and
to call a functor supplied by the caller to captures any errors that occur. 
revert_helper uses this to supply a lambda function that stashes the error
within the chord's body namespace, so that it can then separately call 
rescan_on_error when the chord is completed (or unlock_index, if no error
was captured), which might be substantially after checkout_index encounters
its error. If it turns out that a rescan is called for, it is done once the
deletion is complete.

This is the seventh revision of this change, which differs from the sixth
version in the following ways (all related to the second commit updating the
status bar):

 * The do_gitk and do_git_gui helper functions in git-gui.sh have been
   updated to use status bar operations to show their "Starting" messages.
   This eliminates the need for global variable starting_gitk_msg, and
   corrects an issue where do_git_gui would say it was starting gitk rather
   than git-gui by generalizing the localized message so the tool name can
   be injected. The time to the message being removed is reduced to 3.5
   seconds.
   
   
 * In blame.tcl, the comment on status_operation is made clearer.
   
   
 * In blame.tcl, when the status operation $cur_s string changes and there's
   already an existing status bar operation, its text is updated to match.
   
   
 * The choose_repository.tcl file has been updated to work with the new
   status bar model. There were some unnecessary complications that have
   been sorted out: The o_cons field is no longer overloaded in meaning, and
   the lifetimes of different status bar widgets is explicitly documented
   (one gets created and then destroyed during _do_clone2, and another
   separate one is greated during do_clone_checkout).
   
   
 * In choose_repository.tcl, there is a sequence of functions involved
   performing the checkout on the clone: _do_clone_checkout => 
   _readtree_wait => _postcheckout_wait => _do_clone_submodules => 
   _do_validate_submodule_cloning. The functions have been re-ordered in the
   source code to match the sequence in which they execute to improve
   clarity.
   
   
 * The two_line constructor in status_bar.tcl now also initializes 
   completed_operation_count.
   
   
 * The start method on the status_bar class now no longer requires units to
   be supplied. If they are omitted, a blank string is used. It is assumed
   that the caller will not be calling update or update_meter in this
   circumstance (though nothing should break if they do, it just won't show
   any units).
   
   

git remote add logiclrd https://github.com/logiclrd/git.git
git fetch logiclrd git-gui-revert-untracked revision6
git diff d0d6593b42..3388407871

Jonathan Gilbert (3):
  git-gui: consolidate naming conventions
  git-gui: update status bar to track operations
  git-gui: revert untracked files by deleting them

 git-gui.sh                |  31 ++-
 lib/blame.tcl             |  24 +-
 lib/checkout_op.tcl       |  15 +-
 lib/choose_repository.tcl | 120 ++++++---
 lib/chord.tcl             | 160 ++++++++++++
 lib/index.tcl             | 523 ++++++++++++++++++++++++++++----------
 lib/merge.tcl             |  14 +-
 lib/status_bar.tcl        | 229 +++++++++++++++--
 8 files changed, 889 insertions(+), 227 deletions(-)
 create mode 100644 lib/chord.tcl


base-commit: b524f6b399c77b40c8bf2b6217585fde4731472a
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-436%2Flogiclrd%2Fgit-gui-revert-untracked-v6
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-436/logiclrd/git-gui-revert-untracked-v6
Pull-Request: https://github.com/gitgitgadget/git/pull/436

Range-diff vs v5:

 1:  da1704c56e = 1:  da1704c56e git-gui: consolidate naming conventions
 2:  aa05a78d28 ! 2:  ab3d8e54c3 git-gui: update status bar to track operations
     @@ -12,6 +12,17 @@
       diff --git a/git-gui.sh b/git-gui.sh
       --- a/git-gui.sh
       +++ b/git-gui.sh
     +@@
     + ##
     + ## Tcl/Tk sanity check
     + 
     +-if {[catch {package require Tcl 8.4} err]
     +- || [catch {package require Tk  8.4} err]
     ++if {[catch {package require Tcl 8.6} err]
     ++ || [catch {package require Tk  8.6} err]
     + } {
     + 	catch {wm withdraw .}
     + 	tk_messageBox \
      @@
       	}
       }
     @@ -25,6 +36,47 @@
       	}
       }
       
     +@@
     + ##
     + ## ui commands
     + 
     +-set starting_gitk_msg [mc "Starting gitk... please wait..."]
     +-
     + proc do_gitk {revs {is_submodule false}} {
     + 	global current_diff_path file_states current_diff_side ui_index
     + 	global _gitdir _gitworktree
     +@@
     + 		set env(GIT_WORK_TREE) $_gitworktree
     + 		cd $pwd
     + 
     +-		ui_status $::starting_gitk_msg
     +-		after 10000 {
     +-			ui_ready $starting_gitk_msg
     +-		}
     ++		set status_operation [$::main_status \
     ++			start \
     ++			[mc "Starting %s... please wait..." "gitk"]]
     ++
     ++		after 3500 [list $status_operation stop]
     + 	}
     + }
     + 
     +@@
     + 		set env(GIT_WORK_TREE) $_gitworktree
     + 		cd $pwd
     + 
     +-		ui_status $::starting_gitk_msg
     +-		after 10000 {
     +-			ui_ready $starting_gitk_msg
     +-		}
     ++		set status_operation [$::main_status \
     ++			start \
     ++			[mc "Starting %s... please wait..." "git-gui"]]
     ++
     ++		after 3500 [list $status_operation stop]
     + 	}
     + }
     + 
      @@
       	do_explore
       }
     @@ -43,7 +95,7 @@
       field finder     ; # find mini-dialog frame
       field gotoline   ; # line goto mini-dialog frame
       field status     ; # status mega-widget instance
     -+field status_operation ; # status operation
     ++field status_operation ; # operation displayed by status mega-widget
       field old_height ; # last known height of $w.file_pane
       
       
     @@ -66,6 +118,8 @@
      +		set status_operation [$status start \
      +			$cur_s \
      +			[mc "lines annotated"]]
     ++	} else {
     ++		$status_operation show $cur_s
      +	}
      +
       	lappend options -- $path
     @@ -162,6 +216,255 @@
       }
       
      
     + diff --git a/lib/choose_repository.tcl b/lib/choose_repository.tcl
     + --- a/lib/choose_repository.tcl
     + +++ b/lib/choose_repository.tcl
     +@@
     + field w_next      ; # Next button
     + field w_quit      ; # Quit button
     + field o_cons      ; # Console object (if active)
     ++
     ++# Status mega-widget instance during _do_clone2 (used by _copy_files and
     ++# _link_files). Widget is destroyed before _do_clone2 calls
     ++# _do_clone_checkout
     ++field o_status
     ++
     ++# Operation displayed by status mega-widget during _do_clone_checkout =>
     ++# _readtree_wait => _postcheckout_wait => _do_clone_submodules =>
     ++# _do_validate_submodule_cloning. The status mega-widget is a difference
     ++# instance than that stored in $o_status in earlier operations.
     ++field o_status_op
     ++
     + field w_types     ; # List of type buttons in clone
     + field w_recentlist ; # Listbox containing recent repositories
     + field w_localpath  ; # Entry widget bound to local_path
     +@@
     + 
     + 	switch -exact -- $clone_type {
     + 	hardlink {
     +-		set o_cons [status_bar::two_line $w_body]
     ++		set o_status [status_bar::two_line $w_body]
     + 		pack $w_body -fill x -padx 10 -pady 10
     + 
     +-		$o_cons start \
     ++		set status_op [$o_status start \
     + 			[mc "Counting objects"] \
     +-			[mc "buckets"]
     ++			[mc "buckets"]]
     + 		update
     + 
     + 		if {[file exists [file join $objdir info alternates]]} {
     +@@
     + 			} err]} {
     + 				catch {cd $pwd}
     + 				_clone_failed $this [mc "Unable to copy objects/info/alternates: %s" $err]
     ++				$status_op stop
     + 				return
     + 			}
     + 		}
     +@@
     + 			-directory [file join $objdir] ??]
     + 		set bcnt [expr {[llength $buckets] + 2}]
     + 		set bcur 1
     +-		$o_cons update $bcur $bcnt
     ++		$status_op update $bcur $bcnt
     + 		update
     + 
     + 		file mkdir [file join .git objects pack]
     +@@
     + 			-directory [file join $objdir pack] *] {
     + 			lappend tolink [file join pack $i]
     + 		}
     +-		$o_cons update [incr bcur] $bcnt
     ++		$status_op update [incr bcur] $bcnt
     + 		update
     + 
     + 		foreach i $buckets {
     +@@
     + 				-directory [file join $objdir $i] *] {
     + 				lappend tolink [file join $i $j]
     + 			}
     +-			$o_cons update [incr bcur] $bcnt
     ++			$status_op update [incr bcur] $bcnt
     + 			update
     + 		}
     +-		$o_cons stop
     ++		$status_op stop
     + 
     + 		if {$tolink eq {}} {
     + 			info_popup [strcat \
     +@@
     + 		if {!$i} return
     + 
     + 		destroy $w_body
     ++
     ++		set o_status {}
     + 	}
     + 	full {
     + 		set o_cons [console::embed \
     +@@
     + }
     + 
     + method _copy_files {objdir tocopy} {
     +-	$o_cons start \
     ++	set status_op [$o_status start \
     + 		[mc "Copying objects"] \
     +-		[mc "KiB"]
     ++		[mc "KiB"]]
     + 	set tot 0
     + 	set cmp 0
     + 	foreach p $tocopy {
     +@@
     + 
     + 				while {![eof $f_in]} {
     + 					incr cmp [fcopy $f_in $f_cp -size 16384]
     +-					$o_cons update \
     ++					$status_op update \
     + 						[expr {$cmp / 1024}] \
     + 						[expr {$tot / 1024}]
     + 					update
     +@@
     + 				close $f_cp
     + 			} err]} {
     + 			_clone_failed $this [mc "Unable to copy object: %s" $err]
     ++			$status_op stop
     + 			return 0
     + 		}
     + 	}
     ++	$status_op stop
     + 	return 1
     + }
     + 
     + method _link_files {objdir tolink} {
     + 	set total [llength $tolink]
     +-	$o_cons start \
     ++	set status_op [$o_status start \
     + 		[mc "Linking objects"] \
     +-		[mc "objects"]
     ++		[mc "objects"]]
     + 	for {set i 0} {$i < $total} {} {
     + 		set p [lindex $tolink $i]
     + 		if {[catch {
     +@@
     + 					[file join $objdir $p]
     + 			} err]} {
     + 			_clone_failed $this [mc "Unable to hardlink object: %s" $err]
     ++			$status_op stop
     + 			return 0
     + 		}
     + 
     + 		incr i
     + 		if {$i % 5 == 0} {
     +-			$o_cons update $i $total
     ++			$status_op update $i $total
     + 			update
     + 		}
     + 	}
     ++	$status_op stop
     + 	return 1
     + }
     + 
     +@@
     + 		return
     + 	}
     + 
     +-	set o_cons [status_bar::two_line $w_body]
     ++	set status [status_bar::two_line $w_body]
     + 	pack $w_body -fill x -padx 10 -pady 10
     +-	$o_cons start \
     ++
     ++	# We start the status operation here.
     ++	#
     ++	# This function calls _readtree_wait as a callback.
     ++	#
     ++	# _readtree_wait in turn either calls _do_clone_submodules directly,
     ++	# or calls _postcheckout_wait as a callback which then calls
     ++	# _do_clone_submodules.
     ++	#
     ++	# _do_clone_submodules calls _do_validate_submodule_cloning.
     ++	#
     ++	# _do_validate_submodule_cloning stops the status operation.
     ++	#
     ++	# There are no other calls into this chain from other code.
     ++
     ++	set o_status_op [$status start \
     + 		[mc "Creating working directory"] \
     +-		[mc "files"]
     ++		[mc "files"]]
     + 
     + 	set readtree_err {}
     + 	set fd [git_read --stderr read-tree \
     +@@
     + 	fileevent $fd readable [cb _readtree_wait $fd]
     + }
     + 
     +-method _do_validate_submodule_cloning {ok} {
     +-	if {$ok} {
     +-		$o_cons done $ok
     +-		set done 1
     +-	} else {
     +-		_clone_failed $this [mc "Cannot clone submodules."]
     +-	}
     +-}
     +-
     +-method _do_clone_submodules {} {
     +-	if {$recursive eq {true}} {
     +-		destroy $w_body
     +-		set o_cons [console::embed \
     +-			$w_body \
     +-			[mc "Cloning submodules"]]
     +-		pack $w_body -fill both -expand 1 -padx 10
     +-		$o_cons exec \
     +-			[list git submodule update --init --recursive] \
     +-			[cb _do_validate_submodule_cloning]
     +-	} else {
     +-		set done 1
     +-	}
     +-}
     +-
     + method _readtree_wait {fd} {
     + 	set buf [read $fd]
     +-	$o_cons update_meter $buf
     ++	$o_status_op update_meter $buf
     + 	append readtree_err $buf
     + 
     + 	fconfigure $fd -blocking 1
     +@@
     + 	fconfigure $fd_ph -blocking 0
     + }
     + 
     ++method _do_clone_submodules {} {
     ++	if {$recursive eq {true}} {
     ++		$o_status_op stop
     ++		set o_status_op {}
     ++
     ++		destroy $w_body
     ++
     ++		set o_cons [console::embed \
     ++			$w_body \
     ++			[mc "Cloning submodules"]]
     ++		pack $w_body -fill both -expand 1 -padx 10
     ++		$o_cons exec \
     ++			[list git submodule update --init --recursive] \
     ++			[cb _do_validate_submodule_cloning]
     ++	} else {
     ++		set done 1
     ++	}
     ++}
     ++
     ++method _do_validate_submodule_cloning {ok} {
     ++	if {$ok} {
     ++		$o_cons done $ok
     ++		set done 1
     ++	} else {
     ++		_clone_failed $this [mc "Cannot clone submodules."]
     ++	}
     ++}
     ++
     + ######################################################################
     + ##
     + ## Open Existing Repository
     +
       diff --git a/lib/index.tcl b/lib/index.tcl
       --- a/lib/index.tcl
       +++ b/lib/index.tcl
     @@ -413,6 +716,7 @@
      +
      +	set baseline_text ""
      +	set operations [list]
     ++	set completed_operation_count 0
      +
       	${NS}::frame $w
       	${NS}::label $w_l \
     @@ -442,7 +746,7 @@
      +	$this refresh
      +}
      +
     -+method start {msg uds} {
     ++method start {msg {uds {}}} {
      +	set baseline_text ""
      +
      +	if {!$allow_multiple && [llength $operations]} {
 3:  d0d6593b42 ! 3:  3388407871 git-gui: revert untracked files by deleting them
     @@ -26,21 +26,6 @@
      
          Signed-off-by: Jonathan Gilbert <JonathanG@iQmetrix.com>
      
     - diff --git a/git-gui.sh b/git-gui.sh
     - --- a/git-gui.sh
     - +++ b/git-gui.sh
     -@@
     - ##
     - ## Tcl/Tk sanity check
     - 
     --if {[catch {package require Tcl 8.4} err]
     -- || [catch {package require Tk  8.4} err]
     -+if {[catch {package require Tcl 8.6} err]
     -+ || [catch {package require Tk  8.6} err]
     - } {
     - 	catch {wm withdraw .}
     - 	tk_messageBox \
     -
       diff --git a/lib/chord.tcl b/lib/chord.tcl
       new file mode 100644
       --- /dev/null

-- 
gitgitgadget

[PATCH v6 1/3] git-gui: consolidate naming conventions

[Jonathan Gilbert via GitGitGadget]

From: Jonathan Gilbert <JonathanG@iQmetrix.com>

A few variables in this file use camelCase, while the overall standard
is snake_case. A consistent naming scheme will improve readability of
future changes. To avoid mixing naming changes with semantic changes,
this commit contains only naming changes.

Signed-off-by: Jonathan Gilbert <JonathanG@iQmetrix.com>
---
 lib/index.tcl | 92 +++++++++++++++++++++++++--------------------------
 1 file changed, 46 insertions(+), 46 deletions(-)

diff --git a/lib/index.tcl b/lib/index.tcl
index e07b7a3762..28d4d2a54e 100644
--- a/lib/index.tcl
+++ b/lib/index.tcl
@@ -56,15 +56,15 @@ proc _close_updateindex {fd after} {
 	uplevel #0 $after
 }
 
-proc update_indexinfo {msg pathList after} {
+proc update_indexinfo {msg path_list after} {
 	global update_index_cp
 
 	if {![lock_index update]} return
 
 	set update_index_cp 0
-	set pathList [lsort $pathList]
-	set totalCnt [llength $pathList]
-	set batch [expr {int($totalCnt * .01) + 1}]
+	set path_list [lsort $path_list]
+	set total_cnt [llength $path_list]
+	set batch [expr {int($total_cnt * .01) + 1}]
 	if {$batch > 25} {set batch 25}
 
 	$::main_status start $msg [mc "files"]
@@ -78,26 +78,26 @@ proc update_indexinfo {msg pathList after} {
 	fileevent $fd writable [list \
 		write_update_indexinfo \
 		$fd \
-		$pathList \
-		$totalCnt \
+		$path_list \
+		$total_cnt \
 		$batch \
 		$after \
 		]
 }
 
-proc write_update_indexinfo {fd pathList totalCnt batch after} {
+proc write_update_indexinfo {fd path_list total_cnt batch after} {
 	global update_index_cp
 	global file_states current_diff_path
 
-	if {$update_index_cp >= $totalCnt} {
+	if {$update_index_cp >= $total_cnt} {
 		_close_updateindex $fd $after
 		return
 	}
 
 	for {set i $batch} \
-		{$update_index_cp < $totalCnt && $i > 0} \
+		{$update_index_cp < $total_cnt && $i > 0} \
 		{incr i -1} {
-		set path [lindex $pathList $update_index_cp]
+		set path [lindex $path_list $update_index_cp]
 		incr update_index_cp
 
 		set s $file_states($path)
@@ -119,18 +119,18 @@ proc write_update_indexinfo {fd pathList totalCnt batch after} {
 		display_file $path $new
 	}
 
-	$::main_status update $update_index_cp $totalCnt
+	$::main_status update $update_index_cp $total_cnt
 }
 
-proc update_index {msg pathList after} {
+proc update_index {msg path_list after} {
 	global update_index_cp
 
 	if {![lock_index update]} return
 
 	set update_index_cp 0
-	set pathList [lsort $pathList]
-	set totalCnt [llength $pathList]
-	set batch [expr {int($totalCnt * .01) + 1}]
+	set path_list [lsort $path_list]
+	set total_cnt [llength $path_list]
+	set batch [expr {int($total_cnt * .01) + 1}]
 	if {$batch > 25} {set batch 25}
 
 	$::main_status start $msg [mc "files"]
@@ -144,26 +144,26 @@ proc update_index {msg pathList after} {
 	fileevent $fd writable [list \
 		write_update_index \
 		$fd \
-		$pathList \
-		$totalCnt \
+		$path_list \
+		$total_cnt \
 		$batch \
 		$after \
 		]
 }
 
-proc write_update_index {fd pathList totalCnt batch after} {
+proc write_update_index {fd path_list total_cnt batch after} {
 	global update_index_cp
 	global file_states current_diff_path
 
-	if {$update_index_cp >= $totalCnt} {
+	if {$update_index_cp >= $total_cnt} {
 		_close_updateindex $fd $after
 		return
 	}
 
 	for {set i $batch} \
-		{$update_index_cp < $totalCnt && $i > 0} \
+		{$update_index_cp < $total_cnt && $i > 0} \
 		{incr i -1} {
-		set path [lindex $pathList $update_index_cp]
+		set path [lindex $path_list $update_index_cp]
 		incr update_index_cp
 
 		switch -glob -- [lindex $file_states($path) 0] {
@@ -190,18 +190,18 @@ proc write_update_index {fd pathList totalCnt batch after} {
 		display_file $path $new
 	}
 
-	$::main_status update $update_index_cp $totalCnt
+	$::main_status update $update_index_cp $total_cnt
 }
 
-proc checkout_index {msg pathList after} {
+proc checkout_index {msg path_list after} {
 	global update_index_cp
 
 	if {![lock_index update]} return
 
 	set update_index_cp 0
-	set pathList [lsort $pathList]
-	set totalCnt [llength $pathList]
-	set batch [expr {int($totalCnt * .01) + 1}]
+	set path_list [lsort $path_list]
+	set total_cnt [llength $path_list]
+	set batch [expr {int($total_cnt * .01) + 1}]
 	if {$batch > 25} {set batch 25}
 
 	$::main_status start $msg [mc "files"]
@@ -221,26 +221,26 @@ proc checkout_index {msg pathList after} {
 	fileevent $fd writable [list \
 		write_checkout_index \
 		$fd \
-		$pathList \
-		$totalCnt \
+		$path_list \
+		$total_cnt \
 		$batch \
 		$after \
 		]
 }
 
-proc write_checkout_index {fd pathList totalCnt batch after} {
+proc write_checkout_index {fd path_list total_cnt batch after} {
 	global update_index_cp
 	global file_states current_diff_path
 
