[RFC PATCH 0/7] rebase -i: Implement `reword` and `squash` in terms of `do_pick`

[RFC PATCH 0/7] rebase -i: Implement `reword` and `squash` in terms of `do_pick`

[Fabian Ruch]

Hi,

This patch series is part of the undertaking to add command line options
to to-do list commands. The goal is to be able to write something
similar to

    pick --reset-author --signoff a Some changes
    pick                          b Some more changes
    squash --no-edit              c Ack Some more changes.

The first submission to the mailing list adds options parsing to
`do_pick` and reimplements the current set of to-do list commands in
terms[1] of a parametrized `do_pick`. It neither adds new commands to
to-do lists nor exposes the command line options feature to the user.
Still it makes the implementation of `do_next` slightly more
straight-forward and the function `do_pick` behave more like an internal
git-cherry-pick.

The patches try to accomplish one thing at a time but are not standalone
in the sense that each of them constitutes a frame only in which a
subsequent patch can express its one thing. For instance, only
committing once and not dying in `do_pick` are things specific to
implementing `squash` in terms of `do_pick` but presented as separate
patches so that their correctness can be discussed independently.

The last patch contains some notes about when to run the post-rewrite
hook, something I could not figure out myself.

Thanks for your time,
   Fabian

[1] pick, reword, squash, fixup

Fabian Ruch (7):
  rebase -i: Make option handling in pick_one more flexible
  rebase -i: Teach do_pick the option --edit
  rebase -i: Stop on root commits with empty log messages
  rebase -i: Commit only once when rewriting picks
  rebase -i: Do not die in do_pick
  rebase -i: Prepare for squash in terms of do_pick --amend
  rebase -i: Teach do_pick the options --amend and --file

 git-rebase--interactive.sh    | 194 +++++++++++++++++++++++++++++++-----------
 t/t3404-rebase-interactive.sh |   8 ++
 t/t3412-rebase-root.sh        |  39 +++++++++
 3 files changed, 193 insertions(+), 48 deletions(-)

-- 
2.0.0

[PATCH RFC v2 00/19] Enable options --signoff, --reset-author for pick, reword

[Fabian Ruch]

Hi,

this reroll applies the comments from Eric, Junio and Michael. In
particular,

 * It turned out that `pick_one` does not need option handling at all
   and the option-like argument `-n` determines whether `pick_one` or
   `do_pick` creates the replay commit. The latter happens if the
   task wants to rewrite the commit being picked (f.i., for the
   purpose of editing the log message or resetting the authorship).

   `do_pick` still seems to require a flexible parsing of options,
   i.e. a relatively expensive loop, since it receives the
   whitelisted user-supplied options. Unsupported and unknown options
   are treated as an "unknown command" error.

 * The `do_pick` options are documented in the same order they are
   listed in the function signature. Moreover, it is mentioned which
   options rewrite commits being picked.

 * The test cases output differing actual values as changes to the
   expected values and not the other way around. Moreover, the failed
   rebases are not cleaned up until the respective test succeeds.

Two stages (and two sub-stages) can be identified in the rerolled
patch series:

 1. Route primary to-do list commands through `do_pick`

     a. Implement reword in terms of do_pick (5/19)
     b. Implement squash in terms of do_pick (14/19)

 2. Add user options to main commands

    Enable options --signoff, --reset-author for pick, reword (19/19)

The last stage was added in this reroll. It enables the parsing of
line options for to-do list commands, which is still restricted to
options without arguments because it is unclear how spaces can be
parsed as characters rather than separators where needed. For
instance, if we were to support

    pick --author="A U Thor" fa1afe1 Some changes

then read(1) would hand us the tokens `--author="A`, `U` and `Thor"`
instead of `--author=A U Thor`, which we would want to relay to
`do_pick`. Interpreting the shell quoting would help. However,
eval(1) seems to disqualify itself as an interpreter because the
to-do list entry could potentially contain any shell command line.
This could be both a security and a usability issue. For this reason,
the patch series still hasn't graduated from being RFC.

   Fabian

Fabian Ruch (19):
  rebase -i: Failed reword prints redundant error message
  rebase -i: reword complains about empty commit despite --keep-empty
  rebase -i: reword executes pre-commit hook on interim commit
  rebase -i: Teach do_pick the option --edit
  rebase -i: Implement reword in terms of do_pick
  rebase -i: Stop on root commits with empty log messages
  rebase -i: The replay of root commits is not shown with --verbose
  rebase -i: Root commits are replayed with an unnecessary option
  rebase -i: Commit only once when rewriting picks
  rebase -i: Do not die in do_pick
  rebase -i: Teach do_pick the option --amend
  rebase -i: Teach do_pick the option --file
  rebase -i: Prepare for squash in terms of do_pick --amend
  rebase -i: Implement squash in terms of do_pick
  rebase -i: Explicitly distinguish replay commands and exec tasks
  rebase -i: Parse to-do list command line options
  rebase -i: Teach do_pick the option --reset-author
  rebase -i: Teach do_pick the option --signoff
  rebase -i: Enable options --signoff, --reset-author for pick, reword

 git-rebase--interactive.sh    | 277 ++++++++++++++++++++++++++++++++++--------
 t/t3404-rebase-interactive.sh |   8 ++
 t/t3412-rebase-root.sh        |  39 ++++++
 3 files changed, 273 insertions(+), 51 deletions(-)

-- 
2.0.0

[PATCH RFC v2 01/19] rebase -i: Failed reword prints redundant error message

[Fabian Ruch]

The to-do list command `reword` replays a commit like `pick` but lets
the user also edit the commit's log message. If the edited log
message is empty or is found ill-formatted by one of the commit
hooks, git-rebase--interactive prints three error messages to the
console.

    1. The git-commit output, which contains all the output from hook
       scripts.
    2. A rebase diagnosis saying at which task on the to-do list it
       got stuck.
    3. Generic presumptions about what could have triggered the
       error.

The third message contains redundant information and does not add any
enlightenment either, which makes the output unnecessarily longish
and different from the other command's output. For instance, this is
what the output looks like if the log message is empty (contains
duplicate Signed-off-by lines).

    (1.) Aborting commit due to empty commit message. (Duplicate Signed-off-by lines.)
    (2.) Could not amend commit after successfully picking fa1afe1... Some change
    (3.) This is most likely due to an empty commit message, or the pre-commit hook
         failed. If the pre-commit hook failed, you may need to resolve the issue before
         you are able to reword the commit.

Discard the third message.

It is true that a failed hook script might not output any diagnosis
but then the generic message is not of much help either. Since this
lack of information affects the built-in git commands for commit,
merge and cherry-pick first, the solution would be to keep track of
the failed hooks in their output so that the user knows which of her
hooks require improvement.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 7e1eda0..e733d7f 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -506,9 +506,6 @@ do_next () {
 		do_pick $sha1 "$rest"
 		git commit --amend --no-post-rewrite ${gpg_sign_opt:+"$gpg_sign_opt"} || {
 			warn "Could not amend commit after successfully picking $sha1... $rest"
-			warn "This is most likely due to an empty commit message, or the pre-commit hook"
-			warn "failed. If the pre-commit hook failed, you may need to resolve the issue before"
-			warn "you are able to reword the commit."
 			exit_with_patch $sha1 1
 		}
 		record_in_rewritten $sha1
-- 
2.0.0

Re: [PATCH RFC v2 01/19] rebase -i: Failed reword prints redundant error message

[Junio C Hamano]

Fabian Ruch <bafain@gmail.com> writes:

> The to-do list command `reword` replays a commit like `pick` but lets
> the user also edit the commit's log message. If the edited log
> message is empty or is found ill-formatted by one of the commit
> hooks, git-rebase--interactive prints three error messages to the
> console.
>
>     1. The git-commit output, which contains all the output from hook
>        scripts.
>     2. A rebase diagnosis saying at which task on the to-do list it
>        got stuck.
>     3. Generic presumptions about what could have triggered the
>        error.
>
> The third message contains redundant information and does not add any
> enlightenment either, which makes the output unnecessarily longish
> and different from the other command's output. For instance, this is
> what the output looks like if the log message is empty (contains
> duplicate Signed-off-by lines).
>
>     (1.) Aborting commit due to empty commit message. (Duplicate Signed-off-by lines.)
>     (2.) Could not amend commit after successfully picking fa1afe1... Some change
>     (3.) This is most likely due to an empty commit message, or the pre-commit hook
>          failed. If the pre-commit hook failed, you may need to resolve the issue before
>          you are able to reword the commit.
>
> Discard the third message.
>
> It is true that a failed hook script might not output any diagnosis...

I think the message originally came from 0becb3e4 (rebase -i:
interrupt rebase when "commit --amend" failed during "reword",
2011-11-30); it seems that the primary point of the change was to
make sure it exits and the warning message may not have been well
thought out, but before discarding the result of somebody else's
work, it may not be a bad idea to ask just in case you may have
overlooked something (Andrew Wong Cc'ed).





> but then the generic message is not of much help either. Since this
> lack of information affects the built-in git commands for commit,
> merge and cherry-pick first, the solution would be to keep track of
> the failed hooks in their output so that the user knows which of her
> hooks require improvement.
>
> Signed-off-by: Fabian Ruch <bafain@gmail.com>
> ---
>  git-rebase--interactive.sh | 3 ---
>  1 file changed, 3 deletions(-)
>
> diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
> index 7e1eda0..e733d7f 100644
> --- a/git-rebase--interactive.sh
> +++ b/git-rebase--interactive.sh
> @@ -506,9 +506,6 @@ do_next () {
>  		do_pick $sha1 "$rest"
>  		git commit --amend --no-post-rewrite ${gpg_sign_opt:+"$gpg_sign_opt"} || {
>  			warn "Could not amend commit after successfully picking $sha1... $rest"
> -			warn "This is most likely due to an empty commit message, or the pre-commit hook"
> -			warn "failed. If the pre-commit hook failed, you may need to resolve the issue before"
> -			warn "you are able to reword the commit."
>  			exit_with_patch $sha1 1
>  		}
>  		record_in_rewritten $sha1

Re: [PATCH RFC v2 01/19] rebase -i: Failed reword prints redundant error message

[Andrew Wong]

On Tue, Jul 8, 2014 at 4:31 PM, Junio C Hamano <gitster@pobox.com> wrote:
> Fabian Ruch <bafain@gmail.com> writes:
>> It is true that a failed hook script might not output any diagnosis...
>
> I think the message originally came from 0becb3e4 (rebase -i:
> interrupt rebase when "commit --amend" failed during "reword",
> 2011-11-30); it seems that the primary point of the change was to
> make sure it exits and the warning message may not have been well
> thought out, but before discarding the result of somebody else's
> work, it may not be a bad idea to ask just in case you may have
> overlooked something (Andrew Wong Cc'ed).
>
>
>
>
>
>> but then the generic message is not of much help either. Since this
>> lack of information affects the built-in git commands for commit,
>> merge and cherry-pick first, the solution would be to keep track of
>> the failed hooks in their output so that the user knows which of her
>> hooks require improvement.

Since "git commit" already prints out error messages for failing due
to empty commit message, the third message is really about giving
hints in the case where pre-commit fails. We could probably assume
that pre-commit would also print out error messages. So I'd be fine
with removing the third message. But I wonder if we need to explain
that the user needs to run "git rebase --continue" to resume the
rebase?

Re: [PATCH RFC v2 01/19] rebase -i: Failed reword prints redundant error message

[Fabian Ruch]

Hi Andrew,

thanks for your review and sorry that I forgot to cc the bug fix to you.

Andrew Wong writes:
> On Tue, Jul 8, 2014 at 4:31 PM, Junio C Hamano <gitster@pobox.com> wrote:
>> Fabian Ruch <bafain@gmail.com> writes:
>>> It is true that a failed hook script might not output any diagnosis...
>>
>> I think the message originally came from 0becb3e4 (rebase -i:
>> interrupt rebase when "commit --amend" failed during "reword",
>> 2011-11-30); it seems that the primary point of the change was to
>> make sure it exits and the warning message may not have been well
>> thought out, but before discarding the result of somebody else's
>> work, it may not be a bad idea to ask just in case you may have
>> overlooked something (Andrew Wong Cc'ed).
>>
>>> but then the generic message is not of much help either. Since this
>>> lack of information affects the built-in git commands for commit,
>>> merge and cherry-pick first, the solution would be to keep track of
>>> the failed hooks in their output so that the user knows which of her
>>> hooks require improvement.
> 
> Since "git commit" already prints out error messages for failing due
> to empty commit message, the third message is really about giving
> hints in the case where pre-commit fails. We could probably assume
> that pre-commit would also print out error messages. So I'd be fine
> with removing the third message. But I wonder if we need to explain
> that the user needs to run "git rebase --continue" to resume the
> rebase?

That is still taken care of by exit_with_patch here. When called in the
error case, it prints

    You can amend the commit now, with

    	git commit --amend

    Once you are satisfied with your changes, run

    	git rebase --continue

to standard error. I might have overlooked this in one of the later
patches though.

   Fabian

Re: [PATCH RFC v2 01/19] rebase -i: Failed reword prints redundant error message

[Andrew Wong]

On Thu, Jul 10, 2014 at 12:35 PM, Fabian Ruch <bafain@gmail.com> wrote:
> That is still taken care of by exit_with_patch here.

Oh, that's right. Ok, go ahead and remove the third warning then. Thanks!

[PATCH RFC v2 02/19] rebase -i: reword complains about empty commit despite --keep-empty

[Fabian Ruch]

The to-do list command `reword` replays a commit like `pick` but lets
the user also edit the commit's log message. If `--keep-empty` is
passed as option to git-rebase--interactive, empty commits ought to
be replayed without complaints. However, if the users chooses to
reword an empty commit by changing the respective to-do list entry
from

    pick fa1afe1 Empty commit

to

    reword fa1afe1 Empty commit

, then git-rebase--interactive suddenly fails to replay the empty
commit. This is especially counterintuitive because `reword` is
thought of as a `pick` that alters the log message in some way but
nothing more and the unchanged to-do list entry would not fail.

Handle `reword` by cherry-picking the named commit and editing the
log message using

    git commit --allow-empty --amend

instead of

    git commit --amend.

Add test.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh    | 2 +-
 t/t3404-rebase-interactive.sh | 8 ++++++++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index e733d7f..689400e 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -504,7 +504,7 @@ do_next () {
 
 		mark_action_done
 		do_pick $sha1 "$rest"
-		git commit --amend --no-post-rewrite ${gpg_sign_opt:+"$gpg_sign_opt"} || {
+		git commit --allow-empty --amend --no-post-rewrite ${gpg_sign_opt:+"$gpg_sign_opt"} || {
 			warn "Could not amend commit after successfully picking $sha1... $rest"
 			exit_with_patch $sha1 1
 		}
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index 8197ed2..9931143 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -75,6 +75,14 @@ test_expect_success 'rebase --keep-empty' '
 	test_line_count = 6 actual
 '
 
+test_expect_success 'rebase --keep-empty' '
+	git checkout emptybranch &&
+	set_fake_editor &&
+	FAKE_LINES="1 reword 2" git rebase --keep-empty -i HEAD~2 &&
+	git log --oneline >actual &&
+	test_line_count = 6 actual
+'
+
 test_expect_success 'rebase -i with the exec command' '
 	git checkout master &&
 	(
-- 
2.0.0

Re: [PATCH RFC v2 02/19] rebase -i: reword complains about empty commit despite --keep-empty

[Junio C Hamano]

Fabian Ruch <bafain@gmail.com> writes:

> Subject: rebase -i: reword complains about empty commit despite --keep-empty

I had to read the title and then the log twice before understanding
that the above is not "change the complaint message" (i.e. "reword
complaints" spelled incorrectly) but is a description of the current
behaviour (i.e. "the command complains when 'reword' is used on an
empty commit") that is not accompanied by an evaluation ("ok, it
complains; are you saying it is a good thing or a bad thing?") or an
action ("if it is a bad thing, what are you doing about it?").

Perhaps

	rebase -i: allow rewording an empty commit

or something?

> The to-do list command `reword` replays a commit like `pick` but lets
> the user also edit the commit's log message. If `--keep-empty` is
> passed as option to git-rebase--interactive, empty commits ought to
> be replayed without complaints. However, if the users chooses to
> reword an empty commit by changing the respective to-do list entry
> from
>
>     pick fa1afe1 Empty commit
>
> to
>
>     reword fa1afe1 Empty commit
>
> , then git-rebase--interactive suddenly fails to replay the empty
> commit. This is especially counterintuitive because `reword` is
> thought of as a `pick` that alters the log message in some way but
> nothing more and the unchanged to-do list entry would not fail.
>
> Handle `reword` by cherry-picking the named commit and editing the
> log message using
>
>     git commit --allow-empty --amend
>
> instead of
>
>     git commit --amend.
>
> Add test.
>
> Signed-off-by: Fabian Ruch <bafain@gmail.com>
> ---
>  git-rebase--interactive.sh    | 2 +-
>  t/t3404-rebase-interactive.sh | 8 ++++++++
>  2 files changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
> index e733d7f..689400e 100644
> --- a/git-rebase--interactive.sh
> +++ b/git-rebase--interactive.sh
> @@ -504,7 +504,7 @@ do_next () {
>  
>  		mark_action_done
>  		do_pick $sha1 "$rest"
> -		git commit --amend --no-post-rewrite ${gpg_sign_opt:+"$gpg_sign_opt"} || {
> +		git commit --allow-empty --amend --no-post-rewrite ${gpg_sign_opt:+"$gpg_sign_opt"} || {
>  			warn "Could not amend commit after successfully picking $sha1... $rest"
>  			exit_with_patch $sha1 1
>  		}
> diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
> index 8197ed2..9931143 100755
> --- a/t/t3404-rebase-interactive.sh
> +++ b/t/t3404-rebase-interactive.sh
> @@ -75,6 +75,14 @@ test_expect_success 'rebase --keep-empty' '
>  	test_line_count = 6 actual
>  '
>  
> +test_expect_success 'rebase --keep-empty' '
> +	git checkout emptybranch &&
> +	set_fake_editor &&
> +	FAKE_LINES="1 reword 2" git rebase --keep-empty -i HEAD~2 &&
> +	git log --oneline >actual &&
> +	test_line_count = 6 actual
> +'
> +
>  test_expect_success 'rebase -i with the exec command' '
>  	git checkout master &&
>  	(

Re: [PATCH RFC v2 02/19] rebase -i: reword complains about empty commit despite --keep-empty

[Fabian Ruch]

Junio C Hamano writes:
> Fabian Ruch <bafain@gmail.com> writes:
>> Subject: rebase -i: reword complains about empty commit despite --keep-empty
> 
> I had to read the title and then the log twice before understanding
> that the above is not "change the complaint message" (i.e. "reword
> complaints" spelled incorrectly) but is a description of the current
> behaviour (i.e. "the command complains when 'reword' is used on an
> empty commit") that is not accompanied by an evaluation ("ok, it
> complains; are you saying it is a good thing or a bad thing?") or an
> action ("if it is a bad thing, what are you doing about it?").
> 
> Perhaps
> 
> 	rebase -i: allow rewording an empty commit
> 
> or something?

I thought "...despite --keep-empty" would already imply that "reword
complains about empty commit" is not supposed to happen, the action
would have been obvious. However, I understand that --keep-empty is
first of all concerned with which commits of $upstream...$orig_head end
up on the initial to-do list and the git-rebase manual page doesn't
mention that it picks commits using the --allow-empty option. It is
simply a necessity of a script not to complain about something it put on
the to-do list itself.

The subject reads now

    rebase -i: allow rewording an empty commit without complaints

trying to convey that this is not a new feature but a bug fix.

   Fabian

[PATCH RFC v2 03/19] rebase -i: reword executes pre-commit hook on interim commit

[Fabian Ruch]

The to-do list command `reword` replays a commit like `pick` but lets
the user also edit the commit's log message. This happens in two
steps. Firstly, the named commit is cherry-picked. Secondly, the
commit created in the first step is amended using an unchanged index
to edit the log message. The pre-commit hook is meant to verify the
changes introduced by a commit (for instance, catching inserted
trailing white space). Since the committed tree is not changed
between the two steps, do not execute the pre-commit hook in the
second step.

Specify the git-commit option `--no-verify` to disable the pre-commit
hook when editing the log message. Because `--no-verify` also skips
the commit-msg hook, execute the hook from within
git-rebase--interactive after the commit is created. Fortunately, the
commit message is still available in `$GIT_DIR/COMMIT_EDITMSG` after
git-commit terminates. Caveat: In case the commit-msg hook finds the
new log message ill-formatted, the user is only notified of the
failed commit-msg hook but the log message is used for the commit
anyway. git-commit ought to offer more fine-grained control over
which hooks are executed.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 689400e..b50770d 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -504,10 +504,19 @@ do_next () {
 
 		mark_action_done
 		do_pick $sha1 "$rest"
-		git commit --allow-empty --amend --no-post-rewrite ${gpg_sign_opt:+"$gpg_sign_opt"} || {
-			warn "Could not amend commit after successfully picking $sha1... $rest"
-			exit_with_patch $sha1 1
-		}
+		# TODO: Work around the fact that git-commit lets us
+		# disable either both the pre-commit and the commit-msg
+		# hook or none. Disable the pre-commit hook because the
+		# tree is left unchanged but run the commit-msg hook
+		# from here because the log message is altered.
+		git commit --allow-empty --amend --no-post-rewrite -n ${gpg_sign_opt:+"$gpg_sign_opt"} &&
+			if test -x "$GIT_DIR"/hooks/commit-msg
+			then
+				"$GIT_DIR"/hooks/commit-msg "$GIT_DIR"/COMMIT_EDITMSG
+			fi || {
+				warn "Could not amend commit after successfully picking $sha1... $rest"
+				exit_with_patch $sha1 1
+			}
 		record_in_rewritten $sha1
 		;;
 	edit|e)
-- 
2.0.0

Re: [PATCH RFC v2 03/19] rebase -i: reword executes pre-commit hook on interim commit

[Junio C Hamano]

Fabian Ruch <bafain@gmail.com> writes:

> The to-do list command `reword` replays a commit like `pick` but lets
> the user also edit the commit's log message. This happens in two
> steps. Firstly, the named commit is cherry-picked. Secondly, the
> commit created in the first step is amended using an unchanged index
> to edit the log message. The pre-commit hook is meant to verify the
> changes introduced by a commit (for instance, catching inserted
> trailing white space). Since the committed tree is not changed
> between the two steps, do not execute the pre-commit hook in the
> second step.

It is not like the second step is built as a child commit of the
result from the first step, recording the same tree without any
change.  Why is it a good thing not to run the pre-commit hook (or
other hooks for that matter)?  After all, the result of the second
step is what is recorded in the final history; it just feels wrong
not to test that one, even if it were a good idea to test only once.

> Specify the git-commit option `--no-verify` to disable the pre-commit
> hook when editing the log message. Because `--no-verify` also skips
> the commit-msg hook, execute the hook from within
> git-rebase--interactive after the commit is created. Fortunately, the
> commit message is still available in `$GIT_DIR/COMMIT_EDITMSG` after
> git-commit terminates. Caveat: In case the commit-msg hook finds the
> new log message ill-formatted, the user is only notified of the
> failed commit-msg hook but the log message is used for the commit
> anyway. git-commit ought to offer more fine-grained control over
> which hooks are executed.
>
> Signed-off-by: Fabian Ruch <bafain@gmail.com>
> ---
>  git-rebase--interactive.sh | 17 +++++++++++++----
>  1 file changed, 13 insertions(+), 4 deletions(-)
>
> diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
> index 689400e..b50770d 100644
> --- a/git-rebase--interactive.sh
> +++ b/git-rebase--interactive.sh
> @@ -504,10 +504,19 @@ do_next () {
>  
>  		mark_action_done
>  		do_pick $sha1 "$rest"
> -		git commit --allow-empty --amend --no-post-rewrite ${gpg_sign_opt:+"$gpg_sign_opt"} || {
> -			warn "Could not amend commit after successfully picking $sha1... $rest"
> -			exit_with_patch $sha1 1
> -		}
> +		# TODO: Work around the fact that git-commit lets us
> +		# disable either both the pre-commit and the commit-msg
> +		# hook or none. Disable the pre-commit hook because the
> +		# tree is left unchanged but run the commit-msg hook
> +		# from here because the log message is altered.
> +		git commit --allow-empty --amend --no-post-rewrite -n ${gpg_sign_opt:+"$gpg_sign_opt"} &&
> +			if test -x "$GIT_DIR"/hooks/commit-msg
> +			then
> +				"$GIT_DIR"/hooks/commit-msg "$GIT_DIR"/COMMIT_EDITMSG
> +			fi || {
> +				warn "Could not amend commit after successfully picking $sha1... $rest"
> +				exit_with_patch $sha1 1
> +			}
>  		record_in_rewritten $sha1
>  		;;
>  	edit|e)

Re: [PATCH RFC v2 03/19] rebase -i: reword executes pre-commit hook on interim commit

[Fabian Ruch]

Hi Junio,

Junio C Hamano writes:
> Fabian Ruch <bafain@gmail.com> writes:
>> The to-do list command `reword` replays a commit like `pick` but lets
>> the user also edit the commit's log message. This happens in two
>> steps. Firstly, the named commit is cherry-picked. Secondly, the
>> commit created in the first step is amended using an unchanged index
>> to edit the log message. The pre-commit hook is meant to verify the
>> changes introduced by a commit (for instance, catching inserted
>> trailing white space). Since the committed tree is not changed
>> between the two steps, do not execute the pre-commit hook in the
>> second step.
> 
> It is not like the second step is built as a child commit of the
> result from the first step, recording the same tree without any
> change.  Why is it a good thing not to run the pre-commit hook (or
> other hooks for that matter)?  After all, the result of the second
> step is what is recorded in the final history; it just feels wrong
> not to test that one, even if it were a good idea to test only once.

if I understand correctly, the tree of the (amended) commit isn't tested
at all by git-rebase--interactive because git-cherry-pick, and therefore
pick_one, commits with both the pre-commit and commit-msg hook disabled
(see the "git commit -n" command line being built in
sequencer.c#run_git_commit since revision 9fa4db5).

The "commit --amend" we are concerned with here amends using an
untouched tree so that the history ought to record exactly the same
trees as prior to "commit --amend". If git-cherry-pick was testing the
tree, then it would be unnecessary to test the tree a second time. Since
git-cherry-pick is not testing as of yet, testing and possibly rejecting
a tree in the second step would actually be wrong. I totally neglected
to look for a test case when I submitted this patch, so I'd like to
supply one late now:

> test_expect_success 'reword a commit violating pre-commit' '
> 	mkdir -p .git/hooks &&
> 	PRE_COMMIT=.git/hooks/pre-commit &&
> 	cat >"$PRE_COMMIT" <<EOF
> #!/bin/sh
> echo running pre-commit
> exit 1
> EOF
> 	chmod +x "$PRE_COMMIT" &&
> 	test_must_fail test_commit file &&
> 	test_commit --no-verify file &&
> 	set_fake_editor &&
> 	FAKE_LINES="pick 1" git rebase -i HEAD^ &&
> 	FAKE_LINES="pick 1" git rebase -i --no-ff HEAD^ &&
> 	FAKE_LINES="reword 1" git rebase -i HEAD^
> '

(This addition to t3404-rebase--interactive.sh is based on the test case
"rebase a commit violating pre-commit"; "test_commit --no-verify" will
be implemented the obvious way.)

In both cases, it's correct to disable the pre-commit hook when editing
the log message and it just makes sense to test changes where you make
them. Unfortunately, it is not obvious that "git commit --amend" merely
edits the log message rather than committing a new tree.

For what it's worth, if we were to create an empty child commit and
squash it into the parent instead of amending immediately, then
git-rebase--interactive would disable tree verification in the second
step as well. This behaviour was introduced by commit c5b09fe. Although
the change seems to have been triggered by something completely
different back then, the correctness criterion remains the same, i.e.
recording previously committed trees.

Best regards,
   Fabian

>> Specify the git-commit option `--no-verify` to disable the pre-commit
>> hook when editing the log message. Because `--no-verify` also skips
>> the commit-msg hook, execute the hook from within
>> git-rebase--interactive after the commit is created. Fortunately, the
>> commit message is still available in `$GIT_DIR/COMMIT_EDITMSG` after
>> git-commit terminates. Caveat: In case the commit-msg hook finds the
>> new log message ill-formatted, the user is only notified of the
>> failed commit-msg hook but the log message is used for the commit
>> anyway. git-commit ought to offer more fine-grained control over
>> which hooks are executed.
>>
>> Signed-off-by: Fabian Ruch <bafain@gmail.com>
>> ---
>>  git-rebase--interactive.sh | 17 +++++++++++++----
>>  1 file changed, 13 insertions(+), 4 deletions(-)
>>
>> diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
>> index 689400e..b50770d 100644
>> --- a/git-rebase--interactive.sh
>> +++ b/git-rebase--interactive.sh
>> @@ -504,10 +504,19 @@ do_next () {
>>  
>>  		mark_action_done
>>  		do_pick $sha1 "$rest"
>> -		git commit --allow-empty --amend --no-post-rewrite ${gpg_sign_opt:+"$gpg_sign_opt"} || {
>> -			warn "Could not amend commit after successfully picking $sha1... $rest"
>> -			exit_with_patch $sha1 1
>> -		}
>> +		# TODO: Work around the fact that git-commit lets us
>> +		# disable either both the pre-commit and the commit-msg
>> +		# hook or none. Disable the pre-commit hook because the
>> +		# tree is left unchanged but run the commit-msg hook
>> +		# from here because the log message is altered.
>> +		git commit --allow-empty --amend --no-post-rewrite -n ${gpg_sign_opt:+"$gpg_sign_opt"} &&
>> +			if test -x "$GIT_DIR"/hooks/commit-msg
>> +			then
>> +				"$GIT_DIR"/hooks/commit-msg "$GIT_DIR"/COMMIT_EDITMSG
>> +			fi || {
>> +				warn "Could not amend commit after successfully picking $sha1... $rest"
>> +				exit_with_patch $sha1 1
>> +			}
>>  		record_in_rewritten $sha1
>>  		;;
>>  	edit|e)

[PATCH RFC v2 04/19] rebase -i: Teach do_pick the option --edit

[Fabian Ruch]

`do_pick` is the git-cherry-pick wrapper in git-rebase--interactive
that is used to implement the to-do list command `pick`. To cater for
the different pick behaviours (like `reword`), `do_pick` accepts
several options not only from the git-cherry-pick but also the
git-commit interface. Add the common option `--edit` to let the user
edit the log message of the named commit.

Loop over `$@` to parse the `do_pick` arguments. Assign the local
variable `edit` if one of the options is `--edit` so that the
remainder of `do_pick` can easily check whether the client code asked
to edit the commit message. If one of the options is unknown, mention
it on the console and `die`. Break the loop on the first non-option
and do some sanity checking to ensure that there exactly two
non-options, which are interpreted by the remainder as `<commit>` and
`<title>` like before.

`do_pick` ought to act as a wrapper around `cherry-pick`.
Unfortunately, it cannot just forward `--edit` to the `cherry-pick`
command line. The assembled command line is executed within a command
substitution for controlling the verbosity of `rebase--interactive`.
Passing `--edit` would either hang the terminal or clutter the
substituted command output with control sequences. Execute the
`reword` code from `do_next` instead if the option `--edit` is
specified.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 52 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index b50770d..e06d9b6 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -461,7 +461,42 @@ record_in_rewritten() {
 	esac
 }
 
+# Apply the changes introduced by the given commit to the current head.
+#
+# do_pick [--edit] <commit> <title>
+#
+# Wrapper around git-cherry-pick.
+#
+# -e, --edit
+#     After picking <commit>, open an editor and let the user edit the
+#     commit message. The editor contents becomes the commit message of
+#     the new head. This creates a fresh commit.
+#
+# <commit>
+#     The commit to cherry-pick.
+#
+# <title>
+#     The commit message title of <commit>. Used for information
+#     purposes only.
 do_pick () {
+	edit=
+	while test $# -gt 0
+	do
+		case "$1" in
+		-e|--edit)
+			edit=y
+			;;
+		-*)
+			die "do_pick: unrecognized option -- $1"
+			;;
+		*)
+			break
+			;;
+		esac
+		shift
+	done
+	test $# -ne 2 && die "do_pick: wrong number of arguments"
+
 	if test "$(git rev-parse HEAD)" = "$squash_onto"
 	then
 		# Set the correct commit message and author info on the
@@ -483,6 +518,23 @@ do_pick () {
 		pick_one $1 ||
 			die_with_patch $1 "Could not apply $1... $2"
 	fi
+
+	if test -n "$edit"
+	then
+		# TODO: Work around the fact that git-commit lets us
+		# disable either both the pre-commit and the commit-msg
+		# hook or none. Disable the pre-commit hook because the
+		# tree is left unchanged but run the commit-msg hook
+		# from here because the log message is altered.
+		git commit --allow-empty --amend --no-post-rewrite -n ${gpg_sign_opt:+"$gpg_sign_opt"} &&
+			if test -x "$GIT_DIR"/hooks/commit-msg
+			then
+				"$GIT_DIR"/hooks/commit-msg "$GIT_DIR"/COMMIT_EDITMSG
+			fi || {
+				warn "Could not amend commit after successfully picking $1... $2"
+				exit_with_patch $1 1
+			}
+	fi
 }
 
 do_next () {
-- 
2.0.0

[PATCH RFC v2 05/19] rebase -i: Implement reword in terms of do_pick

[Fabian Ruch]

The to-do list command `reword` replays a commit like `pick` but lets
the user also edit the commit's log message. If one thinks of `pick`
entries as scheduled `cherry-pick` command lines, then `reword`
becomes an alias for the command line `cherry-pick --edit`. The
porcelain `rebase--interactive` defines a function `do_pick` for
processing the `pick` entries on to-do lists. Reimplement `reword` in
terms of `do_pick --edit`.

If the user picks a commit using the to-do list line

    reword fa1afe1 Some change

execute the command `do_pick --edit fa1afe1 "Some change"` which
carries out exactly the same steps as the case arm for `reword` in
`do_next` so far.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 15 +--------------
 1 file changed, 1 insertion(+), 14 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index e06d9b6..4c875d5 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -555,20 +555,7 @@ do_next () {
 		comment_for_reflog reword
 
 		mark_action_done
-		do_pick $sha1 "$rest"
-		# TODO: Work around the fact that git-commit lets us
-		# disable either both the pre-commit and the commit-msg
-		# hook or none. Disable the pre-commit hook because the
-		# tree is left unchanged but run the commit-msg hook
-		# from here because the log message is altered.
-		git commit --allow-empty --amend --no-post-rewrite -n ${gpg_sign_opt:+"$gpg_sign_opt"} &&
-			if test -x "$GIT_DIR"/hooks/commit-msg
-			then
-				"$GIT_DIR"/hooks/commit-msg "$GIT_DIR"/COMMIT_EDITMSG
-			fi || {
-				warn "Could not amend commit after successfully picking $sha1... $rest"
-				exit_with_patch $sha1 1
-			}
+		do_pick --edit $sha1 "$rest"
 		record_in_rewritten $sha1
 		;;
 	edit|e)
-- 
2.0.0

Re: [PATCH RFC v2 05/19] rebase -i: Implement reword in terms of do_pick

[Matthieu Moy]

Fabian Ruch <bafain@gmail.com> writes:

> --- a/git-rebase--interactive.sh
> +++ b/git-rebase--interactive.sh
> @@ -555,20 +555,7 @@ do_next () {
>  		comment_for_reflog reword
>  
>  		mark_action_done
> -		do_pick $sha1 "$rest"
> -		# TODO: Work around the fact that git-commit lets us
> -		# disable either both the pre-commit and the commit-msg
> -		# hook or none. Disable the pre-commit hook because the
> -		# tree is left unchanged but run the commit-msg hook
> -		# from here because the log message is altered.
> -		git commit --allow-empty --amend --no-post-rewrite -n ${gpg_sign_opt:+"$gpg_sign_opt"} &&
> -			if test -x "$GIT_DIR"/hooks/commit-msg
> -			then
> -				"$GIT_DIR"/hooks/commit-msg "$GIT_DIR"/COMMIT_EDITMSG
> -			fi || {
> -				warn "Could not amend commit after successfully picking $sha1... $rest"
> -				exit_with_patch $sha1 1
> -			}
> +		do_pick --edit $sha1 "$rest"

I would have found this easier to review if squashed into the previous
patch. My reaction reading the previous patch was "Uh, why duplicate
code?", and reading this one "Ah, that's OK". A single patch doing both
would have avoided the confusion.

-- 
Matthieu Moy
http://www-verimag.imag.fr/~moy/

Re: [PATCH RFC v2 05/19] rebase -i: Implement reword in terms of do_pick

[Fabian Ruch]

Hi Matthieu,

thanks for taking a look at this patch series. I might have caused some
confusion by starting with version v1 again after removing the RFC tag.
The current reroll[1] is tagged with PATCH v1, not PATCH RFC v2.

I'm sorry if this is the reason why your reply appears on this sub-thread.

Your concerns below are of course noted.

   Fabian

[1] http://article.gmane.org/gmane.comp.version-control.git/254361

Matthieu Moy writes:
> Fabian Ruch <bafain@gmail.com> writes:
>> --- a/git-rebase--interactive.sh
>> +++ b/git-rebase--interactive.sh
>> @@ -555,20 +555,7 @@ do_next () {
>>  		comment_for_reflog reword
>>  
>>  		mark_action_done
>> -		do_pick $sha1 "$rest"
>> -		# TODO: Work around the fact that git-commit lets us
>> -		# disable either both the pre-commit and the commit-msg
>> -		# hook or none. Disable the pre-commit hook because the
>> -		# tree is left unchanged but run the commit-msg hook
>> -		# from here because the log message is altered.
>> -		git commit --allow-empty --amend --no-post-rewrite -n ${gpg_sign_opt:+"$gpg_sign_opt"} &&
>> -			if test -x "$GIT_DIR"/hooks/commit-msg
>> -			then
>> -				"$GIT_DIR"/hooks/commit-msg "$GIT_DIR"/COMMIT_EDITMSG
>> -			fi || {
>> -				warn "Could not amend commit after successfully picking $sha1... $rest"
>> -				exit_with_patch $sha1 1
>> -			}
>> +		do_pick --edit $sha1 "$rest"
> 
> I would have found this easier to review if squashed into the previous
> patch. My reaction reading the previous patch was "Uh, why duplicate
> code?", and reading this one "Ah, that's OK". A single patch doing both
> would have avoided the confusion.

[PATCH RFC v2 06/19] rebase -i: Stop on root commits with empty log messages

[Fabian Ruch]

The command line used to recreate root commits specifies the
erroneous option `--allow-empty-message`. If the root commit has an
empty log message, the replay of this commit should fail and the
rebase should be interrupted like for any other commit that is on the
to-do list and has an empty commit message. Remove the option.

The option might have been introduced by copy-and-paste of the first
part of the command line which initializes the authorship of the
sentinel commit. Indeed, the sentinel commit has an empty log message
and this should not trigger a failure, which is why the option
`--allow-empty-message` is correctly specified here.

Add test.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh |  2 +-
 t/t3412-rebase-root.sh     | 39 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 4c875d5..0af96f2 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -510,7 +510,7 @@ do_pick () {
 		git commit --allow-empty --allow-empty-message --amend \
 			   --no-post-rewrite -n -q -C $1 &&
 			pick_one -n $1 &&
-			git commit --allow-empty --allow-empty-message \
+			git commit --allow-empty \
 				   --amend --no-post-rewrite -n -q -C $1 \
 				   ${gpg_sign_opt:+"$gpg_sign_opt"} ||
 			die_with_patch $1 "Could not apply $1... $2"
diff --git a/t/t3412-rebase-root.sh b/t/t3412-rebase-root.sh
index 0b52105..9867705 100755
--- a/t/t3412-rebase-root.sh
+++ b/t/t3412-rebase-root.sh
@@ -278,4 +278,43 @@ test_expect_success 'rebase -i -p --root with conflict (second part)' '
 	test_cmp expect-conflict-p out
 '
 
+test_expect_success 'stop rebase --root on empty root log message' '
+	# create a root commit with a non-empty tree so that rebase does
+	# not fail because of an empty commit, and an empty log message
+	echo root-commit >file &&
+	git add file &&
+	tree=$(git write-tree) &&
+	root=$(git commit-tree $tree </dev/null) &&
+	git checkout -b no-message-root-commit $root &&
+	# do not ff because otherwise neither the patch nor the message
+	# are looked at and checked for emptiness
+	test_when_finished git rebase --abort &&
+	test_must_fail env EDITOR=true git rebase -i --force-rebase --root &&
+	echo root-commit >file.expected &&
+	test_cmp file.expected file
+'
+
+test_expect_success 'stop rebase --root on empty child log message' '
+	# create a root commit with a non-empty tree and provide a log
+	# message so that rebase does not fail until the root commit is
+	# successfully replayed
+	echo root-commit >file &&
+	git add file &&
+	tree=$(git write-tree) &&
+	root=$(git commit-tree $tree -m root-commit) &&
+	git checkout -b no-message-child-commit $root &&
+	# create a child commit with a non-empty patch so that rebase
+	# does not fail because of an empty commit, but an empty log
+	# message
+	echo child-commit >file &&
+	git add file &&
+	git commit --allow-empty-message --no-edit &&
+	# do not ff because otherwise neither the patch nor the message
+	# are looked at and checked for emptiness
+	test_when_finished git rebase --abort &&
+	test_must_fail env EDITOR=true git rebase -i --force-rebase --root &&
+	echo child-commit >file.expected &&
+	test_cmp file.expected file
+'
+
 test_done
-- 
2.0.0

Re: [PATCH RFC v2 06/19] rebase -i: Stop on root commits with empty log messages

[Junio C Hamano]

Fabian Ruch <bafain@gmail.com> writes:

> The command line used to recreate root commits specifies the
> erroneous option `--allow-empty-message`. If the root commit has an
> empty log message, the replay of this commit should fail and the
> rebase should be interrupted like for any other commit that is on the
> to-do list and has an empty commit message. Remove the option.
>
> The option might have been introduced by copy-and-paste of the first
> part of the command line which initializes the authorship of the
> sentinel commit. Indeed, the sentinel commit has an empty log message
> and this should not trigger a failure, which is why the option
> `--allow-empty-message` is correctly specified here.

The first "commit --amend" uses -C "$1" to give the amended result
not just the authorship but also the log message taken from "$1".
If we are allowing a commit without any message to be used as "$1",
I think --allow-empty-message needs to be there.  If "$1" requires
the option here, why doesn't the second one, that records the
updated tree with the metainformation taken from the same commit
"$1" can successfully commit without the option?

Puzzled...

> Add test.
>
> Signed-off-by: Fabian Ruch <bafain@gmail.com>
> ---
>  git-rebase--interactive.sh |  2 +-
>  t/t3412-rebase-root.sh     | 39 +++++++++++++++++++++++++++++++++++++++
>  2 files changed, 40 insertions(+), 1 deletion(-)
>
> diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
> index 4c875d5..0af96f2 100644
> --- a/git-rebase--interactive.sh
> +++ b/git-rebase--interactive.sh
> @@ -510,7 +510,7 @@ do_pick () {
>  		git commit --allow-empty --allow-empty-message --amend \
>  			   --no-post-rewrite -n -q -C $1 &&
>  			pick_one -n $1 &&
> -			git commit --allow-empty --allow-empty-message \
> +			git commit --allow-empty \
>  				   --amend --no-post-rewrite -n -q -C $1 \
>  				   ${gpg_sign_opt:+"$gpg_sign_opt"} ||
>  			die_with_patch $1 "Could not apply $1... $2"
> diff --git a/t/t3412-rebase-root.sh b/t/t3412-rebase-root.sh
> index 0b52105..9867705 100755
> --- a/t/t3412-rebase-root.sh
> +++ b/t/t3412-rebase-root.sh
> @@ -278,4 +278,43 @@ test_expect_success 'rebase -i -p --root with conflict (second part)' '
>  	test_cmp expect-conflict-p out
>  '
>  
> +test_expect_success 'stop rebase --root on empty root log message' '
> +	# create a root commit with a non-empty tree so that rebase does
> +	# not fail because of an empty commit, and an empty log message
> +	echo root-commit >file &&
> +	git add file &&
> +	tree=$(git write-tree) &&
> +	root=$(git commit-tree $tree </dev/null) &&
> +	git checkout -b no-message-root-commit $root &&
> +	# do not ff because otherwise neither the patch nor the message
> +	# are looked at and checked for emptiness
> +	test_when_finished git rebase --abort &&
> +	test_must_fail env EDITOR=true git rebase -i --force-rebase --root &&
> +	echo root-commit >file.expected &&
> +	test_cmp file.expected file
> +'
> +
> +test_expect_success 'stop rebase --root on empty child log message' '
> +	# create a root commit with a non-empty tree and provide a log
> +	# message so that rebase does not fail until the root commit is
> +	# successfully replayed
> +	echo root-commit >file &&
> +	git add file &&
> +	tree=$(git write-tree) &&
> +	root=$(git commit-tree $tree -m root-commit) &&
> +	git checkout -b no-message-child-commit $root &&
> +	# create a child commit with a non-empty patch so that rebase
> +	# does not fail because of an empty commit, but an empty log
> +	# message
> +	echo child-commit >file &&
> +	git add file &&
> +	git commit --allow-empty-message --no-edit &&
> +	# do not ff because otherwise neither the patch nor the message
> +	# are looked at and checked for emptiness
> +	test_when_finished git rebase --abort &&
> +	test_must_fail env EDITOR=true git rebase -i --force-rebase --root &&
> +	echo child-commit >file.expected &&
> +	test_cmp file.expected file
> +'
> +
>  test_done

Re: [PATCH RFC v2 06/19] rebase -i: Stop on root commits with empty log messages

[Fabian Ruch]

Hi Junio,

Junio C Hamano writes:
> Fabian Ruch <bafain@gmail.com> writes:
>> The command line used to recreate root commits specifies the
>> erroneous option `--allow-empty-message`. If the root commit has an
>> empty log message, the replay of this commit should fail and the
>> rebase should be interrupted like for any other commit that is on the
>> to-do list and has an empty commit message. Remove the option.
>>
>> The option might have been introduced by copy-and-paste of the first
>> part of the command line which initializes the authorship of the
>> sentinel commit. Indeed, the sentinel commit has an empty log message
>> and this should not trigger a failure, which is why the option
>> `--allow-empty-message` is correctly specified here.
> 
> The first "commit --amend" uses -C "$1" to give the amended result
> not just the authorship but also the log message taken from "$1".
> If we are allowing a commit without any message to be used as "$1",
> I think --allow-empty-message needs to be there.  If "$1" requires
> the option here, why doesn't the second one, that records the
> updated tree with the metainformation taken from the same commit
> "$1" can successfully commit without the option?

(I realize now that the emptiness of the sentinel log message is
irrelevant to the success of the first "commit --amend" since we are
amending using -C. I'll rewrite the second paragraph of the patch
description.)

The first "commit --amend" requires --allow-empty-message because we do
not want to fail without the authorship or log message of $1 being in
place. It's not a matter of allowing or disallowing empty log messages yet.

git-rebase--interactive can come across an empty log message in three
different ways, which are, depicted as to-do list tasks, the following.

 1) pick --ff $1
 2) pick --no-ff $1
 3) reword $1

This patch is concerned with consistency in the second case.
git-rebase--root does not handle the first case yet and the third case
is handled somewhere else in the script independent of the first two.

The --root option handling was added to the script as a special case
later in the revision history. It's that option handling which
introduced the inconsistency that non-fast-forwards of commits with
empty log messages succeed if they are root commits but have always
failed otherwise.

Your reply suggests that git-rebase--interactive was wrong from the
beginning and that the replay of commits without any message should be
allowed. This would reconcile the first case with the second. In fact,
since neither of them alters the changes introduced by $1 or its log
message, it might be incorrect to complain about a missing message in
the first place.

Do you want me to replace this patch with a patch

    rebase -i: Always allow picking of commits with empty log messages

that makes git-rebase--interactive cherry-pick commits using
--allow-empty-message? The script would still abort an empty reword with
the new patch and the user could then still force the empty log message
with "git commit --amend --allow-empty-message".

   Fabian

> Puzzled...
> 
>> Add test.
>>
>> Signed-off-by: Fabian Ruch <bafain@gmail.com>
>> ---
>>  git-rebase--interactive.sh |  2 +-
>>  t/t3412-rebase-root.sh     | 39 +++++++++++++++++++++++++++++++++++++++
>>  2 files changed, 40 insertions(+), 1 deletion(-)
>>
>> diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
>> index 4c875d5..0af96f2 100644
>> --- a/git-rebase--interactive.sh
>> +++ b/git-rebase--interactive.sh
>> @@ -510,7 +510,7 @@ do_pick () {
>>  		git commit --allow-empty --allow-empty-message --amend \
>>  			   --no-post-rewrite -n -q -C $1 &&
>>  			pick_one -n $1 &&
>> -			git commit --allow-empty --allow-empty-message \
>> +			git commit --allow-empty \
>>  				   --amend --no-post-rewrite -n -q -C $1 \
>>  				   ${gpg_sign_opt:+"$gpg_sign_opt"} ||
>>  			die_with_patch $1 "Could not apply $1... $2"

Re: [PATCH RFC v2 06/19] rebase -i: Stop on root commits with empty log messages

[Junio C Hamano]

Fabian Ruch <bafain@gmail.com> writes:

> ...
> Do you want me to replace this patch with a patch
>
>     rebase -i: Always allow picking of commits with empty log messages
>
> that makes git-rebase--interactive cherry-pick commits using
> --allow-empty-message?

I do not "want" any particular behaviour change.  I wanted you to
clarify what changed behaviour you are trying to implement and why,
and that was why I was asking these questions.

Re: [PATCH RFC v2 06/19] rebase -i: Stop on root commits with empty log messages

[Junio C Hamano]

Fabian Ruch <bafain@gmail.com> writes:

> Your reply suggests that git-rebase--interactive was wrong from the
> beginning and that the replay of commits without any message should be
> allowed. This would reconcile the first case with the second. In fact,
> since neither of them alters the changes introduced by $1 or its log
> message, it might be incorrect to complain about a missing message in
> the first place.
> ...
> Do you want me to replace this patch with a patch

Now you explained your line of thought more clearly and I have
thought about it a bit more, I think I agree with the conclusion of
the above.

An alternative may be to teach a new option --allow-empty-message to
rebase to allow people to replay/reproduce an existing history with
commits without any message, and uniformly tighten to refuse replaying
a commit without message by default.  But I am not sure if that is a
good direction to go.  Doesn't "rebase" without "-i" by default replay
a commit without message faithfully?  It might be debatable to allow
a commit that we would normally would flag as suspicious (i.e. no
change relative to its parent, or no log message) when replaying
with "reword" or "edit", but when replaying with "pick", "rebase -i"
should behave just like "rebase" without interactive.

Thanks.

[PATCH RFC v2 07/19] rebase -i: The replay of root commits is not shown with --verbose

[Fabian Ruch]

The command line used to recreate root commits specifies the
erroneous option `-q` which suppresses the commit summary message.
However, git-rebase--interactive tends to tell the user about the
commits it creates, if she wishes (cf. command line option
`--verbose`). The code parts handling non-root commits or squash
commits all output commit summary messages. Do not make the replay of
root commits an exception. Remove the option.

It is OK to suppress the commit summary when git-commit is used to
initialize the authorship of the sentinel commit because the
existence of this additional commit is a detail of
git-rebase--interactive's implementation. The option `-q` was
probably introduced as a copy-and-paste error stemming from that part
of the root commit handling code.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 0af96f2..ff04d5d 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -511,7 +511,7 @@ do_pick () {
 			   --no-post-rewrite -n -q -C $1 &&
 			pick_one -n $1 &&
 			git commit --allow-empty \
-				   --amend --no-post-rewrite -n -q -C $1 \
+				   --amend --no-post-rewrite -n -C $1 \
 				   ${gpg_sign_opt:+"$gpg_sign_opt"} ||
 			die_with_patch $1 "Could not apply $1... $2"
 	else
-- 
2.0.0

Re: [PATCH RFC v2 07/19] rebase -i: The replay of root commits is not shown with --verbose

[Junio C Hamano]

Fabian Ruch <bafain@gmail.com> writes:

> The command line used to recreate root commits specifies the
> erroneous option `-q` which suppresses the commit summary message.
> However, git-rebase--interactive tends to tell the user about the
> commits it creates, if she wishes (cf. command line option
> `--verbose`). The code parts handling non-root commits or squash
> commits all output commit summary messages. Do not make the replay of
> root commits an exception. Remove the option.
>
> It is OK to suppress the commit summary when git-commit is used to
> initialize the authorship of the sentinel commit because the
> existence of this additional commit is a detail of
> git-rebase--interactive's implementation. The option `-q` was
> probably introduced as a copy-and-paste error stemming from that part
> of the root commit handling code.
>
> Signed-off-by: Fabian Ruch <bafain@gmail.com>
> ---

This one I can buy; there is no reason to drop "-q" from both (which
would give us the same thing twice and the one before the "pick_one
-n" runs is not the final one anyway) and the later one that records
the updated tree would be the one to report what it did.

>  git-rebase--interactive.sh | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
> index 0af96f2..ff04d5d 100644
> --- a/git-rebase--interactive.sh
> +++ b/git-rebase--interactive.sh
> @@ -511,7 +511,7 @@ do_pick () {
>  			   --no-post-rewrite -n -q -C $1 &&
>  			pick_one -n $1 &&
>  			git commit --allow-empty \
> -				   --amend --no-post-rewrite -n -q -C $1 \
> +				   --amend --no-post-rewrite -n -C $1 \
>  				   ${gpg_sign_opt:+"$gpg_sign_opt"} ||
>  			die_with_patch $1 "Could not apply $1... $2"
>  	else

Re: [PATCH RFC v2 07/19] rebase -i: The replay of root commits is not shown with --verbose

[Fabian Ruch]

Hi Chris,

you're the original author of the code touched by this patch. Is the
second -q option really a simple copy-and-paste of the first or am I
overlooking something here? I'd like to confirm this as, in retrospect,
I feel a bit uncertain about the hasty claim in the log message.

Kind regards,
   Fabian

Fabian Ruch writes:
> The command line used to recreate root commits specifies the
> erroneous option `-q` which suppresses the commit summary message.
> However, git-rebase--interactive tends to tell the user about the
> commits it creates, if she wishes (cf. command line option
> `--verbose`). The code parts handling non-root commits or squash
> commits all output commit summary messages. Do not make the replay of
> root commits an exception. Remove the option.
> 
> It is OK to suppress the commit summary when git-commit is used to
> initialize the authorship of the sentinel commit because the
> existence of this additional commit is a detail of
> git-rebase--interactive's implementation. The option `-q` was
> probably introduced as a copy-and-paste error stemming from that part
> of the root commit handling code.
> 
> Signed-off-by: Fabian Ruch <bafain@gmail.com>
> ---
>  git-rebase--interactive.sh | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
> index 0af96f2..ff04d5d 100644
> --- a/git-rebase--interactive.sh
> +++ b/git-rebase--interactive.sh
> @@ -511,7 +511,7 @@ do_pick () {
>  			   --no-post-rewrite -n -q -C $1 &&
>  			pick_one -n $1 &&
>  			git commit --allow-empty \
> -				   --amend --no-post-rewrite -n -q -C $1 \
> +				   --amend --no-post-rewrite -n -C $1 \
>  				   ${gpg_sign_opt:+"$gpg_sign_opt"} ||
>  			die_with_patch $1 "Could not apply $1... $2"
>  	else

Re: [PATCH RFC v2 07/19] rebase -i: The replay of root commits is not shown with --verbose

[Chris Webb]

Fabian Ruch <bafain@gmail.com> wrote:

> you're the original author of the code touched by this patch. Is the
> second -q option really a simple copy-and-paste of the first or am I
> overlooking something here? I'd like to confirm this as, in retrospect,
> I feel a bit uncertain about the hasty claim in the log message.

It was a while ago and I don't remember the details of this patch I'm
afraid, but your rationale here looks sensible to me. I tend to find git too
noisy by default rather than too quiet, so it wouldn't surprise me if I
never thought to try the --verbose version.

Cheers,

Chris.

[PATCH RFC v2 08/19] rebase -i: Root commits are replayed with an unnecessary option

[Fabian Ruch]

The command line used to recreate root commits specifies the
effectless option `-C`. It is used to reuse commit message and
authorship from the named commit but the commit being amended here,
which is the sentinel commit, already carries the authorship and log
message of the processed commit. Note that the committer email and
commit date fields do not match the root commit either way. Remove
the option. However, `-C` (other than `-c`) does not invoke the
editor and the `--amend` option invokes it by default. Disable editor
invocation again by specifying `--no-edit`.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index ff04d5d..17836d5 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -511,7 +511,7 @@ do_pick () {
 			   --no-post-rewrite -n -q -C $1 &&
 			pick_one -n $1 &&
 			git commit --allow-empty \
-				   --amend --no-post-rewrite -n -C $1 \
+				   --amend --no-post-rewrite -n --no-edit \
 				   ${gpg_sign_opt:+"$gpg_sign_opt"} ||
 			die_with_patch $1 "Could not apply $1... $2"
 	else
-- 
2.0.0

Re: [PATCH RFC v2 08/19] rebase -i: Root commits are replayed with an unnecessary option

[Junio C Hamano]

Fabian Ruch <bafain@gmail.com> writes:

> The command line used to recreate root commits specifies the
> effectless option `-C`. It is used to reuse commit message and
> authorship from the named commit but the commit being amended here,
> which is the sentinel commit, already carries the authorship and log
> message of the processed commit. Note that the committer email and
> commit date fields do not match the root commit either way. Remove
> the option. However, `-C` (other than `-c`) does not invoke the
> editor and the `--amend` option invokes it by default. Disable editor
> invocation again by specifying `--no-edit`.

I'd say this is a no-value change, in the sense that it can be
written either way for the same effect and if the original were
written with "--amend --no-edit" then there would be no reason to
change it to "-C $1" because such a change would also be equally a
no-value change.

What exactly are we gaining?  Performance?  Correctness?


> Signed-off-by: Fabian Ruch <bafain@gmail.com>
> ---
>  git-rebase--interactive.sh | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
> index ff04d5d..17836d5 100644
> --- a/git-rebase--interactive.sh
> +++ b/git-rebase--interactive.sh
> @@ -511,7 +511,7 @@ do_pick () {
>  			   --no-post-rewrite -n -q -C $1 &&
>  			pick_one -n $1 &&
>  			git commit --allow-empty \
> -				   --amend --no-post-rewrite -n -C $1 \
> +				   --amend --no-post-rewrite -n --no-edit \
>  				   ${gpg_sign_opt:+"$gpg_sign_opt"} ||
>  			die_with_patch $1 "Could not apply $1... $2"
>  	else

Re: [PATCH RFC v2 08/19] rebase -i: Root commits are replayed with an unnecessary option

[Fabian Ruch]

Hi Junio,

Junio C Hamano writes:
> Fabian Ruch <bafain@gmail.com> writes:
>> The command line used to recreate root commits specifies the
>> effectless option `-C`. It is used to reuse commit message and
>> authorship from the named commit but the commit being amended here,
>> which is the sentinel commit, already carries the authorship and log
>> message of the processed commit. Note that the committer email and
>> commit date fields do not match the root commit either way. Remove
>> the option. However, `-C` (other than `-c`) does not invoke the
>> editor and the `--amend` option invokes it by default. Disable editor
>> invocation again by specifying `--no-edit`.
> 
> I'd say this is a no-value change, in the sense that it can be
> written either way for the same effect and if the original were
> written with "--amend --no-edit" then there would be no reason to
> change it to "-C $1" because such a change would also be equally a
> no-value change.
> 
> What exactly are we gaining?  Performance?  Correctness?

I submitted this change separately from the next ("rebase -i: Commit
only once when rewriting picks") for the following reasons, at least I
thought they were.

It makes the next patch easier to understand because the finalising
command line "git commit --allow-empty --amend --no-post-rewrite -n
--no-edit" seems to be simply moved to the end of do_pick. Substituting
--no-edit for -C there would make that log message overly long and the
paragraph saying why this substitution is correct would be distracting
(it's a little unfortunate that there is this special case in the first
place). While the resulting history stays the same of course, it might
be confusing to someone reading the code that the log message gets
replaced with itself.

I know the last point is rather weak but aren't the two patches and log
messages easier to read?

   Fabian

>> Signed-off-by: Fabian Ruch <bafain@gmail.com>
>> ---
>>  git-rebase--interactive.sh | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
>> index ff04d5d..17836d5 100644
>> --- a/git-rebase--interactive.sh
>> +++ b/git-rebase--interactive.sh
>> @@ -511,7 +511,7 @@ do_pick () {
>>  			   --no-post-rewrite -n -q -C $1 &&
>>  			pick_one -n $1 &&
>>  			git commit --allow-empty \
>> -				   --amend --no-post-rewrite -n -C $1 \
>> +				   --amend --no-post-rewrite -n --no-edit \
>>  				   ${gpg_sign_opt:+"$gpg_sign_opt"} ||
>>  			die_with_patch $1 "Could not apply $1... $2"
>>  	else

Re: [PATCH RFC v2 08/19] rebase -i: Root commits are replayed with an unnecessary option

[Junio C Hamano]

Fabian Ruch <bafain@gmail.com> writes:

> It makes the next patch easier to understand because the finalising
> command line "git commit --allow-empty --amend --no-post-rewrite -n
> --no-edit" seems to be simply moved to the end of do_pick. Substituting
> --no-edit for -C there would make that log message overly long ...

And the reason why the same "-C $1" is not used and "--no-edit" is used
in the final version that is moved to the end of do_pick is...?

Re: [PATCH RFC v2 08/19] rebase -i: Root commits are replayed with an unnecessary option

[Fabian Ruch]

Hi Junio,

Junio C Hamano writes:
> Fabian Ruch <bafain@gmail.com> writes:
>> It makes the next patch easier to understand because the finalising
>> command line "git commit --allow-empty --amend --no-post-rewrite -n
>> --no-edit" seems to be simply moved to the end of do_pick. Substituting
>> --no-edit for -C there would make that log message overly long ...
> 
> And the reason why the same "-C $1" is not used and "--no-edit" is used
> in the final version that is moved to the end of do_pick is...?

The finalising command line is executed by do_pick to rewrite $1 when it
is being replayed.

For instance, one purpose of rewriting is amending the current head with
the changes introduced by $1. In this case, we don't want the log
message of $1 to be the final log message. Another purpose of rewriting
is using a text file or a string as log message, which would be defeated
by "-C $1" as well.

It's true that, by the time the next patch is introduced, do_pick
doesn't yet implement either rewriting mechanism (they are both used to
thread "squash" through do_pick later on) but these considerations
suggest that "-C $1" might not be what we want to use to disable the log
message editor.

   Fabian

[PATCH RFC v2 09/19] rebase -i: Commit only once when rewriting picks

[Fabian Ruch]

The options passed to `do_pick` determine whether the picked commit
will be rewritten or not. If the commit gets rewritten, because the
user requested to edit the commit message for instance, let
`pick_one` merely apply the changes introduced by the commit and do
not commit the resulting tree yet. If the commit is replayed as is,
leave it to `pick_one` to recreate the commit (possibly by
fast-forwarding the head). This makes it easier to combine git-commit
options like `--edit` and `--amend` in `do_pick` because
git-cherry-pick does not support `--amend`.

In the case of `--edit`, do not `exit_with_patch` but assign
`rewrite` to pick the changes with `-n`. If the pick conflicts, no
commit is created which we would have to amend when continuing the
rebase. To complete the pick after the conflicts are resolved the
user just resumes with `git rebase --continue`.

git-commit lets the user edit the commit log message by default. We
do not want that for the rewriting git-commit command line because
the default behaviour of git-cherry-pick is exactly the opposite.
Pass `--no-edit` when rewriting a picked commit. An explicit `--edit`
passed to `do_pick` (for instance, when reword is executed) enables
the editor launch again.

If `rebase--interactive` is used to rebase a complete branch onto
some head, `rebase` creates a sentinel commit that requires special
treatment by `do_pick`. Do not finalize the pick here either because
its commit message can be altered as for any other pick. Since the
orphaned root commit gets a temporary parent, it is always rewritten.
Safely use the rewrite infrastructure of `do_pick` to create the
final commit.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 55 +++++++++++++++++++++++++++-------------------
 1 file changed, 33 insertions(+), 22 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 17836d5..46b2db1 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -63,7 +63,8 @@ msgnum="$state_dir"/msgnum
 author_script="$state_dir"/author-script
 
 # When an "edit" rebase command is being processed, the SHA1 of the
-# commit to be edited is recorded in this file.  When "git rebase
+# commit to be edited is recorded in this file.  The same happens when
+# rewriting a commit fails, for instance "reword".  When "git rebase
 # --continue" is executed, if there are any staged changes then they
 # will be amended to the HEAD commit, but only provided the HEAD
 # commit is still the commit to be edited.  When any other rebase
@@ -479,12 +480,15 @@ record_in_rewritten() {
 #     The commit message title of <commit>. Used for information
 #     purposes only.
 do_pick () {
-	edit=
+	rewrite=
+	rewrite_amend=
+	rewrite_edit=
 	while test $# -gt 0
 	do
 		case "$1" in
 		-e|--edit)
-			edit=y
+			rewrite=y
+			rewrite_edit=y
 			;;
 		-*)
 			die "do_pick: unrecognized option -- $1"
@@ -499,6 +503,10 @@ do_pick () {
 
 	if test "$(git rev-parse HEAD)" = "$squash_onto"
 	then
+		rewrite=y
+		rewrite_amend=y
+		git rev-parse --verify HEAD >"$amend"
+
 		# Set the correct commit message and author info on the
 		# sentinel root before cherry-picking the original changes
 		# without committing (-n).  Finally, update the sentinel again
@@ -509,31 +517,34 @@ do_pick () {
 		# rebase --continue.
 		git commit --allow-empty --allow-empty-message --amend \
 			   --no-post-rewrite -n -q -C $1 &&
-			pick_one -n $1 &&
-			git commit --allow-empty \
-				   --amend --no-post-rewrite -n --no-edit \
-				   ${gpg_sign_opt:+"$gpg_sign_opt"} ||
+			pick_one -n $1 ||
 			die_with_patch $1 "Could not apply $1... $2"
 	else
-		pick_one $1 ||
+		pick_one ${rewrite:+-n} $1 ||
 			die_with_patch $1 "Could not apply $1... $2"
 	fi
 
-	if test -n "$edit"
+	if test -n "$rewrite"
 	then
-		# TODO: Work around the fact that git-commit lets us
-		# disable either both the pre-commit and the commit-msg
-		# hook or none. Disable the pre-commit hook because the
-		# tree is left unchanged but run the commit-msg hook
-		# from here because the log message is altered.
-		git commit --allow-empty --amend --no-post-rewrite -n ${gpg_sign_opt:+"$gpg_sign_opt"} &&
-			if test -x "$GIT_DIR"/hooks/commit-msg
-			then
-				"$GIT_DIR"/hooks/commit-msg "$GIT_DIR"/COMMIT_EDITMSG
-			fi || {
-				warn "Could not amend commit after successfully picking $1... $2"
-				exit_with_patch $1 1
-			}
+		git commit --allow-empty --no-post-rewrite -n --no-edit \
+			   ${rewrite_amend:+--amend} \
+			   ${rewrite_edit:+--edit} \
+			   ${gpg_sign_opt:+"$gpg_sign_opt"} ||
+			die_with_patch $1 "Could not rewrite commit after successfully picking $1... $2"
+	fi
+
+	# TODO: Work around the fact that git-commit lets us
+	# disable either both the pre-commit and the commit-msg
+	# hook or none. Disable the pre-commit hook because the
+	# tree is left unchanged but run the commit-msg hook
+	# from here because the log message is altered.
+	if test -n "$rewrite_edit"
+	then
+		if test -x "$GIT_DIR"/hooks/commit-msg
+		then
+			"$GIT_DIR"/hooks/commit-msg "$GIT_DIR"/COMMIT_EDITMSG
+		fi ||
+			die_with_patch $1 "Could not rewrite commit after successfully picking $1... $2"
 	fi
 }
 
-- 
2.0.0

[PATCH RFC v2 10/19] rebase -i: Do not die in do_pick

[Fabian Ruch]

Since `do_pick` might be executed in a sub-shell (a modified author
environment for instance), calling `die` in `do_pick` has no effect
but exiting the sub-shell with a failure exit status. The
git-rebase--interactive script is not terminated. Moreover, if
`do_pick` is called while a squash or fixup is in effect,
`die_with_patch` will discard `$squash_msg` as commit message.
Lastly, after a `die` in `do_pick` `do_next` has no chance to
reschedule tasks that failed before changes could be applied.

Indicate an error in `do_pick` using return statements and properly
kill the script at the call sites. Although possible in principle,
the issued error messages are no more indicating whether `do_pick`
failed while applying or while committing the changes. This reduces
code complexity at the call site and does not matter from a user's
point of view because a glance at the index reveals whether there are
conflicts or not and in-depth troubleshooting is still possible using
the `--verbose` option.

Remove the commit message title argument from `do_pick`'s interface,
which has become unused.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 37 ++++++++++++++++++++-----------------
 1 file changed, 20 insertions(+), 17 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 46b2db1..0070b3e 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -464,7 +464,7 @@ record_in_rewritten() {
 
 # Apply the changes introduced by the given commit to the current head.
 #
-# do_pick [--edit] <commit> <title>
+# do_pick [--edit] <commit>
 #
 # Wrapper around git-cherry-pick.
 #
@@ -476,9 +476,11 @@ record_in_rewritten() {
 # <commit>
 #     The commit to cherry-pick.
 #
-# <title>
-#     The commit message title of <commit>. Used for information
-#     purposes only.
+# The return value is 1 if applying the changes resulted in a conflict
+# and 2 if the specified arguments were incorrect. If the changes could
+# be applied successfully but creating the commit failed, a value
+# greater than 2 is returned. No commit is created in either case and
+# the index is left with the (conflicting) changes in place.
 do_pick () {
 	rewrite=
 	rewrite_amend=
@@ -491,7 +493,8 @@ do_pick () {
 			rewrite_edit=y
 			;;
 		-*)
-			die "do_pick: unrecognized option -- $1"
+			warn "do_pick: unrecognized option -- $1"
+			return 2
 			;;
 		*)
 			break
@@ -499,7 +502,11 @@ do_pick () {
 		esac
 		shift
 	done
-	test $# -ne 2 && die "do_pick: wrong number of arguments"
+	if test $# -ne 1
+	then
+		warn "do_pick: wrong number of arguments"
+		return 2
+	fi
 
 	if test "$(git rev-parse HEAD)" = "$squash_onto"
 	then
@@ -517,11 +524,9 @@ do_pick () {
 		# rebase --continue.
 		git commit --allow-empty --allow-empty-message --amend \
 			   --no-post-rewrite -n -q -C $1 &&
-			pick_one -n $1 ||
-			die_with_patch $1 "Could not apply $1... $2"
+			pick_one -n $1 || return 1
 	else
-		pick_one ${rewrite:+-n} $1 ||
-			die_with_patch $1 "Could not apply $1... $2"
+		pick_one ${rewrite:+-n} $1 || return 1
 	fi
 
 	if test -n "$rewrite"
@@ -529,8 +534,7 @@ do_pick () {
 		git commit --allow-empty --no-post-rewrite -n --no-edit \
 			   ${rewrite_amend:+--amend} \
 			   ${rewrite_edit:+--edit} \
-			   ${gpg_sign_opt:+"$gpg_sign_opt"} ||
-			die_with_patch $1 "Could not rewrite commit after successfully picking $1... $2"
+			   ${gpg_sign_opt:+"$gpg_sign_opt"} || return 3
 	fi
 
 	# TODO: Work around the fact that git-commit lets us
@@ -543,8 +547,7 @@ do_pick () {
 		if test -x "$GIT_DIR"/hooks/commit-msg
 		then
 			"$GIT_DIR"/hooks/commit-msg "$GIT_DIR"/COMMIT_EDITMSG
-		fi ||
-			die_with_patch $1 "Could not rewrite commit after successfully picking $1... $2"
+		fi || return 3
 	fi
 }
 
@@ -559,21 +562,21 @@ do_next () {
 		comment_for_reflog pick
 
 		mark_action_done
-		do_pick $sha1 "$rest"
+		do_pick $sha1 || die_with_patch $sha1 "Could not apply $sha1... $rest"
 		record_in_rewritten $sha1
 		;;
 	reword|r)
 		comment_for_reflog reword
 
 		mark_action_done
-		do_pick --edit $sha1 "$rest"
+		do_pick --edit $sha1 || die_with_patch $sha1 "Could not apply $sha1... $rest"
 		record_in_rewritten $sha1
 		;;
 	edit|e)
 		comment_for_reflog edit
 
 		mark_action_done
-		do_pick $sha1 "$rest"
+		do_pick $sha1 || die_with_patch $sha1 "Could not apply $sha1... $rest"
 		warn "Stopped at $sha1... $rest"
 		exit_with_patch $sha1 0
 		;;
-- 
2.0.0

[PATCH RFC v2 11/19] rebase -i: Teach do_pick the option --amend

[Fabian Ruch]

`do_pick` is the git-cherry-pick wrapper in git-rebase--interactive
that is used to implement the to-do list commands `pick`, `reword`
and `edit`. To cater for the different pick behaviours (like
`squash`), `do_pick` accepts several options not only from the
git-cherry-pick but also the git-commit interface.