-	if {$update_index_cp >= $totalCnt} {
+	if {$update_index_cp >= $total_cnt} {
 		_close_updateindex $fd $after
 		return
 	}
 
 	for {set i $batch} \
-		{$update_index_cp < $totalCnt && $i > 0} \
+		{$update_index_cp < $total_cnt && $i > 0} \
 		{incr i -1} {
-		set path [lindex $pathList $update_index_cp]
+		set path [lindex $path_list $update_index_cp]
 		incr update_index_cp
 		switch -glob -- [lindex $file_states($path) 0] {
 		U? {continue}
@@ -253,7 +253,7 @@ proc write_checkout_index {fd pathList totalCnt batch after} {
 		}
 	}
 
-	$::main_status update $update_index_cp $totalCnt
+	$::main_status update $update_index_cp $total_cnt
 }
 
 proc unstage_helper {txt paths} {
@@ -261,7 +261,7 @@ proc unstage_helper {txt paths} {
 
 	if {![lock_index begin-update]} return
 
-	set pathList [list]
+	set path_list [list]
 	set after {}
 	foreach path $paths {
 		switch -glob -- [lindex $file_states($path) 0] {
@@ -269,19 +269,19 @@ proc unstage_helper {txt paths} {
 		M? -
 		T? -
 		D? {
-			lappend pathList $path
+			lappend path_list $path
 			if {$path eq $current_diff_path} {
 				set after {reshow_diff;}
 			}
 		}
 		}
 	}
-	if {$pathList eq {}} {
+	if {$path_list eq {}} {
 		unlock_index
 	} else {
 		update_indexinfo \
 			$txt \
-			$pathList \
+			$path_list \
 			[concat $after [list ui_ready]]
 	}
 }
@@ -305,7 +305,7 @@ proc add_helper {txt paths} {
 
 	if {![lock_index begin-update]} return
 
-	set pathList [list]
+	set path_list [list]
 	set after {}
 	foreach path $paths {
 		switch -glob -- [lindex $file_states($path) 0] {
@@ -321,19 +321,19 @@ proc add_helper {txt paths} {
 		?M -
 		?D -
 		?T {
-			lappend pathList $path
+			lappend path_list $path
 			if {$path eq $current_diff_path} {
 				set after {reshow_diff;}
 			}
 		}
 		}
 	}
-	if {$pathList eq {}} {
+	if {$path_list eq {}} {
 		unlock_index
 	} else {
 		update_index \
 			$txt \
-			$pathList \
+			$path_list \
 			[concat $after {ui_status [mc "Ready to commit."]}]
 	}
 }
@@ -393,7 +393,7 @@ proc revert_helper {txt paths} {
 
 	if {![lock_index begin-update]} return
 
-	set pathList [list]
+	set path_list [list]
 	set after {}
 	foreach path $paths {
 		switch -glob -- [lindex $file_states($path) 0] {
@@ -401,7 +401,7 @@ proc revert_helper {txt paths} {
 		?M -
 		?T -
 		?D {
-			lappend pathList $path
+			lappend path_list $path
 			if {$path eq $current_diff_path} {
 				set after {reshow_diff;}
 			}
@@ -420,12 +420,12 @@ proc revert_helper {txt paths} {
 	# as they have quite complex plural-form rules. Unfortunately,
 	# msgcat doesn't seem to support that kind of string translation.
 	#
-	set n [llength $pathList]
+	set n [llength $path_list]
 	if {$n == 0} {
 		unlock_index
 		return
 	} elseif {$n == 1} {
-		set query [mc "Revert changes in file %s?" [short_path [lindex $pathList]]]
+		set query [mc "Revert changes in file %s?" [short_path [lindex $path_list]]]
 	} else {
 		set query [mc "Revert changes in these %i files?" $n]
 	}
@@ -444,7 +444,7 @@ proc revert_helper {txt paths} {
 	if {$reply == 1} {
 		checkout_index \
 			$txt \
-			$pathList \
+			$path_list \
 			[concat $after [list ui_ready]]
 	} else {
 		unlock_index
-- 
gitgitgadget

[PATCH v6 2/3] git-gui: update status bar to track operations

[Jonathan Gilbert via GitGitGadget]

From: Jonathan Gilbert <JonathanG@iQmetrix.com>

Update the status bar to track updates as individual "operations" that
can overlap. Update all call sites to interact with the new status bar
mechanism. Update initialization to explicitly clear status text,
since otherwise it may persist across future operations.

Signed-off-by: Jonathan Gilbert <JonathanG@iQmetrix.com>
---
 git-gui.sh                |  31 +++---
 lib/blame.tcl             |  24 ++--
 lib/checkout_op.tcl       |  15 +--
 lib/choose_repository.tcl | 120 +++++++++++++-------
 lib/index.tcl             |  31 ++++--
 lib/merge.tcl             |  14 ++-
 lib/status_bar.tcl        | 229 +++++++++++++++++++++++++++++++++-----
 7 files changed, 354 insertions(+), 110 deletions(-)

diff --git a/git-gui.sh b/git-gui.sh
index 0d21f5688b..6dcf6551b6 100755
--- a/git-gui.sh
+++ b/git-gui.sh
@@ -30,8 +30,8 @@ along with this program; if not, see <http://www.gnu.org/licenses/>.}]
 ##
 ## Tcl/Tk sanity check
 
-if {[catch {package require Tcl 8.4} err]
- || [catch {package require Tk  8.4} err]
+if {[catch {package require Tcl 8.6} err]
+ || [catch {package require Tk  8.6} err]
 } {
 	catch {wm withdraw .}
 	tk_messageBox \
@@ -1797,10 +1797,10 @@ proc ui_status {msg} {
 	}
 }
 
-proc ui_ready {{test {}}} {
+proc ui_ready {} {
 	global main_status
 	if {[info exists main_status]} {
-		$main_status show [mc "Ready."] $test
+		$main_status show [mc "Ready."]
 	}
 }
 
@@ -2150,8 +2150,6 @@ proc incr_font_size {font {amt 1}} {
 ##
 ## ui commands
 
-set starting_gitk_msg [mc "Starting gitk... please wait..."]
-
 proc do_gitk {revs {is_submodule false}} {
 	global current_diff_path file_states current_diff_side ui_index
 	global _gitdir _gitworktree
@@ -2206,10 +2204,11 @@ proc do_gitk {revs {is_submodule false}} {
 		set env(GIT_WORK_TREE) $_gitworktree
 		cd $pwd
 
-		ui_status $::starting_gitk_msg
-		after 10000 {
-			ui_ready $starting_gitk_msg
-		}
+		set status_operation [$::main_status \
+			start \
+			[mc "Starting %s... please wait..." "gitk"]]
+
+		after 3500 [list $status_operation stop]
 	}
 }
 
@@ -2240,10 +2239,11 @@ proc do_git_gui {} {
 		set env(GIT_WORK_TREE) $_gitworktree
 		cd $pwd
 
-		ui_status $::starting_gitk_msg
-		after 10000 {
-			ui_ready $starting_gitk_msg
-		}
+		set status_operation [$::main_status \
+			start \
+			[mc "Starting %s... please wait..." "git-gui"]]
+
+		after 3500 [list $status_operation stop]
 	}
 }
 
@@ -4159,6 +4159,9 @@ if {$picked && [is_config_true gui.autoexplore]} {
 	do_explore
 }
 
+# Clear "Initializing..." status
+after 500 {$main_status show ""}
+
 # Local variables:
 # mode: tcl
 # indent-tabs-mode: t
diff --git a/lib/blame.tcl b/lib/blame.tcl
index a1aeb8b96e..bfcacd5584 100644
--- a/lib/blame.tcl
+++ b/lib/blame.tcl
@@ -24,6 +24,7 @@ field w_cviewer  ; # pane showing commit message
 field finder     ; # find mini-dialog frame
 field gotoline   ; # line goto mini-dialog frame
 field status     ; # status mega-widget instance
+field status_operation ; # operation displayed by status mega-widget
 field old_height ; # last known height of $w.file_pane
 
 
@@ -274,6 +275,7 @@ constructor new {i_commit i_path i_jump} {
 	pack $w_cviewer -expand 1 -fill both
 
 	set status [::status_bar::new $w.status]
+	set status_operation {}
 
 	menu $w.ctxm -tearoff 0
 	$w.ctxm add command \
@@ -602,16 +604,23 @@ method _exec_blame {cur_w cur_d options cur_s} {
 	} else {
 		lappend options $commit
 	}
+
+	# We may recurse in from another call to _exec_blame and already have
+	# a status operation.
+	if {$status_operation == {}} {
+		set status_operation [$status start \
+			$cur_s \
+			[mc "lines annotated"]]
+	} else {
+		$status_operation show $cur_s
+	}
+
 	lappend options -- $path
 	set fd [eval git_read --nice blame $options]
 	fconfigure $fd -blocking 0 -translation lf -encoding utf-8
 	fileevent $fd readable [cb _read_blame $fd $cur_w $cur_d]
 	set current_fd $fd
 	set blame_lines 0
-
-	$status start \
-		$cur_s \
-		[mc "lines annotated"]
 }
 
 method _read_blame {fd cur_w cur_d} {
@@ -806,10 +815,11 @@ method _read_blame {fd cur_w cur_d} {
 				[mc "Loading original location annotations..."]
 		} else {
 			set current_fd {}
-			$status stop [mc "Annotation complete."]
+			$status_operation stop [mc "Annotation complete."]
+			set status_operation {}
 		}
 	} else {
-		$status update $blame_lines $total_lines
+		$status_operation update $blame_lines $total_lines
 	}
 } ifdeleted { catch {close $fd} }
 
@@ -1124,7 +1134,7 @@ method _blameparent {} {
 			set diffcmd [list diff-tree --unified=0 $cparent $cmit -- $new_path]
 		}
 		if {[catch {set fd [eval git_read $diffcmd]} err]} {
-			$status stop [mc "Unable to display parent"]
+			$status_operation stop [mc "Unable to display parent"]
 			error_popup [strcat [mc "Error loading diff:"] "\n\n$err"]
 			return
 		}
diff --git a/lib/checkout_op.tcl b/lib/checkout_op.tcl
index a5228297db..21ea768d80 100644
--- a/lib/checkout_op.tcl
+++ b/lib/checkout_op.tcl
@@ -341,9 +341,9 @@ method _readtree {} {
 	global HEAD
 
 	set readtree_d {}
-	$::main_status start \
+	set status_bar_operation [$::main_status start \
 		[mc "Updating working directory to '%s'..." [_name $this]] \
-		[mc "files checked out"]
+		[mc "files checked out"]]
 
 	set fd [git_read --stderr read-tree \
 		-m \
@@ -354,26 +354,27 @@ method _readtree {} {
 		$new_hash \
 		]
 	fconfigure $fd -blocking 0 -translation binary
-	fileevent $fd readable [cb _readtree_wait $fd]
+	fileevent $fd readable [cb _readtree_wait $fd $status_bar_operation]
 }
 
-method _readtree_wait {fd} {
+method _readtree_wait {fd status_bar_operation} {
 	global current_branch
 
 	set buf [read $fd]
-	$::main_status update_meter $buf
+	$status_bar_operation update_meter $buf
 	append readtree_d $buf
 
 	fconfigure $fd -blocking 1
 	if {![eof $fd]} {
 		fconfigure $fd -blocking 0
+		$status_bar_operation stop
 		return
 	}
 
 	if {[catch {close $fd}]} {
 		set err $readtree_d
 		regsub {^fatal: } $err {} err
-		$::main_status stop [mc "Aborted checkout of '%s' (file level merging is required)." [_name $this]]
+		$status_bar_operation stop [mc "Aborted checkout of '%s' (file level merging is required)." [_name $this]]
 		warn_popup [strcat [mc "File level merge required."] "
 
 $err
@@ -384,7 +385,7 @@ $err
 		return
 	}
 
-	$::main_status stop
+	$status_bar_operation stop
 	_after_readtree $this
 }
 
diff --git a/lib/choose_repository.tcl b/lib/choose_repository.tcl
index 80f5a59bbb..1ea0c9f7b8 100644
--- a/lib/choose_repository.tcl
+++ b/lib/choose_repository.tcl
@@ -9,6 +9,18 @@ field w_body      ; # Widget holding the center content
 field w_next      ; # Next button
 field w_quit      ; # Quit button
 field o_cons      ; # Console object (if active)
+
+# Status mega-widget instance during _do_clone2 (used by _copy_files and
+# _link_files). Widget is destroyed before _do_clone2 calls
+# _do_clone_checkout
+field o_status
+
+# Operation displayed by status mega-widget during _do_clone_checkout =>
+# _readtree_wait => _postcheckout_wait => _do_clone_submodules =>
+# _do_validate_submodule_cloning. The status mega-widget is a difference
+# instance than that stored in $o_status in earlier operations.
+field o_status_op
+
 field w_types     ; # List of type buttons in clone
 field w_recentlist ; # Listbox containing recent repositories
 field w_localpath  ; # Entry widget bound to local_path
@@ -659,12 +671,12 @@ method _do_clone2 {} {
 
 	switch -exact -- $clone_type {
 	hardlink {
-		set o_cons [status_bar::two_line $w_body]
+		set o_status [status_bar::two_line $w_body]
 		pack $w_body -fill x -padx 10 -pady 10
 
-		$o_cons start \
+		set status_op [$o_status start \
 			[mc "Counting objects"] \
-			[mc "buckets"]
+			[mc "buckets"]]
 		update
 
 		if {[file exists [file join $objdir info alternates]]} {
@@ -689,6 +701,7 @@ method _do_clone2 {} {
 			} err]} {
 				catch {cd $pwd}
 				_clone_failed $this [mc "Unable to copy objects/info/alternates: %s" $err]
+				$status_op stop
 				return
 			}
 		}
@@ -700,7 +713,7 @@ method _do_clone2 {} {
 			-directory [file join $objdir] ??]
 		set bcnt [expr {[llength $buckets] + 2}]
 		set bcur 1
-		$o_cons update $bcur $bcnt
+		$status_op update $bcur $bcnt
 		update
 
 		file mkdir [file join .git objects pack]
@@ -708,7 +721,7 @@ method _do_clone2 {} {
 			-directory [file join $objdir pack] *] {
 			lappend tolink [file join pack $i]
 		}
-		$o_cons update [incr bcur] $bcnt
+		$status_op update [incr bcur] $bcnt
 		update
 
 		foreach i $buckets {
@@ -717,10 +730,10 @@ method _do_clone2 {} {
 				-directory [file join $objdir $i] *] {
 				lappend tolink [file join $i $j]
 			}
-			$o_cons update [incr bcur] $bcnt
+			$status_op update [incr bcur] $bcnt
 			update
 		}
-		$o_cons stop
+		$status_op stop
 
 		if {$tolink eq {}} {
 			info_popup [strcat \
@@ -747,6 +760,8 @@ method _do_clone2 {} {
 		if {!$i} return
 
 		destroy $w_body
+
+		set o_status {}
 	}
 	full {
 		set o_cons [console::embed \
@@ -781,9 +796,9 @@ method _do_clone2 {} {
 }
 
 method _copy_files {objdir tocopy} {
-	$o_cons start \
+	set status_op [$o_status start \
 		[mc "Copying objects"] \
-		[mc "KiB"]
+		[mc "KiB"]]
 	set tot 0
 	set cmp 0
 	foreach p $tocopy {
@@ -798,7 +813,7 @@ method _copy_files {objdir tocopy} {
 
 				while {![eof $f_in]} {
 					incr cmp [fcopy $f_in $f_cp -size 16384]
-					$o_cons update \
+					$status_op update \
 						[expr {$cmp / 1024}] \
 						[expr {$tot / 1024}]
 					update
@@ -808,17 +823,19 @@ method _copy_files {objdir tocopy} {
 				close $f_cp
 			} err]} {
 			_clone_failed $this [mc "Unable to copy object: %s" $err]
+			$status_op stop
 			return 0
 		}
 	}
+	$status_op stop
 	return 1
 }
 
 method _link_files {objdir tolink} {
 	set total [llength $tolink]
-	$o_cons start \
+	set status_op [$o_status start \
 		[mc "Linking objects"] \
-		[mc "objects"]
+		[mc "objects"]]
 	for {set i 0} {$i < $total} {} {
 		set p [lindex $tolink $i]
 		if {[catch {
@@ -827,15 +844,17 @@ method _link_files {objdir tolink} {
 					[file join $objdir $p]
 			} err]} {
 			_clone_failed $this [mc "Unable to hardlink object: %s" $err]
+			$status_op stop
 			return 0
 		}
 
 		incr i
 		if {$i % 5 == 0} {
-			$o_cons update $i $total
+			$status_op update $i $total
 			update
 		}
 	}
+	$status_op stop
 	return 1
 }
 
@@ -958,11 +977,26 @@ method _do_clone_checkout {HEAD} {
 		return
 	}
 
-	set o_cons [status_bar::two_line $w_body]
+	set status [status_bar::two_line $w_body]
 	pack $w_body -fill x -padx 10 -pady 10
-	$o_cons start \
+
+	# We start the status operation here.
+	#
+	# This function calls _readtree_wait as a callback.
+	#
+	# _readtree_wait in turn either calls _do_clone_submodules directly,
+	# or calls _postcheckout_wait as a callback which then calls
+	# _do_clone_submodules.
+	#
+	# _do_clone_submodules calls _do_validate_submodule_cloning.
+	#
+	# _do_validate_submodule_cloning stops the status operation.
+	#
+	# There are no other calls into this chain from other code.
+
+	set o_status_op [$status start \
 		[mc "Creating working directory"] \
-		[mc "files"]
+		[mc "files"]]
 
 	set readtree_err {}
 	set fd [git_read --stderr read-tree \
@@ -976,33 +1010,9 @@ method _do_clone_checkout {HEAD} {
 	fileevent $fd readable [cb _readtree_wait $fd]
 }
 
-method _do_validate_submodule_cloning {ok} {
-	if {$ok} {
-		$o_cons done $ok
-		set done 1
-	} else {
-		_clone_failed $this [mc "Cannot clone submodules."]
-	}
-}
-
-method _do_clone_submodules {} {
-	if {$recursive eq {true}} {
-		destroy $w_body
-		set o_cons [console::embed \
-			$w_body \
-			[mc "Cloning submodules"]]
-		pack $w_body -fill both -expand 1 -padx 10
-		$o_cons exec \
-			[list git submodule update --init --recursive] \
-			[cb _do_validate_submodule_cloning]
-	} else {
-		set done 1
-	}
-}
-
 method _readtree_wait {fd} {
 	set buf [read $fd]
-	$o_cons update_meter $buf
+	$o_status_op update_meter $buf
 	append readtree_err $buf
 
 	fconfigure $fd -blocking 1
@@ -1050,6 +1060,34 @@ method _postcheckout_wait {fd_ph} {
 	fconfigure $fd_ph -blocking 0
 }
 
+method _do_clone_submodules {} {
+	if {$recursive eq {true}} {
+		$o_status_op stop
+		set o_status_op {}
+
+		destroy $w_body
+
+		set o_cons [console::embed \
+			$w_body \
+			[mc "Cloning submodules"]]
+		pack $w_body -fill both -expand 1 -padx 10
+		$o_cons exec \
+			[list git submodule update --init --recursive] \
+			[cb _do_validate_submodule_cloning]
+	} else {
+		set done 1
+	}
+}
+
+method _do_validate_submodule_cloning {ok} {
+	if {$ok} {
+		$o_cons done $ok
+		set done 1
+	} else {
+		_clone_failed $this [mc "Cannot clone submodules."]
+	}
+}
+
 ######################################################################
 ##
 ## Open Existing Repository
diff --git a/lib/index.tcl b/lib/index.tcl
index 28d4d2a54e..62f4773ef4 100644
--- a/lib/index.tcl
+++ b/lib/index.tcl
@@ -45,13 +45,13 @@ proc _close_updateindex {fd after} {
 		wm deiconify $w
 		tkwait window $w
 
-		$::main_status stop
+		$::main_status stop_all
 		unlock_index
 		rescan $after 0
 		return
 	}
 
-	$::main_status stop
+	$::main_status stop_all
 	unlock_index
 	uplevel #0 $after
 }
@@ -67,7 +67,7 @@ proc update_indexinfo {msg path_list after} {
 	set batch [expr {int($total_cnt * .01) + 1}]
 	if {$batch > 25} {set batch 25}
 
-	$::main_status start $msg [mc "files"]
+	set status_bar_operation [$::main_status start $msg [mc "files"]]
 	set fd [git_write update-index -z --index-info]
 	fconfigure $fd \
 		-blocking 0 \
@@ -81,15 +81,18 @@ proc update_indexinfo {msg path_list after} {
 		$path_list \
 		$total_cnt \
 		$batch \
+		$status_bar_operation \
 		$after \
 		]
 }
 
-proc write_update_indexinfo {fd path_list total_cnt batch after} {
+proc write_update_indexinfo {fd path_list total_cnt batch status_bar_operation \
+	after} {
 	global update_index_cp
 	global file_states current_diff_path
 
 	if {$update_index_cp >= $total_cnt} {
+		$status_bar_operation stop
 		_close_updateindex $fd $after
 		return
 	}
@@ -119,7 +122,7 @@ proc write_update_indexinfo {fd path_list total_cnt batch after} {
 		display_file $path $new
 	}
 
-	$::main_status update $update_index_cp $total_cnt
+	$status_bar_operation update $update_index_cp $total_cnt
 }
 
 proc update_index {msg path_list after} {
@@ -133,7 +136,7 @@ proc update_index {msg path_list after} {
 	set batch [expr {int($total_cnt * .01) + 1}]
 	if {$batch > 25} {set batch 25}
 