Add the option `--amend` from the git-commit interface to the options
pool of `do_pick`. It creates a new commit for the changes introduced
by the picked commit and the previous one. The previous commit is
then replaced with the new commit. If no other options are specified,
the log message of the previous commit is used.

Be careful when `--amend` is used to pick a root commit because HEAD
might point to the sentinel commit but there is still nothing to
amend. Be sure to initialize `amend` so that commits are squashed
even when git-rebase--interactive is interrupted for resolving
conflicts. It is not a mistake to do the initialization regardless of
any conflicts because `amend` is always cleared before the next to-do
item is processed.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 0070b3e..046d358 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -464,10 +464,16 @@ record_in_rewritten() {
 
 # Apply the changes introduced by the given commit to the current head.
 #
-# do_pick [--edit] <commit>
+# do_pick [--amend] [--edit] <commit>
 #
 # Wrapper around git-cherry-pick.
 #
+# --amend
+#     After picking <commit>, replace the current head commit with a new
+#     commit that also introduces the changes of <commit>.
+#
+#     _This is not a git-cherry-pick option._
+#
 # -e, --edit
 #     After picking <commit>, open an editor and let the user edit the
 #     commit message. The editor contents becomes the commit message of
@@ -488,6 +494,16 @@ do_pick () {
 	while test $# -gt 0
 	do
 		case "$1" in
+		--amend)
+			if test "$(git rev-parse HEAD)" = "$squash_onto" || ! git rev-parse --verify HEAD
+			then
+				warn "do_pick: nothing to amend"
+				return 2
+			fi
+			rewrite=y
+			rewrite_amend=y
+			git rev-parse --verify HEAD >"$amend"
+			;;
 		-e|--edit)
 			rewrite=y
 			rewrite_edit=y
-- 
2.0.0

[PATCH RFC v2 12/19] rebase -i: Teach do_pick the option --file

[Fabian Ruch]

`do_pick` is the git-cherry-pick wrapper in git-rebase--interactive
that is used to implement the to-do list command `pick`, `reword` and
`edit`. To cater for the different pick behaviours (like `squash`),
`do_pick` accepts several options not only from the git-cherry-pick
but also the git-commit interface.

Add the option `--file` from the git-commit interface to the options
pool of `do_pick`. It expects an argument itself which is interpreted
as a file path and takes the commit message from the given file. If
`--file` is passed to `do_pick`, assign the given file path to the
local variable `rewrite_message` and relay the option

    --file "$rewrite_message"

to the git-commit command line which creates the commit.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 046d358..47e3edf 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -464,7 +464,7 @@ record_in_rewritten() {
 
 # Apply the changes introduced by the given commit to the current head.
 #
-# do_pick [--amend] [--edit] <commit>
+# do_pick [--amend] [--file <file>] [--edit] <commit>
 #
 # Wrapper around git-cherry-pick.
 #
@@ -474,6 +474,12 @@ record_in_rewritten() {
 #
 #     _This is not a git-cherry-pick option._
 #
+# -F <file>, --file <file>
+#     Take the commit message from the given file. This creates a fresh
+#     commit.
+#
+#     _This is not a git-cherry-pick option._
+#
 # -e, --edit
 #     After picking <commit>, open an editor and let the user edit the
 #     commit message. The editor contents becomes the commit message of
@@ -491,6 +497,7 @@ do_pick () {
 	rewrite=
 	rewrite_amend=
 	rewrite_edit=
+	rewrite_message=
 	while test $# -gt 0
 	do
 		case "$1" in
@@ -504,6 +511,16 @@ do_pick () {
 			rewrite_amend=y
 			git rev-parse --verify HEAD >"$amend"
 			;;
+		-F|--file)
+			if test $# -eq 0
+			then
+				warn "do_pick: option --file specified but no <file> given"
+				return 2
+			fi
+			rewrite=y
+			rewrite_message=$2
+			shift
+			;;
 		-e|--edit)
 			rewrite=y
 			rewrite_edit=y
@@ -550,6 +567,7 @@ do_pick () {
 		git commit --allow-empty --no-post-rewrite -n --no-edit \
 			   ${rewrite_amend:+--amend} \
 			   ${rewrite_edit:+--edit} \
+			   ${rewrite_message:+--file "$rewrite_message"} \
 			   ${gpg_sign_opt:+"$gpg_sign_opt"} || return 3
 	fi
 
-- 
2.0.0

[PATCH RFC v2 13/19] rebase -i: Prepare for squash in terms of do_pick --amend

[Fabian Ruch]

Rewrite `squash` and `fixup` handling in `do_next` using the sequence

    pick_one
    commit

in order to test the correctness of a single `do_squash` or
parameterised `do_pick` and make the subsequent patch reimplementing
`squash` in terms of such a single function more readable.

Do not call `rm -f "$GIT_DIR"/MERGE_MSG` since it has no effect on
the state after git-rebase--interactive terminates. The option `-F`
makes git-commit ignore `MERGE_MSG` for the log message. If
git-commit succeeds, `MERGE_MSG` is removed, and if it fails,
`MERGE_MSG` is overwritten by the error sequence `die_failed_squash`.
In summary, removing `MERGE_MSG` neither influences the squash commit
message nor the file state after git-commit returns.

Moreover, `pick_one` ignores `$GIT_DIR/SQUASH_MSG` and does not touch
`$squash_msg` so that it is correct to execute `pick_one` immediately
before git-commit.

Might be squashed into the subsequent commit.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 47e3edf..37800be 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -633,15 +633,15 @@ do_next () {
 		author_script_content=$(get_author_ident_from_commit HEAD)
 		echo "$author_script_content" > "$author_script"
 		eval "$author_script_content"
-		if ! pick_one -n $sha1
-		then
-			git rev-parse --verify HEAD >"$amend"
-			die_failed_squash $sha1 "$rest"
-		fi
 		case "$(peek_next_command)" in
 		squash|s|fixup|f)
 			# This is an intermediate commit; its message will only be
 			# used in case of trouble.  So use the long version:
+			if ! pick_one -n $sha1
+			then
+				git rev-parse --verify HEAD >"$amend"
+				die_failed_squash $sha1 "Could not apply $sha1... $rest"
+			fi
 			do_with_author output git commit --amend --no-verify -F "$squash_msg" \
 				${gpg_sign_opt:+"$gpg_sign_opt"} ||
 				die_failed_squash $sha1 "$rest"
@@ -650,12 +650,21 @@ do_next () {
 			# This is the final command of this squash/fixup group
 			if test -f "$fixup_msg"
 			then
+				if ! pick_one -n $sha1
+				then
+					git rev-parse --verify HEAD >"$amend"
+					die_failed_squash $sha1 "Could not apply $sha1... $rest"
+				fi
 				do_with_author git commit --amend --no-verify -F "$fixup_msg" \
 					${gpg_sign_opt:+"$gpg_sign_opt"} ||
 					die_failed_squash $sha1 "$rest"
 			else
 				cp "$squash_msg" "$GIT_DIR"/SQUASH_MSG || exit
-				rm -f "$GIT_DIR"/MERGE_MSG
+				if ! pick_one -n $sha1
+				then
+					git rev-parse --verify HEAD >"$amend"
+					die_failed_squash $sha1 "Could not apply $sha1... $rest"
+				fi
 				do_with_author git commit --amend --no-verify -F "$GIT_DIR"/SQUASH_MSG -e \
 					${gpg_sign_opt:+"$gpg_sign_opt"} ||
 					die_failed_squash $sha1 "$rest"
-- 
2.0.0

[PATCH RFC v2 14/19] rebase -i: Implement squash in terms of do_pick

[Fabian Ruch]

The to-do list command `squash` and its close relative `fixup` replay
the changes of a commit like `pick` but do not recreate the commit.
Instead they replace the previous commit with a new commit that also
introduces the changes of the squashed commit. This is roughly like
cherry-picking without committing and using git-commit to amend the
previous commit.

The to-do list

    pick   a Some changes
    squash b Some more changes

gets translated into the sequence of git commands

    git cherry-pick a
    git cherry-pick -n b
    git commit --amend

and if git-cherry-pick supported `--amend` this would look even more
like the to-do list it is based on

    git cherry-pick a
    git cherry-pick --amend b.

Since `do_pick` takes care of `pick` entries and the above suggests
`squash` as an alias for `pick --amend`, reimplement `squash` in
terms of `do_pick --amend`. Introduce `$squash_msg` as the commit
message via the `--file` option. When the last commit of a squash
series is processed, the user is asked to review the log message.
Pass `--edit` as additional option in this case. The only difference
in the options passed to git-commit and `do_pick` is the omitted
`--no-verify`. However, `do_pick` does not execute the verification
hooks anyway because it solely replays commits and assumes that they
have been verified before.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 30 ++++++------------------------
 1 file changed, 6 insertions(+), 24 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 37800be..008f3a0 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -637,37 +637,19 @@ do_next () {
 		squash|s|fixup|f)
 			# This is an intermediate commit; its message will only be
 			# used in case of trouble.  So use the long version:
-			if ! pick_one -n $sha1
-			then
-				git rev-parse --verify HEAD >"$amend"
-				die_failed_squash $sha1 "Could not apply $sha1... $rest"
-			fi
-			do_with_author output git commit --amend --no-verify -F "$squash_msg" \
-				${gpg_sign_opt:+"$gpg_sign_opt"} ||
-				die_failed_squash $sha1 "$rest"
+			do_with_author do_pick --amend -F "$squash_msg" $sha1 \
+				|| die_failed_squash $sha1 "Could not apply $sha1... $rest"
 			;;
 		*)
 			# This is the final command of this squash/fixup group
 			if test -f "$fixup_msg"
 			then
-				if ! pick_one -n $sha1
-				then
-					git rev-parse --verify HEAD >"$amend"
-					die_failed_squash $sha1 "Could not apply $sha1... $rest"
-				fi
-				do_with_author git commit --amend --no-verify -F "$fixup_msg" \
-					${gpg_sign_opt:+"$gpg_sign_opt"} ||
-					die_failed_squash $sha1 "$rest"
+				do_with_author do_pick --amend -F "$fixup_msg" $sha1 \
+					|| die_failed_squash $sha1 "Could not apply $sha1... $rest"
 			else
 				cp "$squash_msg" "$GIT_DIR"/SQUASH_MSG || exit
-				if ! pick_one -n $sha1
-				then
-					git rev-parse --verify HEAD >"$amend"
-					die_failed_squash $sha1 "Could not apply $sha1... $rest"
-				fi
-				do_with_author git commit --amend --no-verify -F "$GIT_DIR"/SQUASH_MSG -e \
-					${gpg_sign_opt:+"$gpg_sign_opt"} ||
-					die_failed_squash $sha1 "$rest"
+				do_with_author do_pick --amend -F "$GIT_DIR"/SQUASH_MSG -e $sha1 \
+					|| die_failed_squash $sha1 "Could not apply $sha1... $rest"
 			fi
 			rm -f "$squash_msg" "$fixup_msg"
 			;;
-- 
2.0.0

[PATCH RFC v2 15/19] rebase -i: Explicitly distinguish replay commands and exec tasks

[Fabian Ruch]

There are two kinds of to-do list commands available. One kind
replays a commit (`pick`, `reword`, `edit`, `squash` and `fixup` that
is) and the other executes a shell command (`exec`). We will call the
first kind replay commands.

The two kinds of tasks are scheduled using different line formats.
Replay commands expect a commit hash argument following the command
name and exec concatenates all arguments to assemble a command line.

Adhere to the distinction of formats by not trying to parse the
`sha1` field unless we are dealing with a replay command. Move the
replay command handling code to a new function `do_replay` which
assumes the first argument to be a commit hash and make no more such
assumptions in `do_next`.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 42 ++++++++++++++++++++++++++++--------------
 1 file changed, 28 insertions(+), 14 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 008f3a0..9de7441 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -585,13 +585,12 @@ do_pick () {
 	fi
 }
 
-do_next () {
-	rm -f "$msg" "$author_script" "$amend" || exit
-	read -r command sha1 rest < "$todo"
+do_replay () {
+	command=$1
+	sha1=$2
+	rest=$3
+
 	case "$command" in
-	"$comment_char"*|''|noop)
-		mark_action_done
-		;;
 	pick|p)
 		comment_for_reflog pick
 
@@ -656,6 +655,28 @@ do_next () {
 		esac
 		record_in_rewritten $sha1
 		;;
+	*)
+		read -r command <"$todo"
+		warn "Unknown command: $command"
+		fixtodo="Please fix this using 'git rebase --edit-todo'."
+		if git rev-parse --verify -q "$sha1" >/dev/null
+		then
+			die_with_patch $sha1 "$fixtodo"
+		else
+			die "$fixtodo"
+		fi
+		;;
+	esac
+}
+
+do_next () {
+	rm -f "$msg" "$author_script" "$amend" || exit
+	read -r command sha1 rest <"$todo"
+
+	case "$command" in
+	"$comment_char"*|''|noop)
+		mark_action_done
+		;;
 	x|"exec")
 		read -r command rest < "$todo"
 		mark_action_done
@@ -695,14 +716,7 @@ do_next () {
 		fi
 		;;
 	*)
-		warn "Unknown command: $command $sha1 $rest"
-		fixtodo="Please fix this using 'git rebase --edit-todo'."
-		if git rev-parse --verify -q "$sha1" >/dev/null
-		then
-			die_with_patch $sha1 "$fixtodo"
-		else
-			die "$fixtodo"
-		fi
+		do_replay $command $sha1 "$rest"
 		;;
 	esac
 	test -s "$todo" && return
-- 
2.0.0

Re: [PATCH RFC v2 15/19] rebase -i: Explicitly distinguish replay commands and exec tasks

[Junio C Hamano]

Fabian Ruch <bafain@gmail.com> writes:

> There are two kinds of to-do list commands available. One kind
> replays a commit (`pick`, `reword`, `edit`, `squash` and `fixup` that
> is) and the other executes a shell command (`exec`). We will call the
> first kind replay commands.
>
> The two kinds of tasks are scheduled using different line formats.
> Replay commands expect a commit hash argument following the command
> name and exec concatenates all arguments to assemble a command line.
>
> Adhere to the distinction of formats by not trying to parse the
> `sha1` field unless we are dealing with a replay command. Move the
> replay command handling code to a new function `do_replay` which
> assumes the first argument to be a commit hash and make no more such
> assumptions in `do_next`.

In do_next(), we used read the first line of the insn sheet into
three variables, assuming the common case of handling one of the
replay commands, and (somewhat wastefully) re-read the same line
into two variables when we realize that the command was "exec".

After you split do_replay() out of do_next() with this patch, we
seem to do exactly the same thing.

What exactly is the problem this change wants to fix?

Puzzled...


>
> Signed-off-by: Fabian Ruch <bafain@gmail.com>
> ---
>  git-rebase--interactive.sh | 42 ++++++++++++++++++++++++++++--------------
>  1 file changed, 28 insertions(+), 14 deletions(-)
>
> diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
> index 008f3a0..9de7441 100644
> --- a/git-rebase--interactive.sh
> +++ b/git-rebase--interactive.sh
> @@ -585,13 +585,12 @@ do_pick () {
>  	fi
>  }
>  
> -do_next () {
> -	rm -f "$msg" "$author_script" "$amend" || exit
> -	read -r command sha1 rest < "$todo"
> +do_replay () {
> +	command=$1
> +	sha1=$2
> +	rest=$3
> +
>  	case "$command" in
> -	"$comment_char"*|''|noop)
> -		mark_action_done
> -		;;
>  	pick|p)
>  		comment_for_reflog pick
>  
> @@ -656,6 +655,28 @@ do_next () {
>  		esac
>  		record_in_rewritten $sha1
>  		;;
> +	*)
> +		read -r command <"$todo"
> +		warn "Unknown command: $command"
> +		fixtodo="Please fix this using 'git rebase --edit-todo'."
> +		if git rev-parse --verify -q "$sha1" >/dev/null
> +		then
> +			die_with_patch $sha1 "$fixtodo"
> +		else
> +			die "$fixtodo"
> +		fi
> +		;;
> +	esac
> +}
> +
> +do_next () {
> +	rm -f "$msg" "$author_script" "$amend" || exit
> +	read -r command sha1 rest <"$todo"
> +
> +	case "$command" in
> +	"$comment_char"*|''|noop)
> +		mark_action_done
> +		;;
>  	x|"exec")
>  		read -r command rest < "$todo"
>  		mark_action_done
> @@ -695,14 +716,7 @@ do_next () {
>  		fi
>  		;;
>  	*)
> -		warn "Unknown command: $command $sha1 $rest"
> -		fixtodo="Please fix this using 'git rebase --edit-todo'."
> -		if git rev-parse --verify -q "$sha1" >/dev/null
> -		then
> -			die_with_patch $sha1 "$fixtodo"
> -		else
> -			die "$fixtodo"
> -		fi
> +		do_replay $command $sha1 "$rest"
>  		;;
>  	esac
>  	test -s "$todo" && return

[PATCH RFC v2 16/19] rebase -i: Parse to-do list command line options

[Fabian Ruch]

Read in to-do list lines as

    command args

instead of

    command sha1 rest

so that to-do list command lines can specify additional arguments
apart from the commit hash and the log message title, which become
the non-options in `args`. Loop over `args`, put all options (an
argument beginning with a dash) in `opts`, stop the loop on the first
non-option and assign it to `sha1`. The loop does not know the
options it parses so that options that take an argument themselves
are not supported at the moment. Neither are options that contain
spaces because the shell expansion of `args` in `do_next` interprets
white space characters as argument separator, that is a command line
like

    pick --author "A U Thor" fa1afe1 Some change

is parsed as the pick command

    pick --author

and the commit hash

    "A

which obviously results in an unknown revision error. For the sake of
completeness, in the example above the message title variable `rest`
is assigned the string 'U Thor" fa1afe1 Some change' (without the
single quotes).

Print an error message for unknown or unsupported command line
options, which means an error for all specified options at the
moment. Cleanly break the `do_next` loop by assigning the special
value 'unknown' to the local variable `command`, which triggers the
unknown command case in `do_cmd`.

The to-do list is also parsed when the commit hashes are translated
between long and short format before and after the to-do list is
edited. Apply the same procedure as in `do_cmd` with the exception
that we only care about where the options stop and the commit hash
begins. Do not reject any options when transforming the commit
hashes.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 49 ++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 41 insertions(+), 8 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 9de7441..2119d00 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -587,8 +587,26 @@ do_pick () {
 
 do_replay () {
 	command=$1
-	sha1=$2
-	rest=$3
+	shift
+
+	opts=
+	while test $# -gt 0
+	do
+		case "$1" in
+		-*)
+			warn "Unknown option: $1"
+			command=unknown
+			;;
+		*)
+			break
+			;;
+		esac
+		opts="$opts $(git rev-parse --sq-quote "$1")"
+		shift
+	done
+	sha1=$1
+	shift
+	rest=$*
 
 	case "$command" in
 	pick|p)
@@ -671,7 +689,7 @@ do_replay () {
 
 do_next () {
 	rm -f "$msg" "$author_script" "$amend" || exit
-	read -r command sha1 rest <"$todo"
+	read -r command args <"$todo"
 
 	case "$command" in
 	"$comment_char"*|''|noop)
@@ -716,7 +734,7 @@ do_next () {
 		fi
 		;;
 	*)
-		do_replay $command $sha1 "$rest"
+		do_replay $command $args
 		;;
 	esac
 	test -s "$todo" && return
@@ -796,19 +814,34 @@ skip_unnecessary_picks () {
 }
 
 transform_todo_ids () {
-	while read -r command rest
+	while read -r command args
 	do
 		case "$command" in
 		"$comment_char"* | exec)
 			# Be careful for oddball commands like 'exec'
 			# that do not have a SHA-1 at the beginning of $rest.
+			newargs=\ $args
 			;;
 		*)
-			sha1=$(git rev-parse --verify --quiet "$@" ${rest%% *}) &&
-			rest="$sha1 ${rest#* }"
+			newargs=
+			sha1=
+			for arg in $args
+			do
+				case "$arg" in
+				-*)
+					newargs="$newargs $arg"
+					;;
+				*)
+					test -z "$sha1" &&
+						sha1=$(git rev-parse --verify --quiet "$@" $arg) &&
+						arg=$sha1
+					newargs="$newargs $arg"
+					;;
+				esac
+			done
 			;;
 		esac
-		printf '%s\n' "$command${rest:+ }$rest"
+		printf '%s\n' "$command$newargs"
 	done <"$todo" >"$todo.new" &&
 	mv -f "$todo.new" "$todo"
 }
-- 
2.0.0

[PATCH RFC v2 17/19] rebase -i: Teach do_pick the option --reset-author

[Fabian Ruch]

`do_pick` is the git-cherry-pick wrapper in git-rebase--interactive
that is used to implement many of the to-do list commands.
Eventually, the complete `do_pick` interface will be exposed to the
user in some form or another and those commands will become simple
aliases for the `do_pick` options now used to implement them.

Add the git-commit option `--reset-author` to the options pool of
`do_pick`. It rewrites the author date and name of the picked commit
to match the committer date and name.

If `--reset-author` is passed to `do_pick`, set the `rewrite` flag
and relay the option to the git-commit command line which creates the
final commit. If `--amend` is not passed as well, the fresh
authorship effect is achieved by the mere fact that we are creating a
new commit.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 2119d00..a9fcb76 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -464,10 +464,18 @@ record_in_rewritten() {
 
 # Apply the changes introduced by the given commit to the current head.
 #
-# do_pick [--amend] [--file <file>] [--edit] <commit>
+# do_pick [--reset-author] [--amend] [--file <file>] [--edit] <commit>
 #
 # Wrapper around git-cherry-pick.
 #
+# --reset-author
+#     Pretend the changes were made for the first time. Declare that the
+#     authorship of the resulting commit now belongs to the committer.
+#     This also renews the author timestamp. This creates a fresh
+#     commit.
+#
+#     _This is not a git-cherry-pick option._
+#
 # --amend
 #     After picking <commit>, replace the current head commit with a new
 #     commit that also introduces the changes of <commit>.
@@ -501,6 +509,10 @@ do_pick () {
 	while test $# -gt 0
 	do
 		case "$1" in
+		--reset-author)
+			rewrite=y
+			rewrite_author=y
+			;;
 		--amend)
 			if test "$(git rev-parse HEAD)" = "$squash_onto" || ! git rev-parse --verify HEAD
 			then
@@ -562,12 +574,21 @@ do_pick () {
 		pick_one ${rewrite:+-n} $1 || return 1
 	fi
 
+	if test -n "$rewrite_author" && test -z "$rewrite_amend"
+	then
+		# keep rewrite flag to create a new commit, rewrite
+		# without --reset-author though because it can only be
+		# used with -C, -c or --amend
+		rewrite_author=
+	fi
+
 	if test -n "$rewrite"
 	then
 		git commit --allow-empty --no-post-rewrite -n --no-edit \
 			   ${rewrite_amend:+--amend} \
 			   ${rewrite_edit:+--edit} \
 			   ${rewrite_message:+--file "$rewrite_message"} \
+			   ${rewrite_author:+--reset-author} \
 			   ${gpg_sign_opt:+"$gpg_sign_opt"} || return 3
 	fi
 
-- 
2.0.0

[PATCH RFC v2 18/19] rebase -i: Teach do_pick the option --signoff

[Fabian Ruch]

`do_pick` is the git-cherry-pick wrapper in git-rebase--interactive
that is currently used to implement most of the to-do list commands
and offers additional options that will eventually find their way
onto to-do lists.

To extend the repertoire of available options, add the git-commit and
git-cherry-pick option `--signoff` to the `do_pick` interface. It
appends a Signed-off-by: line using the committer identity to the log
message of the picked commit.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index a9fcb76..bb258bb 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -464,10 +464,15 @@ record_in_rewritten() {
 
 # Apply the changes introduced by the given commit to the current head.
 #
-# do_pick [--reset-author] [--amend] [--file <file>] [--edit] <commit>
+# do_pick [--signoff] [--reset-author] [--amend] [--file <file>]
+#         [--edit] <commit>
 #
 # Wrapper around git-cherry-pick.
 #
+# -s, --signoff
+#     Insert a Signed-off-by: line using the committer identity at the
+#     end of the commit log message. This creates a fresh commit.
+#
 # --reset-author
 #     Pretend the changes were made for the first time. Declare that the
 #     authorship of the resulting commit now belongs to the committer.
@@ -509,6 +514,10 @@ do_pick () {
 	while test $# -gt 0
 	do
 		case "$1" in
+		-s|--signoff)
+			rewrite=y
+			rewrite_signoff=y
+			;;
 		--reset-author)
 			rewrite=y
 			rewrite_author=y
@@ -585,6 +594,7 @@ do_pick () {
 	if test -n "$rewrite"
 	then
 		git commit --allow-empty --no-post-rewrite -n --no-edit \
+			   ${rewrite_signoff:+--signoff} \
 			   ${rewrite_amend:+--amend} \
 			   ${rewrite_edit:+--edit} \
 			   ${rewrite_message:+--file "$rewrite_message"} \
-- 
2.0.0

[PATCH RFC v2 19/19] rebase -i: Enable options --signoff, --reset-author for pick, reword

[Fabian Ruch]

pick and reword are atomic to-do list commands in the sense that they
open a new task which is closed after the respective command is
completed. squash and fixup are not atomic. They create a new task
which is not completed until the last squash or fixup is processed.

Lift the general unknown option blockade for the pick and reword
commands. If `do_cmd` comes across one of the options `--signoff` and
`--reset-author` while parsing a to-do entry and the scheduled
command is either `pick` or `reword`, relay the option to `do_pick`.

The `do_pick` options `--gpg-sign` and `--file` are not yet supported
because `do_cmd` cannot handle option arguments and options with
spaces at the moment. It is true that edit is one of the atomic
commands but it displays hash information when the rebase is stopped
and some options rewrite the picked commit which alters that
information. squash and fixup still do not accept user options as the
interplay of `--reset-author` and the author script are yet to be
determined.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index bb258bb..c34a9a7 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -624,6 +624,16 @@ do_replay () {
 	while test $# -gt 0
 	do
 		case "$1" in
+		--signoff|--reset-author)
+			case "$command" in
+			pick|reword)
+				;;
+			*)
+				warn "Unsupported option: $1"
+				command=unknown
+				;;
+			esac
+			;;
 		-*)
 			warn "Unknown option: $1"
 			command=unknown
@@ -644,21 +654,24 @@ do_replay () {
 		comment_for_reflog pick
 
 		mark_action_done
-		do_pick $sha1 || die_with_patch $sha1 "Could not apply $sha1... $rest"
+		eval do_pick $opts $sha1 \
+			|| die_with_patch $sha1 "Could not apply $sha1... $rest"
 		record_in_rewritten $sha1
 		;;
 	reword|r)
 		comment_for_reflog reword
 
 		mark_action_done
-		do_pick --edit $sha1 || die_with_patch $sha1 "Could not apply $sha1... $rest"
+		eval do_pick --edit $opts $sha1 \
+			|| die_with_patch $sha1 "Could not apply $sha1... $rest"
 		record_in_rewritten $sha1
 		;;
 	edit|e)
 		comment_for_reflog edit
 
 		mark_action_done
-		do_pick $sha1 || die_with_patch $sha1 "Could not apply $sha1... $rest"
+		eval do_pick $opts $sha1 \
+			|| die_with_patch $sha1 "Could not apply $sha1... $rest"
 		warn "Stopped at $sha1... $rest"
 		exit_with_patch $sha1 0
 		;;
-- 
2.0.0

Re: [PATCH RFC v2 00/19] Enable options --signoff, --reset-author for pick, reword

[Michael Haggerty]

On 07/02/2014 07:47 PM, Fabian Ruch wrote:
> [...]
>  2. Add user options to main commands
> 
>     Enable options --signoff, --reset-author for pick, reword (19/19)
> 
> The last stage was added in this reroll. It enables the parsing of
> line options for to-do list commands, which is still restricted to
> options without arguments because it is unclear how spaces can be
> parsed as characters rather than separators where needed. For
> instance, if we were to support
> 
>     pick --author="A U Thor" fa1afe1 Some changes
> 
> then read(1) would hand us the tokens `--author="A`, `U` and `Thor"`
> instead of `--author=A U Thor`, which we would want to relay to
> `do_pick`. Interpreting the shell quoting would help. However,
> eval(1) seems to disqualify itself as an interpreter because the
> to-do list entry could potentially contain any shell command line.
> This could be both a security and a usability issue. For this reason,
> the patch series still hasn't graduated from being RFC.
> [...]

It is not required that a patch series solves all of the problems in the
universe.  If these patches implements some useful features robustly,
and if there is no reason to expect that future enhancements will
require the user interface to be changed in a backwards-compatible way,
then there is no reason that this patch series has to be held as an RFC
hostage to some hypothetical future.

Michael

-- 
Michael Haggerty
mhagger@alum.mit.edu

Re: [PATCH RFC v2 00/19] Enable options --signoff, --reset-author for pick, reword

[Junio C Hamano]

Fabian Ruch <bafain@gmail.com> writes:

> Fabian Ruch (19):
>   rebase -i: Failed reword prints redundant error message
>   rebase -i: reword complains about empty commit despite --keep-empty
>   rebase -i: reword executes pre-commit hook on interim commit
>   rebase -i: Teach do_pick the option --edit
>   rebase -i: Implement reword in terms of do_pick
>   rebase -i: Stop on root commits with empty log messages
>   rebase -i: The replay of root commits is not shown with --verbose
>   rebase -i: Root commits are replayed with an unnecessary option
>   rebase -i: Commit only once when rewriting picks
>   rebase -i: Do not die in do_pick
>   rebase -i: Teach do_pick the option --amend
>   rebase -i: Teach do_pick the option --file
>   rebase -i: Prepare for squash in terms of do_pick --amend
>   rebase -i: Implement squash in terms of do_pick
>   rebase -i: Explicitly distinguish replay commands and exec tasks
>   rebase -i: Parse to-do list command line options
>   rebase -i: Teach do_pick the option --reset-author
>   rebase -i: Teach do_pick the option --signoff
>   rebase -i: Enable options --signoff, --reset-author for pick, reword

After "rebase -i:", some begin with lowercase and many begin with
capital, which makes the short-log output look distracting.

Re: [PATCH RFC v2 00/19] Enable options --signoff, --reset-author for pick, reword

[Fabian Ruch]

On 07/08/2014 10:45 PM, Junio C Hamano wrote:
> Fabian Ruch <bafain@gmail.com> writes:
>> Fabian Ruch (19):
>>   rebase -i: Failed reword prints redundant error message
>>   rebase -i: reword complains about empty commit despite --keep-empty
>>   rebase -i: reword executes pre-commit hook on interim commit
>>   rebase -i: Teach do_pick the option --edit
>>   rebase -i: Implement reword in terms of do_pick
>>   rebase -i: Stop on root commits with empty log messages
>>   rebase -i: The replay of root commits is not shown with --verbose
>>   rebase -i: Root commits are replayed with an unnecessary option
>>   rebase -i: Commit only once when rewriting picks
>>   rebase -i: Do not die in do_pick
>>   rebase -i: Teach do_pick the option --amend
>>   rebase -i: Teach do_pick the option --file
>>   rebase -i: Prepare for squash in terms of do_pick --amend
>>   rebase -i: Implement squash in terms of do_pick
>>   rebase -i: Explicitly distinguish replay commands and exec tasks
>>   rebase -i: Parse to-do list command line options
>>   rebase -i: Teach do_pick the option --reset-author
>>   rebase -i: Teach do_pick the option --signoff
>>   rebase -i: Enable options --signoff, --reset-author for pick, reword
> 
> After "rebase -i:", some begin with lowercase and many begin with
> capital, which makes the short-log output look distracting.

The ones that begin with lower-case letters are the ones that begin with
the command name "reword". All first lines are typed in lower case now.

Sorry for the noise.

   Fabian

Re: [PATCH RFC v2 00/19] Enable options --signoff, --reset-author for pick, reword

[Thomas Rast]

Fabian Ruch <bafain@gmail.com> writes:

> On 07/08/2014 10:45 PM, Junio C Hamano wrote:
>> Fabian Ruch <bafain@gmail.com> writes:
>>> Fabian Ruch (19):
>>>   rebase -i: Failed reword prints redundant error message
>>>   rebase -i: reword complains about empty commit despite --keep-empty
>>>   rebase -i: reword executes pre-commit hook on interim commit
>>>   rebase -i: Teach do_pick the option --edit
>>>   rebase -i: Implement reword in terms of do_pick
>>>   rebase -i: Stop on root commits with empty log messages
>>>   rebase -i: The replay of root commits is not shown with --verbose
>>>   rebase -i: Root commits are replayed with an unnecessary option
>>>   rebase -i: Commit only once when rewriting picks
>>>   rebase -i: Do not die in do_pick
>>>   rebase -i: Teach do_pick the option --amend
>>>   rebase -i: Teach do_pick the option --file
>>>   rebase -i: Prepare for squash in terms of do_pick --amend
>>>   rebase -i: Implement squash in terms of do_pick
>>>   rebase -i: Explicitly distinguish replay commands and exec tasks
>>>   rebase -i: Parse to-do list command line options
>>>   rebase -i: Teach do_pick the option --reset-author
>>>   rebase -i: Teach do_pick the option --signoff
>>>   rebase -i: Enable options --signoff, --reset-author for pick, reword
>> 
>> After "rebase -i:", some begin with lowercase and many begin with
>> capital, which makes the short-log output look distracting.
>
> The ones that begin with lower-case letters are the ones that begin with
> the command name "reword". All first lines are typed in lower case now.

You could spell it 'reword' (with the quotes), which also disambiguates
the command from the verb.

-- 
Thomas Rast
tr@thomasrast.ch

[PATCH v1 00/19] Enable options --signoff, --reset-author for pick, reword

[Fabian Ruch]

Hi,

this is a reroll of the patch series that enables rudimentary support
of line options for git-rebase's to-do list commands and reimplements
the well-known commands `reword` and `squash` in terms of a
parameterised `do_pick`.

I tried to address all the issues raised by Junio in this reroll.
Here is a short summary.

 - Test that `reword` behaves like `pick` regarding the `pre-commit`
   hook and executes `commit-msg` for the new log message.

 - Instead of disallowing empty log messages for root commits allow
   empty log messages for all unchanged commits.

 - The patch "root commits are replayed with an unnecessary option"
   does not change the behaviour of git-rebase but it makes the
   subsequent patch easier to read.

   The hidden agenda is to have one git-commit command line in
   `do_pick` that takes care of rewriting commits as they are being
   replayed, be they parentless or not. The advantage of having one
   rewrite command instead of one for root commits and one for
   non-root commits is that changes to the rewrite mechanism entail
   less code changes. As more rewriting mechanisms are being added to
   `do_pick`, it becomes important that they compose well with each
   other to avoid having a series of amending commits. The `-C`
   option conflicts with other ways of substituting the log message,
   like files and strings, which is why it seems not to compose so
   well.

 - The patch "explicitly distinguish replay commands and exec tasks"
   does not change behaviour either but is again a separated
   refactoring patch.

   The distinction of the `exec` command and the replay commands,
   which all share the same line format `command args sha1 rest`,
   allows us to employ the positional parameters feature of the shell
   without introducing another indentation level in `do_pick`.

Thanks for your time,
   Fabian

Fabian Ruch (19):
  rebase -i: failed reword prints redundant error message
  rebase -i: allow rewording an empty commit without complaints
  rebase -i: reword executes pre-commit hook on interim commit
  rebase -i: teach do_pick the option --edit
  rebase -i: implement reword in terms of do_pick
  rebase -i: allow replaying commits with empty log messages
  rebase -i: log the replay of root commits
  rebase -i: root commits are replayed with an unnecessary option
  rebase -i: commit only once when rewriting picks
  rebase -i: do not die in do_pick
  rebase -i: teach do_pick the option --amend
  rebase -i: teach do_pick the option --file
  rebase -i: prepare for squash in terms of do_pick --amend
  rebase -i: implement squash in terms of do_pick
  rebase -i: explicitly distinguish replay commands and exec tasks
  rebase -i: parse to-do list command line options
  rebase -i: teach do_pick the option --reset-author
  rebase -i: teach do_pick the option --signoff
  rebase -i: enable options --signoff, --reset-author for pick, reword

 git-rebase--interactive.sh    | 284 ++++++++++++++++++++++++++++++++++--------
 t/t3404-rebase-interactive.sh |  70 +++++++++++
 t/t3412-rebase-root.sh        |  19 +++
 t/test-lib-functions.sh       |   6 +-
 4 files changed, 325 insertions(+), 54 deletions(-)

-- 
2.0.1

[PATCH v1 01/19] rebase -i: failed reword prints redundant error message

[Fabian Ruch]

The to-do list command `reword` replays a commit like `pick` but lets
the user also edit the commit's log message. If the edited log
message is empty or is found ill-formatted by one of the commit
hooks, git-rebase--interactive prints three error messages to the
console.

    1. The git-commit output, which contains all the output from hook
       scripts.
    2. A rebase diagnosis saying at which task on the to-do list it
       got stuck.
    3. Generic presumptions about what could have triggered the
       error.

The third message contains redundant information and does not add any
enlightenment either, which makes the output unnecessarily longish
and different from the other command's output. For instance, this is
what the output looks like if the log message is empty (contains
duplicate Signed-off-by lines).

    (1.) Aborting commit due to empty commit message. (Duplicate Signed-off-by lines.)
    (2.) Could not amend commit after successfully picking fa1afe1... Some change
    (3.) This is most likely due to an empty commit message, or the pre-commit hook
         failed. If the pre-commit hook failed, you may need to resolve the issue before
         you are able to reword the commit.

Discard the third message.

It is true that a failed hook script might not output any diagnosis
but then the generic message is not of much help either. Since this
lack of information affects the built-in git commands for commit,
merge and cherry-pick first, the solution would be to keep track of
the failed hooks in their output so that the user knows which of her
hooks require improvement.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 7e1eda0..e733d7f 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -506,9 +506,6 @@ do_next () {
 		do_pick $sha1 "$rest"
 		git commit --amend --no-post-rewrite ${gpg_sign_opt:+"$gpg_sign_opt"} || {
 			warn "Could not amend commit after successfully picking $sha1... $rest"
-			warn "This is most likely due to an empty commit message, or the pre-commit hook"
-			warn "failed. If the pre-commit hook failed, you may need to resolve the issue before"
-			warn "you are able to reword the commit."
 			exit_with_patch $sha1 1
 		}
 		record_in_rewritten $sha1
-- 
2.0.1

[PATCH v1 02/19] rebase -i: allow rewording an empty commit without complaints

[Fabian Ruch]

The to-do list command `reword` replays a commit like `pick` but lets
the user also edit the commit's log message. If `--keep-empty` is
passed as option to git-rebase--interactive, empty commits ought to
be replayed without complaints. However, if the users chooses to
reword an empty commit by changing the respective to-do list entry
from

    pick fa1afe1 Empty commit

to

    reword fa1afe1 Empty commit

, then git-rebase--interactive suddenly fails to replay the empty
commit. This is especially counterintuitive because `reword` is
thought of as a `pick` that alters the log message in some way but
nothing more and the unchanged to-do list entry would not fail.

Handle `reword` by cherry-picking the named commit and editing the
log message using

    git commit --allow-empty --amend

instead of

    git commit --amend.

Add test.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh    | 2 +-
 t/t3404-rebase-interactive.sh | 8 ++++++++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index e733d7f..689400e 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -504,7 +504,7 @@ do_next () {
 
 		mark_action_done
 		do_pick $sha1 "$rest"
-		git commit --amend --no-post-rewrite ${gpg_sign_opt:+"$gpg_sign_opt"} || {
+		git commit --allow-empty --amend --no-post-rewrite ${gpg_sign_opt:+"$gpg_sign_opt"} || {
 			warn "Could not amend commit after successfully picking $sha1... $rest"
 			exit_with_patch $sha1 1
 		}
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index 8197ed2..9931143 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -75,6 +75,14 @@ test_expect_success 'rebase --keep-empty' '
 	test_line_count = 6 actual
 '
 
+test_expect_success 'rebase --keep-empty' '
+	git checkout emptybranch &&
+	set_fake_editor &&
+	FAKE_LINES="1 reword 2" git rebase --keep-empty -i HEAD~2 &&
+	git log --oneline >actual &&
+	test_line_count = 6 actual
+'
+
 test_expect_success 'rebase -i with the exec command' '
 	git checkout master &&
 	(
-- 
2.0.1

[PATCH v1 03/19] rebase -i: reword executes pre-commit hook on interim commit

[Fabian Ruch]

The to-do list command `reword` replays a commit like `pick` but lets
the user also edit the commit's log message. This happens in two
steps. Firstly, the named commit is cherry-picked. Secondly, the
commit created in the first step is amended using an unchanged index
to edit the log message. The pre-commit hook is meant to verify the
changes introduced by a commit (for instance, catching inserted
trailing white space). Since the committed tree is not changed
between the two steps and we do not verify rebased patches, do not
execute the pre-commit hook in the second step.

Specify the git-commit option `--no-verify` to disable the pre-commit
hook when editing the log message. Because `--no-verify` also skips
the commit-msg hook, execute the hook from within
git-rebase--interactive after the commit is created. Fortunately, the
commit message is still available in `$GIT_DIR/COMMIT_EDITMSG` after
git-commit terminates. Caveat: In case the commit-msg hook finds the
new log message ill-formatted, the user is only notified of the
failed commit-msg hook but the log message is used for the commit
anyway. git-commit ought to offer more fine-grained control over
which hooks are executed.

Teach `test_commit` the `--no-verify` option and add test.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh    | 17 +++++++++++++----
 t/t3404-rebase-interactive.sh | 38 ++++++++++++++++++++++++++++++++++++++
 t/test-lib-functions.sh       |  6 +++++-
 3 files changed, 56 insertions(+), 5 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 689400e..b50770d 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -504,10 +504,19 @@ do_next () {
 
 		mark_action_done
 		do_pick $sha1 "$rest"
-		git commit --allow-empty --amend --no-post-rewrite ${gpg_sign_opt:+"$gpg_sign_opt"} || {
-			warn "Could not amend commit after successfully picking $sha1... $rest"
-			exit_with_patch $sha1 1
-		}
+		# TODO: Work around the fact that git-commit lets us
+		# disable either both the pre-commit and the commit-msg
+		# hook or none. Disable the pre-commit hook because the
+		# tree is left unchanged but run the commit-msg hook
+		# from here because the log message is altered.
+		git commit --allow-empty --amend --no-post-rewrite -n ${gpg_sign_opt:+"$gpg_sign_opt"} &&
+			if test -x "$GIT_DIR"/hooks/commit-msg
+			then
+				"$GIT_DIR"/hooks/commit-msg "$GIT_DIR"/COMMIT_EDITMSG
+			fi || {
+				warn "Could not amend commit after successfully picking $sha1... $rest"
+				exit_with_patch $sha1 1
+			}
 		record_in_rewritten $sha1
 		;;
 	edit|e)
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index 9931143..2da4b9c 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -577,6 +577,44 @@ test_expect_success 'rebase a commit violating pre-commit' '
 
 '
 
+test_expect_success 'reword a commit violating pre-commit' '
+	test_when_finished rm -r .git/hooks &&
+	mkdir -p .git/hooks &&
+	PRE_COMMIT=.git/hooks/pre-commit &&
+	cat >"$PRE_COMMIT" <<EOF
+#!/bin/sh
+echo running pre-commit: exit 1
+exit 1
+EOF
+	chmod +x "$PRE_COMMIT" &&
+	test_must_fail test_commit pre-commit-violated &&
+	test_commit --no-verify pre-commit-violated &&
+	test_when_finished reset_rebase &&
+	set_fake_editor &&
+	FAKE_LINES="pick 1" git rebase -i HEAD^ &&
+	FAKE_LINES="pick 1" git rebase -i --no-ff HEAD^ &&
+	FAKE_LINES="reword 1" git rebase -i HEAD^
+'
+
+test_expect_success 'reword a commit violating commit-msg' '
+	test_when_finished rm -r .git/hooks &&
+	mkdir -p .git/hooks &&
+	COMMIT_MSG=.git/hooks/commit-msg &&
+	cat >"$COMMIT_MSG" <<EOF
+#!/bin/sh
+echo running commit-msg: exit 1
+exit 1
+EOF
+	chmod +x "$COMMIT_MSG" &&
+	test_must_fail test_commit commit-msg-violated &&
+	test_commit --no-verify commit-msg-violated &&
+	test_when_finished reset_rebase &&
+	set_fake_editor &&
+	FAKE_LINES="pick 1" git rebase -i HEAD^ &&
+	FAKE_LINES="pick 1" git rebase -i --no-ff HEAD^ &&
+	test_must_fail env FAKE_LINES="reword 1" git rebase -i HEAD^
+'
+
 test_expect_success 'rebase with a file named HEAD in worktree' '
 
 	rm -fr .git/hooks &&
diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
index 0377d3e..db65653 100644
--- a/t/test-lib-functions.sh
+++ b/t/test-lib-functions.sh
@@ -155,6 +155,7 @@ test_pause () {
 test_commit () {
 	notick= &&
 	signoff= &&
+	noverify= &&
 	while test $# != 0
 	do
 		case "$1" in
@@ -164,6 +165,9 @@ test_commit () {
 		--signoff)
 			signoff="$1"
 			;;
+		--no-verify)
+			noverify="$1"
+			;;
 		*)
 			break
 			;;
@@ -177,7 +181,7 @@ test_commit () {
 	then
 		test_tick
 	fi &&
-	git commit $signoff -m "$1" &&
+	git commit $signoff $noverify -m "$1" &&
 	git tag "${4:-$1}"
 }
 
-- 
2.0.1

Re: [PATCH v1 03/19] rebase -i: reword executes pre-commit hook on interim commit

[Jeff King]

On Tue, Jul 29, 2014 at 01:18:03AM +0200, Fabian Ruch wrote:

> Specify the git-commit option `--no-verify` to disable the pre-commit
> hook when editing the log message. Because `--no-verify` also skips
> the commit-msg hook, execute the hook from within
> git-rebase--interactive after the commit is created. Fortunately, the
> commit message is still available in `$GIT_DIR/COMMIT_EDITMSG` after
> git-commit terminates. Caveat: In case the commit-msg hook finds the
> new log message ill-formatted, the user is only notified of the
> failed commit-msg hook but the log message is used for the commit
> anyway. git-commit ought to offer more fine-grained control over
> which hooks are executed.

Thanks for a nice explanation of the tradeoff. Have you looked at adding
an option to git-commit? We already have --no-post-rewrite. I think you
would just need:

diff --git a/builtin/commit.c b/builtin/commit.c
index 5ed6036..f7af220 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -102,6 +102,7 @@ static int quiet, verbose, no_verify, allow_empty, dry_run, renew_authorship;
 static int no_post_rewrite, allow_empty_message;
 static char *untracked_files_arg, *force_date, *ignore_submodule_arg;
 static char *sign_commit;
+static int no_pre_commit;
 
 /*
  * The default commit message cleanup mode will remove the lines
@@ -661,7 +662,8 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
 	/* This checks and barfs if author is badly specified */
 	determine_author_info(author_ident);
 
-	if (!no_verify && run_commit_hook(use_editor, index_file, "pre-commit", NULL))
+	if (!no_verify && !no_pre_commit &&
+	    run_commit_hook(use_editor, index_file, "pre-commit", NULL))
 		return 0;
 
 	if (squash_message) {
@@ -1604,6 +1606,7 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
 			 N_("terminate entries with NUL")),
 		OPT_BOOL(0, "amend", &amend, N_("amend previous commit")),
 		OPT_BOOL(0, "no-post-rewrite", &no_post_rewrite, N_("bypass post-rewrite hook")),
+		OPT_BOOL(0, "no-pre-commit", &no_pre_commit, N_("bypass pre-commit hook")),
 		{ OPTION_STRING, 'u', "untracked-files", &untracked_files_arg, N_("mode"), N_("show untracked files, optional modes: all, normal, no. (Default: all)"), PARSE_OPT_OPTARG, NULL, (intptr_t)"all" },
 		/* end commit contents options */
 

though I would also not be opposed to some more uniform hook selection
mechanism (e.g., "--no-verify=pre-commit" or something).

-Peff

Re: [PATCH v1 03/19] rebase -i: reword executes pre-commit hook on interim commit

[Fabian Ruch]

Hi,

Jeff King writes:
> On Tue, Jul 29, 2014 at 01:18:03AM +0200, Fabian Ruch wrote:
> 
>> Specify the git-commit option `--no-verify` to disable the pre-commit
>> hook when editing the log message. Because `--no-verify` also skips
>> the commit-msg hook, execute the hook from within
>> git-rebase--interactive after the commit is created. Fortunately, the
>> commit message is still available in `$GIT_DIR/COMMIT_EDITMSG` after
>> git-commit terminates. Caveat: In case the commit-msg hook finds the
>> new log message ill-formatted, the user is only notified of the
>> failed commit-msg hook but the log message is used for the commit
>> anyway. git-commit ought to offer more fine-grained control over
>> which hooks are executed.
> 
> Thanks for a nice explanation of the tradeoff. Have you looked at adding
> an option to git-commit? We already have --no-post-rewrite. I think you
> would just need:
> 
> diff --git a/builtin/commit.c b/builtin/commit.c
> index 5ed6036..f7af220 100644
> --- a/builtin/commit.c
> +++ b/builtin/commit.c
> @@ -102,6 +102,7 @@ static int quiet, verbose, no_verify, allow_empty, dry_run, renew_authorship;
>  static int no_post_rewrite, allow_empty_message;
>  static char *untracked_files_arg, *force_date, *ignore_submodule_arg;
>  static char *sign_commit;
> +static int no_pre_commit;
>  
>  /*
>   * The default commit message cleanup mode will remove the lines
> @@ -661,7 +662,8 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
>  	/* This checks and barfs if author is badly specified */
>  	determine_author_info(author_ident);
>  
> -	if (!no_verify && run_commit_hook(use_editor, index_file, "pre-commit", NULL))
> +	if (!no_verify && !no_pre_commit &&
> +	    run_commit_hook(use_editor, index_file, "pre-commit", NULL))
>  		return 0;
>  
>  	if (squash_message) {
> @@ -1604,6 +1606,7 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
>  			 N_("terminate entries with NUL")),
>  		OPT_BOOL(0, "amend", &amend, N_("amend previous commit")),
>  		OPT_BOOL(0, "no-post-rewrite", &no_post_rewrite, N_("bypass post-rewrite hook")),
> +		OPT_BOOL(0, "no-pre-commit", &no_pre_commit, N_("bypass pre-commit hook")),
>  		{ OPTION_STRING, 'u', "untracked-files", &untracked_files_arg, N_("mode"), N_("show untracked files, optional modes: all, normal, no. (Default: all)"), PARSE_OPT_OPTARG, NULL, (intptr_t)"all" },
>  		/* end commit contents options */
>  
> 
> though I would also not be opposed to some more uniform hook selection
> mechanism (e.g., "--no-verify=pre-commit" or something).

While the --no-verify= mechanism doesn't add a new option to the
git-commit interface but lets one refine the --no-verify option, users
might find it weird to have an argument to name disabled hooks but then
not be able to disable all hooks that way.

To have that uniform hook selection without duplicating code, we might
want to have something like --bypass-hook= right away. This would cover
--no-post-rewrite as well and add support for disabling
prepare-commit-msg and post-commit, whose execution cannot be controlled
via the git-commit interface at the moment.

Since the hook selection wouldn't have to change, the options parsing
code seems to be simpler (--bypass-hook= would have to support several
occurrences with different arguments which could be implemented as an
OPT_CALLBACK?) and git-commit decided to have --no- options for hook
selection so far, I would lean towards your patch from above.

I know you didn't say anything otherwise, I just wanted to expand a
little. You find an amended version of your patch below that documents
--no-verify as a synonym for --no-pre-commit and --no-commit-msg, and
adds tests.

> diff --git a/builtin/commit.c b/builtin/commit.c
> index 5e2221c..813aa78 100644
> --- a/builtin/commit.c
> +++ b/builtin/commit.c
> @@ -98,12 +98,27 @@ static char *edit_message, *use_message;
>  static char *fixup_message, *squash_message;
>  static int all, also, interactive, patch_interactive, only, amend, signoff;
>  static int edit_flag = -1; /* unspecified */
> -static int quiet, verbose, no_verify, allow_empty, dry_run, renew_authorship;
> +static int quiet, verbose, allow_empty, dry_run, renew_authorship;
>  static int no_post_rewrite, allow_empty_message;
>  static char *untracked_files_arg, *force_date, *ignore_submodule_arg;
>  static char *sign_commit;
>  
>  /*
> + * The verify variable is interpreted as a bitmap of enabled commit
> + * verification hooks according to the legend below.
> + *
> + * By default, the pre-commit and commit-msg hooks are enabled. This
> + * is represented by both the PRE_COMMIT and COMMIT_MSG bits being
> + * set.
> + *
> + * The bitmap is changed through the command line options
> + * --no-verify, --no-pre-commit and --no-commit-msg.
> + */
> +#define PRE_COMMIT (1<<0)
> +#define COMMIT_MSG (1<<1)
> +static int verify = PRE_COMMIT | COMMIT_MSG;
> +
> +/*
>   * The default commit message cleanup mode will remove the lines
>   * beginning with # (shell comments) and leading and trailing
>   * whitespaces (empty lines or containing only whitespaces)
> @@ -667,7 +682,8 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
>  	/* This checks and barfs if author is badly specified */
>  	determine_author_info(author_ident);
>  
> -	if (!no_verify && run_commit_hook(use_editor, index_file, "pre-commit", NULL))
> +	if (verify & PRE_COMMIT &&
> +	    run_commit_hook(use_editor, index_file, "pre-commit", NULL))
>  		return 0;
>  
>  	if (squash_message) {
> @@ -968,7 +984,7 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
>  		}
>  	}
>  
> -	if (!no_verify &&
> +	if (verify & COMMIT_MSG &&
>  	    run_commit_hook(use_editor, index_file, "commit-msg", git_path(commit_editmsg), NULL)) {
>  		return 0;
>  	}
> @@ -1597,7 +1613,9 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
>  		OPT_BOOL(0, "interactive", &interactive, N_("interactively add files")),
>  		OPT_BOOL('p', "patch", &patch_interactive, N_("interactively add changes")),
>  		OPT_BOOL('o', "only", &only, N_("commit only specified files")),
> -		OPT_BOOL('n', "no-verify", &no_verify, N_("bypass pre-commit hook")),
> +		OPT_NEGBIT('n', "no-verify", &verify,
> +			   N_("synonym for --no-pre-commit --no-commit-msg"),
> +			   PRE_COMMIT | COMMIT_MSG),
>  		OPT_BOOL(0, "dry-run", &dry_run, N_("show what would be committed")),
>  		OPT_SET_INT(0, "short", &status_format, N_("show status concisely"),
>  			    STATUS_FORMAT_SHORT),
> @@ -1610,6 +1628,12 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
>  		OPT_BOOL('z', "null", &s.null_termination,
>  			 N_("terminate entries with NUL")),
>  		OPT_BOOL(0, "amend", &amend, N_("amend previous commit")),
> +		OPT_NEGBIT(0, "no-pre-commit", &verify,
> +			   N_("bypass pre-commit hook"),
> +			   PRE_COMMIT),
> +		OPT_NEGBIT(0, "no-commit-msg", &verify,
> +			   N_("bypass commit-msg hook"),
> +			   COMMIT_MSG),
>  		OPT_BOOL(0, "no-post-rewrite", &no_post_rewrite, N_("bypass post-rewrite hook")),
>  		{ OPTION_STRING, 'u', "untracked-files", &untracked_files_arg, N_("mode"), N_("show untracked files, optional modes: all, normal, no. (Default: all)"), PARSE_OPT_OPTARG, NULL, (intptr_t)"all" },
>  		/* end commit contents options */

Since all of the hook options are motivated by internal usage from
git-rebase, perhaps they should be configured as PARSE_OPT_HIDDEN. Any
thoughts on this?

    Fabian

Re: [PATCH v1 03/19] rebase -i: reword executes pre-commit hook on interim commit

[Jeff King]

On Mon, Aug 04, 2014 at 08:51:42PM +0200, Fabian Ruch wrote:

> > though I would also not be opposed to some more uniform hook selection
> > mechanism (e.g., "--no-verify=pre-commit" or something).
> 
> While the --no-verify= mechanism doesn't add a new option to the
> git-commit interface but lets one refine the --no-verify option, users
> might find it weird to have an argument to name disabled hooks but then
> not be able to disable all hooks that way.

Right, I think that is only worth doing if we add it uniformly for all
hooks. I wonder if it should be a "git" option, not one to specific
commands. Like:

  git --disable-hook=pre-commit commit ...

and then the run_hook code can just respect the disabled list.

I think a name like "--disable-hook" or your "--bypass-hook" is
better than "--no-verify" here, too. Not all hooks are about verifying
(I also think "disable" is better than "bypass" for that reason, too).

> Since the hook selection wouldn't have to change, the options parsing
> code seems to be simpler (--bypass-hook= would have to support several
> occurrences with different arguments which could be implemented as an
> OPT_CALLBACK?) and git-commit decided to have --no- options for hook
> selection so far, I would lean towards your patch from above.

You'd probably implement --disable-hook with OPT_STRING_LIST (or just do
it by hand if it's the git.c option parser). And then the
--no-post-rewrite arguments remain for historical compatibility, and can
be implemented as synonyms for "--disable-hook=post-rewrite", etc.

I think people have also asked for the ability to override hooks, too,
though I do not remember the exact details.  Instead of --disable-hook,
we could have an option for setting specific hooks (and setting them to
nothing to disable would just be one possibility).

This is getting bigger in scope, though. I was trying not to derail you
too much from your GSoC project, but see if we could just fix this one
hacky corner easily.

> Since all of the hook options are motivated by internal usage from
> git-rebase, perhaps they should be configured as PARSE_OPT_HIDDEN. Any
> thoughts on this?

I could go either way. Just because they are motivated by git-rebase
does not mean other callers might not find them useful (after all, git
commands are often meant to be scripted). As long as we promise to
support them in future versions as we do with normal options, I do not
think there is any problem in advertising them.

That being said, "git commit -h" is already getting pretty long. It
might be worth cutting some seldom-used options from that list just to
make it more palatable to normal users.

-Peff

[PATCH v1 04/19] rebase -i: teach do_pick the option --edit

[Fabian Ruch]

`do_pick` is the git-cherry-pick wrapper in git-rebase--interactive
that is used to implement the to-do list command `pick`. To cater for
the different pick behaviours (like `reword`), `do_pick` accepts
several options not only from the git-cherry-pick but also the
git-commit interface. Add the common option `--edit` to let the user
edit the log message of the named commit.

Loop over `$@` to parse the `do_pick` arguments. Assign the local
variable `edit` if one of the options is `--edit` so that the
remainder of `do_pick` can easily check whether the client code asked
to edit the commit message. If one of the options is unknown, mention
it on the console and `die`. Break the loop on the first non-option
and do some sanity checking to ensure that there exactly two
non-options, which are interpreted by the remainder as `<commit>` and
`<title>` like before.

`do_pick` ought to act as a wrapper around `cherry-pick`.
Unfortunately, it cannot just forward `--edit` to the `cherry-pick`
command line. The assembled command line is executed within a command
substitution for controlling the verbosity of `rebase--interactive`.
Passing `--edit` would either hang the terminal or clutter the
substituted command output with control sequences. Execute the
`reword` code from `do_next` instead if the option `--edit` is
specified.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 52 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index b50770d..e06d9b6 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -461,7 +461,42 @@ record_in_rewritten() {
 	esac
 }
 
+# Apply the changes introduced by the given commit to the current head.
+#
+# do_pick [--edit] <commit> <title>
+#
+# Wrapper around git-cherry-pick.
+#
+# -e, --edit
+#     After picking <commit>, open an editor and let the user edit the
+#     commit message. The editor contents becomes the commit message of
+#     the new head. This creates a fresh commit.
+#
+# <commit>
+#     The commit to cherry-pick.
+#
+# <title>
+#     The commit message title of <commit>. Used for information
+#     purposes only.
 do_pick () {
+	edit=
+	while test $# -gt 0
+	do
+		case "$1" in
+		-e|--edit)
+			edit=y
+			;;
+		-*)
+			die "do_pick: unrecognized option -- $1"
+			;;
+		*)
+			break
+			;;
+		esac
+		shift
+	done
+	test $# -ne 2 && die "do_pick: wrong number of arguments"
+
 	if test "$(git rev-parse HEAD)" = "$squash_onto"
 	then
 		# Set the correct commit message and author info on the
@@ -483,6 +518,23 @@ do_pick () {
 		pick_one $1 ||
 			die_with_patch $1 "Could not apply $1... $2"
 	fi
+
+	if test -n "$edit"
+	then
+		# TODO: Work around the fact that git-commit lets us
+		# disable either both the pre-commit and the commit-msg
+		# hook or none. Disable the pre-commit hook because the
+		# tree is left unchanged but run the commit-msg hook
+		# from here because the log message is altered.
+		git commit --allow-empty --amend --no-post-rewrite -n ${gpg_sign_opt:+"$gpg_sign_opt"} &&
+			if test -x "$GIT_DIR"/hooks/commit-msg
+			then
+				"$GIT_DIR"/hooks/commit-msg "$GIT_DIR"/COMMIT_EDITMSG
+			fi || {
+				warn "Could not amend commit after successfully picking $1... $2"
+				exit_with_patch $1 1
+			}
+	fi
 }
 
 do_next () {
-- 
2.0.1

[PATCH v1 05/19] rebase -i: implement reword in terms of do_pick

[Fabian Ruch]

The to-do list command `reword` replays a commit like `pick` but lets
the user also edit the commit's log message. If one thinks of `pick`
entries as scheduled `cherry-pick` command lines, then `reword`
becomes an alias for the command line `cherry-pick --edit`. The
porcelain `rebase--interactive` defines a function `do_pick` for
processing the `pick` entries on to-do lists. Reimplement `reword` in
terms of `do_pick --edit`.

If the user picks a commit using the to-do list line

    reword fa1afe1 Some change

execute the command `do_pick --edit fa1afe1 "Some change"` which
carries out exactly the same steps as the case arm for `reword` in
`do_next` so far.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 15 +--------------
 1 file changed, 1 insertion(+), 14 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index e06d9b6..4c875d5 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -555,20 +555,7 @@ do_next () {
 		comment_for_reflog reword
 
 		mark_action_done
-		do_pick $sha1 "$rest"
-		# TODO: Work around the fact that git-commit lets us
-		# disable either both the pre-commit and the commit-msg
-		# hook or none. Disable the pre-commit hook because the
-		# tree is left unchanged but run the commit-msg hook
-		# from here because the log message is altered.
-		git commit --allow-empty --amend --no-post-rewrite -n ${gpg_sign_opt:+"$gpg_sign_opt"} &&
-			if test -x "$GIT_DIR"/hooks/commit-msg
-			then
-				"$GIT_DIR"/hooks/commit-msg "$GIT_DIR"/COMMIT_EDITMSG
-			fi || {
-				warn "Could not amend commit after successfully picking $sha1... $rest"
-				exit_with_patch $sha1 1
-			}
+		do_pick --edit $sha1 "$rest"
 		record_in_rewritten $sha1
 		;;
 	edit|e)
-- 
2.0.1

[PATCH v1 06/19] rebase -i: allow replaying commits with empty log messages

[Fabian Ruch]

git-rebase--interactive handles empty log messages inconsistently
between enabled and disabled fast-forwards. By default, commits with
empty log messages are rebased successfully like in non-interactive
mode. In contrast, the `--no-ff` option aborts the replay of such
commits.

In line with not verifying rebased commits and behaving like
git-rebase for `pick` lines, use the `--allow-empty-message` option
to replay commits. Root commits are replayed by recreating them in
`do_pick` using git-commit and commits with parents are replayed
using git-cherry-pick in `pick_one`. Apply the option, understood by
both git-commit and git-cherry-pick, at the respective sites.

In case of `reword` and `squash`/`fixup` continue to abort the rebase
if the resulting commit would have no commit message. The rationale
behind this default is that patches and their log messages should be
verified at least once. For unchanged commits this is assumed to have
happened according to the author's standards when she created the
commits the first time. While the empty log message can always be
kept in place by editing and resuming the aborted rebase, a debatable
alternative could be to teach git-rebase--interactive the option
`--allow-empty-message` for disabling complaints about empty log
messages in changed commits. The to-do list command `edit` is handled
just like `pick` for this matter, because git-rebase--interactive
replays the named commit without changes before the rebase is
interrupted and the user can make her changes to the replayed commit.

Add tests.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh    |  4 ++--
 t/t3404-rebase-interactive.sh | 24 ++++++++++++++++++++++++
 t/t3412-rebase-root.sh        | 19 +++++++++++++++++++
 3 files changed, 45 insertions(+), 2 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 4c875d5..6e2c429 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -249,7 +249,7 @@ pick_one () {
 
 	test -d "$rewritten" &&
 		pick_one_preserving_merges "$@" && return
-	output eval git cherry-pick \
+	output eval git cherry-pick --allow-empty-message \
 			${gpg_sign_opt:+$(git rev-parse --sq-quote "$gpg_sign_opt")} \
 			"$strategy_args" $empty_args $ff "$@"
 }
@@ -363,7 +363,7 @@ pick_one_preserving_merges () {
 			echo "$sha1 $(git rev-parse HEAD^0)" >> "$rewritten_list"
 			;;
 		*)
-			output eval git cherry-pick \
+			output eval git cherry-pick --allow-empty-message \
 				${gpg_sign_opt:+$(git rev-parse --sq-quote "$gpg_sign_opt")} \
 				"$strategy_args" "$@" ||
 				die_with_patch $sha1 "Could not pick $sha1"
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index 2da4b9c..2e8fa27 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -1085,4 +1085,28 @@ test_expect_success 'short SHA-1 collide' '
 	)
 '
 
+test_expect_success 'rebase commits with empty commit log messages' '
+	git checkout -b no-msg-commit &&
+	test_commit no-msg-commit-1 &&
+	git commit --amend --allow-empty-message -m " " &&
+	test_commit no-msg-commit-2 &&
+	git commit --amend --allow-empty-message -m " " &&
+	EDITOR=true git rebase -i HEAD^ &&
+	EDITOR=true git rebase -i --no-ff HEAD^
+'
+
+test_expect_success 'reword commit with empty commit log message' '
+	git checkout no-msg-commit &&
+	test_when_finished reset_rebase &&
+	set_fake_editor &&
+	test_must_fail env FAKE_LINES="reword 1" git rebase -i HEAD^
+'
+
+test_expect_success 'squash commits with empty commit log messages' '
+	git checkout no-msg-commit &&
+	test_when_finished reset_rebase &&
+	set_fake_editor &&
+	test_must_fail env FAKE_LINES="1 squash 2" git rebase -i HEAD^^
+'
+
 test_done
diff --git a/t/t3412-rebase-root.sh b/t/t3412-rebase-root.sh
index 0b52105..798c9f1 100755
--- a/t/t3412-rebase-root.sh
+++ b/t/t3412-rebase-root.sh
@@ -278,4 +278,23 @@ test_expect_success 'rebase -i -p --root with conflict (second part)' '
 	test_cmp expect-conflict-p out
 '
 
+test_expect_success 'rebase --root with empty root log message' '
+	git checkout --orphan no-msg-root-commit &&
+	test_commit no-msg-root-commit &&
+	git commit --amend -m " " --allow-empty-message &&
+	git rebase --root &&
+	test_path_is_file no-msg-root-commit.t &&
+	git rebase --root --no-ff &&
+	test_path_is_file no-msg-root-commit.t
+'
+
+test_expect_success 'rebase --root with empty child log message' '
+	test_commit no-msg-child-commit &&
+	git commit --amend -m " " --allow-empty-message &&
+	git rebase --root &&
+	test_path_is_file no-msg-child-commit.t &&
+	git rebase --root --no-ff &&
+	test_path_is_file no-msg-child-commit.t
+'
+
 test_done
-- 
2.0.1

[PATCH v1 07/19] rebase -i: log the replay of root commits

[Fabian Ruch]

The command line used to recreate root commits specifies the option
`-q` which suppresses the commit summary message. However,
git-rebase--interactive tends to tell the user about the commits it
creates in the final history, if she wishes (cf. command line option
`--verbose`). The code parts handling non-root commits and squash
commits all output commit summary messages. Do not make the replay of
root commits an exception. Remove the option to make the report of
the rebased history complete.

It is OK that the commit summary is still suppressed when git-commit
is used to initialize the authorship of the sentinel commit because
this additional commit is an implementation detail hidden from the
final history. The removed `-q` option was probably introduced as a
copy-and-paste error stemming from that part of the root commit
handling code.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 6e2c429..576e0b1 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -511,7 +511,7 @@ do_pick () {
 			   --no-post-rewrite -n -q -C $1 &&
 			pick_one -n $1 &&
 			git commit --allow-empty --allow-empty-message \
-				   --amend --no-post-rewrite -n -q -C $1 \
+				   --amend --no-post-rewrite -n -C $1 \
 				   ${gpg_sign_opt:+"$gpg_sign_opt"} ||
 			die_with_patch $1 "Could not apply $1... $2"
 	else
-- 
2.0.1

Re: [PATCH v1 07/19] rebase -i: log the replay of root commits

[Jeff King]

On Tue, Jul 29, 2014 at 01:18:07AM +0200, Fabian Ruch wrote:

> The command line used to recreate root commits specifies the option
> `-q` which suppresses the commit summary message. However,
> git-rebase--interactive tends to tell the user about the commits it
> creates in the final history, if she wishes (cf. command line option
> `--verbose`). The code parts handling non-root commits and squash
> commits all output commit summary messages. Do not make the replay of
> root commits an exception. Remove the option to make the report of
> the rebased history complete.
> 
> It is OK that the commit summary is still suppressed when git-commit
> is used to initialize the authorship of the sentinel commit because
> this additional commit is an implementation detail hidden from the
> final history. The removed `-q` option was probably introduced as a
> copy-and-paste error stemming from that part of the root commit
> handling code.