-	$::main_status start $msg [mc "files"]
+	set status_bar_operation [$::main_status start $msg [mc "files"]]
 	set fd [git_write update-index --add --remove -z --stdin]
 	fconfigure $fd \
 		-blocking 0 \
@@ -147,15 +150,18 @@ proc update_index {msg path_list after} {
 		$path_list \
 		$total_cnt \
 		$batch \
+		$status_bar_operation \
 		$after \
 		]
 }
 
-proc write_update_index {fd path_list total_cnt batch after} {
+proc write_update_index {fd path_list total_cnt batch status_bar_operation \
+	after} {
 	global update_index_cp
 	global file_states current_diff_path
 
 	if {$update_index_cp >= $total_cnt} {
+		$status_bar_operation stop
 		_close_updateindex $fd $after
 		return
 	}
@@ -190,7 +196,7 @@ proc write_update_index {fd path_list total_cnt batch after} {
 		display_file $path $new
 	}
 
-	$::main_status update $update_index_cp $total_cnt
+	$status_bar_operation update $update_index_cp $total_cnt
 }
 
 proc checkout_index {msg path_list after} {
@@ -204,7 +210,7 @@ proc checkout_index {msg path_list after} {
 	set batch [expr {int($total_cnt * .01) + 1}]
 	if {$batch > 25} {set batch 25}
 
-	$::main_status start $msg [mc "files"]
+	set status_bar_operation [$::main_status start $msg [mc "files"]]
 	set fd [git_write checkout-index \
 		--index \
 		--quiet \
@@ -224,15 +230,18 @@ proc checkout_index {msg path_list after} {
 		$path_list \
 		$total_cnt \
 		$batch \
+		$status_bar_operation \
 		$after \
 		]
 }
 
-proc write_checkout_index {fd path_list total_cnt batch after} {
+proc write_checkout_index {fd path_list total_cnt batch status_bar_operation \
+	after} {
 	global update_index_cp
 	global file_states current_diff_path
 
 	if {$update_index_cp >= $total_cnt} {
+		$status_bar_operation stop
 		_close_updateindex $fd $after
 		return
 	}
@@ -253,7 +262,7 @@ proc write_checkout_index {fd path_list total_cnt batch after} {
 		}
 	}
 
-	$::main_status update $update_index_cp $total_cnt
+	$status_bar_operation update $update_index_cp $total_cnt
 }
 
 proc unstage_helper {txt paths} {
diff --git a/lib/merge.tcl b/lib/merge.tcl
index 9f253db5b3..8df8ffae55 100644
--- a/lib/merge.tcl
+++ b/lib/merge.tcl
@@ -241,23 +241,27 @@ Continue with resetting the current changes?"]
 	if {[ask_popup $op_question] eq {yes}} {
 		set fd [git_read --stderr read-tree --reset -u -v HEAD]
 		fconfigure $fd -blocking 0 -translation binary
-		fileevent $fd readable [namespace code [list _reset_wait $fd]]
-		$::main_status start [mc "Aborting"] [mc "files reset"]
+		set status_bar_operation [$::main_status \
+			start \
+			[mc "Aborting"] \
+			[mc "files reset"]
+		fileevent $fd readable [namespace code [list \
+			_reset_wait $fd $status_bar_operation]]
 	} else {
 		unlock_index
 	}
 }
 
-proc _reset_wait {fd} {
+proc _reset_wait {fd status_bar_operation} {
 	global ui_comm
 
-	$::main_status update_meter [read $fd]
+	$status_bar_operation update_meter [read $fd]
 
 	fconfigure $fd -blocking 1
 	if {[eof $fd]} {
 		set fail [catch {close $fd} err]
-		$::main_status stop
 		unlock_index
+		$status_bar_operation stop
 
 		$ui_comm delete 0.0 end
 		$ui_comm edit modified false
diff --git a/lib/status_bar.tcl b/lib/status_bar.tcl
index 02111a1742..32193d23ec 100644
--- a/lib/status_bar.tcl
+++ b/lib/status_bar.tcl
@@ -1,16 +1,42 @@
 # git-gui status bar mega-widget
 # Copyright (C) 2007 Shawn Pearce
 
+# The status_bar class manages the entire status bar. It is possible for
+# multiple overlapping asynchronous operations to want to display status
+# simultaneously. Each one receives a status_bar_operation when it calls the
+# start method, and the status bar combines all active operations into the
+# line of text it displays. Most of the time, there will be at most one
+# ongoing operation.
+#
+# Note that the entire status bar can be either in single-line or two-line
+# mode, depending on the constructor. Multiple active operations are only
+# supported for single-line status bars.
+
 class status_bar {
 
+field allow_multiple ; # configured at construction
+
 field w         ; # our own window path
 field w_l       ; # text widget we draw messages into
 field w_c       ; # canvas we draw a progress bar into
 field c_pack    ; # script to pack the canvas with
-field status  {}; # single line of text we show
-field prefix  {}; # text we format into status
-field units   {}; # unit of progress
-field meter   {}; # current core git progress meter (if active)
+
+field baseline_text   ; # text to show if there are no operations
+field status_bar_text ; # combined text for all operations
+
+field operations ; # list of current ongoing operations
+
+# The status bar can display a progress bar, updated when consumers call the
+# update method on their status_bar_operation. When there are multiple
+# operations, the status bar shows the combined status of all operations.
+#
+# When an overlapping operation completes, the progress bar is going to
+# abruptly have one fewer operation in the calculation, causing a discontinuity.
+# Therefore, whenever an operation completes, if it is not the last operation,
+# this counter is increased, and the progress bar is calculated as though there
+# were still another operation at 100%. When the last operation completes, this
+# is reset to 0.
+field completed_operation_count
 
 constructor new {path} {
 	global use_ttk NS
@@ -18,12 +44,19 @@ constructor new {path} {
 	set w_l $w.l
 	set w_c $w.c
 
+	# Standard single-line status bar: Permit overlapping operations
+	set allow_multiple 1
+
+	set baseline_text ""
+	set operations [list]
+	set completed_operation_count 0
+
 	${NS}::frame $w
 	if {!$use_ttk} {
 		$w configure -borderwidth 1 -relief sunken
 	}
 	${NS}::label $w_l \
-		-textvariable @status \
+		-textvariable @status_bar_text \
 		-anchor w \
 		-justify left
 	pack $w_l -side left
@@ -44,9 +77,16 @@ constructor two_line {path} {
 	set w_l $w.l
 	set w_c $w.c
 
+	# Two-line status bar: Only one ongoing operation permitted.
+	set allow_multiple 0
+
+	set baseline_text ""
+	set operations [list]
+	set completed_operation_count 0
+
 	${NS}::frame $w
 	${NS}::label $w_l \
-		-textvariable @status \
+		-textvariable @status_bar_text \
 		-anchor w \
 		-justify left
 	pack $w_l -anchor w -fill x
@@ -56,7 +96,7 @@ constructor two_line {path} {
 	return $this
 }
 
-method start {msg uds} {
+method ensure_canvas {} {
 	if {[winfo exists $w_c]} {
 		$w_c coords bar 0 0 0 20
 	} else {
@@ -68,31 +108,170 @@ method start {msg uds} {
 		$w_c create rectangle 0 0 0 20 -tags bar -fill navy
 		eval $c_pack
 	}
+}
+
+method show {msg} {
+	$this ensure_canvas
+	set baseline_text $msg
+	$this refresh
+}
+
+method start {msg {uds {}}} {
+	set baseline_text ""
+
+	if {!$allow_multiple && [llength $operations]} {
+		return [lindex $operations 0]
+	}
+
+	$this ensure_canvas
+
+	set operation [status_bar_operation::new $this $msg $uds]
+
+	lappend operations $operation
+
+	$this refresh
+
+	return $operation
+}
+
+method refresh {} {
+	set new_text ""
+
+	set total [expr $completed_operation_count * 100]
+	set have $total
+
+	foreach operation $operations {
+		if {$new_text != ""} {
+			append new_text " / "
+		}
+
+		append new_text [$operation get_status]
+
+		set total [expr $total + 100]
+		set have [expr $have + [$operation get_progress]]
+	}
+
+	if {$new_text == ""} {
+		set new_text $baseline_text
+	}
+
+	set status_bar_text $new_text
+
+	if {[winfo exists $w_c]} {
+		set pixel_width 0
+		if {$have > 0} {
+			set pixel_width [expr {[winfo width $w_c] * $have / $total}]
+		}
+
+		$w_c coords bar 0 0 $pixel_width 20
+	}
+}
+
+method stop {operation stop_msg} {
+	set idx [lsearch $operations $operation]
+
+	if {$idx >= 0} {
+		set operations [lreplace $operations $idx $idx]
+		set completed_operation_count [expr \
+			$completed_operation_count + 1]
+
+		if {[llength $operations] == 0} {
+			set completed_operation_count 0
+
+			destroy $w_c
+			if {$stop_msg ne {}} {
+				set baseline_text $stop_msg
+			}
+		}
+
+		$this refresh
+	}
+}
+
+method stop_all {{stop_msg {}}} {
+	# This makes the operation's call to stop a no-op.
+	set operations_copy $operations
+	set operations [list]
+
+	foreach operation $operations_copy {
+		$operation stop
+	}
+
+	if {$stop_msg ne {}} {
+		set baseline_text $stop_msg
+	}
+
+	$this refresh
+}
+
+method _delete {current} {
+	if {$current eq $w} {
+		delete_this
+	}
+}
+
+}
+
+# The status_bar_operation class tracks a single consumer's ongoing status bar
+# activity, with the context that there are a few situations where multiple
+# overlapping asynchronous operations might want to display status information
+# simultaneously. Instances of status_bar_operation are created by calling
+# start on the status_bar, and when the caller is done with its stauts bar
+# operation, it calls stop on the operation.
+
+class status_bar_operation {
+
+field status_bar; # reference back to the status_bar that owns this object
+
+field is_active;
+
+field status   {}; # single line of text we show
+field progress {}; # current progress (0 to 100)
+field prefix   {}; # text we format into status
+field units    {}; # unit of progress
+field meter    {}; # current core git progress meter (if active)
+
+constructor new {owner msg uds} {
+	set status_bar $owner
 
 	set status $msg
+	set progress 0
 	set prefix $msg
 	set units  $uds
 	set meter  {}
+
+	set is_active 1
+
+	return $this
 }
 
+method get_is_active {} { return $is_active }
+method get_status {} { return $status }
+method get_progress {} { return $progress }
+
 method update {have total} {
-	set pdone 0
-	set cdone 0
+	if {!$is_active} { return }
+
+	set progress 0
+
 	if {$total > 0} {
-		set pdone [expr {100 * $have / $total}]
-		set cdone [expr {[winfo width $w_c] * $have / $total}]
+		set progress [expr {100 * $have / $total}]
 	}
 
 	set prec [string length [format %i $total]]
+
 	set status [mc "%s ... %*i of %*i %s (%3i%%)" \
 		$prefix \
 		$prec $have \
 		$prec $total \
-		$units $pdone]
-	$w_c coords bar 0 0 $cdone 20
+		$units $progress]
+
+	$status_bar refresh
 }
 
 method update_meter {buf} {
+	if {!$is_active} { return }
+
 	append meter $buf
 	set r [string last "\r" $meter]
 	if {$r == -1} {
@@ -109,23 +288,23 @@ method update_meter {buf} {
 	}
 }
 
-method stop {{msg {}}} {
-	destroy $w_c
-	if {$msg ne {}} {
-		set status $msg
+method stop {{stop_msg {}}} {
+	if {$is_active} {
+		set is_active 0
+		$status_bar stop $this $stop_msg
 	}
 }
 
-method show {msg {test {}}} {
-	if {$test eq {} || $status eq $test} {
-		set status $msg
-	}
+method show {msg} {
+	if {!$is_active} { return }
+
+	set status $msg
+	$status_bar refresh
 }
 
-method _delete {current} {
-	if {$current eq $w} {
-		delete_this
-	}
+method _delete {} {
+	stop
+	delete_this
 }
 
 }
-- 
gitgitgadget

Re: [PATCH v6 2/3] git-gui: update status bar to track operations

[Pratyush Yadav]

Hi Jonathan,

Thanks for the re-roll.

On 28/11/19 08:30AM, Jonathan Gilbert via GitGitGadget wrote:
> From: Jonathan Gilbert <JonathanG@iQmetrix.com>
> 
> Update the status bar to track updates as individual "operations" that
> can overlap. Update all call sites to interact with the new status bar
> mechanism. Update initialization to explicitly clear status text,
> since otherwise it may persist across future operations.
> 
> Signed-off-by: Jonathan Gilbert <JonathanG@iQmetrix.com>
> ---
>  git-gui.sh                |  31 +++---
>  lib/blame.tcl             |  24 ++--
>  lib/checkout_op.tcl       |  15 +--
>  lib/choose_repository.tcl | 120 +++++++++++++-------
>  lib/index.tcl             |  31 ++++--
>  lib/merge.tcl             |  14 ++-
>  lib/status_bar.tcl        | 229 +++++++++++++++++++++++++++++++++-----
>  7 files changed, 354 insertions(+), 110 deletions(-)
> 
> diff --git a/git-gui.sh b/git-gui.sh
> index 0d21f5688b..6dcf6551b6 100755
> --- a/git-gui.sh
> +++ b/git-gui.sh
> @@ -30,8 +30,8 @@ along with this program; if not, see <http://www.gnu.org/licenses/>.}]
>  ##
>  ## Tcl/Tk sanity check
>  
> -if {[catch {package require Tcl 8.4} err]
> - || [catch {package require Tk  8.4} err]
> +if {[catch {package require Tcl 8.6} err]
> + || [catch {package require Tk  8.6} err]

Nitpick: Since TclOO is introduced in patch 3 (and the commit message of 
patch 3 mentions it), this hunk should be in that patch instead.

>  } {
>  	catch {wm withdraw .}
>  	tk_messageBox \
> @@ -1797,10 +1797,10 @@ proc ui_status {msg} {
>  	}
>  }
>  
> -proc ui_ready {{test {}}} {
> +proc ui_ready {} {
>  	global main_status
>  	if {[info exists main_status]} {
> -		$main_status show [mc "Ready."] $test
> +		$main_status show [mc "Ready."]
>  	}
>  }
>  
> @@ -2150,8 +2150,6 @@ proc incr_font_size {font {amt 1}} {
>  ##
>  ## ui commands
>  
> -set starting_gitk_msg [mc "Starting gitk... please wait..."]
> -
>  proc do_gitk {revs {is_submodule false}} {
>  	global current_diff_path file_states current_diff_side ui_index
>  	global _gitdir _gitworktree
> @@ -2206,10 +2204,11 @@ proc do_gitk {revs {is_submodule false}} {
>  		set env(GIT_WORK_TREE) $_gitworktree
>  		cd $pwd
>  
> -		ui_status $::starting_gitk_msg
> -		after 10000 {
> -			ui_ready $starting_gitk_msg
> -		}
> +		set status_operation [$::main_status \
> +			start \
> +			[mc "Starting %s... please wait..." "gitk"]]
> +
> +		after 3500 [list $status_operation stop]
>  	}
>  }
>  
> @@ -2240,10 +2239,11 @@ proc do_git_gui {} {
>  		set env(GIT_WORK_TREE) $_gitworktree
>  		cd $pwd
>  
> -		ui_status $::starting_gitk_msg
> -		after 10000 {
> -			ui_ready $starting_gitk_msg
> -		}
> +		set status_operation [$::main_status \
> +			start \
> +			[mc "Starting %s... please wait..." "git-gui"]]
> +
> +		after 3500 [list $status_operation stop]
>  	}
>  }

Looks good. Thanks for the cleanup.

>  
> @@ -4159,6 +4159,9 @@ if {$picked && [is_config_true gui.autoexplore]} {
>  	do_explore
>  }
>  
> +# Clear "Initializing..." status
> +after 500 {$main_status show ""}
> +
>  # Local variables:
>  # mode: tcl
>  # indent-tabs-mode: t
> diff --git a/lib/blame.tcl b/lib/blame.tcl
> index a1aeb8b96e..bfcacd5584 100644
> --- a/lib/blame.tcl
> +++ b/lib/blame.tcl
> @@ -24,6 +24,7 @@ field w_cviewer  ; # pane showing commit message
>  field finder     ; # find mini-dialog frame
>  field gotoline   ; # line goto mini-dialog frame
>  field status     ; # status mega-widget instance
> +field status_operation ; # operation displayed by status mega-widget
>  field old_height ; # last known height of $w.file_pane
>  
>  
> @@ -274,6 +275,7 @@ constructor new {i_commit i_path i_jump} {
>  	pack $w_cviewer -expand 1 -fill both
>  
>  	set status [::status_bar::new $w.status]
> +	set status_operation {}
>  
>  	menu $w.ctxm -tearoff 0
>  	$w.ctxm add command \
> @@ -602,16 +604,23 @@ method _exec_blame {cur_w cur_d options cur_s} {
>  	} else {
>  		lappend options $commit
>  	}
> +
> +	# We may recurse in from another call to _exec_blame and already have
> +	# a status operation.
> +	if {$status_operation == {}} {
> +		set status_operation [$status start \
> +			$cur_s \
> +			[mc "lines annotated"]]
> +	} else {
> +		$status_operation show $cur_s
> +	}

IIUC, in the previous version, a 'start' would reset the 
progress/"meter". But this change only resets the label, not the actual 
progress, which I think is what the caller wanted. So I think this 
should be a full re-start instead.

> +
>  	lappend options -- $path
>  	set fd [eval git_read --nice blame $options]
>  	fconfigure $fd -blocking 0 -translation lf -encoding utf-8
>  	fileevent $fd readable [cb _read_blame $fd $cur_w $cur_d]
>  	set current_fd $fd
>  	set blame_lines 0
> -
> -	$status start \
> -		$cur_s \
> -		[mc "lines annotated"]
>  }
>  
>  method _read_blame {fd cur_w cur_d} {
> diff --git a/lib/choose_repository.tcl b/lib/choose_repository.tcl
> index 80f5a59bbb..1ea0c9f7b8 100644
> --- a/lib/choose_repository.tcl
> +++ b/lib/choose_repository.tcl
> @@ -9,6 +9,18 @@ field w_body      ; # Widget holding the center content
>  field w_next      ; # Next button
>  field w_quit      ; # Quit button
>  field o_cons      ; # Console object (if active)
> +
> +# Status mega-widget instance during _do_clone2 (used by _copy_files and
> +# _link_files). Widget is destroyed before _do_clone2 calls
> +# _do_clone_checkout
> +field o_status
> +
> +# Operation displayed by status mega-widget during _do_clone_checkout =>
> +# _readtree_wait => _postcheckout_wait => _do_clone_submodules =>
> +# _do_validate_submodule_cloning. The status mega-widget is a difference
> +# instance than that stored in $o_status in earlier operations.

The last sentence doesn't make a lot of sense to me. What is "earlier 
operations"? If this refers to previous versions of this file, then I 
don't think such a comment belongs here. It should be in the commit 
message instead.

> +field o_status_op
> +
>  field w_types     ; # List of type buttons in clone
>  field w_recentlist ; # Listbox containing recent repositories
>  field w_localpath  ; # Entry widget bound to local_path
> @@ -659,12 +671,12 @@ method _do_clone2 {} {
>  
>  	switch -exact -- $clone_type {
>  	hardlink {
> -		set o_cons [status_bar::two_line $w_body]
> +		set o_status [status_bar::two_line $w_body]
>  		pack $w_body -fill x -padx 10 -pady 10
>  
> -		$o_cons start \
> +		set status_op [$o_status start \
>  			[mc "Counting objects"] \
> -			[mc "buckets"]
> +			[mc "buckets"]]
>  		update
>  
>  		if {[file exists [file join $objdir info alternates]]} {
> @@ -689,6 +701,7 @@ method _do_clone2 {} {
>  			} err]} {
>  				catch {cd $pwd}
>  				_clone_failed $this [mc "Unable to copy objects/info/alternates: %s" $err]
> +				$status_op stop
>  				return
>  			}
>  		}
> @@ -700,7 +713,7 @@ method _do_clone2 {} {
>  			-directory [file join $objdir] ??]
>  		set bcnt [expr {[llength $buckets] + 2}]
>  		set bcur 1
> -		$o_cons update $bcur $bcnt
> +		$status_op update $bcur $bcnt
>  		update
>  
>  		file mkdir [file join .git objects pack]
> @@ -708,7 +721,7 @@ method _do_clone2 {} {
>  			-directory [file join $objdir pack] *] {
>  			lappend tolink [file join pack $i]
>  		}
> -		$o_cons update [incr bcur] $bcnt
> +		$status_op update [incr bcur] $bcnt
>  		update
>  
>  		foreach i $buckets {
> @@ -717,10 +730,10 @@ method _do_clone2 {} {
>  				-directory [file join $objdir $i] *] {
>  				lappend tolink [file join $i $j]
>  			}
> -			$o_cons update [incr bcur] $bcnt
> +			$status_op update [incr bcur] $bcnt
>  			update
>  		}
> -		$o_cons stop
> +		$status_op stop
>  
>  		if {$tolink eq {}} {
>  			info_popup [strcat \
> @@ -747,6 +760,8 @@ method _do_clone2 {} {
>  		if {!$i} return
>  
>  		destroy $w_body
> +
> +		set o_status {}

Should we be calling a destructor for this here? There is the '_delete' 
method in status_bar.tcl, but I don't see any usages of it so I'm not 
sure what exactly it is supposed to do.