I'm confused. This implies that we should be seeing summaries for other
commits, but not root commits, and this patch is bring them into
harmony.  But if I have a repo like this:

  git init -q repo &&
  cd repo &&
  for i in one two; do
    echo $i >file &&
    git add file &&
    git commit -q -m $i
  done

then using stock git gives me this:

  $ GIT_EDITOR=true git rebase -i --root 2>&1 | perl -pe 's/\r/\\r\n/g'
  Rebasing (1/2)\r
  Rebasing (2/2)\r
  Successfully rebased and updated refs/heads/master.

but with your patch, I get:

  $ GIT_EDITOR=true git.compile rebase -i --root 2>&1 | perl -pe 's/\r/\\r\n/g'
  Rebasing (1/2)\r
  [detached HEAD 60834b3] one
   Date: Fri Aug 1 20:00:05 2014 -0400
   1 file changed, 1 insertion(+)
   create mode 100644 file
  Rebasing (2/2)\r
  Successfully rebased and updated refs/heads/master.

Am I misunderstanding the purpose of the patch?

-Peff

Re: [PATCH v1 07/19] rebase -i: log the replay of root commits

[Fabian Ruch]

Hi,

Jeff King writes:
> On Tue, Jul 29, 2014 at 01:18:07AM +0200, Fabian Ruch wrote:
>> The command line used to recreate root commits specifies the option
>> `-q` which suppresses the commit summary message. However,
>> git-rebase--interactive tends to tell the user about the commits it
>> creates in the final history, if she wishes (cf. command line option
>> `--verbose`). The code parts handling non-root commits and squash
>> commits all output commit summary messages. Do not make the replay of
>> root commits an exception. Remove the option to make the report of
>> the rebased history complete.
>>
>> It is OK that the commit summary is still suppressed when git-commit
>> is used to initialize the authorship of the sentinel commit because
>> this additional commit is an implementation detail hidden from the
>> final history. The removed `-q` option was probably introduced as a
>> copy-and-paste error stemming from that part of the root commit
>> handling code.
> 
> I'm confused. This implies that we should be seeing summaries for other
> commits, but not root commits, and this patch is bring them into
> harmony.  But if I have a repo like this:
> 
>   git init -q repo &&
>   cd repo &&
>   for i in one two; do
>     echo $i >file &&
>     git add file &&
>     git commit -q -m $i
>   done
> 
> then using stock git gives me this:
> 
>   $ GIT_EDITOR=true git rebase -i --root 2>&1 | perl -pe 's/\r/\\r\n/g'
>   Rebasing (1/2)\r
>   Rebasing (2/2)\r
>   Successfully rebased and updated refs/heads/master.
> 
> but with your patch, I get:
> 
>   $ GIT_EDITOR=true git.compile rebase -i --root 2>&1 | perl -pe 's/\r/\\r\n/g'
>   Rebasing (1/2)\r
>   [detached HEAD 60834b3] one
>    Date: Fri Aug 1 20:00:05 2014 -0400
>    1 file changed, 1 insertion(+)
>    create mode 100644 file
>   Rebasing (2/2)\r
>   Successfully rebased and updated refs/heads/master.
> 
> Am I misunderstanding the purpose of the patch?

Thanks for laying out the differences in the user visible output. With
stock git we are seeing summaries for other commits, but not root
commits, _with the --verbose option_. It's the fault of my patch to show
the summary even in non-verbose mode. This is now fixed by wrapping the
relevant command in 'output', a shell function defined in git-rebase.sh
as follows:

> output=$("$@" 2>&1 )
> status=$?
> test $status != 0 && printf "%s\n" "$output"
> return $status

The problem that git-rebase--interactive has is that the redirection of
stdin to a variable (or a file) does not work reliably with commands
that invoke the log message editor, that is 'reword' and 'squash'
produce their output both in verbose and non-verbose mode. I wouldn't
know how to fix this but

1) invoking $GIT_EDITOR from git-rebase--interactive.sh, but to make
this right there should be a built-in command for shell scripts and an
interface for git-commit that prepare the editor contents like
git-commit does now, or

2) forcing $GIT_EDITOR and git-commit to print on distinct file
descriptors, which would involve temporarily wrapping the $GIT_EDITOR
call in a shell script that redirects stdin to some other file
descriptor similar to what t/test-lib.sh does, or

>         cat >"$state_dir"/editor.sh <<EOF
> #!/bin/sh
> $(git var GIT_EDITOR) \$* >&3
> EOF
>         chmod +x "$state_dir"/editor.sh
>         (
>                 export GIT_EDITOR="$state_dir"/editor.sh
>                 "$@" 3>&1 >"$state_dir"/output 2>&1
>         )

3) passing the --quiet option in non-verbose mode and omitting it in
verbose mode, which would cover the '$status != 0' above for if a
command fails, it should indicate its error status despite being asked
to be silent.

Options 2) and 3) seem attainable within this patch series and 3) sounds
like the cleanest option but I'm uncertain if I'm missing something
here. The only command line that is wrapped in 'output' and that doesn't
support a --quiet option seems to be a 'warn' line which could simply be
skipped in non-verbose mode. (Johannes Schindelin is cc'd as the
original author of git-rebase--interactive.sh and 'output' in particular).

   Fabian

Re: [PATCH v1 07/19] rebase -i: log the replay of root commits

[Jeff King]

On Mon, Aug 04, 2014 at 11:21:41PM +0200, Fabian Ruch wrote:

> Thanks for laying out the differences in the user visible output. With
> stock git we are seeing summaries for other commits, but not root
> commits, _with the --verbose option_. It's the fault of my patch to show
> the summary even in non-verbose mode. This is now fixed by wrapping the
> relevant command in 'output', a shell function defined in git-rebase.sh
> as follows:

Ah, OK. That makes a lot more sense, then.

> > output=$("$@" 2>&1 )
> > status=$?
> > test $status != 0 && printf "%s\n" "$output"
> > return $status
> 
> The problem that git-rebase--interactive has is that the redirection of
> stdin to a variable (or a file) does not work reliably with commands
> that invoke the log message editor, that is 'reword' and 'squash'
> produce their output both in verbose and non-verbose mode. I wouldn't
> know how to fix this but
> 
> 1) invoking $GIT_EDITOR from git-rebase--interactive.sh, but to make
> this right there should be a built-in command for shell scripts and an
> interface for git-commit that prepare the editor contents like
> git-commit does now, or
> 
> 2) forcing $GIT_EDITOR and git-commit to print on distinct file
> descriptors, which would involve temporarily wrapping the $GIT_EDITOR
> call in a shell script that redirects stdin to some other file
> descriptor similar to what t/test-lib.sh does, or

Hmm. In the test scripts, we send stdout and stderr for sub-commands to
fds 3 and 4 respectively. And then we either point those at /dev/null or
to >&1 and >&2, depending on whether $verbose mode was specified.

I don't think that will work here, though. You literally have one "git
commit" command to run, and you want its stderr/stdout to go somewhere
different than the $GIT_EDITOR it will invoke. Your (2) makes some sense
to me. Something like:

  GIT_EDITOR="$(shellquote "$(git var GIT_EDITOR)") >&3 2>&4" \
    git commit ... 3>&1 4>&2 >wherever 2>&1

Or we could just point it at /dev/tty, though I guess that may open
another can of worms (systems without /dev/tty, what happens when you do
not have a terminal, etc).

> 3) passing the --quiet option in non-verbose mode and omitting it in
> verbose mode, which would cover the '$status != 0' above for if a
> command fails, it should indicate its error status despite being asked
> to be silent.

Yeah, that is probably the cleanest option if it works. I would just
worry that it is not as complete. It works for "git commit", but are
there are other commands wrapped in the verbose output that would want
the same treatment (that might not know about --quiet)? Your paragraph
below says it would not be that big a deal, so as long as we don't plan
to add anything in the future that could not handle the requirement,
that may be enough.

-Peff

[PATCH v1 08/19] rebase -i: root commits are replayed with an unnecessary option

[Fabian Ruch]

The command line used to recreate root commits specifies the
effectless option `-C`. It makes git-commit reuse commit message and
authorship of the named commit. However, the commit being amended
here, which is the sentinel commit, already carries the authorship
and log message of the commit being replayed. Remove the option.

Since `-C` (in contrast to `-c`) does not invoke the editor and the
`--amend` option invokes it by default, disable editor invocation
again by specifying `--no-edit`.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 576e0b1..46f436f 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -511,7 +511,7 @@ do_pick () {
 			   --no-post-rewrite -n -q -C $1 &&
 			pick_one -n $1 &&
 			git commit --allow-empty --allow-empty-message \
-				   --amend --no-post-rewrite -n -C $1 \
+				   --amend --no-post-rewrite -n --no-edit \
 				   ${gpg_sign_opt:+"$gpg_sign_opt"} ||
 			die_with_patch $1 "Could not apply $1... $2"
 	else
-- 
2.0.1

Re: [PATCH v1 08/19] rebase -i: root commits are replayed with an unnecessary option

[Jeff King]

On Tue, Jul 29, 2014 at 01:18:08AM +0200, Fabian Ruch wrote:

> The command line used to recreate root commits specifies the
> effectless option `-C`. It makes git-commit reuse commit message and
> authorship of the named commit. However, the commit being amended
> here, which is the sentinel commit, already carries the authorship
> and log message of the commit being replayed. Remove the option.
> 
> Since `-C` (in contrast to `-c`) does not invoke the editor and the
> `--amend` option invokes it by default, disable editor invocation
> again by specifying `--no-edit`.

I found this description a little backwards. The "-C" does have an
effect, as you noticed in the second paragraph.

I think the reasoning is more like:

  The command line used to recreate root commits uses "-C" to
  suppress the commit editor. This is unnecessarily confusing,
  though, because that suppression is a secondary effect of the
  option. The main purpose of "-C" is to pull the metadata from
  another commit, but here we know that this is a noop, since we
  are amending a commit just created from the same data.

  At the time, commit did not yet know "--no-edit", and this was a
  reasonable way to get the desired behavior. We can switch it to
  use "--no-edit" to make the intended effect more obvious.

-Peff

Re: [PATCH v1 08/19] rebase -i: root commits are replayed with an unnecessary option

[Fabian Ruch]

Hi Jeff,

Jeff King writes:
> On Tue, Jul 29, 2014 at 01:18:08AM +0200, Fabian Ruch wrote:
>> The command line used to recreate root commits specifies the
>> effectless option `-C`. It makes git-commit reuse commit message and
>> authorship of the named commit. However, the commit being amended
>> here, which is the sentinel commit, already carries the authorship
>> and log message of the commit being replayed. Remove the option.
>>
>> Since `-C` (in contrast to `-c`) does not invoke the editor and the
>> `--amend` option invokes it by default, disable editor invocation
>> again by specifying `--no-edit`.
> 
> I found this description a little backwards. The "-C" does have an
> effect, as you noticed in the second paragraph.
> 
> I think the reasoning is more like:
> 
>   The command line used to recreate root commits uses "-C" to
>   suppress the commit editor. This is unnecessarily confusing,
>   though, because that suppression is a secondary effect of the
>   option. The main purpose of "-C" is to pull the metadata from
>   another commit, but here we know that this is a noop, since we
>   are amending a commit just created from the same data.
> 
>   At the time, commit did not yet know "--no-edit", and this was a
>   reasonable way to get the desired behavior. We can switch it to
>   use "--no-edit" to make the intended effect more obvious.

Thanks again, I shamelessly copied your formulation but squeezed in an
"undocumented" because --no-edit had just been implemented (commit
ca1ba2010), though was then still missing from the git-commit manpage.

    Fabian

[PATCH v1 09/19] rebase -i: commit only once when rewriting picks

[Fabian Ruch]

The options passed to `do_pick` determine whether the picked commit
will be rewritten or not. If the commit gets rewritten, because the
user requested to edit the commit message for instance, let
`pick_one` merely apply the changes introduced by the commit and do
not commit the resulting tree yet. If the commit is replayed as is,
leave it to `pick_one` to recreate the commit (possibly by
fast-forwarding the head). This makes it easier to combine git-commit
options like `--edit` and `--amend` in `do_pick` because
git-cherry-pick does not support `--amend`.

In the case of `--edit`, do not `exit_with_patch` but assign
`rewrite` to pick the changes with `-n`. If the pick conflicts, no
commit is created which we would have to amend when continuing the
rebase. To complete the pick after the conflicts are resolved the
user just resumes with `git rebase --continue`.

git-commit lets the user edit the commit log message by default. We
do not want that for the rewriting git-commit command line because
the default behaviour of git-rebase is exactly the opposite. Pass
`--no-edit` when rewriting a picked commit. An explicit `--edit`
passed to `do_pick` (for instance, when reword is executed) enables
the editor launch again. Similarly, pass `--allow-empty-message`
unless the log message is edited.

If `rebase--interactive` is used to rebase a complete branch onto
some head, `rebase` creates a sentinel commit that requires special
treatment by `do_pick`. Do not finalize the pick here either because
its commit message can be altered as for any other pick. Since the
orphaned root commit gets a temporary parent, it is always rewritten.
Safely use the rewrite infrastructure of `do_pick` to create the
final commit.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 58 ++++++++++++++++++++++++++++------------------
 1 file changed, 36 insertions(+), 22 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 46f436f..96c24e8 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -63,7 +63,8 @@ msgnum="$state_dir"/msgnum
 author_script="$state_dir"/author-script
 
 # When an "edit" rebase command is being processed, the SHA1 of the
-# commit to be edited is recorded in this file.  When "git rebase
+# commit to be edited is recorded in this file.  The same happens when
+# rewriting a commit fails, for instance "reword".  When "git rebase
 # --continue" is executed, if there are any staged changes then they
 # will be amended to the HEAD commit, but only provided the HEAD
 # commit is still the commit to be edited.  When any other rebase
@@ -479,12 +480,17 @@ record_in_rewritten() {
 #     The commit message title of <commit>. Used for information
 #     purposes only.
 do_pick () {
-	edit=
+	allow_empty_message=y
+	rewrite=
+	rewrite_amend=
+	rewrite_edit=
 	while test $# -gt 0
 	do
 		case "$1" in
 		-e|--edit)
-			edit=y
+			rewrite=y
+			rewrite_edit=y
+			allow_empty_message=
 			;;
 		-*)
 			die "do_pick: unrecognized option -- $1"
@@ -499,6 +505,10 @@ do_pick () {
 
 	if test "$(git rev-parse HEAD)" = "$squash_onto"
 	then
+		rewrite=y
+		rewrite_amend=y
+		git rev-parse --verify HEAD >"$amend"
+
 		# Set the correct commit message and author info on the
 		# sentinel root before cherry-picking the original changes
 		# without committing (-n).  Finally, update the sentinel again
@@ -509,31 +519,35 @@ do_pick () {
 		# rebase --continue.
 		git commit --allow-empty --allow-empty-message --amend \
 			   --no-post-rewrite -n -q -C $1 &&
-			pick_one -n $1 &&
-			git commit --allow-empty --allow-empty-message \
-				   --amend --no-post-rewrite -n --no-edit \
-				   ${gpg_sign_opt:+"$gpg_sign_opt"} ||
+			pick_one -n $1 ||
 			die_with_patch $1 "Could not apply $1... $2"
 	else
-		pick_one $1 ||
+		pick_one ${rewrite:+-n} $1 ||
 			die_with_patch $1 "Could not apply $1... $2"
 	fi
 
-	if test -n "$edit"
+	if test -n "$rewrite"
 	then
-		# TODO: Work around the fact that git-commit lets us
-		# disable either both the pre-commit and the commit-msg
-		# hook or none. Disable the pre-commit hook because the
-		# tree is left unchanged but run the commit-msg hook
-		# from here because the log message is altered.
-		git commit --allow-empty --amend --no-post-rewrite -n ${gpg_sign_opt:+"$gpg_sign_opt"} &&
-			if test -x "$GIT_DIR"/hooks/commit-msg
-			then
-				"$GIT_DIR"/hooks/commit-msg "$GIT_DIR"/COMMIT_EDITMSG
-			fi || {
-				warn "Could not amend commit after successfully picking $1... $2"
-				exit_with_patch $1 1
-			}
+		git commit --allow-empty --no-post-rewrite -n --no-edit \
+			   ${allow_empty_message:+--allow-empty-message} \
+			   ${rewrite_amend:+--amend} \
+			   ${rewrite_edit:+--edit} \
+			   ${gpg_sign_opt:+"$gpg_sign_opt"} ||
+			die_with_patch $1 "Could not rewrite commit after successfully picking $1... $2"
+	fi
+
+	# TODO: Work around the fact that git-commit lets us
+	# disable either both the pre-commit and the commit-msg
+	# hook or none. Disable the pre-commit hook because the
+	# tree is left unchanged but run the commit-msg hook
+	# from here because the log message is altered.
+	if test -n "$rewrite_edit"
+	then
+		if test -x "$GIT_DIR"/hooks/commit-msg
+		then
+			"$GIT_DIR"/hooks/commit-msg "$GIT_DIR"/COMMIT_EDITMSG
+		fi ||
+			die_with_patch $1 "Could not rewrite commit after successfully picking $1... $2"
 	fi
 }
 
-- 
2.0.1

Re: [PATCH v1 09/19] rebase -i: commit only once when rewriting picks

[Jeff King]

On Tue, Jul 29, 2014 at 01:18:09AM +0200, Fabian Ruch wrote:

> The options passed to `do_pick` determine whether the picked commit
> will be rewritten or not. If the commit gets rewritten, because the
> user requested to edit the commit message for instance, let
> `pick_one` merely apply the changes introduced by the commit and do
> not commit the resulting tree yet. If the commit is replayed as is,
> leave it to `pick_one` to recreate the commit (possibly by
> fast-forwarding the head). This makes it easier to combine git-commit
> options like `--edit` and `--amend` in `do_pick` because
> git-cherry-pick does not support `--amend`.
> 
> In the case of `--edit`, do not `exit_with_patch` but assign
> `rewrite` to pick the changes with `-n`. If the pick conflicts, no
> commit is created which we would have to amend when continuing the
> rebase. To complete the pick after the conflicts are resolved the
> user just resumes with `git rebase --continue`.

Hmm. So does this mean the user will actually see a different state
during such a conflict?

E.g., if I have instructions like:

  pick A
  squash B
  squash C

and there is a conflict picking C, then what state do I see? Right now I
see a commit with the A+B squash prepared. But your description sounds
to me like we would avoid the squash for "B", and the user would see a
different state.

However, I couldn't trigger that behavior in a few experiments. Am I
misunderstanding, or is there some case where the user-visible state
will be different?

-Peff

Re: [PATCH v1 09/19] rebase -i: commit only once when rewriting picks

[Fabian Ruch]

Hi Jeff,

Jeff King writes:
> On Tue, Jul 29, 2014 at 01:18:09AM +0200, Fabian Ruch wrote:
>> The options passed to `do_pick` determine whether the picked commit
>> will be rewritten or not. If the commit gets rewritten, because the
>> user requested to edit the commit message for instance, let
>> `pick_one` merely apply the changes introduced by the commit and do
>> not commit the resulting tree yet. If the commit is replayed as is,
>> leave it to `pick_one` to recreate the commit (possibly by
>> fast-forwarding the head). This makes it easier to combine git-commit
>> options like `--edit` and `--amend` in `do_pick` because
>> git-cherry-pick does not support `--amend`.
>>
>> In the case of `--edit`, do not `exit_with_patch` but assign
>> `rewrite` to pick the changes with `-n`. If the pick conflicts, no
>> commit is created which we would have to amend when continuing the
>> rebase. To complete the pick after the conflicts are resolved the
>> user just resumes with `git rebase --continue`.
> 
> Hmm. So does this mean the user will actually see a different state
> during such a conflict?
> 
> E.g., if I have instructions like:
> 
>   pick A
>   squash B
>   squash C
> 
> and there is a conflict picking C, then what state do I see? Right now I
> see a commit with the A+B squash prepared. But your description sounds
> to me like we would avoid the squash for "B", and the user would see a
> different state.

The squash state will not be different. squash sequences are still taken
care of one line after the other: committing A, committing A+B,
committing A+B+C. If there is a conflict picking C, HEAD will point to
A+B and the index will record the conflicting changes.

> However, I couldn't trigger that behavior in a few experiments. Am I
> misunderstanding, or is there some case where the user-visible state
> will be different?

The user-visible state will be different for rewords. For instance,
let's consider

    pick A
    reword B.

The verbose log used to show two commits for B (with ff disabled), one
after picking and one after editing. Now the log will show a single
commit in connection with 'reword B' which might be less confusing.

Thanks for raising your eyebrows. I noticed now that the last paragraph
is plainly wrong. The described amend situation did not arise "if the
pick conflicted" but "if the edited commit did not verify". There will
be no "after the conflicts are resolved" but the user can either commit
manually and circumvent log message verification if she knows what she's
doing, or provide a corrected log message in the editor launched by 'git
rebase --continue'. The _incomplete_ 'git commit --amend' tip which used
to be displayed after a failed verification hook could become
unnecessary and this would possibly spare us including correct GPG sign
options for instance.

However, this patch is mostly motivated by the unification of how
commits are rewritten. Before, rewords and squashes went about this
differently, now both fail with an uncommitted index if there are
conflicts or the log message is ill-formatted.

The log message must be corrected and the following bug, which was
noticed after PATCH v2, must be fixed.

    cat >.git/hooks/commit-msg <<-EOF
    #!/bin/sh
    exit 1
    EOF
    chmod +x .git/hooks/commit-msg
    test_must_fail env FAKE_LINES="reword 1" git rebase -i
    test_must_fail git rebase --continue
    # the last command succeeds because --continue does not verify

   Fabian

[PATCH v1 10/19] rebase -i: do not die in do_pick

[Fabian Ruch]

Since `do_pick` might be executed in a sub-shell (a modified author
environment for instance), calling `die` in `do_pick` has no effect
but exiting the sub-shell with a failure exit status. The
git-rebase--interactive script is not terminated. Moreover, if
`do_pick` is called while a squash or fixup is in effect,
`die_with_patch` will discard `$squash_msg` as commit message.
Lastly, after a `die` in `do_pick` `do_next` has no chance to
reschedule tasks that failed before changes could be applied.

Indicate an error in `do_pick` using return statements and properly
kill the script at the call sites. Although possible in principle,
the issued error messages are no more indicating whether `do_pick`
failed while applying or while committing the changes. This reduces
code complexity at the call site and does not matter from a user's
point of view because a glance at the index reveals whether there are
conflicts or not and in-depth troubleshooting is still possible using
the `--verbose` option.

Remove the commit message title argument from `do_pick`'s interface,
which has become unused.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 37 ++++++++++++++++++++-----------------
 1 file changed, 20 insertions(+), 17 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 96c24e8..9f08f1b 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -464,7 +464,7 @@ record_in_rewritten() {
 
 # Apply the changes introduced by the given commit to the current head.
 #
-# do_pick [--edit] <commit> <title>
+# do_pick [--edit] <commit>
 #
 # Wrapper around git-cherry-pick.
 #
@@ -476,9 +476,11 @@ record_in_rewritten() {
 # <commit>
 #     The commit to cherry-pick.
 #
-# <title>
-#     The commit message title of <commit>. Used for information
-#     purposes only.
+# The return value is 1 if applying the changes resulted in a conflict
+# and 2 if the specified arguments were incorrect. If the changes could
+# be applied successfully but creating the commit failed, a value
+# greater than 2 is returned. No commit is created in either case and
+# the index is left with the (conflicting) changes in place.
 do_pick () {
 	allow_empty_message=y
 	rewrite=
@@ -493,7 +495,8 @@ do_pick () {
 			allow_empty_message=
 			;;
 		-*)
-			die "do_pick: unrecognized option -- $1"
+			warn "do_pick: unrecognized option -- $1"
+			return 2
 			;;
 		*)
 			break
@@ -501,7 +504,11 @@ do_pick () {
 		esac
 		shift
 	done
-	test $# -ne 2 && die "do_pick: wrong number of arguments"
+	if test $# -ne 1
+	then
+		warn "do_pick: wrong number of arguments"
+		return 2
+	fi
 
 	if test "$(git rev-parse HEAD)" = "$squash_onto"
 	then
@@ -519,11 +526,9 @@ do_pick () {
 		# rebase --continue.
 		git commit --allow-empty --allow-empty-message --amend \
 			   --no-post-rewrite -n -q -C $1 &&
-			pick_one -n $1 ||
-			die_with_patch $1 "Could not apply $1... $2"
+			pick_one -n $1 || return 1
 	else
-		pick_one ${rewrite:+-n} $1 ||
-			die_with_patch $1 "Could not apply $1... $2"
+		pick_one ${rewrite:+-n} $1 || return 1
 	fi
 
 	if test -n "$rewrite"
@@ -532,8 +537,7 @@ do_pick () {
 			   ${allow_empty_message:+--allow-empty-message} \
 			   ${rewrite_amend:+--amend} \
 			   ${rewrite_edit:+--edit} \
-			   ${gpg_sign_opt:+"$gpg_sign_opt"} ||
-			die_with_patch $1 "Could not rewrite commit after successfully picking $1... $2"
+			   ${gpg_sign_opt:+"$gpg_sign_opt"} || return 3
 	fi
 
 	# TODO: Work around the fact that git-commit lets us
@@ -546,8 +550,7 @@ do_pick () {
 		if test -x "$GIT_DIR"/hooks/commit-msg
 		then
 			"$GIT_DIR"/hooks/commit-msg "$GIT_DIR"/COMMIT_EDITMSG
-		fi ||
-			die_with_patch $1 "Could not rewrite commit after successfully picking $1... $2"
+		fi || return 3
 	fi
 }
 
@@ -562,21 +565,21 @@ do_next () {
 		comment_for_reflog pick
 
 		mark_action_done
-		do_pick $sha1 "$rest"
+		do_pick $sha1 || die_with_patch $sha1 "Could not apply $sha1... $rest"
 		record_in_rewritten $sha1
 		;;
 	reword|r)
 		comment_for_reflog reword
 
 		mark_action_done
-		do_pick --edit $sha1 "$rest"
+		do_pick --edit $sha1 || die_with_patch $sha1 "Could not apply $sha1... $rest"
 		record_in_rewritten $sha1
 		;;
 	edit|e)
 		comment_for_reflog edit
 
 		mark_action_done
-		do_pick $sha1 "$rest"
+		do_pick $sha1 || die_with_patch $sha1 "Could not apply $sha1... $rest"
 		warn "Stopped at $sha1... $rest"
 		exit_with_patch $sha1 0
 		;;
-- 
2.0.1

[PATCH v1 11/19] rebase -i: teach do_pick the option --amend

[Fabian Ruch]

`do_pick` is the git-cherry-pick wrapper in git-rebase--interactive
that is used to implement the to-do list commands `pick`, `reword`
and `edit`. To cater for the different pick behaviours (like
`squash`), `do_pick` accepts several options not only from the
git-cherry-pick but also the git-commit interface.

Add the option `--amend` from the git-commit interface to the options
pool of `do_pick`. It creates a new commit for the changes introduced
by the picked commit and the previous one. The previous commit is
then replaced with the new commit. If no other options are specified,
the log message of the previous commit is used.

Be careful when `--amend` is used to pick a root commit because HEAD
might point to the sentinel commit but there is still nothing to
amend. Be sure to initialize `amend` so that commits are squashed
even when git-rebase--interactive is interrupted for resolving
conflicts. It is not a mistake to do the initialization regardless of
any conflicts because `amend` is always cleared before the next to-do
item is processed.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 9f08f1b..22a8f7b 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -464,10 +464,16 @@ record_in_rewritten() {
 
 # Apply the changes introduced by the given commit to the current head.
 #
-# do_pick [--edit] <commit>
+# do_pick [--amend] [--edit] <commit>
 #
 # Wrapper around git-cherry-pick.
 #
+# --amend
+#     After picking <commit>, replace the current head commit with a new
+#     commit that also introduces the changes of <commit>.
+#
+#     _This is not a git-cherry-pick option._
+#
 # -e, --edit
 #     After picking <commit>, open an editor and let the user edit the
 #     commit message. The editor contents becomes the commit message of
@@ -489,6 +495,16 @@ do_pick () {
 	while test $# -gt 0
 	do
 		case "$1" in
+		--amend)
+			if test "$(git rev-parse HEAD)" = "$squash_onto" || ! git rev-parse --verify HEAD
+			then
+				warn "do_pick: nothing to amend"
+				return 2
+			fi
+			rewrite=y
+			rewrite_amend=y
+			git rev-parse --verify HEAD >"$amend"
+			;;
 		-e|--edit)
 			rewrite=y
 			rewrite_edit=y
-- 
2.0.1

[PATCH v1 12/19] rebase -i: teach do_pick the option --file

[Fabian Ruch]

`do_pick` is the git-cherry-pick wrapper in git-rebase--interactive
that is used to implement the to-do list command `pick`, `reword` and
`edit`. To cater for the different pick behaviours (like `squash`),
`do_pick` accepts several options not only from the git-cherry-pick
but also the git-commit interface.

Add the option `--file` from the git-commit interface to the options
pool of `do_pick`. It expects an argument itself which is interpreted
as a file path and takes the commit message from the given file. If
`--file` is passed to `do_pick`, assign the given file path to the
local variable `rewrite_message` and relay the option

    --file "$rewrite_message"

to the git-commit command line which creates the commit.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 22a8f7b..5df1086 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -464,7 +464,7 @@ record_in_rewritten() {
 
 # Apply the changes introduced by the given commit to the current head.
 #
-# do_pick [--amend] [--edit] <commit>
+# do_pick [--amend] [--file <file>] [--edit] <commit>
 #
 # Wrapper around git-cherry-pick.
 #
@@ -474,6 +474,12 @@ record_in_rewritten() {
 #
 #     _This is not a git-cherry-pick option._
 #
+# -F <file>, --file <file>
+#     Take the commit message from the given file. This creates a fresh
+#     commit.
+#
+#     _This is not a git-cherry-pick option._
+#
 # -e, --edit
 #     After picking <commit>, open an editor and let the user edit the
 #     commit message. The editor contents becomes the commit message of
@@ -492,6 +498,7 @@ do_pick () {
 	rewrite=
 	rewrite_amend=
 	rewrite_edit=
+	rewrite_message=
 	while test $# -gt 0
 	do
 		case "$1" in
@@ -505,6 +512,16 @@ do_pick () {
 			rewrite_amend=y
 			git rev-parse --verify HEAD >"$amend"
 			;;
+		-F|--file)
+			if test $# -eq 0
+			then
+				warn "do_pick: option --file specified but no <file> given"
+				return 2
+			fi
+			rewrite=y
+			rewrite_message=$2
+			shift
+			;;
 		-e|--edit)
 			rewrite=y
 			rewrite_edit=y
@@ -553,6 +570,7 @@ do_pick () {
 			   ${allow_empty_message:+--allow-empty-message} \
 			   ${rewrite_amend:+--amend} \
 			   ${rewrite_edit:+--edit} \
+			   ${rewrite_message:+--file "$rewrite_message"} \
 			   ${gpg_sign_opt:+"$gpg_sign_opt"} || return 3
 	fi
 
-- 
2.0.1

[PATCH v1 13/19] rebase -i: prepare for squash in terms of do_pick --amend

[Fabian Ruch]

Rewrite `squash` and `fixup` handling in `do_next` using the sequence

    pick_one
    commit

in order to test the correctness of a single `do_squash` or
parameterised `do_pick` and make the subsequent patch reimplementing
`squash` in terms of such a single function more readable.

Do not call `rm -f "$GIT_DIR"/MERGE_MSG` since it has no effect on
the state after git-rebase--interactive terminates. The option `-F`
makes git-commit ignore `MERGE_MSG` for the log message. If
git-commit succeeds, `MERGE_MSG` is removed, and if it fails,
`MERGE_MSG` is overwritten by the error sequence `die_failed_squash`.
In summary, removing `MERGE_MSG` neither influences the squash commit
message nor the file state after git-commit returns.

Moreover, `pick_one` ignores `$GIT_DIR/SQUASH_MSG` and does not touch
`$squash_msg` so that it is correct to execute `pick_one` immediately
before git-commit.

Might be squashed into the subsequent commit.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 5df1086..d85e55d 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -636,15 +636,15 @@ do_next () {
 		author_script_content=$(get_author_ident_from_commit HEAD)
 		echo "$author_script_content" > "$author_script"
 		eval "$author_script_content"
-		if ! pick_one -n $sha1
-		then
-			git rev-parse --verify HEAD >"$amend"
-			die_failed_squash $sha1 "$rest"
-		fi
 		case "$(peek_next_command)" in
 		squash|s|fixup|f)
 			# This is an intermediate commit; its message will only be
 			# used in case of trouble.  So use the long version:
+			if ! pick_one -n $sha1
+			then
+				git rev-parse --verify HEAD >"$amend"
+				die_failed_squash $sha1 "Could not apply $sha1... $rest"
+			fi
 			do_with_author output git commit --amend --no-verify -F "$squash_msg" \
 				${gpg_sign_opt:+"$gpg_sign_opt"} ||
 				die_failed_squash $sha1 "$rest"
@@ -653,12 +653,21 @@ do_next () {
 			# This is the final command of this squash/fixup group
 			if test -f "$fixup_msg"
 			then
+				if ! pick_one -n $sha1
+				then
+					git rev-parse --verify HEAD >"$amend"
+					die_failed_squash $sha1 "Could not apply $sha1... $rest"
+				fi
 				do_with_author git commit --amend --no-verify -F "$fixup_msg" \
 					${gpg_sign_opt:+"$gpg_sign_opt"} ||
 					die_failed_squash $sha1 "$rest"
 			else
 				cp "$squash_msg" "$GIT_DIR"/SQUASH_MSG || exit
-				rm -f "$GIT_DIR"/MERGE_MSG
+				if ! pick_one -n $sha1
+				then
+					git rev-parse --verify HEAD >"$amend"
+					die_failed_squash $sha1 "Could not apply $sha1... $rest"
+				fi
 				do_with_author git commit --amend --no-verify -F "$GIT_DIR"/SQUASH_MSG -e \
 					${gpg_sign_opt:+"$gpg_sign_opt"} ||
 					die_failed_squash $sha1 "$rest"
-- 
2.0.1

[PATCH v1 14/19] rebase -i: implement squash in terms of do_pick

[Fabian Ruch]

The to-do list command `squash` and its close relative `fixup` replay
the changes of a commit like `pick` but do not recreate the commit.
Instead they replace the previous commit with a new commit that also
introduces the changes of the squashed commit. This is roughly like
cherry-picking without committing and using git-commit to amend the
previous commit.

The to-do list

    pick   a Some changes
    squash b Some more changes

gets translated into the sequence of git commands

    git cherry-pick a
    git cherry-pick -n b
    git commit --amend

and if git-cherry-pick supported `--amend` this would look even more
like the to-do list it is based on

    git cherry-pick a
    git cherry-pick --amend b.