That said, the previous version of this file doesn't call any sort of 
destructor either, so maybe we should just leave it like it is for now. 
I dunno.

>  	}
>  	full {
>  		set o_cons [console::embed \
> @@ -976,33 +1010,9 @@ method _do_clone_checkout {HEAD} {
>  	fileevent $fd readable [cb _readtree_wait $fd]
>  }
>  
> -method _do_validate_submodule_cloning {ok} {
> -	if {$ok} {
> -		$o_cons done $ok
> -		set done 1
> -	} else {
> -		_clone_failed $this [mc "Cannot clone submodules."]
> -	}
> -}
> -
> -method _do_clone_submodules {} {
> -	if {$recursive eq {true}} {
> -		destroy $w_body
> -		set o_cons [console::embed \
> -			$w_body \
> -			[mc "Cloning submodules"]]
> -		pack $w_body -fill both -expand 1 -padx 10
> -		$o_cons exec \
> -			[list git submodule update --init --recursive] \
> -			[cb _do_validate_submodule_cloning]
> -	} else {
> -		set done 1
> -	}
> -}
> -

Is there a reason for moving these two methods around? Not that its a 
bad thing, I'm just curious.

>  method _readtree_wait {fd} {
>  	set buf [read $fd]
> -	$o_cons update_meter $buf
> +	$o_status_op update_meter $buf
>  	append readtree_err $buf
>  
>  	fconfigure $fd -blocking 1

Everything other than a couple of minor comments above looks good. 
Thanks for the quality contribution. Looking forward to finally merging 
the next and final version of the series :)

-- 
Regards,
Pratyush Yadav

Re: [PATCH v6 2/3] git-gui: update status bar to track operations

[Jonathan Gilbert]

On Sat, Nov 30, 2019 at 5:05 PM Pratyush Yadav me-at-yadavpratyush.com
|GitHub Public/Example Allow| <172q77k4bxwj0zt@sneakemail.com> wrote:
> Hi Jonathan,
>
> Thanks for the re-roll.

You are most welcome :-)

> On 28/11/19 08:30AM, Jonathan Gilbert via GitGitGadget wrote:
> > +# Operation displayed by status mega-widget during _do_clone_checkout =>
> > +# _readtree_wait => _postcheckout_wait => _do_clone_submodules =>
> > +# _do_validate_submodule_cloning. The status mega-widget is a difference
> > +# instance than that stored in $o_status in earlier operations.
>
> The last sentence doesn't make a lot of sense to me. What is "earlier
> operations"? If this refers to previous versions of this file, then I
> don't think such a comment belongs here. It should be in the commit
> message instead.

A clone starts out by calling `_do_clone2`, which, for `$clone_type`
of `hardlink`, creates a status "mega-widget" and uses it to track
linking and/or copying the underlying files. Then, this part of the UI
is destroyed. Later, the code calls into _do_clone_checkout, which
sets up its own, different view. This view _also_ uses a status
"mega-widget", but it's not the same one as before. This wasn't
obvious to me in my first read-through, and I erroneously wrote code
that assumed the widget objects would carry forward. As such, I felt
it might be useful to other readers to have this detail called out
up-front. In the context of `_do_clone_checkout`, the "earlier
operations" is what happens in `_do_clone2`.

> >               destroy $w_body
> > +
> > +             set o_status {}
>
> Should we be calling a destructor for this here? There is the '_delete'
> method in status_bar.tcl, but I don't see any usages of it so I'm not
> sure what exactly it is supposed to do.
>
> That said, the previous version of this file doesn't call any sort of
> destructor either, so maybe we should just leave it like it is for now.
> I dunno.

As far as I can tell, `destroy $w_body` automatically deletes the
entire subtree of UI components. I mentioned that I had written broken
code at first because I didn't realize the status widget got replaced
between `_do_clone2` and `_do_clone_checkout` -- that code encountered
an error that indicated that the status widget object no longer
existed at all. Thus, I have proceeded on the assumption that `destroy
$w_body` handles that particular detail, and all that's left is to
clear `o_status` of its dangling reference to the object that no
longer exists.

> > -method _do_validate_submodule_cloning {ok} {
> > [..]
> > -method _do_clone_submodules {} {
>
> Is there a reason for moving these two methods around? Not that its a
> bad thing, I'm just curious.

I touched on this in the cover letter. I'll just copy/paste that text
since it says it just as well as I could re-synthesize here :-)

* In `choose_repository.tcl`, there is a sequence of functions
involved performing the checkout on the clone: `_do_clone_checkout` =>
`_readtree_wait` => `_postcheckout_wait` => `_do_clone_submodules` =>
`_do_validate_submodule_cloning`. The functions have been re-ordered
in the source code to match the sequence in which they execute to
improve clarity.

Re-roll (final?) incoming.

Thanks,

Jonathan Gilbert

Re: [PATCH v6 2/3] git-gui: update status bar to track operations

[Philip Oakley]

On 30/11/2019 23:05, Pratyush Yadav wrote:
 > On 28/11/19 08:30AM, Jonathan Gilbert via GitGitGadget wrote:
>> +# Operation displayed by status mega-widget during _do_clone_checkout =>
>> +# _readtree_wait => _postcheckout_wait => _do_clone_submodules =>
>> +# _do_validate_submodule_cloning. The status mega-widget is a difference
should this be "different", rather than 'difference'?

>> +# instance than that stored in $o_status in earlier operations.
> The last sentence doesn't make a lot of sense to me. What is "earlier
> operations"? If this refers to previous versions of this file, then I
> don't think such a comment belongs here. It should be in the commit
> message instead.
>
Philip

Re: [PATCH v6 2/3] git-gui: update status bar to track operations

[Jonathan Gilbert]

On Sun, Dec 1, 2019 at 5:43 AM Philip Oakley philipoakley-at-iee.email
|GitHub Public/Example Allow| <ogvdf9gsg7oxult@sneakemail.com> wrote:
> On 30/11/2019 23:05, Pratyush Yadav wrote:
>  > On 28/11/19 08:30AM, Jonathan Gilbert via GitGitGadget wrote:
> >> +# Operation displayed by status mega-widget during _do_clone_checkout =>
> >> +# _readtree_wait => _postcheckout_wait => _do_clone_submodules =>
> >> +# _do_validate_submodule_cloning. The status mega-widget is a difference
>
> should this be "different", rather than 'difference'?

It absolutely should and I have corrected that in the re-roll.

Thanks :-)

Jonathan

[PATCH v6 3/3] git-gui: revert untracked files by deleting them

[Jonathan Gilbert via GitGitGadget]

From: Jonathan Gilbert <JonathanG@iQmetrix.com>

Update the revert_helper proc to check for untracked files as well as
changes, and then handle changes to be reverted and untracked files with
independent blocks of code. Prompt the user independently for untracked
files, since the underlying action is fundamentally different (rm -f).
If after deleting untracked files, the directory containing them becomes
empty, then remove the directory as well. Migrate unlocking of the index
out of _close_updateindex to a responsibility of the caller, to permit
paths that don't directly unlock the index, and refactor the error
handling added in d4e890e5 so that callers can make flow control
decisions in the event of errors. Update Tcl/Tk dependency from 8.4 to
8.6 in git-gui.sh.

A new proc delete_files takes care of actually deleting the files in
batches, using the Tcler's Wiki recommended approach for keeping the UI
responsive.

Since the checkout_index and delete_files calls are both asynchronous
and could potentially complete in any order, a "chord" is used to
coordinate unlocking the index and returning the UI to a usable state
only after both operations are complete. The `SimpleChord` class,
based on TclOO (Tcl/Tk 8.6), is added in this commit.

Signed-off-by: Jonathan Gilbert <JonathanG@iQmetrix.com>
---
 lib/chord.tcl | 160 +++++++++++++++++++
 lib/index.tcl | 422 ++++++++++++++++++++++++++++++++++++++++----------
 2 files changed, 500 insertions(+), 82 deletions(-)
 create mode 100644 lib/chord.tcl

diff --git a/lib/chord.tcl b/lib/chord.tcl
new file mode 100644
index 0000000000..275a6cd4a1
--- /dev/null
+++ b/lib/chord.tcl
@@ -0,0 +1,160 @@
+# Simple Chord for Tcl
+#
+# A "chord" is a method with more than one entrypoint and only one body, such
+# that the body runs only once all the entrypoints have been called by
+# different asynchronous tasks. In this implementation, the chord is defined
+# dynamically for each invocation. A SimpleChord object is created, supplying
+# body script to be run when the chord is completed, and then one or more notes
+# are added to the chord. Each note can be called like a proc, and returns
+# immediately if the chord isn't yet complete. When the last remaining note is
+# called, the body runs before the note returns.
+#
+# The SimpleChord class has a constructor that takes the body script, and a
+# method add_note that returns a note object. Since the body script does not
+# run in the context of the procedure that defined it, a mechanism is provided
+# for injecting variables into the chord for use by the body script. The
+# activation of a note is idempotent; multiple calls have the same effect as
+# a simple call.
+#
+# If you are invoking asynchronous operations with chord notes as completion
+# callbacks, and there is a possibility that earlier operations could complete
+# before later ones are started, it is a good practice to create a "common"
+# note on the chord that prevents it from being complete until you're certain
+# you've added all the notes you need.
+#
+# Example:
+#
+#   # Turn off the UI while running a couple of async operations.
+#   lock_ui
+#
+#   set chord [SimpleChord new {
+#     unlock_ui
+#     # Note: $notice here is not referenced in the calling scope
+#     if {$notice} { info_popup $notice }
+#   }
+#
+#   # Configure a note to keep the chord from completing until
+#   # all operations have been initiated.
+#   set common_note [$chord add_note]
+#
+#   # Pass notes as 'after' callbacks to other operations
+#   async_operation $args [$chord add_note]
+#   other_async_operation $args [$chord add_note]
+#
+#   # Communicate with the chord body
+#   if {$condition} {
+#     # This sets $notice in the same context that the chord body runs in.
+#     $chord eval { set notice "Something interesting" }
+#   }
+#
+#   # Activate the common note, making the chord eligible to complete
+#   $common_note
+#
+# At this point, the chord will complete at some unknown point in the future.
+# The common note might have been the first note activated, or the async
+# operations might have completed synchronously and the common note is the
+# last one, completing the chord before this code finishes, or anything in
+# between. The purpose of the chord is to not have to worry about the order.
+
+# SimpleChord class:
+#   Represents a procedure that conceptually has multiple entrypoints that must
+#   all be called before the procedure executes. Each entrypoint is called a
+#   "note". The chord is only "completed" when all the notes are "activated".
+oo::class create SimpleChord {
+	variable notes body is_completed
+
+	# Constructor:
+	#   set chord [SimpleChord new {body}]
+	#     Creates a new chord object with the specified body script. The
+	#     body script is evaluated at most once, when a note is activated
+	#     and the chord has no other non-activated notes.
+	constructor {body} {
+		set notes [list]
+		my eval [list set body $body]
+		set is_completed 0
+	}
+
+	# Method:
+	#   $chord eval {script}
+	#     Runs the specified script in the same context (namespace) in which
+	#     the chord body will be evaluated. This can be used to set variable
+	#     values for the chord body to use.
+	method eval {script} {
+		namespace eval [self] $script
+	}
+
+	# Method:
+	#   set note [$chord add_note]
+	#     Adds a new note to the chord, an instance of ChordNote. Raises an
+	#     error if the chord is already completed, otherwise the chord is
+	#     updated so that the new note must also be activated before the
+	#     body is evaluated.
+	method add_note {} {
+		if {$is_completed} { error "Cannot add a note to a completed chord" }
+
+		set note [ChordNote new [self]]
+
+		lappend notes $note
+
+		return $note
+	}
+
+	# This method is for internal use only and is intentionally undocumented.
+	method notify_note_activation {} {
+		if {!$is_completed} {
+			foreach note $notes {
+				if {![$note is_activated]} { return }
+			}
+
+			set is_completed 1
+
+			namespace eval [self] $body
+			namespace delete [self]
+		}
+	}
+}
+
+# ChordNote class:
+#   Represents a note within a chord, providing a way to activate it. When the
+#   final note of the chord is activated (this can be any note in the chord,
+#   with all other notes already previously activated in any order), the chord's
+#   body is evaluated.
+oo::class create ChordNote {
+	variable chord is_activated
+
+	# Constructor:
+	#   Instances of ChordNote are created internally by calling add_note on
+	#   SimpleChord objects.
+	constructor {chord} {
+		my eval set chord $chord
+		set is_activated 0
+	}
+
+	# Method:
+	#   [$note is_activated]
+	#     Returns true if this note has already been activated.
+	method is_activated {} {
+		return $is_activated
+	}
+
+	# Method:
+	#   $note
+	#     Activates the note, if it has not already been activated, and
+	#     completes the chord if there are no other notes awaiting
+	#     activation. Subsequent calls will have no further effect.
+	#
+	# NB: In TclOO, if an object is invoked like a method without supplying
+	#     any method name, then this internal method `unknown` is what
+	#     actually runs (with no parameters). It is used in the ChordNote
+	#     class for the purpose of allowing the note object to be called as
+	#     a function (see example above). (The `unknown` method can also be
+	#     used to support dynamic dispatch, but must take parameters to
+	#     identify the "unknown" method to be invoked. In this form, this
+	#     proc serves only to make instances behave directly like methods.)
+	method unknown {} {
+		if {!$is_activated} {
+			set is_activated 1
+			$chord notify_note_activation
+		}
+	}
+}
diff --git a/lib/index.tcl b/lib/index.tcl
index 62f4773ef4..1254145634 100644
--- a/lib/index.tcl
+++ b/lib/index.tcl
@@ -7,53 +7,60 @@ proc _delete_indexlock {} {
 	}
 }
 
-proc _close_updateindex {fd after} {
-	global use_ttk NS
-	fconfigure $fd -blocking 1
-	if {[catch {close $fd} err]} {
-		set w .indexfried
-		Dialog $w
-		wm withdraw $w
-		wm title $w [strcat "[appname] ([reponame]): " [mc "Index Error"]]
-		wm geometry $w "+[winfo rootx .]+[winfo rooty .]"
-		set s [mc "Updating the Git index failed.  A rescan will be automatically started to resynchronize git-gui."]
-		text $w.msg -yscrollcommand [list $w.vs set] \
-			-width [string length $s] -relief flat \
-			-borderwidth 0 -highlightthickness 0 \
-			-background [get_bg_color $w]
-		$w.msg tag configure bold -font font_uibold -justify center
-		${NS}::scrollbar $w.vs -command [list $w.msg yview]
-		$w.msg insert end $s bold \n\n$err {}
-		$w.msg configure -state disabled
-
-		${NS}::button $w.continue \
-			-text [mc "Continue"] \
-			-command [list destroy $w]
-		${NS}::button $w.unlock \
-			-text [mc "Unlock Index"] \
-			-command "destroy $w; _delete_indexlock"
-		grid $w.msg - $w.vs -sticky news
-		grid $w.unlock $w.continue - -sticky se -padx 2 -pady 2
-		grid columnconfigure $w 0 -weight 1
-		grid rowconfigure $w 0 -weight 1
-
-		wm protocol $w WM_DELETE_WINDOW update
-		bind $w.continue <Visibility> "
-			grab $w
-			focus %W
-		"
-		wm deiconify $w
-		tkwait window $w
-
-		$::main_status stop_all
+proc close_and_unlock_index {fd after} {
+	if {![catch {_close_updateindex $fd} err]} {
 		unlock_index
-		rescan $after 0
-		return
+		uplevel #0 $after
+	} else {
+		rescan_on_error $err $after
 	}
+}
+
+proc _close_updateindex {fd} {
+	fconfigure $fd -blocking 1
+	close $fd
+}
+
+proc rescan_on_error {err {after {}}} {
+	global use_ttk NS
+
+	set w .indexfried
+	Dialog $w
+	wm withdraw $w
+	wm title $w [strcat "[appname] ([reponame]): " [mc "Index Error"]]
+	wm geometry $w "+[winfo rootx .]+[winfo rooty .]"
+	set s [mc "Updating the Git index failed.  A rescan will be automatically started to resynchronize git-gui."]
+	text $w.msg -yscrollcommand [list $w.vs set] \
+		-width [string length $s] -relief flat \
+		-borderwidth 0 -highlightthickness 0 \
+		-background [get_bg_color $w]
+	$w.msg tag configure bold -font font_uibold -justify center
+	${NS}::scrollbar $w.vs -command [list $w.msg yview]
+	$w.msg insert end $s bold \n\n$err {}
+	$w.msg configure -state disabled
+
+	${NS}::button $w.continue \
+		-text [mc "Continue"] \
+		-command [list destroy $w]
+	${NS}::button $w.unlock \
+		-text [mc "Unlock Index"] \
+		-command "destroy $w; _delete_indexlock"
+	grid $w.msg - $w.vs -sticky news
+	grid $w.unlock $w.continue - -sticky se -padx 2 -pady 2
+	grid columnconfigure $w 0 -weight 1
+	grid rowconfigure $w 0 -weight 1
+
+	wm protocol $w WM_DELETE_WINDOW update
+	bind $w.continue <Visibility> "
+		grab $w
+		focus %W
+	"
+	wm deiconify $w
+	tkwait window $w
 
 	$::main_status stop_all
 	unlock_index
-	uplevel #0 $after
+	rescan [concat $after [list ui_ready]] 0
 }
 
 proc update_indexinfo {msg path_list after} {
@@ -93,7 +100,7 @@ proc write_update_indexinfo {fd path_list total_cnt batch status_bar_operation \
 
 	if {$update_index_cp >= $total_cnt} {
 		$status_bar_operation stop
-		_close_updateindex $fd $after
+		close_and_unlock_index $fd $after
 		return
 	}
 
@@ -162,7 +169,7 @@ proc write_update_index {fd path_list total_cnt batch status_bar_operation \
 
 	if {$update_index_cp >= $total_cnt} {
 		$status_bar_operation stop
-		_close_updateindex $fd $after
+		close_and_unlock_index $fd $after
 		return
 	}
 
@@ -199,7 +206,7 @@ proc write_update_index {fd path_list total_cnt batch status_bar_operation \
 	$status_bar_operation update $update_index_cp $total_cnt
 }
 
-proc checkout_index {msg path_list after} {
+proc checkout_index {msg path_list after capture_error} {
 	global update_index_cp
 
 	if {![lock_index update]} return
@@ -232,17 +239,33 @@ proc checkout_index {msg path_list after} {
 		$batch \
 		$status_bar_operation \
 		$after \
+		$capture_error \
 		]
 }
 
 proc write_checkout_index {fd path_list total_cnt batch status_bar_operation \
-	after} {
+	after capture_error} {
 	global update_index_cp
 	global file_states current_diff_path
 
 	if {$update_index_cp >= $total_cnt} {
 		$status_bar_operation stop
-		_close_updateindex $fd $after
+
+		# We do not unlock the index directly here because this
+		# operation expects to potentially run in parallel with file
+		# deletions scheduled by revert_helper. We're done with the
+		# update index, so we close it, but actually unlocking the index
+		# and dealing with potential errors is deferred to the chord
+		# body that runs when all async operations are completed.
+		#
+		# (See after_chord in revert_helper.)
+
+		if {[catch {_close_updateindex $fd} err]} {
+			uplevel #0 $capture_error [list $err]
+		}
+
+		uplevel #0 $after
+
 		return
 	}
 
@@ -397,66 +420,301 @@ proc do_add_all {} {
 	add_helper [mc "Adding all changed files"] $paths
 }
 
+# Copied from TclLib package "lambda".
+proc lambda {arguments body args} {
+	return [list ::apply [list $arguments $body] {*}$args]
+}
+
 proc revert_helper {txt paths} {
 	global file_states current_diff_path
 
 	if {![lock_index begin-update]} return
 
+	# Common "after" functionality that waits until multiple asynchronous
+	# operations are complete (by waiting for them to activate their notes
+	# on the chord).
+	#
+	# The asynchronous operations are each indicated below by a comment
+	# before the code block that starts the async operation.
+	set after_chord [SimpleChord new {
+		if {[string trim $err] != ""} {
+			rescan_on_error $err
+		} else {
+			unlock_index
+			if {$should_reshow_diff} { reshow_diff }
+			ui_ready
+		}
+	}]
+
+	$after_chord eval { set should_reshow_diff 0 }
+
+	# This function captures an error for processing when after_chord is
+	# completed. (The chord is curried into the lambda function.)
+	set capture_error [lambda \
+		{chord error} \
+		{ $chord eval [list set err $error] } \
+		$after_chord]
+
+	# We don't know how many notes we're going to create (it's dynamic based
+	# on conditional paths below), so create a common note that will delay
+	# the chord's completion until we activate it, and then activate it
+	# after all the other notes have been created.
+	set after_common_note [$after_chord add_note]
+
 	set path_list [list]
-	set after {}
+	set untracked_list [list]
+
 	foreach path $paths {
 		switch -glob -- [lindex $file_states($path) 0] {
 		U? {continue}
+		?O {
+			lappend untracked_list $path
+		}
 		?M -
 		?T -
 		?D {
 			lappend path_list $path
 			if {$path eq $current_diff_path} {
-				set after {reshow_diff;}
+				$after_chord eval { set should_reshow_diff 1 }
 			}
 		}
 		}
 	}
 