Since `do_pick` takes care of `pick` entries and the above suggests
`squash` as an alias for `pick --amend`, reimplement `squash` in
terms of `do_pick --amend`. Introduce `$squash_msg` as the commit
message via the `--file` option. When the last commit of a squash
series is processed, the user is asked to review the log message.
Pass `--edit` as additional option in this case. The only difference
in the options passed to git-commit and `do_pick` is the omitted
`--no-verify`. However, `do_pick` does not execute the verification
hooks anyway because it solely replays commits and assumes that they
have been verified before.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 30 ++++++------------------------
 1 file changed, 6 insertions(+), 24 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index d85e55d..9307fa4 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -640,37 +640,19 @@ do_next () {
 		squash|s|fixup|f)
 			# This is an intermediate commit; its message will only be
 			# used in case of trouble.  So use the long version:
-			if ! pick_one -n $sha1
-			then
-				git rev-parse --verify HEAD >"$amend"
-				die_failed_squash $sha1 "Could not apply $sha1... $rest"
-			fi
-			do_with_author output git commit --amend --no-verify -F "$squash_msg" \
-				${gpg_sign_opt:+"$gpg_sign_opt"} ||
-				die_failed_squash $sha1 "$rest"
+			do_with_author do_pick --amend -F "$squash_msg" $sha1 \
+				|| die_failed_squash $sha1 "Could not apply $sha1... $rest"
 			;;
 		*)
 			# This is the final command of this squash/fixup group
 			if test -f "$fixup_msg"
 			then
-				if ! pick_one -n $sha1
-				then
-					git rev-parse --verify HEAD >"$amend"
-					die_failed_squash $sha1 "Could not apply $sha1... $rest"
-				fi
-				do_with_author git commit --amend --no-verify -F "$fixup_msg" \
-					${gpg_sign_opt:+"$gpg_sign_opt"} ||
-					die_failed_squash $sha1 "$rest"
+				do_with_author do_pick --amend -F "$fixup_msg" $sha1 \
+					|| die_failed_squash $sha1 "Could not apply $sha1... $rest"
 			else
 				cp "$squash_msg" "$GIT_DIR"/SQUASH_MSG || exit
-				if ! pick_one -n $sha1
-				then
-					git rev-parse --verify HEAD >"$amend"
-					die_failed_squash $sha1 "Could not apply $sha1... $rest"
-				fi
-				do_with_author git commit --amend --no-verify -F "$GIT_DIR"/SQUASH_MSG -e \
-					${gpg_sign_opt:+"$gpg_sign_opt"} ||
-					die_failed_squash $sha1 "$rest"
+				do_with_author do_pick --amend -F "$GIT_DIR"/SQUASH_MSG -e $sha1 \
+					|| die_failed_squash $sha1 "Could not apply $sha1... $rest"
 			fi
 			rm -f "$squash_msg" "$fixup_msg"
 			;;
-- 
2.0.1

[PATCH v1 15/19] rebase -i: explicitly distinguish replay commands and exec tasks

[Fabian Ruch]

There are two kinds of to-do list commands available. One kind
replays a commit (`pick`, `reword`, `edit`, `squash` and `fixup` that
is) and the other executes a shell command (`exec`). We will call the
first kind replay commands.

The two kinds of tasks are scheduled using different line formats.
Replay commands expect a commit hash argument following the command
name and exec concatenates all arguments to assemble a command line.

Adhere to the distinction of formats by not trying to parse the
`sha1` field unless we are dealing with a replay command. Move the
replay command handling code to a new function `do_replay` which
assumes the first argument to be a commit hash and make no more such
assumptions in `do_next`.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 42 ++++++++++++++++++++++++++++--------------
 1 file changed, 28 insertions(+), 14 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 9307fa4..8dde8e6 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -588,13 +588,12 @@ do_pick () {
 	fi
 }
 
-do_next () {
-	rm -f "$msg" "$author_script" "$amend" || exit
-	read -r command sha1 rest < "$todo"
+do_replay () {
+	command=$1
+	sha1=$2
+	rest=$3
+
 	case "$command" in
-	"$comment_char"*|''|noop)
-		mark_action_done
-		;;
 	pick|p)
 		comment_for_reflog pick
 
@@ -659,6 +658,28 @@ do_next () {
 		esac
 		record_in_rewritten $sha1
 		;;
+	*)
+		read -r command <"$todo"
+		warn "Unknown command: $command"
+		fixtodo="Please fix this using 'git rebase --edit-todo'."
+		if git rev-parse --verify -q "$sha1" >/dev/null
+		then
+			die_with_patch $sha1 "$fixtodo"
+		else
+			die "$fixtodo"
+		fi
+		;;
+	esac
+}
+
+do_next () {
+	rm -f "$msg" "$author_script" "$amend" || exit
+	read -r command sha1 rest <"$todo"
+
+	case "$command" in
+	"$comment_char"*|''|noop)
+		mark_action_done
+		;;
 	x|"exec")
 		read -r command rest < "$todo"
 		mark_action_done
@@ -698,14 +719,7 @@ do_next () {
 		fi
 		;;
 	*)
-		warn "Unknown command: $command $sha1 $rest"
-		fixtodo="Please fix this using 'git rebase --edit-todo'."
-		if git rev-parse --verify -q "$sha1" >/dev/null
-		then
-			die_with_patch $sha1 "$fixtodo"
-		else
-			die "$fixtodo"
-		fi
+		do_replay $command $sha1 "$rest"
 		;;
 	esac
 	test -s "$todo" && return
-- 
2.0.1

[PATCH v1 16/19] rebase -i: parse to-do list command line options

[Fabian Ruch]

Read in to-do list lines as

    command args

instead of

    command sha1 rest

so that to-do list command lines can specify additional arguments
apart from the commit hash and the log message title, which become
the non-options in `args`. Loop over `args`, put all options (an
argument beginning with a dash) in `opts`, stop the loop on the first
non-option and assign it to `sha1`. The loop does not know the
options it parses so that options that take an argument themselves
are not supported at the moment. Neither are options that contain
spaces because the shell expansion of `args` in `do_next` interprets
white space characters as argument separator, that is a command line
like

    pick --author "A U Thor" fa1afe1 Some change

is parsed as the pick command

    pick --author

and the commit hash

    "A

which obviously results in an unknown revision error. For the sake of
completeness, in the example above the message title variable `rest`
is assigned the string 'U Thor" fa1afe1 Some change' (without the
single quotes).

Print an error message for unknown or unsupported command line
options, which means an error for all specified options at the
moment. Cleanly break the `do_next` loop by assigning the special
value 'unknown' to the local variable `command`, which triggers the
unknown command case in `do_cmd`.

The to-do list is also parsed when the commit hashes are translated
between long and short format before and after the to-do list is
edited. Apply the same procedure as in `do_cmd` with the exception
that we only care about where the options stop and the commit hash
begins. Do not reject any options when transforming the commit
hashes.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 49 ++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 41 insertions(+), 8 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 8dde8e6..ff4ba7f 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -590,8 +590,26 @@ do_pick () {
 
 do_replay () {
 	command=$1
-	sha1=$2
-	rest=$3
+	shift
+
+	opts=
+	while test $# -gt 0
+	do
+		case "$1" in
+		-*)
+			warn "Unknown option: $1"
+			command=unknown
+			;;
+		*)
+			break
+			;;
+		esac
+		opts="$opts $(git rev-parse --sq-quote "$1")"
+		shift
+	done
+	sha1=$1
+	shift
+	rest=$*
 
 	case "$command" in
 	pick|p)
@@ -674,7 +692,7 @@ do_replay () {
 
 do_next () {
 	rm -f "$msg" "$author_script" "$amend" || exit
-	read -r command sha1 rest <"$todo"
+	read -r command args <"$todo"
 
 	case "$command" in
 	"$comment_char"*|''|noop)
@@ -719,7 +737,7 @@ do_next () {
 		fi
 		;;
 	*)
-		do_replay $command $sha1 "$rest"
+		do_replay $command $args
 		;;
 	esac
 	test -s "$todo" && return
@@ -799,19 +817,34 @@ skip_unnecessary_picks () {
 }
 
 transform_todo_ids () {
-	while read -r command rest
+	while read -r command args
 	do
 		case "$command" in
 		"$comment_char"* | exec)
 			# Be careful for oddball commands like 'exec'
 			# that do not have a SHA-1 at the beginning of $rest.
+			newargs=\ $args
 			;;
 		*)
-			sha1=$(git rev-parse --verify --quiet "$@" ${rest%% *}) &&
-			rest="$sha1 ${rest#* }"
+			newargs=
+			sha1=
+			for arg in $args
+			do
+				case "$arg" in
+				-*)
+					newargs="$newargs $arg"
+					;;
+				*)
+					test -z "$sha1" &&
+						sha1=$(git rev-parse --verify --quiet "$@" $arg) &&
+						arg=$sha1
+					newargs="$newargs $arg"
+					;;
+				esac
+			done
 			;;
 		esac
-		printf '%s\n' "$command${rest:+ }$rest"
+		printf '%s\n' "$command$newargs"
 	done <"$todo" >"$todo.new" &&
 	mv -f "$todo.new" "$todo"
 }
-- 
2.0.1

[PATCH v1 17/19] rebase -i: teach do_pick the option --reset-author

[Fabian Ruch]

`do_pick` is the git-cherry-pick wrapper in git-rebase--interactive
that is used to implement many of the to-do list commands.
Eventually, the complete `do_pick` interface will be exposed to the
user in some form or another and those commands will become simple
aliases for the `do_pick` options now used to implement them.

Add the git-commit option `--reset-author` to the options pool of
`do_pick`. It rewrites the author date and name of the picked commit
to match the committer date and name.

If `--reset-author` is passed to `do_pick`, set the `rewrite` flag
and relay the option to the git-commit command line which creates the
final commit. If `--amend` is not passed as well, the fresh
authorship effect is achieved by the mere fact that we are creating a
new commit.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index ff4ba7f..3886a80 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -464,10 +464,18 @@ record_in_rewritten() {
 
 # Apply the changes introduced by the given commit to the current head.
 #
-# do_pick [--amend] [--file <file>] [--edit] <commit>
+# do_pick [--reset-author] [--amend] [--file <file>] [--edit] <commit>
 #
 # Wrapper around git-cherry-pick.
 #
+# --reset-author
+#     Pretend the changes were made for the first time. Declare that the
+#     authorship of the resulting commit now belongs to the committer.
+#     This also renews the author timestamp. This creates a fresh
+#     commit.
+#
+#     _This is not a git-cherry-pick option._
+#
 # --amend
 #     After picking <commit>, replace the current head commit with a new
 #     commit that also introduces the changes of <commit>.
@@ -502,6 +510,10 @@ do_pick () {
 	while test $# -gt 0
 	do
 		case "$1" in
+		--reset-author)
+			rewrite=y
+			rewrite_author=y
+			;;
 		--amend)
 			if test "$(git rev-parse HEAD)" = "$squash_onto" || ! git rev-parse --verify HEAD
 			then
@@ -564,6 +576,14 @@ do_pick () {
 		pick_one ${rewrite:+-n} $1 || return 1
 	fi
 
+	if test -n "$rewrite_author" && test -z "$rewrite_amend"
+	then
+		# keep rewrite flag to create a new commit, rewrite
+		# without --reset-author though because it can only be
+		# used with -C, -c or --amend
+		rewrite_author=
+	fi
+
 	if test -n "$rewrite"
 	then
 		git commit --allow-empty --no-post-rewrite -n --no-edit \
@@ -571,6 +591,7 @@ do_pick () {
 			   ${rewrite_amend:+--amend} \
 			   ${rewrite_edit:+--edit} \
 			   ${rewrite_message:+--file "$rewrite_message"} \
+			   ${rewrite_author:+--reset-author} \
 			   ${gpg_sign_opt:+"$gpg_sign_opt"} || return 3
 	fi
 
-- 
2.0.1

[PATCH v1 18/19] rebase -i: teach do_pick the option --signoff

[Fabian Ruch]

`do_pick` is the git-cherry-pick wrapper in git-rebase--interactive
that is currently used to implement most of the to-do list commands
and offers additional options that will eventually find their way
onto to-do lists.

To extend the repertoire of available options, add the git-commit and
git-cherry-pick option `--signoff` to the `do_pick` interface. It
appends a Signed-off-by: line using the committer identity to the log
message of the picked commit.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 3886a80..9324ed3 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -464,10 +464,15 @@ record_in_rewritten() {
 
 # Apply the changes introduced by the given commit to the current head.
 #
-# do_pick [--reset-author] [--amend] [--file <file>] [--edit] <commit>
+# do_pick [--signoff] [--reset-author] [--amend] [--file <file>]
+#         [--edit] <commit>
 #
 # Wrapper around git-cherry-pick.
 #
+# -s, --signoff
+#     Insert a Signed-off-by: line using the committer identity at the
+#     end of the commit log message. This creates a fresh commit.
+#
 # --reset-author
 #     Pretend the changes were made for the first time. Declare that the
 #     authorship of the resulting commit now belongs to the committer.
@@ -510,6 +515,10 @@ do_pick () {
 	while test $# -gt 0
 	do
 		case "$1" in
+		-s|--signoff)
+			rewrite=y
+			rewrite_signoff=y
+			;;
 		--reset-author)
 			rewrite=y
 			rewrite_author=y
@@ -588,6 +597,7 @@ do_pick () {
 	then
 		git commit --allow-empty --no-post-rewrite -n --no-edit \
 			   ${allow_empty_message:+--allow-empty-message} \
+			   ${rewrite_signoff:+--signoff} \
 			   ${rewrite_amend:+--amend} \
 			   ${rewrite_edit:+--edit} \
 			   ${rewrite_message:+--file "$rewrite_message"} \
-- 
2.0.1

[PATCH v1 19/19] rebase -i: enable options --signoff, --reset-author for pick, reword

[Fabian Ruch]

pick and reword are atomic to-do list commands in the sense that they
open a new task which is closed after the respective command is
completed. squash and fixup are not atomic. They create a new task
which is not completed until the last squash or fixup is processed.

Lift the general unknown option blockade for the pick and reword
commands. If `do_cmd` comes across one of the options `--signoff` and
`--reset-author` while parsing a to-do entry and the scheduled
command is either `pick` or `reword`, relay the option to `do_pick`.

The `do_pick` options `--gpg-sign` and `--file` are not yet supported
because `do_cmd` cannot handle option arguments and options with
spaces at the moment. It is true that edit is one of the atomic
commands but it displays hash information when the rebase is stopped
and some options rewrite the picked commit which alters that
information. squash and fixup still do not accept user options as the
interplay of `--reset-author` and the author script are yet to be
determined.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 9324ed3..32fd047 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -627,6 +627,16 @@ do_replay () {
 	while test $# -gt 0
 	do
 		case "$1" in
+		--signoff|--reset-author)
+			case "$command" in
+			pick|reword)
+				;;
+			*)
+				warn "Unsupported option: $1"
+				command=unknown
+				;;
+			esac
+			;;
 		-*)
 			warn "Unknown option: $1"
 			command=unknown
@@ -647,21 +657,24 @@ do_replay () {
 		comment_for_reflog pick
 
 		mark_action_done
-		do_pick $sha1 || die_with_patch $sha1 "Could not apply $sha1... $rest"
+		eval do_pick $opts $sha1 \
+			|| die_with_patch $sha1 "Could not apply $sha1... $rest"
 		record_in_rewritten $sha1
 		;;
 	reword|r)
 		comment_for_reflog reword
 
 		mark_action_done
-		do_pick --edit $sha1 || die_with_patch $sha1 "Could not apply $sha1... $rest"
+		eval do_pick --edit $opts $sha1 \
+			|| die_with_patch $sha1 "Could not apply $sha1... $rest"
 		record_in_rewritten $sha1
 		;;
 	edit|e)
 		comment_for_reflog edit
 
 		mark_action_done
-		do_pick $sha1 || die_with_patch $sha1 "Could not apply $sha1... $rest"
+		eval do_pick $opts $sha1 \
+			|| die_with_patch $sha1 "Could not apply $sha1... $rest"
 		warn "Stopped at $sha1... $rest"
 		exit_with_patch $sha1 0
 		;;
-- 
2.0.1

Re: [PATCH v1 00/19] Enable options --signoff, --reset-author for pick, reword

[Jeff King]

On Tue, Jul 29, 2014 at 01:18:00AM +0200, Fabian Ruch wrote:

> this is a reroll of the patch series that enables rudimentary support
> of line options for git-rebase's to-do list commands and reimplements
> the well-known commands `reword` and `squash` in terms of a
> parameterised `do_pick`.

I just finished reading over the whole series (which is my first real
exposure to it). With the exception of the comments I already sent, it
looks pretty reasonable to me.

Thanks for splitting it and writing good commit messages; that made it
relatively easy to follow what was going on.

-Peff

Re: [PATCH v1 00/19] Enable options --signoff, --reset-author for pick, reword

[Fabian Ruch]

Hi Peff,

Jeff King writes:
> On Tue, Jul 29, 2014 at 01:18:00AM +0200, Fabian Ruch wrote:
>> this is a reroll of the patch series that enables rudimentary support
>> of line options for git-rebase's to-do list commands and reimplements
>> the well-known commands `reword` and `squash` in terms of a
>> parameterised `do_pick`.
> 
> I just finished reading over the whole series (which is my first real
> exposure to it). With the exception of the comments I already sent, it
> looks pretty reasonable to me.
> 
> Thanks for splitting it and writing good commit messages; that made it
> relatively easy to follow what was going on.

Thanks a lot for taking the time.

Your review revealed more shortcomings of the patch series. Now that the
replay of root commits is logged, the log is dumped on the console even
in non-verbose mode. And, I must admit that the fact that `--no-edit`
hasn't been a (documented) feature of git-commit for all time didn't
struck me at all as a possible reason for using `-C`, which is a little
embarrassing.

I will include more details in separate replies to your comments later.

   Fabian

[PATCH v2 00/23] Enable options --signoff, --reset-author for pick, reword

[Fabian Ruch]

Hi List,

this is the second reroll of the patch series fixing corner-case bugs
regarding empty commits, commits with no log message and root
commits, providing a uniform implementation of the to-do list
commands using the `do_pick` interface.

This reroll includes the following list of changes to PATCH v1 from
last week, mostly induced by Jeff's comments. However, I didn't get
around the most recent discussion from tonight yet.

 - new tests: allow replaying commits with empty log messages
     - coverage of all to-do list commands
 - new patch: allow squashing empty commits without complaints
     - do not complain about an empty squash commit unless it is the
       final one and --keep-empty is not specified on the command line
 - new tests: allow rewording empty commits without complaints
     - coverage of all to-do list commands
 - new patch: hide interactive command messages in verbose mode
     - make it possible to launch an editor inside 'output'
 - new patch: allow disabling pre-commit and commit-msg separately
     - add options --no-pre-commit and --no-commit-msg to git-commit
     - redefine --no-verify as synonym for the above two
 - new patch: squash skips commit-msg hook
     - run commit-msg hook for reworded _and_ squashed commits
 - a change to 'test_commit' options and 'fake_editor' debug output

Thanks for your time and reviews,
   Fabian

Fabian Ruch (23):
  rebase -i: allow replaying commits with empty log messages
  rebase -i: allow squashing empty commits without complaints
  rebase -i: allow rewording empty commits without complaints
  rebase -i: hide interactive command messages in verbose mode
  rebase -i: failed reword prints redundant error message
  commit: allow disabling pre-commit and commit-msg separately
  rebase -i: squash skips commit-msg hook
  rebase -i: reword executes pre-commit hook on interim commit
  rebase -i: teach do_pick the option --edit
  rebase -i: implement reword in terms of do_pick
  rebase -i: log the replay of root commits
  rebase -i: root commits are replayed with an unnecessary option
  rebase -i: commit only once when rewriting picks
  rebase -i: do not die in do_pick
  rebase -i: teach do_pick the option --amend
  rebase -i: teach do_pick the option --file
  rebase -i: prepare for squash in terms of do_pick --amend
  rebase -i: implement squash in terms of do_pick
  rebase -i: explicitly distinguish replay commands and exec tasks
  rebase -i: parse to-do list command line options
  rebase -i: teach do_pick the option --reset-author
  rebase -i: teach do_pick the option --signoff
  rebase -i: enable options --signoff, --reset-author for pick, reword

 Documentation/git-commit.txt  |   8 +-
 builtin/commit.c              |  32 ++++-
 git-rebase--interactive.sh    | 288 ++++++++++++++++++++++++++++++++++--------
 git-rebase.sh                 |  12 +-
 t/lib-rebase.sh               |   8 +-
 t/t3404-rebase-interactive.sh | 234 ++++++++++++++++++++++++++++++++--
 t/t3406-rebase-message.sh     |  18 +++
 t/t3412-rebase-root.sh        |  16 +++
 t/t7503-pre-commit-hook.sh    |  65 ++++++++--
 t/t7504-commit-msg-hook.sh    |  85 ++++++++++---
 t/test-lib-functions.sh       |  23 +++-
 11 files changed, 680 insertions(+), 109 deletions(-)

-- 
2.0.1

[PATCH v2 01/23] rebase -i: allow replaying commits with empty log messages

[Fabian Ruch]

git-rebase--interactive handles empty log messages inconsistently
between enabled and disabled fast-forwards. By default, commits with
empty log messages are rebased successfully like in non-interactive
mode. In contrast, the `--no-ff` option aborts the replay of such
commits.

In line with not verifying rebased commits and behaving like
git-rebase for `pick` lines, use the `--allow-empty-message` option
to replay commits. Root commits are replayed by recreating them in
`do_pick` using git-commit and all other commits are replayed using
git-cherry-pick in `pick_one`. Apply the option, understood by both
git-commit and git-cherry-pick, at the respective sites.

In case of `reword` and `squash`, continue to abort the rebase if the
_resulting_ commit would have no commit message. The rationale behind
this default is that patches and their log messages should be
verified at least once. For unchanged commits this is assumed to have
happened according to the author's standards when she created the
commits for the first time. While the empty log message can always be
kept in place by editing and resuming the aborted rebase, a debatable
alternative could be to teach git-rebase--interactive the option
`--allow-empty-message` for disabling complaints about empty log
messages even in changed commits.

The `fixup` case is different again because it throws away the second
commit's log message and uses the first log message for the changed
commit. Do not abort the rebase if that message is empty either since
it is assumed to have been verified already.

The remaining to-do list command `edit` is handled just like `pick`
for this matter, because git-rebase--interactive replays the named
commit without changes before the rebase is interrupted and the user
can make her changes to the replayed commit.

Add tests. In particular, design the `squash`-specific test case such
that it involves interim commits and `fixup` steps. Interim commits
should not trigger failures themselves and `fixup` steps should not
let git-rebase--interactive forget that it is still dealing with a
`squash` result.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh    | 10 ++++++----
 t/t3404-rebase-interactive.sh | 38 ++++++++++++++++++++++++++++++++++++++
 t/t3412-rebase-root.sh        | 16 ++++++++++++++++
 3 files changed, 60 insertions(+), 4 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index b64dd28..3222bf6 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -249,7 +249,7 @@ pick_one () {
 
 	test -d "$rewritten" &&
 		pick_one_preserving_merges "$@" && return
-	output eval git cherry-pick \
+	output eval git cherry-pick --allow-empty-message \
 			${gpg_sign_opt:+$(git rev-parse --sq-quote "$gpg_sign_opt")} \
 			"$strategy_args" $empty_args $ff "$@"
 }
@@ -363,7 +363,7 @@ pick_one_preserving_merges () {
 			echo "$sha1 $(git rev-parse HEAD^0)" >> "$rewritten_list"
 			;;
 		*)
-			output eval git cherry-pick \
+			output eval git cherry-pick --allow-empty-message \
 				${gpg_sign_opt:+$(git rev-parse --sq-quote "$gpg_sign_opt")} \
 				"$strategy_args" "$@" ||
 				die_with_patch $sha1 "Could not pick $sha1"
@@ -549,7 +549,8 @@ do_next () {
 		squash|s|fixup|f)
 			# This is an intermediate commit; its message will only be
 			# used in case of trouble.  So use the long version:
-			do_with_author output git commit --amend --no-verify -F "$squash_msg" \
+			do_with_author output git commit --allow-empty-message \
+				--amend --no-verify -F "$squash_msg" \
 				${gpg_sign_opt:+"$gpg_sign_opt"} ||
 				die_failed_squash $sha1 "$rest"
 			;;
@@ -557,7 +558,8 @@ do_next () {
 			# This is the final command of this squash/fixup group
 			if test -f "$fixup_msg"
 			then
-				do_with_author git commit --amend --no-verify -F "$fixup_msg" \
+				do_with_author git commit --allow-empty-message \
+					--amend --no-verify -F "$fixup_msg" \
 					${gpg_sign_opt:+"$gpg_sign_opt"} ||
 					die_failed_squash $sha1 "$rest"
 			else
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index 8197ed2..9c71835 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -1039,4 +1039,42 @@ test_expect_success 'short SHA-1 collide' '
 	)
 '
 
+test_expect_success 'setup commits with empty commit log messages' '
+	git checkout -b empty-log-messages master &&
+	test_commit no-msg-commit-1 &&
+	git commit --amend --allow-empty-message -F - </dev/null &&
+	test_commit no-msg-commit-2 &&
+	git commit --amend --allow-empty-message -F - </dev/null &&
+	test_commit no-msg-commit-3 &&
+	git commit --amend --allow-empty-message -F - </dev/null
+'
+
+test_expect_success 'rebase commits with empty commit log messages' '
+	git checkout -b rebase-empty-log-messages empty-log-messages &&
+	set_fake_editor &&
+	test_expect_code 0 env FAKE_LINES="1" git rebase -i master &&
+	test_expect_code 0 env FAKE_LINES="1" git rebase -i --no-ff master
+'
+
+test_expect_success 'reword commits with empty commit log messages' '
+	git checkout -b reword-empty-log-messages empty-log-messages &&
+	test_when_finished reset_rebase &&
+	set_fake_editor &&
+	test_must_fail env FAKE_LINES="reword 1" git rebase -i master
+'
+
+test_expect_success 'squash commits with empty commit log messages' '
+	git checkout -b squash-empty-log-messages empty-log-messages &&
+	set_fake_editor &&
+	test_must_fail env FAKE_LINES="1 squash 2 fixup 3" git rebase -i master &&
+	git commit --allow-empty-message --amend &&
+	git rebase --continue
+'
+
+test_expect_success 'fixup commits with empty commit log messages' '
+	git checkout -b fixup-empty-log-messages empty-log-messages &&
+	set_fake_editor &&
+	env FAKE_LINES="1 fixup 2" git rebase -i master
+'
+
 test_done
diff --git a/t/t3412-rebase-root.sh b/t/t3412-rebase-root.sh
index 0b52105..7add7a1 100755
--- a/t/t3412-rebase-root.sh
+++ b/t/t3412-rebase-root.sh
@@ -278,4 +278,20 @@ test_expect_success 'rebase -i -p --root with conflict (second part)' '
 	test_cmp expect-conflict-p out
 '
 
+test_expect_success 'rebase --root root with empty log message' '
+	git checkout --orphan empty-log-messages-root master &&
+	test_commit no-msg-root-commit &&
+	git commit --amend --allow-empty-message -F - </dev/null &&
+	test_expect_code 0 git rebase --root &&
+	test_expect_code 0 git rebase --root --no-ff
+'
+
+test_expect_success 'rebase --root commits with empty log messages' '
+	git checkout -b empty-log-messages master &&
+	test_commit no-msg-commit &&
+	git commit --amend --allow-empty-message -F - </dev/null &&
+	test_expect_code 0 git rebase --root &&
+	test_expect_code 0 git rebase --root --no-ff
+'
+
 test_done
-- 
2.0.1

[PATCH v2 02/23] rebase -i: allow squashing empty commits without complaints

[Fabian Ruch]

The to-do list commands `squash` and `fixup` apply the changes
introduced by the named commit to the tree but instead of creating
a new commit on top of the current head it replaces the previous
commit with a new commit that records the updated tree. If the
result is an empty commit git-rebase stops with the error message

   You asked to amend the most recent commit, but doing so would make
   it empty. You can repeat your command with --allow-empty, or you can
   remove the commit entirely with "git reset HEAD^".

This message is not very helpful because neither does git-rebase
support an option `--allow-empty` nor does the messages say how to
resume the rebase. Firstly, change the error message to

   The squash result is empty and --keep-empty was not specified.

   You can remove the squash commit now with

     git reset HEAD^

   Once you are down, run

     git rebase --continue

If the user wishes to squash a sequence of commits into one
commit, f. i.

   pick A
   squash Revert "A"
   squash A'

, it does not matter for the end result that the first squash
result, or any sub-sequence in general, is going to be empty. The
squash message is not affected at all by which commits are created
and only the commit created by the last line in the sequence will
end up in the final history. Secondly, print the error message
only if the whole squash sequence produced an empty commit.

Lastly, since an empty squash commit is not a failure to rewrite
the history as planned, issue the message above as a mere warning
and interrupt the rebase with the return value zero. The
interruption should be considered as a notification with the
chance to undo it on the spot. Specifying the `--keep-empty`
option tells git-rebase to keep empty squash commits in the
rebased history without notification.

Add tests.

Reported-by: Peter Krefting <peter@softwolves.pp.se>
Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
Hi,

Peter Krefting is cc'd as the author of the bug report "Confusing
error message in rebase when commit becomes empty" discussed on the
mailing list in June. Phil Hord and Jeff King both participated in
the problem discussion which ended with two proposals by Jeff.

Jeff King writes:
>   1. Always keep such empty commits. A user who is surprised by them
>      being empty can then revisit them. Or drop them by doing another
>      rebase without --keep-empty.
> 
>   2. Notice ourselves that the end-result of the whole squash is an
>      empty commit, and stop to let the user deal with it.

This patch chooses the second alternative. Either way seems OK. The
crucial consensus of the discussion was to silently throw away empty
interim commits.

   Fabian

 git-rebase--interactive.sh    | 20 +++++++++++---
 t/t3404-rebase-interactive.sh | 62 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 79 insertions(+), 3 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 3222bf6..8820eac 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -549,7 +549,7 @@ do_next () {
 		squash|s|fixup|f)
 			# This is an intermediate commit; its message will only be
 			# used in case of trouble.  So use the long version:
-			do_with_author output git commit --allow-empty-message \
+			do_with_author output git commit --allow-empty-message --allow-empty \
 				--amend --no-verify -F "$squash_msg" \
 				${gpg_sign_opt:+"$gpg_sign_opt"} ||
 				die_failed_squash $sha1 "$rest"
@@ -558,18 +558,32 @@ do_next () {
 			# This is the final command of this squash/fixup group
 			if test -f "$fixup_msg"
 			then
-				do_with_author git commit --allow-empty-message \
+				do_with_author git commit --allow-empty-message --allow-empty \
 					--amend --no-verify -F "$fixup_msg" \
 					${gpg_sign_opt:+"$gpg_sign_opt"} ||
 					die_failed_squash $sha1 "$rest"
 			else
 				cp "$squash_msg" "$GIT_DIR"/SQUASH_MSG || exit
 				rm -f "$GIT_DIR"/MERGE_MSG
-				do_with_author git commit --amend --no-verify -F "$GIT_DIR"/SQUASH_MSG -e \
+				do_with_author git commit --allow-empty --amend --no-verify -F "$GIT_DIR"/SQUASH_MSG -e \
 					${gpg_sign_opt:+"$gpg_sign_opt"} ||
 					die_failed_squash $sha1 "$rest"
 			fi
 			rm -f "$squash_msg" "$fixup_msg"
+			if test -z "$keep_empty" && is_empty_commit HEAD
+			then
+				echo "$sha1" >"$state_dir"/stopped-sha
+				warn "The squash result is empty and --keep-empty was not specified."
+				warn
+				warn "You can remove the squash commit now with"
+				warn
+				warn "  git reset HEAD^"
+				warn
+				warn "Once you are down, run"
+				warn
+				warn "  git rebase --continue"
+				exit 0
+			fi
 			;;
 		esac
 		record_in_rewritten $sha1
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index 9c71835..a95cb2a 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -237,6 +237,68 @@ test_expect_success 'retain authorship' '
 	git show HEAD | grep "^Author: Twerp Snog"
 '
 
+test_expect_success 'setup squash/fixup reverted and fixed feature' '
+	git checkout -b reverted-feature master &&
+	test_commit feature &&
+	git revert feature &&
+	git checkout -b fixed-feature reverted-feature &&
+	test_commit featurev2
+'
+
+test_expect_success 'fixup fixed feature (empty interim commit)' '
+	git checkout -b fixup-fixed-feature fixed-feature &&
+	set_fake_editor &&
+	FAKE_LINES="1 fixup 2 fixup 3" git rebase -i master &&
+	git log --oneline master.. >actual &&
+	test_line_count = 1 actual &&
+	git diff --exit-code featurev2
+'
+
+test_expect_success 'squash fixed feature (empty interim commit)' '
+	git checkout -b squash-fixed-feature fixed-feature &&
+	set_fake_editor &&
+	FAKE_LINES="1 squash 2 squash 3" git rebase -i master &&
+	git log --oneline master.. >actual &&
+	test_line_count = 1 actual &&
+	git diff --exit-code featurev2
+'
+
+test_expect_success 'fixup reverted feature (empty final commit)' '
+	git checkout -b fixup-reverted-feature reverted-feature &&
+	set_fake_editor &&
+	FAKE_LINES="1 fixup 2" git rebase -i master &&
+	git reset HEAD^ &&
+	git rebase --continue &&
+	test_cmp_rev master HEAD
+'
+
+test_expect_success 'squash reverted feature (empty final commit)' '
+	git checkout -b squash-reverted-feature reverted-feature &&
+	set_fake_editor &&
+	FAKE_LINES="1 squash 2" git rebase -i master &&
+	git reset HEAD^ &&
+	git rebase --continue &&
+	test_cmp_rev master HEAD
+'
+
+test_expect_success 'fixup reverted feature (empty final commit with --keep-empty)' '
+	git checkout -b fixup-keep-reverted-feature reverted-feature &&
+	set_fake_editor &&
+	FAKE_LINES="1 fixup 2" git rebase -i --keep-empty master &&
+	git log --oneline master.. >actual &&
+	test_line_count = 1 actual &&
+	git diff --exit-code master
+'
+
+test_expect_success 'squash reverted feature (empty final commit with --keep-empty)' '
+	git checkout -b squash-keep-reverted-feature reverted-feature &&
+	set_fake_editor &&
+	FAKE_LINES="1 squash 2" git rebase -i --keep-empty master &&
+	git log --oneline master.. >actual &&
+	test_line_count = 1 actual &&
+	git diff --exit-code master
+'
+
 test_expect_success 'squash' '
 	git reset --hard twerp &&
 	echo B > file7 &&
-- 
2.0.1

Re: [PATCH v2 02/23] rebase -i: allow squashing empty commits without complaints

[Peter Krefting]

Fabian Ruch:

>>   2. Notice ourselves that the end-result of the whole squash is an
>>      empty commit, and stop to let the user deal with it.
>
> This patch chooses the second alternative. Either way seems OK. The 
> crucial consensus of the discussion was to silently throw away empty 
> interim commits.

Yes, the important part is that giving good advice is better than 
giving bad advice. Thank you for taking your time to fix this.

I haven't reviewed the changes themselves, but I am happy with the 
underlying idea.

-- 
\\// Peter - http://www.softwolves.pp.se/

Re: [PATCH v2 02/23] rebase -i: allow squashing empty commits without complaints

[Eric Sunshine]

On Wed, Aug 6, 2014 at 7:59 PM, Fabian Ruch <bafain@gmail.com> wrote:
> The to-do list commands `squash` and `fixup` apply the changes
> introduced by the named commit to the tree but instead of creating
> a new commit on top of the current head it replaces the previous
> commit with a new commit that records the updated tree. If the
> result is an empty commit git-rebase stops with the error message
>
>    You asked to amend the most recent commit, but doing so would make
>    it empty. You can repeat your command with --allow-empty, or you can
>    remove the commit entirely with "git reset HEAD^".
>
> This message is not very helpful because neither does git-rebase
> support an option `--allow-empty` nor does the messages say how to
> resume the rebase. Firstly, change the error message to
>
>    The squash result is empty and --keep-empty was not specified.
>
>    You can remove the squash commit now with
>
>      git reset HEAD^
>
>    Once you are down, run

I guess you meant: s/down/done

Same issue with the actually message in the code (below).