+	set path_cnt [llength $path_list]
+	set untracked_cnt [llength $untracked_list]
+
+	# Asynchronous operation: revert changes by checking them out afresh
+	# from the index.
+	if {$path_cnt > 0} {
+		# Split question between singular and plural cases, because
+		# such distinction is needed in some languages. Previously, the
+		# code used "Revert changes in" for both, but that can't work
+		# in languages where 'in' must be combined with word from
+		# rest of string (in different way for both cases of course).
+		#
+		# FIXME: Unfortunately, even that isn't enough in some languages
+		# as they have quite complex plural-form rules. Unfortunately,
+		# msgcat doesn't seem to support that kind of string
+		# translation.
+		#
+		if {$path_cnt == 1} {
+			set query [mc \
+				"Revert changes in file %s?" \
+				[short_path [lindex $path_list]] \
+				]
+		} else {
+			set query [mc \
+				"Revert changes in these %i files?" \
+				$path_cnt]
+		}
 
-	# Split question between singular and plural cases, because
-	# such distinction is needed in some languages. Previously, the
-	# code used "Revert changes in" for both, but that can't work
-	# in languages where 'in' must be combined with word from
-	# rest of string (in different way for both cases of course).
-	#
-	# FIXME: Unfortunately, even that isn't enough in some languages
-	# as they have quite complex plural-form rules. Unfortunately,
-	# msgcat doesn't seem to support that kind of string translation.
-	#
-	set n [llength $path_list]
-	if {$n == 0} {
-		unlock_index
-		return
-	} elseif {$n == 1} {
-		set query [mc "Revert changes in file %s?" [short_path [lindex $path_list]]]
-	} else {
-		set query [mc "Revert changes in these %i files?" $n]
+		set reply [tk_dialog \
+			.confirm_revert \
+			"[appname] ([reponame])" \
+			"$query
+
+[mc "Any unstaged changes will be permanently lost by the revert."]" \
+			question \
+			1 \
+			[mc "Do Nothing"] \
+			[mc "Revert Changes"] \
+			]
+
+		if {$reply == 1} {
+			checkout_index \
+				$txt \
+				$path_list \
+				[$after_chord add_note] \
+				$capture_error
+		}
 	}
 
-	set reply [tk_dialog \
-		.confirm_revert \
-		"[appname] ([reponame])" \
-		"$query
+	# Asynchronous operation: Deletion of untracked files.
+	if {$untracked_cnt > 0} {
+		# Split question between singular and plural cases, because
+		# such distinction is needed in some languages.
+		#
+		# FIXME: Unfortunately, even that isn't enough in some languages
+		# as they have quite complex plural-form rules. Unfortunately,
+		# msgcat doesn't seem to support that kind of string
+		# translation.
+		#
+		if {$untracked_cnt == 1} {
+			set query [mc \
+				"Delete untracked file %s?" \
+				[short_path [lindex $untracked_list]] \
+				]
+		} else {
+			set query [mc \
+				"Delete these %i untracked files?" \
+				$untracked_cnt \
+				]
+		}
 
-[mc "Any unstaged changes will be permanently lost by the revert."]" \
-		question \
-		1 \
-		[mc "Do Nothing"] \
-		[mc "Revert Changes"] \
-		]
-	if {$reply == 1} {
-		checkout_index \
-			$txt \
+		set reply [tk_dialog \
+			.confirm_revert \
+			"[appname] ([reponame])" \
+			"$query
+
+[mc "Files will be permanently deleted."]" \
+			question \
+			1 \
+			[mc "Do Nothing"] \
+			[mc "Delete Files"] \
+			]
+
+		if {$reply == 1} {
+			$after_chord eval { set should_reshow_diff 1 }
+
+			delete_files $untracked_list [$after_chord add_note]
+		}
+	}
+
+	# Activate the common note. If no other notes were created, this
+	# completes the chord. If other notes were created, then this common
+	# note prevents a race condition where the chord might complete early.
+	$after_common_note
+}
+
+# Delete all of the specified files, performing deletion in batches to allow the
+# UI to remain responsive and updated.
+proc delete_files {path_list after} {
+	# Enable progress bar status updates
+	set status_bar_operation [$::main_status \
+		start \
+		[mc "Deleting"] \
+		[mc "files"]]
+
+	set path_index 0
+	set deletion_errors [list]
+	set batch_size 50
+
+	delete_helper \
+		$path_list \
+		$path_index \
+		$deletion_errors \
+		$batch_size \
+		$status_bar_operation \
+		$after
+}
+
+# Helper function to delete a list of files in batches. Each call deletes one
+# batch of files, and then schedules a call for the next batch after any UI
+# messages have been processed.
+proc delete_helper {path_list path_index deletion_errors batch_size \
+	status_bar_operation after} {
+	global file_states
+
+	set path_cnt [llength $path_list]
+
+	set batch_remaining $batch_size
+
+	while {$batch_remaining > 0} {
+		if {$path_index >= $path_cnt} { break }
+
+		set path [lindex $path_list $path_index]
+
+		set deletion_failed [catch {file delete -- $path} deletion_error]
+
+		if {$deletion_failed} {
+			lappend deletion_errors [list "$deletion_error"]
+		} else {
+			remove_empty_directories [file dirname $path]
+
+			# Don't assume the deletion worked. Remove the file from
+			# the UI, but only if it no longer exists.
+			if {![path_exists $path]} {
+				unset file_states($path)
+				display_file $path __
+			}
+		}
+
+		incr path_index 1
+		incr batch_remaining -1
+	}
+
+	# Update the progress bar to indicate that this batch has been
+	# completed. The update will be visible when this procedure returns
+	# and allows the UI thread to process messages.
+	$status_bar_operation update $path_index $path_cnt
+
+	if {$path_index < $path_cnt} {
+		# The Tcler's Wiki lists this as the best practice for keeping
+		# a UI active and processing messages during a long-running
+		# operation.
+
+		after idle [list after 0 [list \
+			delete_helper \
 			$path_list \
-			[concat $after [list ui_ready]]
+			$path_index \
+			$deletion_errors \
+			$batch_size \
+			$status_bar_operation \
+			$after
+			]]
 	} else {
-		unlock_index
+		# Finish the status bar operation.
+		$status_bar_operation stop
+
+		# Report error, if any, based on how many deletions failed.
+		set deletion_error_cnt [llength $deletion_errors]
+
+		if {($deletion_error_cnt > 0)
+		 && ($deletion_error_cnt <= [MAX_VERBOSE_FILES_IN_DELETION_ERROR])} {
+			set error_text [mc "Encountered errors deleting files:\n"]
+
+			foreach deletion_error $deletion_errors {
+				append error_text "* [lindex $deletion_error 0]\n"
+			}
+
+			error_popup $error_text
+		} elseif {$deletion_error_cnt == $path_cnt} {
+			error_popup [mc \
+				"None of the %d selected files could be deleted." \
+				$path_cnt \
+				]
+		} elseif {$deletion_error_cnt > 1} {
+			error_popup [mc \
+				"%d of the %d selected files could not be deleted." \
+				$deletion_error_cnt \
+				$path_cnt \
+				]
+		}
+
+		uplevel #0 $after
+	}
+}
+
+proc MAX_VERBOSE_FILES_IN_DELETION_ERROR {} { return 10; }
+
+# This function is from the TCL documentation:
+#
+#   https://wiki.tcl-lang.org/page/file+exists
+#
+# [file exists] returns false if the path does exist but is a symlink to a path
+# that doesn't exist. This proc returns true if the path exists, regardless of
+# whether it is a symlink and whether it is broken.
+proc path_exists {name} {
+	expr {![catch {file lstat $name finfo}]}
+}
+
+# Remove as many empty directories as we can starting at the specified path,
+# walking up the directory tree. If we encounter a directory that is not
+# empty, or if a directory deletion fails, then we stop the operation and
+# return to the caller. Even if this procedure fails to delete any
+# directories at all, it does not report failure.
+proc remove_empty_directories {directory_path} {
+	set parent_path [file dirname $directory_path]
+
+	while {$parent_path != $directory_path} {
+		set contents [glob -nocomplain -dir $directory_path *]
+
+		if {[llength $contents] > 0} { break }
+		if {[catch {file delete -- $directory_path}]} { break }
+
+		set directory_path $parent_path
+		set parent_path [file dirname $directory_path]
 	}
 }
 
-- 
gitgitgadget

[PATCH v7 0/3] git-gui: revert untracked files by deleting them

[Jonathan Gilbert via GitGitGadget]

My development environment sometimes makes automatic changes that I don't
want to keep. In some cases, this involves new files being added that I
don't want to commit or keep (but I also don't want to outright .gitignore 
forever). I have typically had to explicitly delete those files externally
to Git Gui, which is a context switch to a manual operation, and I want to
be able to just select those newly-created untracked files in the UI and
"revert" them into oblivion.

This change updates the revert_helper proc to check for untracked files as
well as changes, and then changes to be reverted and untracked files are
handled by independent blocks of code. The user is prompted independently
for untracked files, since the underlying action is fundamentally different
(rm -f). If after deleting untracked files, the directory containing them
becomes empty, then the directory is removed as well. A new proc 
delete_files takes care of actually deleting the files, using the Tcler's
Wiki recommended approach for keeping the UI responsive.

Since the checkout_index and delete_files calls are both asynchronous and
could potentially complete in any order, a "chord" is used to coordinate
unlocking the index and returning the UI to a usable state only after both
operations are complete.

Since the checkout_index and delete_files calls are both asynchronous and
overlap, they clash in wanting to update the status bar. To address this,
the status bar is reworked so that when an operation wants to display
ongoing updates/progress, it explicitly starts an "operation", which is
tracked by its own object, and the status bar handles multiple concurrent
operations by merging their progress and concatenating their text. This is
captured in a separate commit, since it touches a variety of files.

The _close_updateindex proc contains error handling (added in d4e890e5) that
has the potential to interact badly with unlock_index running at the
completion of an async operation. I have refactored the procedure into
separate procs _close_updateindex and rescan_on_error. Call sites that
exercised the combined functionality also unlocked the index, so a combined
proc close_and_unlock_index calls _close_updateindex and then either 
rescan_on_error or unlock_index as appropriate. Call sites have been updated
appropriately.

The revert_helper proc, with its overlapping operations, is an example of a
call site that does not combine the close and unlock/rescan operations. The 
checkout_index proc has been reworked to only call _close_updateindex, and
to call a functor supplied by the caller to captures any errors that occur. 
revert_helper uses this to supply a lambda function that stashes the error
within the chord's body namespace, so that it can then separately call 
rescan_on_error when the chord is completed (or unlock_index, if no error
was captured), which might be substantially after checkout_index encounters
its error. If it turns out that a rescan is called for, it is done once the
deletion is complete.

This is the eighth revision of this change, which differs from the seventh
version in the following ways (most of which are in the second of the three
commits, to do with the status bar rework):

 * The bump of the Tcl/Tk dependency from 8.4 to 8.6 now takes place in the
   third commit, where it is needed and whose commit message actually calls
   it out.
   
   
 * The show method in status_bar_operation has been renamed to restart, and
   the meter is cleared. Also, the supplied message is set as the prefix for
   future update calls.
   
   
 * The call site for $status_operation show in blame.tcl has been
   corresponding changed to $status_operation restart.
   
   
 * A typo has been corrected in a comment. :-)
   
   

git remote add logiclrd https://github.com/logiclrd/git.git
git fetch logiclrd git-gui-revert-untracked revision7
# Compare the second commit from the past submission with the one
# from this submission:
# - revision7~ == ab3d8e54c3d
# - git-gui-revert-untracked~ == 8fe9dfc30771
git diff ab3d8e54c3d..8fe9dfc30771

Jonathan Gilbert (3):
  git-gui: consolidate naming conventions
  git-gui: update status bar to track operations
  git-gui: revert untracked files by deleting them

 git-gui.sh                |  31 ++-
 lib/blame.tcl             |  24 +-
 lib/checkout_op.tcl       |  15 +-
 lib/choose_repository.tcl | 120 ++++++---
 lib/chord.tcl             | 160 ++++++++++++
 lib/index.tcl             | 523 ++++++++++++++++++++++++++++----------
 lib/merge.tcl             |  14 +-
 lib/status_bar.tcl        | 231 +++++++++++++++--
 8 files changed, 891 insertions(+), 227 deletions(-)
 create mode 100644 lib/chord.tcl


base-commit: b524f6b399c77b40c8bf2b6217585fde4731472a
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-436%2Flogiclrd%2Fgit-gui-revert-untracked-v7
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-436/logiclrd/git-gui-revert-untracked-v7
Pull-Request: https://github.com/gitgitgadget/git/pull/436

Range-diff vs v6:

 1:  da1704c56e = 1:  da1704c56e git-gui: consolidate naming conventions
 2:  ab3d8e54c3 ! 2:  8fe9dfc307 git-gui: update status bar to track operations
     @@ -12,17 +12,6 @@
       diff --git a/git-gui.sh b/git-gui.sh
       --- a/git-gui.sh
       +++ b/git-gui.sh
     -@@
     - ##
     - ## Tcl/Tk sanity check
     - 
     --if {[catch {package require Tcl 8.4} err]
     -- || [catch {package require Tk  8.4} err]
     -+if {[catch {package require Tcl 8.6} err]
     -+ || [catch {package require Tk  8.6} err]
     - } {
     - 	catch {wm withdraw .}
     - 	tk_messageBox \
      @@
       	}
       }
     @@ -119,7 +108,7 @@
      +			$cur_s \
      +			[mc "lines annotated"]]
      +	} else {
     -+		$status_operation show $cur_s
     ++		$status_operation restart $cur_s
      +	}
      +
       	lappend options -- $path
     @@ -231,7 +220,7 @@
      +
      +# Operation displayed by status mega-widget during _do_clone_checkout =>
      +# _readtree_wait => _postcheckout_wait => _do_clone_submodules =>
     -+# _do_validate_submodule_cloning. The status mega-widget is a difference
     ++# _do_validate_submodule_cloning. The status mega-widget is a different
      +# instance than that stored in $o_status in earlier operations.
      +field o_status_op
      +
     @@ -930,10 +919,12 @@
      -	if {$test eq {} || $status eq $test} {
      -		set status $msg
      -	}
     -+method show {msg} {
     ++method restart {msg} {
      +	if {!$is_active} { return }
      +
      +	set status $msg
     ++	set prefix $msg
     ++	set meter {}
      +	$status_bar refresh
       }
       
 3:  3388407871 ! 3:  5f8120f359 git-gui: revert untracked files by deleting them
     @@ -26,6 +26,21 @@
      
          Signed-off-by: Jonathan Gilbert <JonathanG@iQmetrix.com>
      
     + diff --git a/git-gui.sh b/git-gui.sh
     + --- a/git-gui.sh
     + +++ b/git-gui.sh
     +@@
     + ##
     + ## Tcl/Tk sanity check
     + 
     +-if {[catch {package require Tcl 8.4} err]
     +- || [catch {package require Tk  8.4} err]
     ++if {[catch {package require Tcl 8.6} err]
     ++ || [catch {package require Tk  8.6} err]
     + } {
     + 	catch {wm withdraw .}
     + 	tk_messageBox \
     +
       diff --git a/lib/chord.tcl b/lib/chord.tcl
       new file mode 100644
       --- /dev/null

-- 
gitgitgadget

[PATCH v7 1/3] git-gui: consolidate naming conventions

[Jonathan Gilbert via GitGitGadget]

From: Jonathan Gilbert <JonathanG@iQmetrix.com>

A few variables in this file use camelCase, while the overall standard
is snake_case. A consistent naming scheme will improve readability of
future changes. To avoid mixing naming changes with semantic changes,
this commit contains only naming changes.

Signed-off-by: Jonathan Gilbert <JonathanG@iQmetrix.com>
---
 lib/index.tcl | 92 +++++++++++++++++++++++++--------------------------
 1 file changed, 46 insertions(+), 46 deletions(-)

diff --git a/lib/index.tcl b/lib/index.tcl
index e07b7a3762..28d4d2a54e 100644
--- a/lib/index.tcl
+++ b/lib/index.tcl
@@ -56,15 +56,15 @@ proc _close_updateindex {fd after} {
 	uplevel #0 $after
 }
 
-proc update_indexinfo {msg pathList after} {
+proc update_indexinfo {msg path_list after} {
 	global update_index_cp
 
 	if {![lock_index update]} return
 
 	set update_index_cp 0
-	set pathList [lsort $pathList]
-	set totalCnt [llength $pathList]
-	set batch [expr {int($totalCnt * .01) + 1}]
+	set path_list [lsort $path_list]
+	set total_cnt [llength $path_list]
+	set batch [expr {int($total_cnt * .01) + 1}]
 	if {$batch > 25} {set batch 25}
 
 	$::main_status start $msg [mc "files"]
@@ -78,26 +78,26 @@ proc update_indexinfo {msg pathList after} {
 	fileevent $fd writable [list \
 		write_update_indexinfo \
 		$fd \
-		$pathList \
-		$totalCnt \
+		$path_list \
+		$total_cnt \
 		$batch \
 		$after \
 		]
 }
 
-proc write_update_indexinfo {fd pathList totalCnt batch after} {
+proc write_update_indexinfo {fd path_list total_cnt batch after} {
 	global update_index_cp
 	global file_states current_diff_path
 
-	if {$update_index_cp >= $totalCnt} {
+	if {$update_index_cp >= $total_cnt} {
 		_close_updateindex $fd $after
 		return
 	}
 
 	for {set i $batch} \
-		{$update_index_cp < $totalCnt && $i > 0} \
+		{$update_index_cp < $total_cnt && $i > 0} \
 		{incr i -1} {
-		set path [lindex $pathList $update_index_cp]
+		set path [lindex $path_list $update_index_cp]
 		incr update_index_cp
 
 		set s $file_states($path)
@@ -119,18 +119,18 @@ proc write_update_indexinfo {fd pathList totalCnt batch after} {
 		display_file $path $new
 	}
 
-	$::main_status update $update_index_cp $totalCnt
+	$::main_status update $update_index_cp $total_cnt
 }
 
-proc update_index {msg pathList after} {
+proc update_index {msg path_list after} {
 	global update_index_cp
 
 	if {![lock_index update]} return
 
 	set update_index_cp 0
-	set pathList [lsort $pathList]
-	set totalCnt [llength $pathList]
-	set batch [expr {int($totalCnt * .01) + 1}]
+	set path_list [lsort $path_list]
+	set total_cnt [llength $path_list]
+	set batch [expr {int($total_cnt * .01) + 1}]
 	if {$batch > 25} {set batch 25}
 
 	$::main_status start $msg [mc "files"]
@@ -144,26 +144,26 @@ proc update_index {msg pathList after} {
 	fileevent $fd writable [list \
 		write_update_index \
 		$fd \
-		$pathList \
-		$totalCnt \
+		$path_list \
+		$total_cnt \
 		$batch \
 		$after \
 		]
 }
 
-proc write_update_index {fd pathList totalCnt batch after} {
+proc write_update_index {fd path_list total_cnt batch after} {
 	global update_index_cp
 	global file_states current_diff_path
 
-	if {$update_index_cp >= $totalCnt} {
+	if {$update_index_cp >= $total_cnt} {
 		_close_updateindex $fd $after
 		return
 	}
 
 	for {set i $batch} \
-		{$update_index_cp < $totalCnt && $i > 0} \
+		{$update_index_cp < $total_cnt && $i > 0} \
 		{incr i -1} {
-		set path [lindex $pathList $update_index_cp]
+		set path [lindex $path_list $update_index_cp]
 		incr update_index_cp
 
 		switch -glob -- [lindex $file_states($path) 0] {
@@ -190,18 +190,18 @@ proc write_update_index {fd pathList totalCnt batch after} {
 		display_file $path $new
 	}
 
-	$::main_status update $update_index_cp $totalCnt
+	$::main_status update $update_index_cp $total_cnt
 }
 
-proc checkout_index {msg pathList after} {
+proc checkout_index {msg path_list after} {
 	global update_index_cp
 
 	if {![lock_index update]} return
 
 	set update_index_cp 0
-	set pathList [lsort $pathList]
-	set totalCnt [llength $pathList]
-	set batch [expr {int($totalCnt * .01) + 1}]
+	set path_list [lsort $path_list]
+	set total_cnt [llength $path_list]
+	set batch [expr {int($total_cnt * .01) + 1}]
 	if {$batch > 25} {set batch 25}
 
 	$::main_status start $msg [mc "files"]
@@ -221,26 +221,26 @@ proc checkout_index {msg pathList after} {
 	fileevent $fd writable [list \
 		write_checkout_index \
 		$fd \
-		$pathList \
-		$totalCnt \
+		$path_list \
+		$total_cnt \
 		$batch \
 		$after \
 		]
 }
 
-proc write_checkout_index {fd pathList totalCnt batch after} {
+proc write_checkout_index {fd path_list total_cnt batch after} {
 	global update_index_cp
 	global file_states current_diff_path
 
-	if {$update_index_cp >= $totalCnt} {
+	if {$update_index_cp >= $total_cnt} {
 		_close_updateindex $fd $after
 		return
 	}
 
 	for {set i $batch} \
-		{$update_index_cp < $totalCnt && $i > 0} \
+		{$update_index_cp < $total_cnt && $i > 0} \
 		{incr i -1} {
-		set path [lindex $pathList $update_index_cp]
+		set path [lindex $path_list $update_index_cp]
 		incr update_index_cp
 		switch -glob -- [lindex $file_states($path) 0] {
 		U? {continue}
@@ -253,7 +253,7 @@ proc write_checkout_index {fd pathList totalCnt batch after} {
 		}
 	}
 