>      git rebase --continue
>
> If the user wishes to squash a sequence of commits into one
> commit, f. i.
>
>    pick A
>    squash Revert "A"
>    squash A'
>
> , it does not matter for the end result that the first squash
> result, or any sub-sequence in general, is going to be empty. The
> squash message is not affected at all by which commits are created
> and only the commit created by the last line in the sequence will
> end up in the final history. Secondly, print the error message
> only if the whole squash sequence produced an empty commit.
>
> Lastly, since an empty squash commit is not a failure to rewrite
> the history as planned, issue the message above as a mere warning
> and interrupt the rebase with the return value zero. The
> interruption should be considered as a notification with the
> chance to undo it on the spot. Specifying the `--keep-empty`
> option tells git-rebase to keep empty squash commits in the
> rebased history without notification.
>
> Add tests.
>
> Reported-by: Peter Krefting <peter@softwolves.pp.se>
> Signed-off-by: Fabian Ruch <bafain@gmail.com>
> ---
> Hi,
>
> Peter Krefting is cc'd as the author of the bug report "Confusing
> error message in rebase when commit becomes empty" discussed on the
> mailing list in June. Phil Hord and Jeff King both participated in
> the problem discussion which ended with two proposals by Jeff.
>
> Jeff King writes:
>>   1. Always keep such empty commits. A user who is surprised by them
>>      being empty can then revisit them. Or drop them by doing another
>>      rebase without --keep-empty.
>>
>>   2. Notice ourselves that the end-result of the whole squash is an
>>      empty commit, and stop to let the user deal with it.
>
> This patch chooses the second alternative. Either way seems OK. The
> crucial consensus of the discussion was to silently throw away empty
> interim commits.
>
>    Fabian
>
>  git-rebase--interactive.sh    | 20 +++++++++++---
>  t/t3404-rebase-interactive.sh | 62 +++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 79 insertions(+), 3 deletions(-)
>
> diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
> index 3222bf6..8820eac 100644
> --- a/git-rebase--interactive.sh
> +++ b/git-rebase--interactive.sh
> @@ -549,7 +549,7 @@ do_next () {
>                 squash|s|fixup|f)
>                         # This is an intermediate commit; its message will only be
>                         # used in case of trouble.  So use the long version:
> -                       do_with_author output git commit --allow-empty-message \
> +                       do_with_author output git commit --allow-empty-message --allow-empty \
>                                 --amend --no-verify -F "$squash_msg" \
>                                 ${gpg_sign_opt:+"$gpg_sign_opt"} ||
>                                 die_failed_squash $sha1 "$rest"
> @@ -558,18 +558,32 @@ do_next () {
>                         # This is the final command of this squash/fixup group
>                         if test -f "$fixup_msg"
>                         then
> -                               do_with_author git commit --allow-empty-message \
> +                               do_with_author git commit --allow-empty-message --allow-empty \
>                                         --amend --no-verify -F "$fixup_msg" \
>                                         ${gpg_sign_opt:+"$gpg_sign_opt"} ||
>                                         die_failed_squash $sha1 "$rest"
>                         else
>                                 cp "$squash_msg" "$GIT_DIR"/SQUASH_MSG || exit
>                                 rm -f "$GIT_DIR"/MERGE_MSG
> -                               do_with_author git commit --amend --no-verify -F "$GIT_DIR"/SQUASH_MSG -e \
> +                               do_with_author git commit --allow-empty --amend --no-verify -F "$GIT_DIR"/SQUASH_MSG -e \
>                                         ${gpg_sign_opt:+"$gpg_sign_opt"} ||
>                                         die_failed_squash $sha1 "$rest"
>                         fi
>                         rm -f "$squash_msg" "$fixup_msg"
> +                       if test -z "$keep_empty" && is_empty_commit HEAD
> +                       then
> +                               echo "$sha1" >"$state_dir"/stopped-sha
> +                               warn "The squash result is empty and --keep-empty was not specified."
> +                               warn
> +                               warn "You can remove the squash commit now with"
> +                               warn
> +                               warn "  git reset HEAD^"
> +                               warn
> +                               warn "Once you are down, run"

s/down/done/

> +                               warn
> +                               warn "  git rebase --continue"
> +                               exit 0
> +                       fi
>                         ;;
>                 esac
>                 record_in_rewritten $sha1
> diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
> index 9c71835..a95cb2a 100755
> --- a/t/t3404-rebase-interactive.sh
> +++ b/t/t3404-rebase-interactive.sh
> @@ -237,6 +237,68 @@ test_expect_success 'retain authorship' '
>         git show HEAD | grep "^Author: Twerp Snog"
>  '
>
> +test_expect_success 'setup squash/fixup reverted and fixed feature' '
> +       git checkout -b reverted-feature master &&
> +       test_commit feature &&
> +       git revert feature &&
> +       git checkout -b fixed-feature reverted-feature &&
> +       test_commit featurev2
> +'
> +
> +test_expect_success 'fixup fixed feature (empty interim commit)' '
> +       git checkout -b fixup-fixed-feature fixed-feature &&
> +       set_fake_editor &&
> +       FAKE_LINES="1 fixup 2 fixup 3" git rebase -i master &&
> +       git log --oneline master.. >actual &&
> +       test_line_count = 1 actual &&
> +       git diff --exit-code featurev2
> +'
> +
> +test_expect_success 'squash fixed feature (empty interim commit)' '
> +       git checkout -b squash-fixed-feature fixed-feature &&
> +       set_fake_editor &&
> +       FAKE_LINES="1 squash 2 squash 3" git rebase -i master &&
> +       git log --oneline master.. >actual &&
> +       test_line_count = 1 actual &&
> +       git diff --exit-code featurev2
> +'
> +
> +test_expect_success 'fixup reverted feature (empty final commit)' '
> +       git checkout -b fixup-reverted-feature reverted-feature &&
> +       set_fake_editor &&
> +       FAKE_LINES="1 fixup 2" git rebase -i master &&
> +       git reset HEAD^ &&
> +       git rebase --continue &&
> +       test_cmp_rev master HEAD
> +'
> +
> +test_expect_success 'squash reverted feature (empty final commit)' '
> +       git checkout -b squash-reverted-feature reverted-feature &&
> +       set_fake_editor &&
> +       FAKE_LINES="1 squash 2" git rebase -i master &&
> +       git reset HEAD^ &&
> +       git rebase --continue &&
> +       test_cmp_rev master HEAD
> +'
> +
> +test_expect_success 'fixup reverted feature (empty final commit with --keep-empty)' '
> +       git checkout -b fixup-keep-reverted-feature reverted-feature &&
> +       set_fake_editor &&
> +       FAKE_LINES="1 fixup 2" git rebase -i --keep-empty master &&
> +       git log --oneline master.. >actual &&
> +       test_line_count = 1 actual &&
> +       git diff --exit-code master
> +'
> +
> +test_expect_success 'squash reverted feature (empty final commit with --keep-empty)' '
> +       git checkout -b squash-keep-reverted-feature reverted-feature &&
> +       set_fake_editor &&
> +       FAKE_LINES="1 squash 2" git rebase -i --keep-empty master &&
> +       git log --oneline master.. >actual &&
> +       test_line_count = 1 actual &&
> +       git diff --exit-code master
> +'
> +
>  test_expect_success 'squash' '
>         git reset --hard twerp &&
>         echo B > file7 &&
> --
> 2.0.1
>
> --
> To unsubscribe from this list: send the line "unsubscribe git" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH v2 02/23] rebase -i: allow squashing empty commits without complaints

[Fabian Ruch]

Hi Eric,

Eric Sunshine writes:
> On Wed, Aug 6, 2014 at 7:59 PM, Fabian Ruch <bafain@gmail.com> wrote:
>> The to-do list commands `squash` and `fixup` apply the changes
>> introduced by the named commit to the tree but instead of creating
>> a new commit on top of the current head it replaces the previous
>> commit with a new commit that records the updated tree. If the
>> result is an empty commit git-rebase stops with the error message
>>
>>    You asked to amend the most recent commit, but doing so would make
>>    it empty. You can repeat your command with --allow-empty, or you can
>>    remove the commit entirely with "git reset HEAD^".
>>
>> This message is not very helpful because neither does git-rebase
>> support an option `--allow-empty` nor does the messages say how to
>> resume the rebase. Firstly, change the error message to
>>
>>    The squash result is empty and --keep-empty was not specified.
>>
>>    You can remove the squash commit now with
>>
>>      git reset HEAD^
>>
>>    Once you are down, run
> 
> I guess you meant: s/down/done
> 
> Same issue with the actually message in the code (below).

Fixed.

>>      git rebase --continue
>>
>> If the user wishes to squash a sequence of commits into one
>> commit, f. i.
>>
>>    pick A
>>    squash Revert "A"
>>    squash A'
>>
>> , it does not matter for the end result that the first squash
>> result, or any sub-sequence in general, is going to be empty. The
>> squash message is not affected at all by which commits are created
>> and only the commit created by the last line in the sequence will
>> end up in the final history. Secondly, print the error message
>> only if the whole squash sequence produced an empty commit.
>>
>> Lastly, since an empty squash commit is not a failure to rewrite
>> the history as planned, issue the message above as a mere warning
>> and interrupt the rebase with the return value zero. The
>> interruption should be considered as a notification with the
>> chance to undo it on the spot. Specifying the `--keep-empty`
>> option tells git-rebase to keep empty squash commits in the
>> rebased history without notification.
>>
>> Add tests.
>>
>> Reported-by: Peter Krefting <peter@softwolves.pp.se>
>> Signed-off-by: Fabian Ruch <bafain@gmail.com>
>> ---
>> Hi,
>>
>> Peter Krefting is cc'd as the author of the bug report "Confusing
>> error message in rebase when commit becomes empty" discussed on the
>> mailing list in June. Phil Hord and Jeff King both participated in
>> the problem discussion which ended with two proposals by Jeff.
>>
>> Jeff King writes:
>>>   1. Always keep such empty commits. A user who is surprised by them
>>>      being empty can then revisit them. Or drop them by doing another
>>>      rebase without --keep-empty.
>>>
>>>   2. Notice ourselves that the end-result of the whole squash is an
>>>      empty commit, and stop to let the user deal with it.
>>
>> This patch chooses the second alternative. Either way seems OK. The
>> crucial consensus of the discussion was to silently throw away empty
>> interim commits.
>>
>>    Fabian
>>
>>  git-rebase--interactive.sh    | 20 +++++++++++---
>>  t/t3404-rebase-interactive.sh | 62 +++++++++++++++++++++++++++++++++++++++++++
>>  2 files changed, 79 insertions(+), 3 deletions(-)
>>
>> diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
>> index 3222bf6..8820eac 100644
>> --- a/git-rebase--interactive.sh
>> +++ b/git-rebase--interactive.sh
>> @@ -549,7 +549,7 @@ do_next () {
>>                 squash|s|fixup|f)
>>                         # This is an intermediate commit; its message will only be
>>                         # used in case of trouble.  So use the long version:
>> -                       do_with_author output git commit --allow-empty-message \
>> +                       do_with_author output git commit --allow-empty-message --allow-empty \
>>                                 --amend --no-verify -F "$squash_msg" \
>>                                 ${gpg_sign_opt:+"$gpg_sign_opt"} ||
>>                                 die_failed_squash $sha1 "$rest"
>> @@ -558,18 +558,32 @@ do_next () {
>>                         # This is the final command of this squash/fixup group
>>                         if test -f "$fixup_msg"
>>                         then
>> -                               do_with_author git commit --allow-empty-message \
>> +                               do_with_author git commit --allow-empty-message --allow-empty \
>>                                         --amend --no-verify -F "$fixup_msg" \
>>                                         ${gpg_sign_opt:+"$gpg_sign_opt"} ||
>>                                         die_failed_squash $sha1 "$rest"
>>                         else
>>                                 cp "$squash_msg" "$GIT_DIR"/SQUASH_MSG || exit
>>                                 rm -f "$GIT_DIR"/MERGE_MSG
>> -                               do_with_author git commit --amend --no-verify -F "$GIT_DIR"/SQUASH_MSG -e \
>> +                               do_with_author git commit --allow-empty --amend --no-verify -F "$GIT_DIR"/SQUASH_MSG -e \
>>                                         ${gpg_sign_opt:+"$gpg_sign_opt"} ||
>>                                         die_failed_squash $sha1 "$rest"
>>                         fi
>>                         rm -f "$squash_msg" "$fixup_msg"
>> +                       if test -z "$keep_empty" && is_empty_commit HEAD
>> +                       then
>> +                               echo "$sha1" >"$state_dir"/stopped-sha
>> +                               warn "The squash result is empty and --keep-empty was not specified."
>> +                               warn
>> +                               warn "You can remove the squash commit now with"
>> +                               warn
>> +                               warn "  git reset HEAD^"
>> +                               warn
>> +                               warn "Once you are down, run"
> 
> s/down/done/

Thanks for the thorough reading.

   Fabian

Re: [PATCH v2 02/23] rebase -i: allow squashing empty commits without complaints

[Phil Hord]

Thanks for working on this.

On Wed, Aug 6, 2014 at 7:59 PM, Fabian Ruch <bafain@gmail.com> wrote:
> The to-do list commands `squash` and `fixup` apply the changes
> introduced by the named commit to the tree but instead of creating
> a new commit on top of the current head it replaces the previous
> commit with a new commit that records the updated tree. If the
> result is an empty commit git-rebase stops with the error message
>
>    You asked to amend the most recent commit, but doing so would make
>    it empty. You can repeat your command with --allow-empty, or you can
>    remove the commit entirely with "git reset HEAD^".
>
> This message is not very helpful because neither does git-rebase
> support an option `--allow-empty` nor does the messages say how to
> resume the rebase. Firstly, change the error message to
>
>    The squash result is empty and --keep-empty was not specified.
>
>    You can remove the squash commit now with
>
>      git reset HEAD^
>
>    Once you are down, run

s/down/done

>
>      git rebase --continue
>

I like the direction of this rewording, but it seems to hide the
instructions for the user who wants to keep the empty commit.

I'm not sure how to improve it.  Maybe this:

    The squash result is empty and --keep-empty was not specified.

    You may remove the squash commit now with

      git reset HEAD^

    or keep it by doing nothing extra.

    Continue the rebase with

      git rebase --continue

> If the user wishes to squash a sequence of commits into one
> commit, f. i.
>
>    pick A
>    squash Revert "A"
>    squash A'
>
> , it does not matter for the end result that the first squash
> result, or any sub-sequence in general, is going to be empty. The
> squash message is not affected at all by which commits are created
> and only the commit created by the last line in the sequence will
> end up in the final history. Secondly, print the error message
> only if the whole squash sequence produced an empty commit.
>
> Lastly, since an empty squash commit is not a failure to rewrite
> the history as planned, issue the message above as a mere warning
> and interrupt the rebase with the return value zero. The
> interruption should be considered as a notification with the
> chance to undo it on the spot. Specifying the `--keep-empty`
> option tells git-rebase to keep empty squash commits in the
> rebased history without notification.
>
> Add tests.
>
> Reported-by: Peter Krefting <peter@softwolves.pp.se>
> Signed-off-by: Fabian Ruch <bafain@gmail.com>
> ---
> Hi,
>
> Peter Krefting is cc'd as the author of the bug report "Confusing
> error message in rebase when commit becomes empty" discussed on the
> mailing list in June. Phil Hord and Jeff King both participated in
> the problem discussion which ended with two proposals by Jeff.
>
> Jeff King writes:
>>   1. Always keep such empty commits. A user who is surprised by them
>>      being empty can then revisit them. Or drop them by doing another
>>      rebase without --keep-empty.
>>
>>   2. Notice ourselves that the end-result of the whole squash is an
>>      empty commit, and stop to let the user deal with it.
>
> This patch chooses the second alternative. Either way seems OK. The
> crucial consensus of the discussion was to silently throw away empty
> interim commits.

This patch does _not_ silently throw away empty commits. I wonder if
such behavior could be triggered with something like --no-keep-empty.
Maybe that belongs in another patch.

>
>    Fabian
>
>  git-rebase--interactive.sh    | 20 +++++++++++---
>  t/t3404-rebase-interactive.sh | 62 +++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 79 insertions(+), 3 deletions(-)
>
> diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
> index 3222bf6..8820eac 100644
> --- a/git-rebase--interactive.sh
> +++ b/git-rebase--interactive.sh
> @@ -549,7 +549,7 @@ do_next () {
>                 squash|s|fixup|f)
>                         # This is an intermediate commit; its message will only be
>                         # used in case of trouble.  So use the long version:
> -                       do_with_author output git commit --allow-empty-message \
> +                       do_with_author output git commit --allow-empty-message --allow-empty \
>                                 --amend --no-verify -F "$squash_msg" \
>                                 ${gpg_sign_opt:+"$gpg_sign_opt"} ||
>                                 die_failed_squash $sha1 "$rest"
> @@ -558,18 +558,32 @@ do_next () {
>                         # This is the final command of this squash/fixup group
>                         if test -f "$fixup_msg"
>                         then
> -                               do_with_author git commit --allow-empty-message \
> +                               do_with_author git commit --allow-empty-message --allow-empty \
>                                         --amend --no-verify -F "$fixup_msg" \
>                                         ${gpg_sign_opt:+"$gpg_sign_opt"} ||
>                                         die_failed_squash $sha1 "$rest"
>                         else
>                                 cp "$squash_msg" "$GIT_DIR"/SQUASH_MSG || exit
>                                 rm -f "$GIT_DIR"/MERGE_MSG
> -                               do_with_author git commit --amend --no-verify -F "$GIT_DIR"/SQUASH_MSG -e \
> +                               do_with_author git commit --allow-empty --amend --no-verify -F "$GIT_DIR"/SQUASH_MSG -e \
>                                         ${gpg_sign_opt:+"$gpg_sign_opt"} ||
>                                         die_failed_squash $sha1 "$rest"
>                         fi
>                         rm -f "$squash_msg" "$fixup_msg"
> +                       if test -z "$keep_empty" && is_empty_commit HEAD
> +                       then
> +                               echo "$sha1" >"$state_dir"/stopped-sha
> +                               warn "The squash result is empty and --keep-empty was not specified."
> +                               warn
> +                               warn "You can remove the squash commit now with"
> +                               warn
> +                               warn "  git reset HEAD^"
> +                               warn
> +                               warn "Once you are down, run"

s/down/done

> +                               warn
> +                               warn "  git rebase --continue"
> +                               exit 0
> +                       fi
>                         ;;
>                 esac
>                 record_in_rewritten $sha1
> diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
> index 9c71835..a95cb2a 100755
> --- a/t/t3404-rebase-interactive.sh
> +++ b/t/t3404-rebase-interactive.sh
> @@ -237,6 +237,68 @@ test_expect_success 'retain authorship' '
>         git show HEAD | grep "^Author: Twerp Snog"
>  '
>
> +test_expect_success 'setup squash/fixup reverted and fixed feature' '
> +       git checkout -b reverted-feature master &&
> +       test_commit feature &&
> +       git revert feature &&
> +       git checkout -b fixed-feature reverted-feature &&
> +       test_commit featurev2
> +'
> +
> +test_expect_success 'fixup fixed feature (empty interim commit)' '
> +       git checkout -b fixup-fixed-feature fixed-feature &&
> +       set_fake_editor &&
> +       FAKE_LINES="1 fixup 2 fixup 3" git rebase -i master &&
> +       git log --oneline master.. >actual &&
> +       test_line_count = 1 actual &&
> +       git diff --exit-code featurev2
> +'
> +
> +test_expect_success 'squash fixed feature (empty interim commit)' '
> +       git checkout -b squash-fixed-feature fixed-feature &&
> +       set_fake_editor &&
> +       FAKE_LINES="1 squash 2 squash 3" git rebase -i master &&
> +       git log --oneline master.. >actual &&
> +       test_line_count = 1 actual &&
> +       git diff --exit-code featurev2
> +'
> +
> +test_expect_success 'fixup reverted feature (empty final commit)' '
> +       git checkout -b fixup-reverted-feature reverted-feature &&
> +       set_fake_editor &&
> +       FAKE_LINES="1 fixup 2" git rebase -i master &&
> +       git reset HEAD^ &&
> +       git rebase --continue &&
> +       test_cmp_rev master HEAD
> +'
> +
> +test_expect_success 'squash reverted feature (empty final commit)' '
> +       git checkout -b squash-reverted-feature reverted-feature &&
> +       set_fake_editor &&
> +       FAKE_LINES="1 squash 2" git rebase -i master &&
> +       git reset HEAD^ &&
> +       git rebase --continue &&
> +       test_cmp_rev master HEAD
> +'
> +
> +test_expect_success 'fixup reverted feature (empty final commit with --keep-empty)' '
> +       git checkout -b fixup-keep-reverted-feature reverted-feature &&
> +       set_fake_editor &&
> +       FAKE_LINES="1 fixup 2" git rebase -i --keep-empty master &&
> +       git log --oneline master.. >actual &&
> +       test_line_count = 1 actual &&
> +       git diff --exit-code master
> +'
> +
> +test_expect_success 'squash reverted feature (empty final commit with --keep-empty)' '
> +       git checkout -b squash-keep-reverted-feature reverted-feature &&
> +       set_fake_editor &&
> +       FAKE_LINES="1 squash 2" git rebase -i --keep-empty master &&
> +       git log --oneline master.. >actual &&
> +       test_line_count = 1 actual &&
> +       git diff --exit-code master
> +'
> +
>  test_expect_success 'squash' '
>         git reset --hard twerp &&
>         echo B > file7 &&
> --
> 2.0.1
>

[PATCH v2 03/23] rebase -i: allow rewording empty commits without complaints

[Fabian Ruch]

The to-do list command `reword` replays a commit like `pick` but lets
the user also edit the commit's log message. If `--keep-empty` is
passed as option to git-rebase--interactive, empty commits ought to
be replayed without complaints. However, if the users chooses to
reword an empty commit by changing the respective to-do list entry
from

    pick fa1afe1 Empty commit

to

    reword fa1afe1 Empty commit

, then git-rebase--interactive suddenly fails to replay the empty
commit. This is especially counterintuitive because `reword` is
thought of as a `pick` that alters the log message in some way but
nothing more and the unchanged to-do list entry would not fail.

Handle `reword` by cherry-picking the named commit and editing the
log message using

    git commit --allow-empty --amend

instead of

    git commit --amend.

Add test.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh    |  2 +-
 t/t3404-rebase-interactive.sh | 24 ++++++++++++++++++++++++
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 8820eac..89ef5e2 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -504,7 +504,7 @@ do_next () {
 
 		mark_action_done
 		do_pick $sha1 "$rest"
-		git commit --amend --no-post-rewrite ${gpg_sign_opt:+"$gpg_sign_opt"} || {
+		git commit --allow-empty --amend --no-post-rewrite ${gpg_sign_opt:+"$gpg_sign_opt"} || {
 			warn "Could not amend commit after successfully picking $sha1... $rest"
 			warn "This is most likely due to an empty commit message, or the pre-commit hook"
 			warn "failed. If the pre-commit hook failed, you may need to resolve the issue before"
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index a95cb2a..3e64280 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -75,6 +75,30 @@ test_expect_success 'rebase --keep-empty' '
 	test_line_count = 6 actual
 '
 
+test_expect_success 'rebase --keep-empty (reword)' '
+	git checkout -b reword-emptybranch emptybranch &&
+	set_fake_editor &&
+	FAKE_LINES="1 reword 2" git rebase --keep-empty -i HEAD~2 &&
+	git log --oneline >actual &&
+	test_line_count = 6 actual
+'
+
+test_expect_success 'rebase --keep-empty (fixup)' '
+	git checkout -b fixup-emptybranch emptybranch &&
+	set_fake_editor &&
+	FAKE_LINES="1 fixup 2" git rebase --keep-empty -i HEAD~2 &&
+	git log --oneline >actual &&
+	test_line_count = 5 actual
+'
+
+test_expect_success 'rebase --keep-empty (squash)' '
+	git checkout -b squash-emptybranch emptybranch &&
+	set_fake_editor &&
+	FAKE_LINES="1 squash 2" git rebase --keep-empty -i HEAD~2 &&
+	git log --oneline >actual &&
+	test_line_count = 5 actual
+'
+
 test_expect_success 'rebase -i with the exec command' '
 	git checkout master &&
 	(
-- 
2.0.1

[PATCH v2 04/23] rebase -i: hide interactive command messages in verbose mode

[Fabian Ruch]

git-rebase--interactive prints summary messages of the commits it
creates in the final history only if the `--verbose` option is
specified by the user and suppresses them otherwise. This behaviour
is implemented by wrapping git-commit calls in a shell function named
`output` which redirects stderr to stdout, captures stdout in a shell
variable and ignores its contents unless the command exits with an
error status.

The command lines used to implement the to-do list commands `reword`
and `squash` print diagnostic messages even in non-verbose mode. The
reason for this inconsistency is that both commands launch the log
message editor which usually requires a working terminal attached to
stdin. Temporarily redirect the editor output to a third file
descriptor in order to ship it around the capture stream. Wrap the
respective git-commit command lines in `output`.

fake_editor prints the to-do list before and after applying the
`FAKE_LINES` rewrite rules to it. Redirect this debug output to
stderr so that it does not interfere with the git-rebase status
output. Add test.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh    |  9 +++++----
 git-rebase.sh                 | 12 ++++++++++--
 t/lib-rebase.sh               |  8 ++++----
 t/t3404-rebase-interactive.sh | 18 ++++++------------
 t/t3406-rebase-message.sh     | 18 ++++++++++++++++++
 5 files changed, 43 insertions(+), 22 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 89ef5e2..5dfdf13 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -504,7 +504,7 @@ do_next () {
 
 		mark_action_done
 		do_pick $sha1 "$rest"
-		git commit --allow-empty --amend --no-post-rewrite ${gpg_sign_opt:+"$gpg_sign_opt"} || {
+		output git commit --allow-empty --amend --no-post-rewrite ${gpg_sign_opt:+"$gpg_sign_opt"} || {
 			warn "Could not amend commit after successfully picking $sha1... $rest"
 			warn "This is most likely due to an empty commit message, or the pre-commit hook"
 			warn "failed. If the pre-commit hook failed, you may need to resolve the issue before"
@@ -558,14 +558,14 @@ do_next () {
 			# This is the final command of this squash/fixup group
 			if test -f "$fixup_msg"
 			then
-				do_with_author git commit --allow-empty-message --allow-empty \
+				do_with_author output git commit --allow-empty-message --allow-empty \
 					--amend --no-verify -F "$fixup_msg" \
 					${gpg_sign_opt:+"$gpg_sign_opt"} ||
 					die_failed_squash $sha1 "$rest"
 			else
 				cp "$squash_msg" "$GIT_DIR"/SQUASH_MSG || exit
 				rm -f "$GIT_DIR"/MERGE_MSG
-				do_with_author git commit --allow-empty --amend --no-verify -F "$GIT_DIR"/SQUASH_MSG -e \
+				do_with_author output git commit --allow-empty --amend --no-verify -F "$GIT_DIR"/SQUASH_MSG -e \
 					${gpg_sign_opt:+"$gpg_sign_opt"} ||
 					die_failed_squash $sha1 "$rest"
 			fi
@@ -923,6 +923,8 @@ EOF
 	;;
 esac
 
+mkdir -p "$state_dir" || die "Could not create temporary $state_dir"
+
 git var GIT_COMMITTER_IDENT >/dev/null ||
 	die "You need to set your committer info first"
 
@@ -938,7 +940,6 @@ then
 fi
 
 orig_head=$(git rev-parse --verify HEAD) || die "No HEAD?"
-mkdir -p "$state_dir" || die "Could not create temporary $state_dir"
 
 : > "$state_dir"/interactive || die "Could not mark as interactive"
 write_basic_state
diff --git a/git-rebase.sh b/git-rebase.sh
index 55da9db..f90541e 100755
--- a/git-rebase.sh
+++ b/git-rebase.sh
@@ -131,9 +131,17 @@ write_basic_state () {
 output () {
 	case "$verbose" in
 	'')
-		output=$("$@" 2>&1 )
+		cat >"$state_dir"/editor.sh <<EOF
+#!/bin/sh
+$(git var GIT_EDITOR) "\$@" >&3
+EOF
+		chmod +x "$state_dir"/editor.sh
+		(
+			export GIT_EDITOR=\""$state_dir"/editor.sh\"
+			"$@" 3>&1 >"$state_dir"/output 2>&1
+		)
 		status=$?
-		test $status != 0 && printf "%s\n" "$output"
+		test $status != 0 && cat "$state_dir"/output
 		return $status
 		;;
 	*)
diff --git a/t/lib-rebase.sh b/t/lib-rebase.sh
index 6bd2522..0cd1193 100644
--- a/t/lib-rebase.sh
+++ b/t/lib-rebase.sh
@@ -41,8 +41,8 @@ set_fake_editor () {
 	test -z "$FAKE_LINES" && exit
 	grep -v '^#' < "$1" > "$1".tmp
 	rm -f "$1"
-	echo 'rebase -i script before editing:'
-	cat "$1".tmp
+	echo 'rebase -i script before editing:' >&2
+	cat "$1".tmp >&2
 	action=pick
 	for line in $FAKE_LINES; do
 		case $line in
@@ -59,8 +59,8 @@ set_fake_editor () {
 			action=pick;;
 		esac
 	done
-	echo 'rebase -i script after editing:'
-	cat "$1"
+	echo 'rebase -i script after editing:' >&2
+	cat "$1" >&2
 	EOF
 
 	test_set_editor "$(pwd)/fake-editor.sh"
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index 3e64280..c6578c3 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -873,9 +873,8 @@ test_expect_success 'running "git rebase -i --exec git show HEAD"' '
 	(
 		FAKE_LINES="1 exec_git_show_HEAD 2 exec_git_show_HEAD" &&
 		export FAKE_LINES &&
-		git rebase -i HEAD~2 >expect
+		git rebase -i HEAD~2 >expected
 	) &&
-	sed -e "1,9d" expect >expected &&
 	test_cmp expected actual
 '
 
@@ -887,9 +886,8 @@ test_expect_success 'running "git rebase --exec git show HEAD -i"' '
 	(
 		FAKE_LINES="1 exec_git_show_HEAD 2 exec_git_show_HEAD" &&
 		export FAKE_LINES &&
-		git rebase -i HEAD~2 >expect
+		git rebase -i HEAD~2 >expected
 	) &&
-	sed -e "1,9d" expect >expected &&
 	test_cmp expected actual
 '
 
@@ -901,9 +899,8 @@ test_expect_success 'running "git rebase -ix git show HEAD"' '
 	(
 		FAKE_LINES="1 exec_git_show_HEAD 2 exec_git_show_HEAD" &&
 		export FAKE_LINES &&
-		git rebase -i HEAD~2 >expect
+		git rebase -i HEAD~2 >expected
 	) &&
-	sed -e "1,9d" expect >expected &&
 	test_cmp expected actual
 '
 
@@ -915,9 +912,8 @@ test_expect_success 'rebase -ix with several <CMD>' '
 	(
 		FAKE_LINES="1 exec_git_show_HEAD;_pwd 2 exec_git_show_HEAD;_pwd" &&
 		export FAKE_LINES &&
-		git rebase -i HEAD~2 >expect
+		git rebase -i HEAD~2 >expected
 	) &&
-	sed -e "1,9d" expect >expected &&
 	test_cmp expected actual
 '
 
@@ -930,9 +926,8 @@ test_expect_success 'rebase -ix with several instances of --exec' '
 		FAKE_LINES="1 exec_git_show_HEAD exec_pwd 2
 				exec_git_show_HEAD exec_pwd" &&
 		export FAKE_LINES &&
-		git rebase -i HEAD~2 >expect
+		git rebase -i HEAD~2 >expected
 	) &&
-	sed -e "1,11d" expect >expected &&
 	test_cmp expected actual
 '
 
@@ -956,9 +951,8 @@ test_expect_success 'rebase -ix with --autosquash' '
 		git checkout -b autosquash_expected &&
 		FAKE_LINES="1 fixup 3 fixup 4 exec_git_show_HEAD 2 exec_git_show_HEAD" &&
 		export FAKE_LINES &&
-		git rebase -i HEAD~4 >expect
+		git rebase -i HEAD~4 >expected
 	) &&
-	sed -e "1,13d" expect >expected &&
 	test_cmp expected actual
 '
 
diff --git a/t/t3406-rebase-message.sh b/t/t3406-rebase-message.sh
index 0392e36..d7003a9 100755
--- a/t/t3406-rebase-message.sh
+++ b/t/t3406-rebase-message.sh
@@ -4,6 +4,8 @@ test_description='messages from rebase operation'
 
 . ./test-lib.sh
 
+. "$TEST_DIRECTORY"/lib-rebase.sh
+
 test_expect_success 'setup' '
 	test_commit O fileO &&
 	test_commit X fileX &&
@@ -84,4 +86,20 @@ test_expect_success 'rebase --onto outputs the invalid ref' '
 	test_i18ngrep "invalid-ref" err
 '
 
+test_expect_success 'commit summary is suppressed in non-verbose mode' '
+	git checkout --detach Y &&
+	cat >expected.out <<-EOF &&
+	Rebasing (1/5)\r
+	Rebasing (2/5)\r
+	Rebasing (3/5)\r
+	Rebasing (4/5)\r
+	Rebasing (5/5)\r
+	EOF
+	set_fake_editor &&
+	FAKE_LINES="reword 1 fixup 2 fixup 3 4 squash 5" \
+	git rebase -i --root >actual.out.tmp &&
+	sed -e "s/\r/\\\\r\n/g" <actual.out.tmp >actual.out &&
+	test_cmp expected.out actual.out
+'
+
 test_done
-- 
2.0.1

Re: [PATCH v2 04/23] rebase -i: hide interactive command messages in verbose mode

[Thomas Rast]

Fabian Ruch <bafain@gmail.com> writes:

> @@ -923,6 +923,8 @@ EOF
>  	;;
>  esac
>  
> +mkdir -p "$state_dir" || die "Could not create temporary $state_dir"
> +
>  git var GIT_COMMITTER_IDENT >/dev/null ||
>  	die "You need to set your committer info first"
>  
> @@ -938,7 +940,6 @@ then
>  fi
>  
>  orig_head=$(git rev-parse --verify HEAD) || die "No HEAD?"
> -mkdir -p "$state_dir" || die "Could not create temporary $state_dir"
>  
>  : > "$state_dir"/interactive || die "Could not mark as interactive"
>  write_basic_state

Why this change?  I can't figure out how it relates to the output
change.

> @@ -873,9 +873,8 @@ test_expect_success 'running "git rebase -i --exec git show HEAD"' '
>  	(
>  		FAKE_LINES="1 exec_git_show_HEAD 2 exec_git_show_HEAD" &&
>  		export FAKE_LINES &&
> -		git rebase -i HEAD~2 >expect
> +		git rebase -i HEAD~2 >expected
>  	) &&
> -	sed -e "1,9d" expect >expected &&
>  	test_cmp expected actual
>  '

Getting rid of these magic removals is a very nice change, thank you.

-- 
Thomas Rast
tr@thomasrast.ch

Re: [PATCH v2 04/23] rebase -i: hide interactive command messages in verbose mode

[Fabian Ruch]

Hi Thomas,

Thomas Rast writes:
> Fabian Ruch <bafain@gmail.com> writes:
>> @@ -923,6 +923,8 @@ EOF
>>  	;;
>>  esac
>>  
>> +mkdir -p "$state_dir" || die "Could not create temporary $state_dir"
>> +
>>  git var GIT_COMMITTER_IDENT >/dev/null ||
>>  	die "You need to set your committer info first"
>>  
>> @@ -938,7 +940,6 @@ then
>>  fi
>>  
>>  orig_head=$(git rev-parse --verify HEAD) || die "No HEAD?"
>> -mkdir -p "$state_dir" || die "Could not create temporary $state_dir"
>>  
>>  : > "$state_dir"/interactive || die "Could not mark as interactive"
>>  write_basic_state
> 
> Why this change?  I can't figure out how it relates to the output
> change.

Creating the state directory a few steps earlier into
'git_rebase__interactive' is necessary because the changed definition of
'output' needs it for 'editor.sh'. This change was triggered by a
failing test case that used the <branch> argument with git-rebase. The
'git checkout <branch>', which is executed if 'switch_to' is set to
<branch>, is wrapped into an 'output' line and 'output' failed because
it wasn't able to create 'editor.sh'.

The state directory (of git-rebase--interactive!) is now created
directly after the case expression that handles --continue, --skip and
--edit-todo. They all assume the existence of the state directory and
either jump into 'do_rest' or 'exit' immediately, that is creating the
directory earlier would make the options handling code somewhat
incorrect and would not change anything for the start sequence of
git-rebase--interactive.