-	$::main_status update $update_index_cp $totalCnt
+	$::main_status update $update_index_cp $total_cnt
 }
 
 proc unstage_helper {txt paths} {
@@ -261,7 +261,7 @@ proc unstage_helper {txt paths} {
 
 	if {![lock_index begin-update]} return
 
-	set pathList [list]
+	set path_list [list]
 	set after {}
 	foreach path $paths {
 		switch -glob -- [lindex $file_states($path) 0] {
@@ -269,19 +269,19 @@ proc unstage_helper {txt paths} {
 		M? -
 		T? -
 		D? {
-			lappend pathList $path
+			lappend path_list $path
 			if {$path eq $current_diff_path} {
 				set after {reshow_diff;}
 			}
 		}
 		}
 	}
-	if {$pathList eq {}} {
+	if {$path_list eq {}} {
 		unlock_index
 	} else {
 		update_indexinfo \
 			$txt \
-			$pathList \
+			$path_list \
 			[concat $after [list ui_ready]]
 	}
 }
@@ -305,7 +305,7 @@ proc add_helper {txt paths} {
 
 	if {![lock_index begin-update]} return
 
-	set pathList [list]
+	set path_list [list]
 	set after {}
 	foreach path $paths {
 		switch -glob -- [lindex $file_states($path) 0] {
@@ -321,19 +321,19 @@ proc add_helper {txt paths} {
 		?M -
 		?D -
 		?T {
-			lappend pathList $path
+			lappend path_list $path
 			if {$path eq $current_diff_path} {
 				set after {reshow_diff;}
 			}
 		}
 		}
 	}
-	if {$pathList eq {}} {
+	if {$path_list eq {}} {
 		unlock_index
 	} else {
 		update_index \
 			$txt \
-			$pathList \
+			$path_list \
 			[concat $after {ui_status [mc "Ready to commit."]}]
 	}
 }
@@ -393,7 +393,7 @@ proc revert_helper {txt paths} {
 
 	if {![lock_index begin-update]} return
 
-	set pathList [list]
+	set path_list [list]
 	set after {}
 	foreach path $paths {
 		switch -glob -- [lindex $file_states($path) 0] {
@@ -401,7 +401,7 @@ proc revert_helper {txt paths} {
 		?M -
 		?T -
 		?D {
-			lappend pathList $path
+			lappend path_list $path
 			if {$path eq $current_diff_path} {
 				set after {reshow_diff;}
 			}
@@ -420,12 +420,12 @@ proc revert_helper {txt paths} {
 	# as they have quite complex plural-form rules. Unfortunately,
 	# msgcat doesn't seem to support that kind of string translation.
 	#
-	set n [llength $pathList]
+	set n [llength $path_list]
 	if {$n == 0} {
 		unlock_index
 		return
 	} elseif {$n == 1} {
-		set query [mc "Revert changes in file %s?" [short_path [lindex $pathList]]]
+		set query [mc "Revert changes in file %s?" [short_path [lindex $path_list]]]
 	} else {
 		set query [mc "Revert changes in these %i files?" $n]
 	}
@@ -444,7 +444,7 @@ proc revert_helper {txt paths} {
 	if {$reply == 1} {
 		checkout_index \
 			$txt \
-			$pathList \
+			$path_list \
 			[concat $after [list ui_ready]]
 	} else {
 		unlock_index
-- 
gitgitgadget

[PATCH v7 2/3] git-gui: update status bar to track operations

[Jonathan Gilbert via GitGitGadget]

From: Jonathan Gilbert <JonathanG@iQmetrix.com>

Update the status bar to track updates as individual "operations" that
can overlap. Update all call sites to interact with the new status bar
mechanism. Update initialization to explicitly clear status text,
since otherwise it may persist across future operations.

Signed-off-by: Jonathan Gilbert <JonathanG@iQmetrix.com>
---
 git-gui.sh                |  27 +++--
 lib/blame.tcl             |  24 ++--
 lib/checkout_op.tcl       |  15 +--
 lib/choose_repository.tcl | 120 +++++++++++++-------
 lib/index.tcl             |  31 +++--
 lib/merge.tcl             |  14 ++-
 lib/status_bar.tcl        | 231 +++++++++++++++++++++++++++++++++-----
 7 files changed, 354 insertions(+), 108 deletions(-)

diff --git a/git-gui.sh b/git-gui.sh
index 0d21f5688b..e317f528af 100755
--- a/git-gui.sh
+++ b/git-gui.sh
@@ -1797,10 +1797,10 @@ proc ui_status {msg} {
 	}
 }
 
-proc ui_ready {{test {}}} {
+proc ui_ready {} {
 	global main_status
 	if {[info exists main_status]} {
-		$main_status show [mc "Ready."] $test
+		$main_status show [mc "Ready."]
 	}
 }
 
@@ -2150,8 +2150,6 @@ proc incr_font_size {font {amt 1}} {
 ##
 ## ui commands
 
-set starting_gitk_msg [mc "Starting gitk... please wait..."]
-
 proc do_gitk {revs {is_submodule false}} {
 	global current_diff_path file_states current_diff_side ui_index
 	global _gitdir _gitworktree
@@ -2206,10 +2204,11 @@ proc do_gitk {revs {is_submodule false}} {
 		set env(GIT_WORK_TREE) $_gitworktree
 		cd $pwd
 
-		ui_status $::starting_gitk_msg
-		after 10000 {
-			ui_ready $starting_gitk_msg
-		}
+		set status_operation [$::main_status \
+			start \
+			[mc "Starting %s... please wait..." "gitk"]]
+
+		after 3500 [list $status_operation stop]
 	}
 }
 
@@ -2240,10 +2239,11 @@ proc do_git_gui {} {
 		set env(GIT_WORK_TREE) $_gitworktree
 		cd $pwd
 
-		ui_status $::starting_gitk_msg
-		after 10000 {
-			ui_ready $starting_gitk_msg
-		}
+		set status_operation [$::main_status \
+			start \
+			[mc "Starting %s... please wait..." "git-gui"]]
+
+		after 3500 [list $status_operation stop]
 	}
 }
 
@@ -4159,6 +4159,9 @@ if {$picked && [is_config_true gui.autoexplore]} {
 	do_explore
 }
 
+# Clear "Initializing..." status
+after 500 {$main_status show ""}
+
 # Local variables:
 # mode: tcl
 # indent-tabs-mode: t
diff --git a/lib/blame.tcl b/lib/blame.tcl
index a1aeb8b96e..62ec083667 100644
--- a/lib/blame.tcl
+++ b/lib/blame.tcl
@@ -24,6 +24,7 @@ field w_cviewer  ; # pane showing commit message
 field finder     ; # find mini-dialog frame
 field gotoline   ; # line goto mini-dialog frame
 field status     ; # status mega-widget instance
+field status_operation ; # operation displayed by status mega-widget
 field old_height ; # last known height of $w.file_pane
 
 
@@ -274,6 +275,7 @@ constructor new {i_commit i_path i_jump} {
 	pack $w_cviewer -expand 1 -fill both
 
 	set status [::status_bar::new $w.status]
+	set status_operation {}
 
 	menu $w.ctxm -tearoff 0
 	$w.ctxm add command \
@@ -602,16 +604,23 @@ method _exec_blame {cur_w cur_d options cur_s} {
 	} else {
 		lappend options $commit
 	}
+
+	# We may recurse in from another call to _exec_blame and already have
+	# a status operation.
+	if {$status_operation == {}} {
+		set status_operation [$status start \
+			$cur_s \
+			[mc "lines annotated"]]
+	} else {
+		$status_operation restart $cur_s
+	}
+
 	lappend options -- $path
 	set fd [eval git_read --nice blame $options]
 	fconfigure $fd -blocking 0 -translation lf -encoding utf-8
 	fileevent $fd readable [cb _read_blame $fd $cur_w $cur_d]
 	set current_fd $fd
 	set blame_lines 0
-
-	$status start \
-		$cur_s \
-		[mc "lines annotated"]
 }
 
 method _read_blame {fd cur_w cur_d} {
@@ -806,10 +815,11 @@ method _read_blame {fd cur_w cur_d} {
 				[mc "Loading original location annotations..."]
 		} else {
 			set current_fd {}
-			$status stop [mc "Annotation complete."]
+			$status_operation stop [mc "Annotation complete."]
+			set status_operation {}
 		}
 	} else {
-		$status update $blame_lines $total_lines
+		$status_operation update $blame_lines $total_lines
 	}
 } ifdeleted { catch {close $fd} }
 
@@ -1124,7 +1134,7 @@ method _blameparent {} {
 			set diffcmd [list diff-tree --unified=0 $cparent $cmit -- $new_path]
 		}
 		if {[catch {set fd [eval git_read $diffcmd]} err]} {
-			$status stop [mc "Unable to display parent"]
+			$status_operation stop [mc "Unable to display parent"]
 			error_popup [strcat [mc "Error loading diff:"] "\n\n$err"]
 			return
 		}
diff --git a/lib/checkout_op.tcl b/lib/checkout_op.tcl
index a5228297db..21ea768d80 100644
--- a/lib/checkout_op.tcl
+++ b/lib/checkout_op.tcl
@@ -341,9 +341,9 @@ method _readtree {} {
 	global HEAD
 
 	set readtree_d {}
-	$::main_status start \
+	set status_bar_operation [$::main_status start \
 		[mc "Updating working directory to '%s'..." [_name $this]] \
-		[mc "files checked out"]
+		[mc "files checked out"]]
 
 	set fd [git_read --stderr read-tree \
 		-m \
@@ -354,26 +354,27 @@ method _readtree {} {
 		$new_hash \
 		]
 	fconfigure $fd -blocking 0 -translation binary
-	fileevent $fd readable [cb _readtree_wait $fd]
+	fileevent $fd readable [cb _readtree_wait $fd $status_bar_operation]
 }
 
-method _readtree_wait {fd} {
+method _readtree_wait {fd status_bar_operation} {
 	global current_branch
 
 	set buf [read $fd]
-	$::main_status update_meter $buf
+	$status_bar_operation update_meter $buf
 	append readtree_d $buf
 
 	fconfigure $fd -blocking 1
 	if {![eof $fd]} {
 		fconfigure $fd -blocking 0
+		$status_bar_operation stop
 		return
 	}
 
 	if {[catch {close $fd}]} {
 		set err $readtree_d
 		regsub {^fatal: } $err {} err
-		$::main_status stop [mc "Aborted checkout of '%s' (file level merging is required)." [_name $this]]
+		$status_bar_operation stop [mc "Aborted checkout of '%s' (file level merging is required)." [_name $this]]
 		warn_popup [strcat [mc "File level merge required."] "
 
 $err
@@ -384,7 +385,7 @@ $err
 		return
 	}
 
-	$::main_status stop
+	$status_bar_operation stop
 	_after_readtree $this
 }
 
diff --git a/lib/choose_repository.tcl b/lib/choose_repository.tcl
index 80f5a59bbb..e54f3e66d8 100644
--- a/lib/choose_repository.tcl
+++ b/lib/choose_repository.tcl
@@ -9,6 +9,18 @@ field w_body      ; # Widget holding the center content
 field w_next      ; # Next button
 field w_quit      ; # Quit button
 field o_cons      ; # Console object (if active)
+
+# Status mega-widget instance during _do_clone2 (used by _copy_files and
+# _link_files). Widget is destroyed before _do_clone2 calls
+# _do_clone_checkout
+field o_status
+
+# Operation displayed by status mega-widget during _do_clone_checkout =>
+# _readtree_wait => _postcheckout_wait => _do_clone_submodules =>
+# _do_validate_submodule_cloning. The status mega-widget is a different
+# instance than that stored in $o_status in earlier operations.
+field o_status_op
+
 field w_types     ; # List of type buttons in clone
 field w_recentlist ; # Listbox containing recent repositories
 field w_localpath  ; # Entry widget bound to local_path
@@ -659,12 +671,12 @@ method _do_clone2 {} {
 
 	switch -exact -- $clone_type {
 	hardlink {
-		set o_cons [status_bar::two_line $w_body]
+		set o_status [status_bar::two_line $w_body]
 		pack $w_body -fill x -padx 10 -pady 10
 
-		$o_cons start \
+		set status_op [$o_status start \
 			[mc "Counting objects"] \
-			[mc "buckets"]
+			[mc "buckets"]]
 		update
 
 		if {[file exists [file join $objdir info alternates]]} {
@@ -689,6 +701,7 @@ method _do_clone2 {} {
 			} err]} {
 				catch {cd $pwd}
 				_clone_failed $this [mc "Unable to copy objects/info/alternates: %s" $err]
+				$status_op stop
 				return
 			}
 		}
@@ -700,7 +713,7 @@ method _do_clone2 {} {
 			-directory [file join $objdir] ??]
 		set bcnt [expr {[llength $buckets] + 2}]
 		set bcur 1
-		$o_cons update $bcur $bcnt
+		$status_op update $bcur $bcnt
 		update
 
 		file mkdir [file join .git objects pack]
@@ -708,7 +721,7 @@ method _do_clone2 {} {
 			-directory [file join $objdir pack] *] {
 			lappend tolink [file join pack $i]
 		}
-		$o_cons update [incr bcur] $bcnt
+		$status_op update [incr bcur] $bcnt
 		update
 
 		foreach i $buckets {
@@ -717,10 +730,10 @@ method _do_clone2 {} {
 				-directory [file join $objdir $i] *] {
 				lappend tolink [file join $i $j]
 			}
-			$o_cons update [incr bcur] $bcnt
+			$status_op update [incr bcur] $bcnt
 			update
 		}
-		$o_cons stop
+		$status_op stop
 
 		if {$tolink eq {}} {
 			info_popup [strcat \
@@ -747,6 +760,8 @@ method _do_clone2 {} {
 		if {!$i} return
 
 		destroy $w_body
+
+		set o_status {}
 	}
 	full {
 		set o_cons [console::embed \
@@ -781,9 +796,9 @@ method _do_clone2 {} {
 }
 
 method _copy_files {objdir tocopy} {
-	$o_cons start \
+	set status_op [$o_status start \
 		[mc "Copying objects"] \
-		[mc "KiB"]
+		[mc "KiB"]]
 	set tot 0
 	set cmp 0
 	foreach p $tocopy {
@@ -798,7 +813,7 @@ method _copy_files {objdir tocopy} {
 
 				while {![eof $f_in]} {
 					incr cmp [fcopy $f_in $f_cp -size 16384]
-					$o_cons update \
+					$status_op update \
 						[expr {$cmp / 1024}] \
 						[expr {$tot / 1024}]
 					update
@@ -808,17 +823,19 @@ method _copy_files {objdir tocopy} {
 				close $f_cp
 			} err]} {
 			_clone_failed $this [mc "Unable to copy object: %s" $err]
+			$status_op stop
 			return 0
 		}
 	}
+	$status_op stop
 	return 1
 }
 
 method _link_files {objdir tolink} {
 	set total [llength $tolink]
-	$o_cons start \
+	set status_op [$o_status start \
 		[mc "Linking objects"] \
-		[mc "objects"]
+		[mc "objects"]]
 	for {set i 0} {$i < $total} {} {
 		set p [lindex $tolink $i]
 		if {[catch {
@@ -827,15 +844,17 @@ method _link_files {objdir tolink} {
 					[file join $objdir $p]
 			} err]} {
 			_clone_failed $this [mc "Unable to hardlink object: %s" $err]
+			$status_op stop
 			return 0
 		}
 
 		incr i
 		if {$i % 5 == 0} {
-			$o_cons update $i $total
+			$status_op update $i $total
 			update
 		}
 	}
+	$status_op stop
 	return 1
 }
 
@@ -958,11 +977,26 @@ method _do_clone_checkout {HEAD} {
 		return
 	}
 
-	set o_cons [status_bar::two_line $w_body]
+	set status [status_bar::two_line $w_body]
 	pack $w_body -fill x -padx 10 -pady 10
-	$o_cons start \
+
+	# We start the status operation here.
+	#
+	# This function calls _readtree_wait as a callback.
+	#
+	# _readtree_wait in turn either calls _do_clone_submodules directly,
+	# or calls _postcheckout_wait as a callback which then calls
+	# _do_clone_submodules.
+	#
+	# _do_clone_submodules calls _do_validate_submodule_cloning.
+	#
+	# _do_validate_submodule_cloning stops the status operation.
+	#
+	# There are no other calls into this chain from other code.
+
+	set o_status_op [$status start \
 		[mc "Creating working directory"] \
-		[mc "files"]
+		[mc "files"]]
 
 	set readtree_err {}
 	set fd [git_read --stderr read-tree \
@@ -976,33 +1010,9 @@ method _do_clone_checkout {HEAD} {
 	fileevent $fd readable [cb _readtree_wait $fd]
 }
 
-method _do_validate_submodule_cloning {ok} {
-	if {$ok} {
-		$o_cons done $ok
-		set done 1
-	} else {
-		_clone_failed $this [mc "Cannot clone submodules."]
-	}
-}
-
-method _do_clone_submodules {} {
-	if {$recursive eq {true}} {
-		destroy $w_body
-		set o_cons [console::embed \
-			$w_body \
-			[mc "Cloning submodules"]]
-		pack $w_body -fill both -expand 1 -padx 10
-		$o_cons exec \
-			[list git submodule update --init --recursive] \
-			[cb _do_validate_submodule_cloning]
-	} else {
-		set done 1
-	}
-}
-
 method _readtree_wait {fd} {
 	set buf [read $fd]
-	$o_cons update_meter $buf
+	$o_status_op update_meter $buf
 	append readtree_err $buf
 
 	fconfigure $fd -blocking 1
@@ -1050,6 +1060,34 @@ method _postcheckout_wait {fd_ph} {
 	fconfigure $fd_ph -blocking 0
 }
 
+method _do_clone_submodules {} {
+	if {$recursive eq {true}} {
+		$o_status_op stop
+		set o_status_op {}
+
+		destroy $w_body
+
+		set o_cons [console::embed \
+			$w_body \
+			[mc "Cloning submodules"]]
+		pack $w_body -fill both -expand 1 -padx 10
+		$o_cons exec \
+			[list git submodule update --init --recursive] \
+			[cb _do_validate_submodule_cloning]
+	} else {
+		set done 1
+	}
+}
+
+method _do_validate_submodule_cloning {ok} {
+	if {$ok} {
+		$o_cons done $ok
+		set done 1
+	} else {
+		_clone_failed $this [mc "Cannot clone submodules."]
+	}
+}
+
 ######################################################################
 ##
 ## Open Existing Repository
diff --git a/lib/index.tcl b/lib/index.tcl
index 28d4d2a54e..62f4773ef4 100644
--- a/lib/index.tcl
+++ b/lib/index.tcl
@@ -45,13 +45,13 @@ proc _close_updateindex {fd after} {
 		wm deiconify $w
 		tkwait window $w
 
-		$::main_status stop
+		$::main_status stop_all
 		unlock_index
 		rescan $after 0
 		return
 	}
 
-	$::main_status stop
+	$::main_status stop_all
 	unlock_index
 	uplevel #0 $after
 }
@@ -67,7 +67,7 @@ proc update_indexinfo {msg path_list after} {
 	set batch [expr {int($total_cnt * .01) + 1}]
 	if {$batch > 25} {set batch 25}
 
-	$::main_status start $msg [mc "files"]
+	set status_bar_operation [$::main_status start $msg [mc "files"]]
 	set fd [git_write update-index -z --index-info]
 	fconfigure $fd \
 		-blocking 0 \
@@ -81,15 +81,18 @@ proc update_indexinfo {msg path_list after} {
 		$path_list \
 		$total_cnt \
 		$batch \
+		$status_bar_operation \
 		$after \
 		]
 }
 
-proc write_update_indexinfo {fd path_list total_cnt batch after} {
+proc write_update_indexinfo {fd path_list total_cnt batch status_bar_operation \
+	after} {
 	global update_index_cp
 	global file_states current_diff_path
 
 	if {$update_index_cp >= $total_cnt} {
+		$status_bar_operation stop
 		_close_updateindex $fd $after
 		return
 	}
@@ -119,7 +122,7 @@ proc write_update_indexinfo {fd path_list total_cnt batch after} {
 		display_file $path $new
 	}
 
-	$::main_status update $update_index_cp $total_cnt
+	$status_bar_operation update $update_index_cp $total_cnt
 }
 
 proc update_index {msg path_list after} {
@@ -133,7 +136,7 @@ proc update_index {msg path_list after} {
 	set batch [expr {int($total_cnt * .01) + 1}]
 	if {$batch > 25} {set batch 25}
 
-	$::main_status start $msg [mc "files"]
+	set status_bar_operation [$::main_status start $msg [mc "files"]]
 	set fd [git_write update-index --add --remove -z --stdin]
 	fconfigure $fd \
 		-blocking 0 \
@@ -147,15 +150,18 @@ proc update_index {msg path_list after} {
 		$path_list \
 		$total_cnt \
 		$batch \
+		$status_bar_operation \
 		$after \
 		]
 }
 
-proc write_update_index {fd path_list total_cnt batch after} {
+proc write_update_index {fd path_list total_cnt batch status_bar_operation \
+	after} {
 	global update_index_cp
 	global file_states current_diff_path
 
 	if {$update_index_cp >= $total_cnt} {
+		$status_bar_operation stop
 		_close_updateindex $fd $after
 		return
 	}
@@ -190,7 +196,7 @@ proc write_update_index {fd path_list total_cnt batch after} {
 		display_file $path $new
 	}
 
-	$::main_status update $update_index_cp $total_cnt
+	$status_bar_operation update $update_index_cp $total_cnt
 }
 
 proc checkout_index {msg path_list after} {
@@ -204,7 +210,7 @@ proc checkout_index {msg path_list after} {
 	set batch [expr {int($total_cnt * .01) + 1}]
 	if {$batch > 25} {set batch 25}
 
-	$::main_status start $msg [mc "files"]
+	set status_bar_operation [$::main_status start $msg [mc "files"]]
 	set fd [git_write checkout-index \
 		--index \
 		--quiet \
@@ -224,15 +230,18 @@ proc checkout_index {msg path_list after} {
 		$path_list \
 		$total_cnt \
 		$batch \
+		$status_bar_operation \
 		$after \
 		]
 }
 
-proc write_checkout_index {fd path_list total_cnt batch after} {
+proc write_checkout_index {fd path_list total_cnt batch status_bar_operation \
+	after} {
 	global update_index_cp
 	global file_states current_diff_path
 
 	if {$update_index_cp >= $total_cnt} {
+		$status_bar_operation stop
 		_close_updateindex $fd $after
 		return
 	}
@@ -253,7 +262,7 @@ proc write_checkout_index {fd path_list total_cnt batch after} {
 		}
 	}
 
-	$::main_status update $update_index_cp $total_cnt
+	$status_bar_operation update $update_index_cp $total_cnt
 }
 
 proc unstage_helper {txt paths} {
diff --git a/lib/merge.tcl b/lib/merge.tcl
index 9f253db5b3..8df8ffae55 100644
--- a/lib/merge.tcl
+++ b/lib/merge.tcl
@@ -241,23 +241,27 @@ Continue with resetting the current changes?"]
 	if {[ask_popup $op_question] eq {yes}} {
 		set fd [git_read --stderr read-tree --reset -u -v HEAD]
 		fconfigure $fd -blocking 0 -translation binary
-		fileevent $fd readable [namespace code [list _reset_wait $fd]]
-		$::main_status start [mc "Aborting"] [mc "files reset"]
+		set status_bar_operation [$::main_status \
+			start \
+			[mc "Aborting"] \
+			[mc "files reset"]
+		fileevent $fd readable [namespace code [list \
+			_reset_wait $fd $status_bar_operation]]
 	} else {
 		unlock_index
 	}
 }
 
-proc _reset_wait {fd} {
+proc _reset_wait {fd status_bar_operation} {
 	global ui_comm
 
-	$::main_status update_meter [read $fd]
+	$status_bar_operation update_meter [read $fd]
 
 	fconfigure $fd -blocking 1
 	if {[eof $fd]} {
 		set fail [catch {close $fd} err]
-		$::main_status stop
 		unlock_index
+		$status_bar_operation stop
 
 		$ui_comm delete 0.0 end
 		$ui_comm edit modified false
diff --git a/lib/status_bar.tcl b/lib/status_bar.tcl
index 02111a1742..d32b14142f 100644
--- a/lib/status_bar.tcl
+++ b/lib/status_bar.tcl
@@ -1,16 +1,42 @@
 # git-gui status bar mega-widget
 # Copyright (C) 2007 Shawn Pearce
 
+# The status_bar class manages the entire status bar. It is possible for
+# multiple overlapping asynchronous operations to want to display status
+# simultaneously. Each one receives a status_bar_operation when it calls the
+# start method, and the status bar combines all active operations into the
+# line of text it displays. Most of the time, there will be at most one
+# ongoing operation.
+#
+# Note that the entire status bar can be either in single-line or two-line
+# mode, depending on the constructor. Multiple active operations are only
+# supported for single-line status bars.
+
 class status_bar {
 
+field allow_multiple ; # configured at construction
+
 field w         ; # our own window path
 field w_l       ; # text widget we draw messages into
 field w_c       ; # canvas we draw a progress bar into
 field c_pack    ; # script to pack the canvas with
-field status  {}; # single line of text we show
-field prefix  {}; # text we format into status
-field units   {}; # unit of progress
-field meter   {}; # current core git progress meter (if active)
+
+field baseline_text   ; # text to show if there are no operations
+field status_bar_text ; # combined text for all operations
+
+field operations ; # list of current ongoing operations
+
+# The status bar can display a progress bar, updated when consumers call the
+# update method on their status_bar_operation. When there are multiple
+# operations, the status bar shows the combined status of all operations.
+#
+# When an overlapping operation completes, the progress bar is going to
+# abruptly have one fewer operation in the calculation, causing a discontinuity.
+# Therefore, whenever an operation completes, if it is not the last operation,
+# this counter is increased, and the progress bar is calculated as though there
+# were still another operation at 100%. When the last operation completes, this
+# is reset to 0.
+field completed_operation_count
 
 constructor new {path} {
 	global use_ttk NS
@@ -18,12 +44,19 @@ constructor new {path} {
 	set w_l $w.l
 	set w_c $w.c
 
+	# Standard single-line status bar: Permit overlapping operations
+	set allow_multiple 1
+
+	set baseline_text ""
+	set operations [list]
+	set completed_operation_count 0
+
 	${NS}::frame $w
 	if {!$use_ttk} {
 		$w configure -borderwidth 1 -relief sunken
 	}
 	${NS}::label $w_l \
-		-textvariable @status \
+		-textvariable @status_bar_text \
 		-anchor w \
 		-justify left
 	pack $w_l -side left
@@ -44,9 +77,16 @@ constructor two_line {path} {
 	set w_l $w.l
 	set w_c $w.c
 
+	# Two-line status bar: Only one ongoing operation permitted.
+	set allow_multiple 0
+
+	set baseline_text ""
+	set operations [list]
+	set completed_operation_count 0
+
 	${NS}::frame $w
 	${NS}::label $w_l \
-		-textvariable @status \
+		-textvariable @status_bar_text \
 		-anchor w \
 		-justify left
 	pack $w_l -anchor w -fill x
@@ -56,7 +96,7 @@ constructor two_line {path} {
 	return $this
 }
 
-method start {msg uds} {
+method ensure_canvas {} {
 	if {[winfo exists $w_c]} {
 		$w_c coords bar 0 0 0 20
 	} else {
@@ -68,31 +108,170 @@ method start {msg uds} {
 		$w_c create rectangle 0 0 0 20 -tags bar -fill navy
 		eval $c_pack
 	}
+}
+
+method show {msg} {
+	$this ensure_canvas
+	set baseline_text $msg
+	$this refresh
+}
+
+method start {msg {uds {}}} {
+	set baseline_text ""
+
+	if {!$allow_multiple && [llength $operations]} {
+		return [lindex $operations 0]
+	}
+
+	$this ensure_canvas
+
+	set operation [status_bar_operation::new $this $msg $uds]
+
+	lappend operations $operation
+
+	$this refresh
+
+	return $operation
+}
+
+method refresh {} {
+	set new_text ""
+
+	set total [expr $completed_operation_count * 100]
+	set have $total
+
+	foreach operation $operations {
+		if {$new_text != ""} {
+			append new_text " / "
+		}
+
+		append new_text [$operation get_status]
+
+		set total [expr $total + 100]
+		set have [expr $have + [$operation get_progress]]
+	}
+
+	if {$new_text == ""} {
+		set new_text $baseline_text
+	}
+
+	set status_bar_text $new_text
+
+	if {[winfo exists $w_c]} {
+		set pixel_width 0
+		if {$have > 0} {
+			set pixel_width [expr {[winfo width $w_c] * $have / $total}]
+		}
+
+		$w_c coords bar 0 0 $pixel_width 20
+	}
+}
+
+method stop {operation stop_msg} {
+	set idx [lsearch $operations $operation]
+
+	if {$idx >= 0} {
+		set operations [lreplace $operations $idx $idx]
+		set completed_operation_count [expr \
+			$completed_operation_count + 1]
+
+		if {[llength $operations] == 0} {
+			set completed_operation_count 0
+
+			destroy $w_c
+			if {$stop_msg ne {}} {
+				set baseline_text $stop_msg
+			}
+		}
+
+		$this refresh
+	}
+}
+
+method stop_all {{stop_msg {}}} {
+	# This makes the operation's call to stop a no-op.
+	set operations_copy $operations
+	set operations [list]
+
+	foreach operation $operations_copy {
+		$operation stop
+	}
+
+	if {$stop_msg ne {}} {
+		set baseline_text $stop_msg
+	}
+
+	$this refresh
+}
+
+method _delete {current} {
+	if {$current eq $w} {
+		delete_this
+	}
+}
+
+}
+
+# The status_bar_operation class tracks a single consumer's ongoing status bar
+# activity, with the context that there are a few situations where multiple
+# overlapping asynchronous operations might want to display status information
+# simultaneously. Instances of status_bar_operation are created by calling
+# start on the status_bar, and when the caller is done with its stauts bar
+# operation, it calls stop on the operation.
+
+class status_bar_operation {
+
+field status_bar; # reference back to the status_bar that owns this object
+
+field is_active;
+
+field status   {}; # single line of text we show
+field progress {}; # current progress (0 to 100)
+field prefix   {}; # text we format into status
+field units    {}; # unit of progress
+field meter    {}; # current core git progress meter (if active)
+
+constructor new {owner msg uds} {
+	set status_bar $owner
 
 	set status $msg
+	set progress 0
 	set prefix $msg
 	set units  $uds
 	set meter  {}
+
+	set is_active 1
+
+	return $this
 }
 
+method get_is_active {} { return $is_active }
+method get_status {} { return $status }
+method get_progress {} { return $progress }
+
 method update {have total} {
-	set pdone 0
-	set cdone 0
+	if {!$is_active} { return }
+
+	set progress 0
+
 	if {$total > 0} {
-		set pdone [expr {100 * $have / $total}]
-		set cdone [expr {[winfo width $w_c] * $have / $total}]
+		set progress [expr {100 * $have / $total}]
 	}
 
 	set prec [string length [format %i $total]]
+
 	set status [mc "%s ... %*i of %*i %s (%3i%%)" \
 		$prefix \
 		$prec $have \
 		$prec $total \
-		$units $pdone]
-	$w_c coords bar 0 0 $cdone 20
+		$units $progress]
+
+	$status_bar refresh
 }
 
 method update_meter {buf} {
+	if {!$is_active} { return }
+
 	append meter $buf
 	set r [string last "\r" $meter]
 	if {$r == -1} {
@@ -109,23 +288,25 @@ method update_meter {buf} {
 	}
 }
 
-method stop {{msg {}}} {
-	destroy $w_c
-	if {$msg ne {}} {
-		set status $msg
+method stop {{stop_msg {}}} {
+	if {$is_active} {
+		set is_active 0
+		$status_bar stop $this $stop_msg
 	}
 }
 
-method show {msg {test {}}} {
-	if {$test eq {} || $status eq $test} {
-		set status $msg
-	}
+method restart {msg} {
+	if {!$is_active} { return }
+
+	set status $msg
+	set prefix $msg
+	set meter {}
+	$status_bar refresh
 }
 
-method _delete {current} {
-	if {$current eq $w} {
-		delete_this
-	}
+method _delete {} {
+	stop
+	delete_this
 }
 
 }
-- 
gitgitgadget

Re: [PATCH v7 2/3] git-gui: update status bar to track operations

[Benjamin Poirier]

On 2019/12/01 02:28 +0000, Jonathan Gilbert via GitGitGadget wrote:
> From: Jonathan Gilbert <JonathanG@iQmetrix.com>
> 
> Update the status bar to track updates as individual "operations" that
> can overlap. Update all call sites to interact with the new status bar
> mechanism. Update initialization to explicitly clear status text,
> since otherwise it may persist across future operations.
> 
> Signed-off-by: Jonathan Gilbert <JonathanG@iQmetrix.com>
> ---

Hi Jonathan,

It appears that this change has caused a regression when using git-gui
blame <file> -> right click on a source line -> "Show History Context"

There is an "Application Error" window that appears with the following
details:
can't read "::main_status": no such variable
can't read "::main_status": no such variable
    while executing
"$::main_status  start  [mc "Starting %s... please wait..." "gitk"]"
    (procedure "do_gitk" line 55)
    invoked from within
"do_gitk $cmdline"
    (procedure "blame::_gitkcommit" line 47)
    invoked from within
"blame::_gitkcommit ::blame::__o1::__d"
    invoked from within
".ctxm invoke active"
    ("uplevel" body line 1)
    invoked from within
"uplevel #0 [list $w invoke active]"
    (procedure "tk::MenuInvoke" line 50)
    invoked from within
"tk::MenuInvoke .ctxm 1"
    (command bound to event)

The rest of the functionality seems unaffected but it's pretty annoying
to have to dismiss this message each time.

Can you please look into it?

Re: [PATCH v7 2/3] git-gui: update status bar to track operations

[Pratyush Yadav]

Hi Benjamin,

On 26/02/20 05:24PM, Benjamin Poirier wrote:
> On 2019/12/01 02:28 +0000, Jonathan Gilbert via GitGitGadget wrote:
> > From: Jonathan Gilbert <JonathanG@iQmetrix.com>
> > 
> > Update the status bar to track updates as individual "operations" that
> > can overlap. Update all call sites to interact with the new status bar
> > mechanism. Update initialization to explicitly clear status text,
> > since otherwise it may persist across future operations.
> > 
> > Signed-off-by: Jonathan Gilbert <JonathanG@iQmetrix.com>
> > ---
> 
> Hi Jonathan,
> 
> It appears that this change has caused a regression when using git-gui
> blame <file> -> right click on a source line -> "Show History Context"
> 
> There is an "Application Error" window that appears with the following
> details:
> can't read "::main_status": no such variable
> can't read "::main_status": no such variable
>     while executing
> "$::main_status  start  [mc "Starting %s... please wait..." "gitk"]"
>     (procedure "do_gitk" line 55)
>     invoked from within
> "do_gitk $cmdline"
>     (procedure "blame::_gitkcommit" line 47)
>     invoked from within
> "blame::_gitkcommit ::blame::__o1::__d"
>     invoked from within
> ".ctxm invoke active"
>     ("uplevel" body line 1)
>     invoked from within
> "uplevel #0 [list $w invoke active]"
>     (procedure "tk::MenuInvoke" line 50)
>     invoked from within
> "tk::MenuInvoke .ctxm 1"
>     (command bound to event)
> 
> The rest of the functionality seems unaffected but it's pretty annoying
> to have to dismiss this message each time.
> 
> Can you please look into it?

Does the following patch fix the problem? I will submit a proper patch 
soon.

-----8<-----
diff --git a/git-gui.sh b/git-gui.sh
index f41ed2e..d939844 100755
--- a/git-gui.sh
+++ b/git-gui.sh
@@ -2205,11 +2205,13 @@ proc do_gitk {revs {is_submodule false}} {
 		set env(GIT_WORK_TREE) $_gitworktree
 		cd $pwd

-		set status_operation [$::main_status \
-			start \
-			[mc "Starting %s... please wait..." "gitk"]]
+		if {[info exists main_status]} {
+			set status_operation [$::main_status \
+				start \
+				[mc "Starting %s... please wait..." "gitk"]]

-		after 3500 [list $status_operation stop]
+			after 3500 [list $status_operation stop]
+		}
 	}
 }
-----8<-----

-- 
Regards,
Pratyush Yadav

[PATCH v7 3/3] git-gui: revert untracked files by deleting them

[Jonathan Gilbert via GitGitGadget]

From: Jonathan Gilbert <JonathanG@iQmetrix.com>

Update the revert_helper proc to check for untracked files as well as
changes, and then handle changes to be reverted and untracked files with
independent blocks of code. Prompt the user independently for untracked
files, since the underlying action is fundamentally different (rm -f).
If after deleting untracked files, the directory containing them becomes
empty, then remove the directory as well. Migrate unlocking of the index
out of _close_updateindex to a responsibility of the caller, to permit
paths that don't directly unlock the index, and refactor the error
handling added in d4e890e5 so that callers can make flow control
decisions in the event of errors. Update Tcl/Tk dependency from 8.4 to
8.6 in git-gui.sh.

A new proc delete_files takes care of actually deleting the files in
batches, using the Tcler's Wiki recommended approach for keeping the UI
responsive.

Since the checkout_index and delete_files calls are both asynchronous
and could potentially complete in any order, a "chord" is used to
coordinate unlocking the index and returning the UI to a usable state
only after both operations are complete. The `SimpleChord` class,
based on TclOO (Tcl/Tk 8.6), is added in this commit.

Signed-off-by: Jonathan Gilbert <JonathanG@iQmetrix.com>
---
 git-gui.sh    |   4 +-
 lib/chord.tcl | 160 +++++++++++++++++++
 lib/index.tcl | 422 ++++++++++++++++++++++++++++++++++++++++----------
 3 files changed, 502 insertions(+), 84 deletions(-)
 create mode 100644 lib/chord.tcl

diff --git a/git-gui.sh b/git-gui.sh
index e317f528af..6dcf6551b6 100755
--- a/git-gui.sh
+++ b/git-gui.sh
@@ -30,8 +30,8 @@ along with this program; if not, see <http://www.gnu.org/licenses/>.}]
 ##
 ## Tcl/Tk sanity check
 
-if {[catch {package require Tcl 8.4} err]
- || [catch {package require Tk  8.4} err]
+if {[catch {package require Tcl 8.6} err]
+ || [catch {package require Tk  8.6} err]
 } {
 	catch {wm withdraw .}
 	tk_messageBox \
diff --git a/lib/chord.tcl b/lib/chord.tcl
new file mode 100644
index 0000000000..275a6cd4a1
--- /dev/null
+++ b/lib/chord.tcl
@@ -0,0 +1,160 @@
+# Simple Chord for Tcl
+#
+# A "chord" is a method with more than one entrypoint and only one body, such
+# that the body runs only once all the entrypoints have been called by
+# different asynchronous tasks. In this implementation, the chord is defined
+# dynamically for each invocation. A SimpleChord object is created, supplying
+# body script to be run when the chord is completed, and then one or more notes
+# are added to the chord. Each note can be called like a proc, and returns
+# immediately if the chord isn't yet complete. When the last remaining note is
+# called, the body runs before the note returns.
+#
+# The SimpleChord class has a constructor that takes the body script, and a
+# method add_note that returns a note object. Since the body script does not
+# run in the context of the procedure that defined it, a mechanism is provided
+# for injecting variables into the chord for use by the body script. The
+# activation of a note is idempotent; multiple calls have the same effect as
+# a simple call.
+#
+# If you are invoking asynchronous operations with chord notes as completion
+# callbacks, and there is a possibility that earlier operations could complete
+# before later ones are started, it is a good practice to create a "common"
+# note on the chord that prevents it from being complete until you're certain
+# you've added all the notes you need.
+#
+# Example:
+#
+#   # Turn off the UI while running a couple of async operations.
+#   lock_ui
+#
+#   set chord [SimpleChord new {
+#     unlock_ui
+#     # Note: $notice here is not referenced in the calling scope
+#     if {$notice} { info_popup $notice }
+#   }
+#
+#   # Configure a note to keep the chord from completing until
+#   # all operations have been initiated.
+#   set common_note [$chord add_note]
+#
+#   # Pass notes as 'after' callbacks to other operations
+#   async_operation $args [$chord add_note]
+#   other_async_operation $args [$chord add_note]
+#
+#   # Communicate with the chord body
+#   if {$condition} {
+#     # This sets $notice in the same context that the chord body runs in.
+#     $chord eval { set notice "Something interesting" }
+#   }
+#
+#   # Activate the common note, making the chord eligible to complete
+#   $common_note
+#
+# At this point, the chord will complete at some unknown point in the future.
+# The common note might have been the first note activated, or the async
+# operations might have completed synchronously and the common note is the
+# last one, completing the chord before this code finishes, or anything in
+# between. The purpose of the chord is to not have to worry about the order.
+
+# SimpleChord class:
+#   Represents a procedure that conceptually has multiple entrypoints that must
+#   all be called before the procedure executes. Each entrypoint is called a
+#   "note". The chord is only "completed" when all the notes are "activated".
+oo::class create SimpleChord {
+	variable notes body is_completed
+
+	# Constructor:
+	#   set chord [SimpleChord new {body}]
+	#     Creates a new chord object with the specified body script. The
+	#     body script is evaluated at most once, when a note is activated
+	#     and the chord has no other non-activated notes.
+	constructor {body} {
+		set notes [list]
+		my eval [list set body $body]
+		set is_completed 0
+	}
+
+	# Method:
+	#   $chord eval {script}
+	#     Runs the specified script in the same context (namespace) in which
+	#     the chord body will be evaluated. This can be used to set variable
+	#     values for the chord body to use.
+	method eval {script} {
+		namespace eval [self] $script
+	}
+
+	# Method:
+	#   set note [$chord add_note]
+	#     Adds a new note to the chord, an instance of ChordNote. Raises an
+	#     error if the chord is already completed, otherwise the chord is
+	#     updated so that the new note must also be activated before the
+	#     body is evaluated.
+	method add_note {} {
+		if {$is_completed} { error "Cannot add a note to a completed chord" }
+
+		set note [ChordNote new [self]]
+
+		lappend notes $note
+
+		return $note
+	}
+
+	# This method is for internal use only and is intentionally undocumented.
+	method notify_note_activation {} {
+		if {!$is_completed} {
+			foreach note $notes {
+				if {![$note is_activated]} { return }
+			}
+
+			set is_completed 1
+
+			namespace eval [self] $body
+			namespace delete [self]
+		}
+	}
+}
+
+# ChordNote class:
+#   Represents a note within a chord, providing a way to activate it. When the
+#   final note of the chord is activated (this can be any note in the chord,
+#   with all other notes already previously activated in any order), the chord's
+#   body is evaluated.
+oo::class create ChordNote {
+	variable chord is_activated
+
+	# Constructor:
+	#   Instances of ChordNote are created internally by calling add_note on
+	#   SimpleChord objects.
+	constructor {chord} {
+		my eval set chord $chord
+		set is_activated 0
+	}
+
+	# Method:
+	#   [$note is_activated]
+	#     Returns true if this note has already been activated.
+	method is_activated {} {
+		return $is_activated
+	}
+
+	# Method:
+	#   $note
+	#     Activates the note, if it has not already been activated, and
+	#     completes the chord if there are no other notes awaiting
+	#     activation. Subsequent calls will have no further effect.
+	#
+	# NB: In TclOO, if an object is invoked like a method without supplying
+	#     any method name, then this internal method `unknown` is what
+	#     actually runs (with no parameters). It is used in the ChordNote
+	#     class for the purpose of allowing the note object to be called as
+	#     a function (see example above). (The `unknown` method can also be
+	#     used to support dynamic dispatch, but must take parameters to
+	#     identify the "unknown" method to be invoked. In this form, this
+	#     proc serves only to make instances behave directly like methods.)
+	method unknown {} {
+		if {!$is_activated} {
+			set is_activated 1
+			$chord notify_note_activation
+		}
+	}
+}
diff --git a/lib/index.tcl b/lib/index.tcl
index 62f4773ef4..1254145634 100644
--- a/lib/index.tcl
+++ b/lib/index.tcl
@@ -7,53 +7,60 @@ proc _delete_indexlock {} {
 	}
 }
 
-proc _close_updateindex {fd after} {
-	global use_ttk NS
-	fconfigure $fd -blocking 1
-	if {[catch {close $fd} err]} {
-		set w .indexfried
-		Dialog $w
-		wm withdraw $w
-		wm title $w [strcat "[appname] ([reponame]): " [mc "Index Error"]]
-		wm geometry $w "+[winfo rootx .]+[winfo rooty .]"
-		set s [mc "Updating the Git index failed.  A rescan will be automatically started to resynchronize git-gui."]
-		text $w.msg -yscrollcommand [list $w.vs set] \
-			-width [string length $s] -relief flat \
-			-borderwidth 0 -highlightthickness 0 \
-			-background [get_bg_color $w]
-		$w.msg tag configure bold -font font_uibold -justify center
-		${NS}::scrollbar $w.vs -command [list $w.msg yview]
-		$w.msg insert end $s bold \n\n$err {}
-		$w.msg configure -state disabled
-
-		${NS}::button $w.continue \
-			-text [mc "Continue"] \
-			-command [list destroy $w]
-		${NS}::button $w.unlock \
-			-text [mc "Unlock Index"] \
-			-command "destroy $w; _delete_indexlock"
-		grid $w.msg - $w.vs -sticky news
-		grid $w.unlock $w.continue - -sticky se -padx 2 -pady 2
-		grid columnconfigure $w 0 -weight 1
-		grid rowconfigure $w 0 -weight 1
-
-		wm protocol $w WM_DELETE_WINDOW update
-		bind $w.continue <Visibility> "
-			grab $w
-			focus %W
-		"
-		wm deiconify $w
-		tkwait window $w
-
-		$::main_status stop_all
+proc close_and_unlock_index {fd after} {
+	if {![catch {_close_updateindex $fd} err]} {
 		unlock_index
-		rescan $after 0
-		return
+		uplevel #0 $after
+	} else {
+		rescan_on_error $err $after
 	}
+}
+
+proc _close_updateindex {fd} {
+	fconfigure $fd -blocking 1
+	close $fd
+}
+
+proc rescan_on_error {err {after {}}} {
+	global use_ttk NS
+
+	set w .indexfried
+	Dialog $w
+	wm withdraw $w
+	wm title $w [strcat "[appname] ([reponame]): " [mc "Index Error"]]
+	wm geometry $w "+[winfo rootx .]+[winfo rooty .]"
+	set s [mc "Updating the Git index failed.  A rescan will be automatically started to resynchronize git-gui."]
+	text $w.msg -yscrollcommand [list $w.vs set] \
+		-width [string length $s] -relief flat \
+		-borderwidth 0 -highlightthickness 0 \
+		-background [get_bg_color $w]
+	$w.msg tag configure bold -font font_uibold -justify center
+	${NS}::scrollbar $w.vs -command [list $w.msg yview]
+	$w.msg insert end $s bold \n\n$err {}
+	$w.msg configure -state disabled
+
+	${NS}::button $w.continue \
+		-text [mc "Continue"] \
+		-command [list destroy $w]
+	${NS}::button $w.unlock \
+		-text [mc "Unlock Index"] \
+		-command "destroy $w; _delete_indexlock"
+	grid $w.msg - $w.vs -sticky news
+	grid $w.unlock $w.continue - -sticky se -padx 2 -pady 2
+	grid columnconfigure $w 0 -weight 1
+	grid rowconfigure $w 0 -weight 1
+
+	wm protocol $w WM_DELETE_WINDOW update
+	bind $w.continue <Visibility> "
+		grab $w
+		focus %W
+	"
+	wm deiconify $w
+	tkwait window $w
 
 	$::main_status stop_all
 	unlock_index
-	uplevel #0 $after
+	rescan [concat $after [list ui_ready]] 0
 }
 
 proc update_indexinfo {msg path_list after} {
@@ -93,7 +100,7 @@ proc write_update_indexinfo {fd path_list total_cnt batch status_bar_operation \
 
 	if {$update_index_cp >= $total_cnt} {
 		$status_bar_operation stop
-		_close_updateindex $fd $after
+		close_and_unlock_index $fd $after
 		return
 	}
 
@@ -162,7 +169,7 @@ proc write_update_index {fd path_list total_cnt batch status_bar_operation \
 
 	if {$update_index_cp >= $total_cnt} {
 		$status_bar_operation stop
-		_close_updateindex $fd $after
+		close_and_unlock_index $fd $after
 		return
 	}
 
@@ -199,7 +206,7 @@ proc write_update_index {fd path_list total_cnt batch status_bar_operation \
 	$status_bar_operation update $update_index_cp $total_cnt
 }
 
-proc checkout_index {msg path_list after} {
+proc checkout_index {msg path_list after capture_error} {
 	global update_index_cp
 
 	if {![lock_index update]} return
@@ -232,17 +239,33 @@ proc checkout_index {msg path_list after} {
 		$batch \
 		$status_bar_operation \
 		$after \
+		$capture_error \
 		]
 }
 
 proc write_checkout_index {fd path_list total_cnt batch status_bar_operation \
-	after} {
+	after capture_error} {
 	global update_index_cp
 	global file_states current_diff_path
 
 	if {$update_index_cp >= $total_cnt} {
 		$status_bar_operation stop
-		_close_updateindex $fd $after
+
+		# We do not unlock the index directly here because this
+		# operation expects to potentially run in parallel with file
+		# deletions scheduled by revert_helper. We're done with the
+		# update index, so we close it, but actually unlocking the index
+		# and dealing with potential errors is deferred to the chord
+		# body that runs when all async operations are completed.
+		#
+		# (See after_chord in revert_helper.)
+
+		if {[catch {_close_updateindex $fd} err]} {
+			uplevel #0 $capture_error [list $err]
+		}
+
+		uplevel #0 $after
+
 		return
 	}
 
@@ -397,66 +420,301 @@ proc do_add_all {} {
 	add_helper [mc "Adding all changed files"] $paths
 }
 
+# Copied from TclLib package "lambda".
+proc lambda {arguments body args} {
+	return [list ::apply [list $arguments $body] {*}$args]
+}
+
 proc revert_helper {txt paths} {
 	global file_states current_diff_path
 
 	if {![lock_index begin-update]} return
 
+	# Common "after" functionality that waits until multiple asynchronous
+	# operations are complete (by waiting for them to activate their notes
+	# on the chord).
+	#
+	# The asynchronous operations are each indicated below by a comment
+	# before the code block that starts the async operation.
+	set after_chord [SimpleChord new {
+		if {[string trim $err] != ""} {
+			rescan_on_error $err
+		} else {
+			unlock_index
+			if {$should_reshow_diff} { reshow_diff }
+			ui_ready
+		}
+	}]
+
+	$after_chord eval { set should_reshow_diff 0 }
+
+	# This function captures an error for processing when after_chord is
+	# completed. (The chord is curried into the lambda function.)
+	set capture_error [lambda \
+		{chord error} \
+		{ $chord eval [list set err $error] } \
+		$after_chord]
+
+	# We don't know how many notes we're going to create (it's dynamic based
+	# on conditional paths below), so create a common note that will delay
+	# the chord's completion until we activate it, and then activate it
+	# after all the other notes have been created.
+	set after_common_note [$after_chord add_note]
+
 	set path_list [list]
-	set after {}
+	set untracked_list [list]
+
 	foreach path $paths {
 		switch -glob -- [lindex $file_states($path) 0] {
 		U? {continue}
+		?O {
+			lappend untracked_list $path
+		}
 		?M -
 		?T -
 		?D {
 			lappend path_list $path
 			if {$path eq $current_diff_path} {
-				set after {reshow_diff;}
+				$after_chord eval { set should_reshow_diff 1 }
 			}
 		}
 		}
 	}
 
+	set path_cnt [llength $path_list]
+	set untracked_cnt [llength $untracked_list]
+
+	# Asynchronous operation: revert changes by checking them out afresh
+	# from the index.
+	if {$path_cnt > 0} {
+		# Split question between singular and plural cases, because
+		# such distinction is needed in some languages. Previously, the
+		# code used "Revert changes in" for both, but that can't work
+		# in languages where 'in' must be combined with word from
+		# rest of string (in different way for both cases of course).
+		#
+		# FIXME: Unfortunately, even that isn't enough in some languages
+		# as they have quite complex plural-form rules. Unfortunately,
+		# msgcat doesn't seem to support that kind of string
+		# translation.
+		#
+		if {$path_cnt == 1} {
+			set query [mc \
+				"Revert changes in file %s?" \
+				[short_path [lindex $path_list]] \
+				]
+		} else {
+			set query [mc \
+				"Revert changes in these %i files?" \
+				$path_cnt]
+		}
 
-	# Split question between singular and plural cases, because
-	# such distinction is needed in some languages. Previously, the
-	# code used "Revert changes in" for both, but that can't work
-	# in languages where 'in' must be combined with word from
-	# rest of string (in different way for both cases of course).
-	#
-	# FIXME: Unfortunately, even that isn't enough in some languages
-	# as they have quite complex plural-form rules. Unfortunately,
-	# msgcat doesn't seem to support that kind of string translation.
-	#
-	set n [llength $path_list]
-	if {$n == 0} {
-		unlock_index
-		return
-	} elseif {$n == 1} {
-		set query [mc "Revert changes in file %s?" [short_path [lindex $path_list]]]
-	} else {
-		set query [mc "Revert changes in these %i files?" $n]
+		set reply [tk_dialog \
+			.confirm_revert \
+			"[appname] ([reponame])" \
+			"$query
+
+[mc "Any unstaged changes will be permanently lost by the revert."]" \
+			question \
+			1 \
+			[mc "Do Nothing"] \
+			[mc "Revert Changes"] \
+			]
+
+		if {$reply == 1} {
+			checkout_index \
+				$txt \
+				$path_list \
+				[$after_chord add_note] \
+				$capture_error
+		}
 	}
 
-	set reply [tk_dialog \
-		.confirm_revert \
-		"[appname] ([reponame])" \
-		"$query
+	# Asynchronous operation: Deletion of untracked files.
+	if {$untracked_cnt > 0} {
+		# Split question between singular and plural cases, because
+		# such distinction is needed in some languages.
+		#
+		# FIXME: Unfortunately, even that isn't enough in some languages
+		# as they have quite complex plural-form rules. Unfortunately,
+		# msgcat doesn't seem to support that kind of string
+		# translation.
+		#
+		if {$untracked_cnt == 1} {
+			set query [mc \
+				"Delete untracked file %s?" \
+				[short_path [lindex $untracked_list]] \
+				]
+		} else {
+			set query [mc \
+				"Delete these %i untracked files?" \
+				$untracked_cnt \
+				]
+		}
 
-[mc "Any unstaged changes will be permanently lost by the revert."]" \
-		question \
-		1 \
-		[mc "Do Nothing"] \
-		[mc "Revert Changes"] \
-		]
-	if {$reply == 1} {
-		checkout_index \
-			$txt \
+		set reply [tk_dialog \
+			.confirm_revert \
+			"[appname] ([reponame])" \
+			"$query
+
+[mc "Files will be permanently deleted."]" \
+			question \
+			1 \
+			[mc "Do Nothing"] \
+			[mc "Delete Files"] \
+			]
+
+		if {$reply == 1} {
+			$after_chord eval { set should_reshow_diff 1 }
+
+			delete_files $untracked_list [$after_chord add_note]
+		}
+	}
+
+	# Activate the common note. If no other notes were created, this
+	# completes the chord. If other notes were created, then this common
+	# note prevents a race condition where the chord might complete early.
+	$after_common_note
+}
+
+# Delete all of the specified files, performing deletion in batches to allow the
+# UI to remain responsive and updated.
+proc delete_files {path_list after} {
+	# Enable progress bar status updates
+	set status_bar_operation [$::main_status \
+		start \
+		[mc "Deleting"] \
+		[mc "files"]]
+
+	set path_index 0
+	set deletion_errors [list]
+	set batch_size 50
+
+	delete_helper \
+		$path_list \
+		$path_index \
+		$deletion_errors \
+		$batch_size \
+		$status_bar_operation \
+		$after
+}
+
+# Helper function to delete a list of files in batches. Each call deletes one
+# batch of files, and then schedules a call for the next batch after any UI
+# messages have been processed.
+proc delete_helper {path_list path_index deletion_errors batch_size \
+	status_bar_operation after} {
+	global file_states
+
+	set path_cnt [llength $path_list]
+
+	set batch_remaining $batch_size
+
+	while {$batch_remaining > 0} {
+		if {$path_index >= $path_cnt} { break }
+
+		set path [lindex $path_list $path_index]
+
+		set deletion_failed [catch {file delete -- $path} deletion_error]
+
+		if {$deletion_failed} {
+			lappend deletion_errors [list "$deletion_error"]
+		} else {
+			remove_empty_directories [file dirname $path]
+
+			# Don't assume the deletion worked. Remove the file from
+			# the UI, but only if it no longer exists.
+			if {![path_exists $path]} {
+				unset file_states($path)
+				display_file $path __
+			}
+		}
+
+		incr path_index 1
+		incr batch_remaining -1
+	}
+
+	# Update the progress bar to indicate that this batch has been
+	# completed. The update will be visible when this procedure returns
+	# and allows the UI thread to process messages.
+	$status_bar_operation update $path_index $path_cnt
+
+	if {$path_index < $path_cnt} {
+		# The Tcler's Wiki lists this as the best practice for keeping
+		# a UI active and processing messages during a long-running
+		# operation.
+
+		after idle [list after 0 [list \
+			delete_helper \
 			$path_list \
-			[concat $after [list ui_ready]]
+			$path_index \
+			$deletion_errors \
+			$batch_size \
+			$status_bar_operation \
+			$after
+			]]
 	} else {
-		unlock_index
+		# Finish the status bar operation.
+		$status_bar_operation stop
+
+		# Report error, if any, based on how many deletions failed.
+		set deletion_error_cnt [llength $deletion_errors]
+
+		if {($deletion_error_cnt > 0)
+		 && ($deletion_error_cnt <= [MAX_VERBOSE_FILES_IN_DELETION_ERROR])} {
+			set error_text [mc "Encountered errors deleting files:\n"]
+
+			foreach deletion_error $deletion_errors {
+				append error_text "* [lindex $deletion_error 0]\n"
+			}
+
+			error_popup $error_text
+		} elseif {$deletion_error_cnt == $path_cnt} {
+			error_popup [mc \
+				"None of the %d selected files could be deleted." \
+				$path_cnt \
+				]
+		} elseif {$deletion_error_cnt > 1} {
+			error_popup [mc \
+				"%d of the %d selected files could not be deleted." \
+				$deletion_error_cnt \
+				$path_cnt \
+				]
+		}
+
+		uplevel #0 $after
+	}
+}
+
+proc MAX_VERBOSE_FILES_IN_DELETION_ERROR {} { return 10; }
+
+# This function is from the TCL documentation:
+#
+#   https://wiki.tcl-lang.org/page/file+exists
+#
+# [file exists] returns false if the path does exist but is a symlink to a path
+# that doesn't exist. This proc returns true if the path exists, regardless of
+# whether it is a symlink and whether it is broken.
+proc path_exists {name} {
+	expr {![catch {file lstat $name finfo}]}
+}
+
+# Remove as many empty directories as we can starting at the specified path,
+# walking up the directory tree. If we encounter a directory that is not
+# empty, or if a directory deletion fails, then we stop the operation and
+# return to the caller. Even if this procedure fails to delete any
+# directories at all, it does not report failure.
+proc remove_empty_directories {directory_path} {
+	set parent_path [file dirname $directory_path]
+
+	while {$parent_path != $directory_path} {
+		set contents [glob -nocomplain -dir $directory_path *]
+
+		if {[llength $contents] > 0} { break }
+		if {[catch {file delete -- $directory_path}]} { break }
+
+		set directory_path $parent_path
+		set parent_path [file dirname $directory_path]
 	}
 }
 
-- 
gitgitgadget

Re: [PATCH v7 0/3] git-gui: revert untracked files by deleting them

[Pratyush Yadav]

Hi Jonathan,

On 01/12/19 02:28AM, Jonathan Gilbert via GitGitGadget wrote:
> My development environment sometimes makes automatic changes that I don't
> want to keep. In some cases, this involves new files being added that I
> don't want to commit or keep (but I also don't want to outright .gitignore 
> forever). I have typically had to explicitly delete those files externally
> to Git Gui, which is a context switch to a manual operation, and I want to
> be able to just select those newly-created untracked files in the UI and
> "revert" them into oblivion.
> 
> This change updates the revert_helper proc to check for untracked files as
> well as changes, and then changes to be reverted and untracked files are
> handled by independent blocks of code. The user is prompted independently
> for untracked files, since the underlying action is fundamentally different
> (rm -f). If after deleting untracked files, the directory containing them
> becomes empty, then the directory is removed as well. A new proc 
> delete_files takes care of actually deleting the files, using the Tcler's
> Wiki recommended approach for keeping the UI responsive.
> 
> Since the checkout_index and delete_files calls are both asynchronous and
> could potentially complete in any order, a "chord" is used to coordinate
> unlocking the index and returning the UI to a usable state only after both
> operations are complete.
> 
> Since the checkout_index and delete_files calls are both asynchronous and
> overlap, they clash in wanting to update the status bar. To address this,
> the status bar is reworked so that when an operation wants to display
> ongoing updates/progress, it explicitly starts an "operation", which is
> tracked by its own object, and the status bar handles multiple concurrent
> operations by merging their progress and concatenating their text. This is
> captured in a separate commit, since it touches a variety of files.
> 
> The _close_updateindex proc contains error handling (added in d4e890e5) that
> has the potential to interact badly with unlock_index running at the
> completion of an async operation. I have refactored the procedure into
> separate procs _close_updateindex and rescan_on_error. Call sites that
> exercised the combined functionality also unlocked the index, so a combined
> proc close_and_unlock_index calls _close_updateindex and then either 
> rescan_on_error or unlock_index as appropriate. Call sites have been updated
> appropriately.
> 
> The revert_helper proc, with its overlapping operations, is an example of a
> call site that does not combine the close and unlock/rescan operations. The 
> checkout_index proc has been reworked to only call _close_updateindex, and
> to call a functor supplied by the caller to captures any errors that occur. 
> revert_helper uses this to supply a lambda function that stashes the error
> within the chord's body namespace, so that it can then separately call 
> rescan_on_error when the chord is completed (or unlock_index, if no error
> was captured), which might be substantially after checkout_index encounters
> its error. If it turns out that a rescan is called for, it is done once the
> deletion is complete.
> 
> This is the eighth revision of this change, which differs from the seventh
> version in the following ways (most of which are in the second of the three
> commits, to do with the status bar rework):
> 
>  * The bump of the Tcl/Tk dependency from 8.4 to 8.6 now takes place in the
>    third commit, where it is needed and whose commit message actually calls
>    it out.
>    
>    
>  * The show method in status_bar_operation has been renamed to restart, and
>    the meter is cleared. Also, the supplied message is set as the prefix for
>    future update calls.
>    
>    
>  * The call site for $status_operation show in blame.tcl has been
>    corresponding changed to $status_operation restart.
>    
>    
>  * A typo has been corrected in a comment. :-)

Thanks for the quality contribution. Merged to 'master'. Will push it 
out soon.

-- 
Regards,
Pratyush Yadav