The patch message now reads as follows (with the reference to 7725cb5 in
the second paragraph and the complete third paragraph added):

> rebase -i: hide interactive command messages in verbose mode
> 
> git-rebase--interactive prints summary messages of the commits it
> creates in the final history only if the `--verbose` option is
> specified by the user and suppresses them otherwise. This behaviour
> is implemented by wrapping git-commit calls in a shell function named
> `output` which redirects stderr to stdout, captures stdout in a shell
> variable and ignores its contents unless the command exits with an
> error status.
> 
> The command lines used to implement the to-do list commands `reword`
> and `squash` print diagnostic messages even in non-verbose mode. The
> reason for this inconsistency is that both commands launch the log
> message editor which usually requires a working terminal attached to
> stdin. Wrapping the `reword` and `squash` command lines in `output`
> would seemingly freeze the terminal (see commit 7725cb5, "rebase -i:
> fix reword when using a terminal editor"). Temporarily redirect the
> editor output to a third file descriptor in order to ship it around
> the capture stream. Wrap the remaining git-commit command lines in
> the new `output`.
> 
> In order to temporarily redirect the editor output, the new
> definition of `output` creates a script in the state directory to be
> used as `GIT_EDITOR`. Make sure the state directory exists before
> `output` is called for the first time.
> 
> fake_editor prints the to-do list before and after applying the
> `FAKE_LINES` rewrite rules to it. Redirect this debug output to
> stderr so that it does not interfere with the git-rebase status
> output. Add test.

   Fabian

Re: [PATCH v2 04/23] rebase -i: hide interactive command messages in verbose mode

[Thomas Rast]

Fabian Ruch <bafain@gmail.com> writes:

> Hi Thomas,
>
> Thomas Rast writes:
>> Fabian Ruch <bafain@gmail.com> writes:
>>> @@ -923,6 +923,8 @@ EOF
>>>  	;;
>>>  esac
>>>  
>>> +mkdir -p "$state_dir" || die "Could not create temporary $state_dir"
>>> +
>>>  git var GIT_COMMITTER_IDENT >/dev/null ||
>>>  	die "You need to set your committer info first"
>>>  
>>> @@ -938,7 +940,6 @@ then
>>>  fi
>>>  
>>>  orig_head=$(git rev-parse --verify HEAD) || die "No HEAD?"
>>> -mkdir -p "$state_dir" || die "Could not create temporary $state_dir"
>>>  
>>>  : > "$state_dir"/interactive || die "Could not mark as interactive"
>>>  write_basic_state
>> 
>> Why this change?  I can't figure out how it relates to the output
>> change.
>
> Creating the state directory a few steps earlier into
> 'git_rebase__interactive' is necessary because the changed definition of
> 'output' needs it for 'editor.sh'. This change was triggered by a
> failing test case that used the <branch> argument with git-rebase. The
> 'git checkout <branch>', which is executed if 'switch_to' is set to
> <branch>, is wrapped into an 'output' line and 'output' failed because
> it wasn't able to create 'editor.sh'.
[...]
>> In order to temporarily redirect the editor output, the new
>> definition of `output` creates a script in the state directory to be
>> used as `GIT_EDITOR`. Make sure the state directory exists before
>> `output` is called for the first time.

Ah, makes sense.  Thanks for the explanations!

-- 
Thomas Rast
tr@thomasrast.ch

[PATCH v2 05/23] rebase -i: failed reword prints redundant error message

[Fabian Ruch]

The to-do list command `reword` replays a commit like `pick` but lets
the user also edit the commit's log message. If the edited log
message is empty or is found ill-formatted by one of the commit
hooks, git-rebase--interactive prints three error messages to the
console.

    1. The git-commit output, which contains all the output from hook
       scripts.
    2. A rebase diagnosis saying at which task on the to-do list it
       got stuck.
    3. Generic presumptions about what could have triggered the
       error.

The third message contains redundant information and does not add any
enlightenment either, which makes the output unnecessarily longish
and different from the other command's output. For instance, this is
what the output looks like if the log message is empty (contains
duplicate Signed-off-by lines).

    (1.) Aborting commit due to empty commit message. (Duplicate Signed-off-by lines.)
    (2.) Could not amend commit after successfully picking fa1afe1... Some change
    (3.) This is most likely due to an empty commit message, or the pre-commit hook
         failed. If the pre-commit hook failed, you may need to resolve the issue before
         you are able to reword the commit.

Discard the third message.

It is true that a failed hook script might not output any diagnosis
but then the generic message is not of much help either. Since this
lack of information affects the built-in git commands for commit,
merge and cherry-pick first, the solution would be to keep track of
the failed hooks in their output so that the user knows which of her
hooks require improvement.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 5dfdf13..3ee13c2 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -506,9 +506,6 @@ do_next () {
 		do_pick $sha1 "$rest"
 		output git commit --allow-empty --amend --no-post-rewrite ${gpg_sign_opt:+"$gpg_sign_opt"} || {
 			warn "Could not amend commit after successfully picking $sha1... $rest"
-			warn "This is most likely due to an empty commit message, or the pre-commit hook"
-			warn "failed. If the pre-commit hook failed, you may need to resolve the issue before"
-			warn "you are able to reword the commit."
 			exit_with_patch $sha1 1
 		}
 		record_in_rewritten $sha1
-- 
2.0.1

[PATCH v2 06/23] commit: allow disabling pre-commit and commit-msg separately

[Fabian Ruch]

Introduce the git-commit command line options `--no-pre-commit` and
`--no-commit-msg` to disable the pre-commit and commit-msg hooks,
respectively. Make `--no-verify` a synonym for specifying both at the
same time.

This change is motivated by an internal usage of git-commit in
git-rebase--interactive to disable pre-commit while keeping
commit-msg enabled when rewording a commit.

Make `test_commit` forward unknown options to git-commit instead of
teaching it all possible options. In order to support leading double
dashes in `<message>`, stop interpreting `test_commit` arguments
following a `--` argument as options. This wasn't a problem before
because the first unknown option would be used as `<message>`.

Allow disabling tag creation to avoid name clashes when using
`test_commit` with the same arguments several times from the same
test suite. By default, `test_commit` tags successful commits using
git-tag for easy reference. The `--notag` option skips this step.

Add tests.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 Documentation/git-commit.txt |  8 ++++-
 builtin/commit.c             | 32 ++++++++++++++---
 t/t7503-pre-commit-hook.sh   | 65 ++++++++++++++++++++++++++++-----
 t/t7504-commit-msg-hook.sh   | 85 ++++++++++++++++++++++++++++++++++----------
 t/test-lib-functions.sh      | 23 ++++++++----
 5 files changed, 176 insertions(+), 37 deletions(-)

diff --git a/Documentation/git-commit.txt b/Documentation/git-commit.txt
index 0bbc8f5..28a2c5c 100644
--- a/Documentation/git-commit.txt
+++ b/Documentation/git-commit.txt
@@ -158,7 +158,7 @@ OPTIONS
 
 -n::
 --no-verify::
-	This option bypasses the pre-commit and commit-msg hooks.
+	A synonym for `--no-pre-commit --no-commit-msg`.
 	See also linkgit:githooks[5].
 
 --allow-empty::
@@ -238,6 +238,12 @@ You should understand the implications of rewriting history if you
 amend a commit that has already been published.  (See the "RECOVERING
 FROM UPSTREAM REBASE" section in linkgit:git-rebase[1].)
 
+--no-pre-commit::
+	This option bypasses the pre-commit hook.
+
+--no-commit-msg::
+	This option bypasses the commit-msg hook.
+
 --no-post-rewrite::
 	Bypass the post-rewrite hook.
 
diff --git a/builtin/commit.c b/builtin/commit.c
index 5ed6036..dfd354e 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -98,12 +98,27 @@ static char *edit_message, *use_message;
 static char *fixup_message, *squash_message;
 static int all, also, interactive, patch_interactive, only, amend, signoff;
 static int edit_flag = -1; /* unspecified */
-static int quiet, verbose, no_verify, allow_empty, dry_run, renew_authorship;
+static int quiet, verbose, allow_empty, dry_run, renew_authorship;
 static int no_post_rewrite, allow_empty_message;
 static char *untracked_files_arg, *force_date, *ignore_submodule_arg;
 static char *sign_commit;
 
 /*
+ * The verify variable is interpreted as a bitmap of enabled commit
+ * verification hooks according to the legend below.
+ *
+ * By default, the pre-commit and commit-msg hooks are enabled. This
+ * is represented by both the PRE_COMMIT and COMMIT_MSG bits being
+ * set.
+ *
+ * The bitmap is changed through the command line options
+ * --no-verify, --no-pre-commit and --no-commit-msg.
+ */
+#define PRE_COMMIT (1<<0)
+#define COMMIT_MSG (1<<1)
+static int verify = PRE_COMMIT | COMMIT_MSG;
+
+/*
  * The default commit message cleanup mode will remove the lines
  * beginning with # (shell comments) and leading and trailing
  * whitespaces (empty lines or containing only whitespaces)
@@ -661,7 +676,8 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
 	/* This checks and barfs if author is badly specified */
 	determine_author_info(author_ident);
 
-	if (!no_verify && run_commit_hook(use_editor, index_file, "pre-commit", NULL))
+	if (verify & PRE_COMMIT &&
+	    run_commit_hook(use_editor, index_file, "pre-commit", NULL))
 		return 0;
 
 	if (squash_message) {
@@ -962,7 +978,7 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
 		}
 	}
 
-	if (!no_verify &&
+	if (verify & COMMIT_MSG &&
 	    run_commit_hook(use_editor, index_file, "commit-msg", git_path(commit_editmsg), NULL)) {
 		return 0;
 	}
@@ -1590,7 +1606,9 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
 		OPT_BOOL(0, "interactive", &interactive, N_("interactively add files")),
 		OPT_BOOL('p', "patch", &patch_interactive, N_("interactively add changes")),
 		OPT_BOOL('o', "only", &only, N_("commit only specified files")),
-		OPT_BOOL('n', "no-verify", &no_verify, N_("bypass pre-commit hook")),
+		OPT_NEGBIT('n', "no-verify", &verify,
+			   N_("synonym for --no-pre-commit --no-commit-msg"),
+			   PRE_COMMIT | COMMIT_MSG),
 		OPT_BOOL(0, "dry-run", &dry_run, N_("show what would be committed")),
 		OPT_SET_INT(0, "short", &status_format, N_("show status concisely"),
 			    STATUS_FORMAT_SHORT),
@@ -1603,6 +1621,12 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
 		OPT_BOOL('z', "null", &s.null_termination,
 			 N_("terminate entries with NUL")),
 		OPT_BOOL(0, "amend", &amend, N_("amend previous commit")),
+		OPT_NEGBIT(0, "no-pre-commit", &verify,
+			   N_("bypass pre-commit hook"),
+			   PRE_COMMIT),
+		OPT_NEGBIT(0, "no-commit-msg", &verify,
+			   N_("bypass commit-msg hook"),
+			   COMMIT_MSG),
 		OPT_BOOL(0, "no-post-rewrite", &no_post_rewrite, N_("bypass post-rewrite hook")),
 		{ OPTION_STRING, 'u', "untracked-files", &untracked_files_arg, N_("mode"), N_("show untracked files, optional modes: all, normal, no. (Default: all)"), PARSE_OPT_OPTARG, NULL, (intptr_t)"all" },
 		/* end commit contents options */
diff --git a/t/t7503-pre-commit-hook.sh b/t/t7503-pre-commit-hook.sh
index 984889b..db5de1c 100755
--- a/t/t7503-pre-commit-hook.sh
+++ b/t/t7503-pre-commit-hook.sh
@@ -12,11 +12,11 @@ test_expect_success 'with no hook' '
 
 '
 
-test_expect_success '--no-verify with no hook' '
+test_expect_success '--no-pre-commit with no hook' '
 
 	echo "bar" > file &&
 	git add file &&
-	git commit --no-verify -m "bar"
+	git commit --no-pre-commit -m "bar"
 
 '
 
@@ -38,11 +38,11 @@ test_expect_success 'with succeeding hook' '
 
 '
 
-test_expect_success '--no-verify with succeeding hook' '
+test_expect_success '--no-pre-commit with succeeding hook' '
 
 	echo "even more" >> file &&
 	git add file &&
-	git commit --no-verify -m "even more"
+	git commit --no-pre-commit -m "even more"
 
 '
 
@@ -60,11 +60,11 @@ test_expect_success 'with failing hook' '
 
 '
 
-test_expect_success '--no-verify with failing hook' '
+test_expect_success '--no-pre-commit with failing hook' '
 
 	echo "stuff" >> file &&
 	git add file &&
-	git commit --no-verify -m "stuff"
+	git commit --no-pre-commit -m "stuff"
 
 '
 
@@ -77,15 +77,64 @@ test_expect_success POSIXPERM 'with non-executable hook' '
 
 '
 
-test_expect_success POSIXPERM '--no-verify with non-executable hook' '
+test_expect_success POSIXPERM '--no-pre-commit with non-executable hook' '
 
 	echo "more content" >> file &&
 	git add file &&
-	git commit --no-verify -m "more content"
+	git commit --no-pre-commit -m "more content"
 
 '
 chmod +x "$HOOK"
 
+test_hook_enabled () {
+	git checkout --detach master &&
+	output="running failing pre-commit hook with ${*:-(none)}..." &&
+	>actual.output &&
+	cat >"$HOOK" <<-EOF &&
+	#!/bin/sh
+	echo "$output" >>actual.output
+	exit 1
+	EOF
+	chmod +x "$HOOK" &&
+	echo "$output" >expected.output &&
+	test_must_fail test_commit $* file &&
+	test_cmp expected.output actual.output
+}
+
+test_hook_disabled () {
+	git checkout --detach master &&
+	output="running failing pre-commit hook with ${*:-(none)}..." &&
+	>actual.output &&
+	cat >"$HOOK" <<-EOF &&
+	#!/bin/sh
+	echo "$output" >>actual.output
+	exit 1
+	EOF
+	chmod +x "$HOOK" &&
+	test_commit --notag $* file &&
+	test_must_be_empty actual.output
+}
+
+test_expect_success 'command line options combinations' '
+	test_hook_enabled &&
+	test_hook_enabled --pre-commit &&
+	test_hook_enabled --no-pre-commit --pre-commit &&
+	test_hook_enabled --no-verify --pre-commit &&
+	test_hook_enabled --verify &&
+	test_hook_enabled --no-pre-commit --verify &&
+	test_hook_enabled --no-verify --verify &&
+	test_hook_enabled --verify --no-commit-msg &&
+	test_hook_enabled --verify --commit-msg &&
+	test_hook_disabled --no-pre-commit &&
+	test_hook_disabled --pre-commit --no-pre-commit &&
+	test_hook_disabled --pre-commit --no-verify &&
+	test_hook_disabled --no-verify &&
+	test_hook_disabled --verify --no-pre-commit &&
+	test_hook_disabled --verify --no-verify &&
+	test_hook_disabled --no-verify --no-commit-msg &&
+	test_hook_disabled --no-verify --commit-msg
+'
+
 # a hook that checks $GIT_PREFIX and succeeds inside the
 # success/ subdirectory only
 cat > "$HOOK" <<EOF
diff --git a/t/t7504-commit-msg-hook.sh b/t/t7504-commit-msg-hook.sh
index 1f53ea8..59642a3 100755
--- a/t/t7504-commit-msg-hook.sh
+++ b/t/t7504-commit-msg-hook.sh
@@ -34,20 +34,20 @@ test_expect_success 'with no hook (editor)' '
 
 '
 
-test_expect_success '--no-verify with no hook' '
+test_expect_success '--no-commit-msg with no hook' '
 
 	echo "bar" > file &&
 	git add file &&
-	git commit --no-verify -m "bar"
+	git commit --no-commit-msg -m "bar"
 
 '
 
-test_expect_success '--no-verify with no hook (editor)' '
+test_expect_success '--no-commit-msg with no hook (editor)' '
 
 	echo "more bar" > file &&
 	git add file &&
 	echo "more bar" > FAKE_MSG &&
-	GIT_EDITOR="\"\$FAKE_EDITOR\"" git commit --no-verify
+	GIT_EDITOR="\"\$FAKE_EDITOR\"" git commit --no-commit-msg
 
 '
 
@@ -78,20 +78,20 @@ test_expect_success 'with succeeding hook (editor)' '
 
 '
 
-test_expect_success '--no-verify with succeeding hook' '
+test_expect_success '--no-commit-msg with succeeding hook' '
 
 	echo "even more" >> file &&
 	git add file &&
-	git commit --no-verify -m "even more"
+	git commit --no-commit-msg -m "even more"
 
 '
 
-test_expect_success '--no-verify with succeeding hook (editor)' '
+test_expect_success '--no-commit-msg with succeeding hook (editor)' '
 
 	echo "even more more" >> file &&
 	git add file &&
 	echo "even more more" > FAKE_MSG &&
-	GIT_EDITOR="\"\$FAKE_EDITOR\"" git commit --no-verify
+	GIT_EDITOR="\"\$FAKE_EDITOR\"" git commit --no-commit-msg
 
 '
 
@@ -118,20 +118,20 @@ test_expect_success 'with failing hook (editor)' '
 
 '
 
-test_expect_success '--no-verify with failing hook' '
+test_expect_success '--no-commit-msg with failing hook' '
 
 	echo "stuff" >> file &&
 	git add file &&
-	git commit --no-verify -m "stuff"
+	git commit --no-commit-msg -m "stuff"
 
 '
 
-test_expect_success '--no-verify with failing hook (editor)' '
+test_expect_success '--no-commit-msg with failing hook (editor)' '
 
 	echo "more stuff" >> file &&
 	git add file &&
 	echo "more stuff" > FAKE_MSG &&
-	GIT_EDITOR="\"\$FAKE_EDITOR\"" git commit --no-verify
+	GIT_EDITOR="\"\$FAKE_EDITOR\"" git commit --no-commit-msg
 
 '
 
@@ -153,23 +153,72 @@ test_expect_success POSIXPERM 'with non-executable hook (editor)' '
 
 '
 
-test_expect_success POSIXPERM '--no-verify with non-executable hook' '
+test_expect_success POSIXPERM '--no-commit-msg with non-executable hook' '
 
 	echo "more content" >> file &&
 	git add file &&
-	git commit --no-verify -m "more content"
+	git commit --no-commit-msg -m "more content"
 
 '
 
-test_expect_success POSIXPERM '--no-verify with non-executable hook (editor)' '
+test_expect_success POSIXPERM '--no-commit-msg with non-executable hook (editor)' '
 
 	echo "even more content" >> file &&
 	git add file &&
 	echo "even more content" > FAKE_MSG &&
-	GIT_EDITOR="\"\$FAKE_EDITOR\"" git commit --no-verify
+	GIT_EDITOR="\"\$FAKE_EDITOR\"" git commit --no-commit-msg
 
 '
 
+test_hook_enabled () {
+	git checkout --detach master &&
+	output="running failing commit-msg hook with ${*:-(none)}..." &&
+	>actual.output &&
+	cat >"$HOOK" <<-EOF &&
+	#!/bin/sh
+	echo "$output" >>actual.output
+	exit 1
+	EOF
+	chmod +x "$HOOK" &&
+	echo "$output" >expected.output &&
+	test_must_fail test_commit $* file &&
+	test_cmp expected.output actual.output
+}
+
+test_hook_disabled () {
+	git checkout --detach master &&
+	output="running failing commit-msg hook with ${*:-(none)}..." &&
+	>actual.output &&
+	cat >"$HOOK" <<-EOF &&
+	#!/bin/sh
+	echo "$output" >>actual.output
+	exit 1
+	EOF
+	chmod +x "$HOOK" &&
+	test_commit --notag $* file &&
+	test_must_be_empty actual.output
+}
+
+test_expect_success 'command line options combinations' '
+	test_hook_enabled &&
+	test_hook_enabled --commit-msg &&
+	test_hook_enabled --no-commit-msg --commit-msg &&
+	test_hook_enabled --no-verify --commit-msg &&
+	test_hook_enabled --verify &&
+	test_hook_enabled --no-commit-msg --verify &&
+	test_hook_enabled --no-verify --verify &&
+	test_hook_enabled --verify --no-pre-commit &&
+	test_hook_enabled --verify --pre-commit &&
+	test_hook_disabled --no-commit-msg &&
+	test_hook_disabled --commit-msg --no-commit-msg &&
+	test_hook_disabled --commit-msg --no-verify &&
+	test_hook_disabled --no-verify &&
+	test_hook_disabled --verify --no-commit-msg &&
+	test_hook_disabled --verify --no-verify &&
+	test_hook_disabled --no-verify --no-pre-commit &&
+	test_hook_disabled --no-verify --pre-commit
+'
+
 # now a hook that edits the commit message
 cat > "$HOOK" <<'EOF'
 #!/bin/sh
@@ -205,7 +254,7 @@ test_expect_success "hook doesn't edit commit message" '
 
 	echo "plus" >> file &&
 	git add file &&
-	git commit --no-verify -m "plus" &&
+	git commit --no-commit-msg -m "plus" &&
 	commit_msg_is "plus"
 
 '
@@ -215,7 +264,7 @@ test_expect_success "hook doesn't edit commit message (editor)" '
 	echo "more plus" >> file &&
 	git add file &&
 	echo "more plus" > FAKE_MSG &&
-	GIT_EDITOR="\"\$FAKE_EDITOR\"" git commit --no-verify &&
+	GIT_EDITOR="\"\$FAKE_EDITOR\"" git commit --no-commit-msg &&
 	commit_msg_is "more plus"
 
 '
diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
index dafd6ad..a107073 100644
--- a/t/test-lib-functions.sh
+++ b/t/test-lib-functions.sh
@@ -154,20 +154,28 @@ test_pause () {
 
 test_commit () {
 	notick= &&
-	signoff= &&
+	notag= &&
+	commit_opts= &&
 	while test $# != 0
 	do
 		case "$1" in
 		--notick)
 			notick=yes
 			;;
-		--signoff)
-			signoff="$1"
+		--notag)
+			notag=yes
+			;;
+		--)
+			shift &&
+			break
+			;;
+		-*)
+			commit_opts="$commit_opts $1"
 			;;
 		*)
 			break
 			;;
-		esac
+		esac &&
 		shift
 	done &&
 	file=${2:-"$1.t"} &&
@@ -177,8 +185,11 @@ test_commit () {
 	then
 		test_tick
 	fi &&
-	git commit $signoff -m "$1" &&
-	git tag "${4:-$1}"
+	git commit $commit_opts -m "$1" &&
+	if test -z "$notag"
+	then
+		git tag "${4:-$1}"
+	fi
 }
 
 # Call test_merge with the arguments "<message> <commit>", where <commit>
-- 
2.0.1

[PATCH v2 07/23] rebase -i: squash skips commit-msg hook

[Fabian Ruch]

Using the to-do list command `squash` the user can specify two or
more commits and git-rebase creates one commit that introduces all
their changes combined. The authorship for the created commit is
taken from the first commit specified and the user can edit the log
message. There is a variant of `squash` available named `fixup` which
also takes the first log message without asking for user input.

While it is reasonable to not verify replayed changes twice or
rejecting some other author's changes in her name, it is insufficient
to not verify the user input used as log message in the case of
`squash`. Specify the git-commit option `--commit-msg` when
committing the squash result to execute the commit-msg hook and
verify the new log message. For the same reasons the pre-commit hook
is disabled in all replay modes, the commit-msg hook gets disabled in
`fixup` mode.

Add tests. In addition to the existing test checking that the
pre-commit hook is disabled when simply picking a commit, provide a
test checking that the commit-msg hook is disabled as well.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh    |  2 +-
 t/t3404-rebase-interactive.sh | 78 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 79 insertions(+), 1 deletion(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 3ee13c2..97386aa 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -562,7 +562,7 @@ do_next () {
 			else
 				cp "$squash_msg" "$GIT_DIR"/SQUASH_MSG || exit
 				rm -f "$GIT_DIR"/MERGE_MSG
-				do_with_author output git commit --allow-empty --amend --no-verify -F "$GIT_DIR"/SQUASH_MSG -e \
+				do_with_author output git commit --allow-empty --amend --no-pre-commit -F "$GIT_DIR"/SQUASH_MSG -e \
 					${gpg_sign_opt:+"$gpg_sign_opt"} ||
 					die_failed_squash $sha1 "$rest"
 			fi
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index c6578c3..bc2dda1 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -655,6 +655,84 @@ test_expect_success 'rebase a commit violating pre-commit' '
 
 '
 
+test_expect_success 'setup failing pre-commit' '
+	HOOKDIR="$(git rev-parse --git-dir)"/hooks &&
+	mkdir -p "$HOOKDIR" &&
+	PRE_COMMIT="$HOOKDIR"/pre-commit &&
+	cat >"$PRE_COMMIT" <<-EOF &&
+	#!/bin/sh
+	echo running failing pre-commit...
+	exit 1
+	EOF
+	chmod +x "$PRE_COMMIT" &&
+	git checkout -b violating-pre-commit master &&
+	test_must_fail test_commit pre-commit-violated-1 &&
+	test_commit --no-verify pre-commit-violated-1 &&
+	test_must_fail test_commit pre-commit-violated-2 &&
+	test_commit --no-verify pre-commit-violated-2
+'
+
+test_expect_success 'squash a commit violating pre-commit' '
+	git checkout -b squash-violating-pre-commit violating-pre-commit &&
+	test_when_finished reset_rebase &&
+	set_fake_editor &&
+	env FAKE_LINES="1 squash 2" git rebase -i master
+'
+
+test_expect_success 'fixup a commit violating pre-commit' '
+	git checkout -b fixup-violating-pre-commit violating-pre-commit &&
+	test_when_finished reset_rebase &&
+	set_fake_editor &&
+	env FAKE_LINES="1 fixup 2" git rebase -i master
+'
+
+test_expect_success 'clean up failing pre-commit' '
+	rm "$PRE_COMMIT"
+'
+
+test_expect_success 'setup failing commit-msg' '
+	HOOKDIR="$(git rev-parse --git-dir)"/hooks &&
+	mkdir -p "$HOOKDIR" &&
+	COMMIT_MSG="$HOOKDIR"/commit-msg &&
+	cat >"$COMMIT_MSG" <<-EOF &&
+	#!/bin/sh
+	echo running failing commit-msg...
+	exit 1
+	EOF
+	chmod +x "$COMMIT_MSG" &&
+	git checkout -b violating-commit-msg master &&
+	test_must_fail test_commit commit-msg-violated-1 &&
+	test_commit --no-verify commit-msg-violated-1 &&
+	test_must_fail test_commit commit-msg-violated-2 &&
+	test_commit --no-verify commit-msg-violated-2 &&
+	test_must_fail test_commit commit-msg-violated-3 &&
+	test_commit --no-verify commit-msg-violated-3
+'
+
+test_expect_success 'rebase a commit violating commit-msg' '
+	git checkout -b rebase-violating-commit-msg violating-commit-msg &&
+	set_fake_editor &&
+	FAKE_LINES="1" git rebase -i master
+'
+
+test_expect_success 'squash a commit violating commit-msg' '
+	git checkout -b squash-violating-commit-msg violating-commit-msg &&
+	set_fake_editor &&
+	test_must_fail env FAKE_LINES="1 squash 2 fixup 3" git rebase -i master &&
+	git commit --no-verify --amend &&
+	git rebase --continue
+'
+
+test_expect_success 'fixup a commit violating commit-msg' '
+	git checkout -b fixup-violating-commit-msg violating-commit-msg &&
+	set_fake_editor &&
+	env FAKE_LINES="1 fixup 2" git rebase -i master
+'
+
+test_expect_success 'clean up failing commit-msg' '
+	rm "$COMMIT_MSG"
+'
+
 test_expect_success 'rebase with a file named HEAD in worktree' '
 
 	rm -fr .git/hooks &&
-- 
2.0.1

[PATCH v2 08/23] rebase -i: reword executes pre-commit hook on interim commit

[Fabian Ruch]

The to-do list command `reword` replays a commit like `pick` but lets
the user also edit the commit's log message. This happens in two
steps. Firstly, the named commit is cherry-picked. Secondly, the
commit created in the first step is amended using an unchanged index
to edit the log message. The pre-commit hook is meant to verify the
changes introduced by a commit (for instance, catching inserted
trailing white space). Since the committed tree is not changed
between the two steps and we do not verify rebased patches, do not
execute the pre-commit hook in the second step.

Specify the git-commit option `--no-pre-commit` to disable the
pre-commit hook when editing the log message. The commit-msg hook
will still be executed to verify the edited commit log message. As
before, if the hook finds the new log message ill-formatted, the
rebase will be interrupted with the unchanged commit replayed and the
new log message in `$GIT_DIR/COMMIT_EDITMSG`.

Add tests.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh    |  2 +-
 t/t3404-rebase-interactive.sh | 14 ++++++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 97386aa..edc323d 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -504,7 +504,7 @@ do_next () {
 
 		mark_action_done
 		do_pick $sha1 "$rest"
-		output git commit --allow-empty --amend --no-post-rewrite ${gpg_sign_opt:+"$gpg_sign_opt"} || {
+		output git commit --allow-empty --amend --no-post-rewrite --no-pre-commit ${gpg_sign_opt:+"$gpg_sign_opt"} || {
 			warn "Could not amend commit after successfully picking $sha1... $rest"
 			exit_with_patch $sha1 1
 		}
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index bc2dda1..3dac022 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -672,6 +672,13 @@ test_expect_success 'setup failing pre-commit' '
 	test_commit --no-verify pre-commit-violated-2
 '
 
+test_expect_success 'reword a commit violating pre-commit' '
+	git checkout -b reword-violating-pre-commit violating-pre-commit &&
+	test_when_finished reset_rebase &&
+	set_fake_editor &&
+	env FAKE_LINES="reword 1" git rebase -i master
+'
+
 test_expect_success 'squash a commit violating pre-commit' '
 	git checkout -b squash-violating-pre-commit violating-pre-commit &&
 	test_when_finished reset_rebase &&
@@ -715,6 +722,13 @@ test_expect_success 'rebase a commit violating commit-msg' '
 	FAKE_LINES="1" git rebase -i master
 '
 
+test_expect_success 'reword a commit violating commit-msg' '
+	git checkout -b reword-violating-commit-msg violating-commit-msg &&
+	test_when_finished reset_rebase &&
+	set_fake_editor &&
+	test_must_fail env FAKE_LINES="reword 1" git rebase -i master
+'
+
 test_expect_success 'squash a commit violating commit-msg' '
 	git checkout -b squash-violating-commit-msg violating-commit-msg &&
 	set_fake_editor &&
-- 
2.0.1

Re: [PATCH v2 08/23] rebase -i: reword executes pre-commit hook on interim commit

[Thomas Rast]

Fabian Ruch <bafain@gmail.com> writes:

> Subject: Re: [PATCH v2 08/23] rebase -i: reword executes pre-commit hook on interim commit

I think the change makes sense, but can you reword the subjects that it
describes the state after the commit (i.e. what you are doing), instead
of before the commit?

-- 
Thomas Rast
tr@thomasrast.ch

Re: [PATCH v2 08/23] rebase -i: reword executes pre-commit hook on interim commit

[Fabian Ruch]

Hi Thomas,

Thomas Rast writes:
> Fabian Ruch <bafain@gmail.com> writes:
>> Subject: Re: [PATCH v2 08/23] rebase -i: reword executes pre-commit hook on interim commit
> 
> I think the change makes sense, but can you reword the subjects that it
> describes the state after the commit (i.e. what you are doing), instead
> of before the commit?

The log message subject now reads as follows:

> rebase -i: do not verify reworded patches using pre-commit

   Fabian

Re: [PATCH v2 08/23] rebase -i: reword executes pre-commit hook on interim commit

[Thomas Rast]

Fabian Ruch <bafain@gmail.com> writes:

> Hi Thomas,
>
> Thomas Rast writes:
>> Fabian Ruch <bafain@gmail.com> writes:
>>> Subject: Re: [PATCH v2 08/23] rebase -i: reword executes pre-commit
>>> hook on interim commit
>> 
>> I think the change makes sense, but can you reword the subjects that it
>> describes the state after the commit (i.e. what you are doing), instead
>> of before the commit?
>
> The log message subject now reads as follows:
>
>> rebase -i: do not verify reworded patches using pre-commit

Excellent wording, thanks!

-- 
Thomas Rast
tr@thomasrast.ch

[PATCH v2 09/23] rebase -i: teach do_pick the option --edit

[Fabian Ruch]

`do_pick` is the git-cherry-pick wrapper in git-rebase--interactive
that is used to implement the to-do list command `pick`. To cater for
the different pick behaviours (like `reword`), `do_pick` accepts
several options not only from the git-cherry-pick but also the
git-commit interface. Add the common option `--edit` to let the user
edit the log message of the named commit.

Loop over `$@` to parse the `do_pick` arguments. Assign the local
variable `edit` if one of the options is `--edit` so that the
remainder of `do_pick` can easily check whether the client code asked
to edit the commit message. If one of the options is unknown, mention
it on the console and `die`. Break the loop on the first non-option
and do some sanity checking to ensure that there exactly two
non-options, which are interpreted by the remainder as `<commit>` and
`<title>` like before.

`do_pick` ought to act as a wrapper around `cherry-pick`.
Unfortunately, it cannot just forward `--edit` to the `cherry-pick`
command line. The assembled command line is executed within a command
substitution for controlling the verbosity of `rebase--interactive`.
Passing `--edit` would either hang the terminal or clutter the
substituted command output with control sequences. Execute the
`reword` code from `do_next` instead if the option `--edit` is
specified.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 43 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index edc323d..aed2f93 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -461,7 +461,42 @@ record_in_rewritten() {
 	esac
 }
 
+# Apply the changes introduced by the given commit to the current head.
+#
+# do_pick [--edit] <commit> <title>
+#
+# Wrapper around git-cherry-pick.
+#
+# -e, --edit
+#     After picking <commit>, open an editor and let the user edit the
+#     commit message. The editor contents becomes the commit message of
+#     the new head. This creates a fresh commit.
+#
+# <commit>
+#     The commit to cherry-pick.
+#
+# <title>
+#     The commit message title of <commit>. Used for information
+#     purposes only.
 do_pick () {
+	edit=
+	while test $# -gt 0
+	do
+		case "$1" in
+		-e|--edit)
+			edit=y
+			;;
+		-*)
+			die "do_pick: unrecognized option -- $1"
+			;;
+		*)
+			break
+			;;
+		esac
+		shift
+	done
+	test $# -ne 2 && die "do_pick: wrong number of arguments"
+
 	if test "$(git rev-parse HEAD)" = "$squash_onto"
 	then
 		# Set the correct commit message and author info on the
@@ -483,6 +518,14 @@ do_pick () {
 		pick_one $1 ||
 			die_with_patch $1 "Could not apply $1... $2"
 	fi
+
+	if test -n "$edit"
+	then
+		output git commit --allow-empty --amend --no-post-rewrite --no-pre-commit ${gpg_sign_opt:+"$gpg_sign_opt"} || {
+			warn "Could not amend commit after successfully picking $1... $2"
+			exit_with_patch $1 1
+		}
+	fi
 }
 
 do_next () {
-- 
2.0.1

[PATCH v2 10/23] rebase -i: implement reword in terms of do_pick

[Fabian Ruch]

The to-do list command `reword` replays a commit like `pick` but lets
the user also edit the commit's log message. If one thinks of `pick`
entries as scheduled `cherry-pick` command lines, then `reword`
becomes an alias for the command line `cherry-pick --edit`. The
porcelain `rebase--interactive` defines a function `do_pick` for
processing the `pick` entries on to-do lists. Reimplement `reword` in
terms of `do_pick --edit`.

If the user picks a commit using the to-do list line

    reword fa1afe1 Some change

execute the command `do_pick --edit fa1afe1 "Some change"` which
carries out exactly the same steps as the case arm for `reword` in
`do_next` so far.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index aed2f93..8e1730c 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -546,11 +546,7 @@ do_next () {
 		comment_for_reflog reword
 
 		mark_action_done
-		do_pick $sha1 "$rest"
-		output git commit --allow-empty --amend --no-post-rewrite --no-pre-commit ${gpg_sign_opt:+"$gpg_sign_opt"} || {
-			warn "Could not amend commit after successfully picking $sha1... $rest"
-			exit_with_patch $sha1 1
-		}
+		do_pick --edit $sha1 "$rest"
 		record_in_rewritten $sha1
 		;;
 	edit|e)
-- 
2.0.1

[PATCH v2 11/23] rebase -i: log the replay of root commits

[Fabian Ruch]

The command line used to recreate root commits specifies the option
`-q` which suppresses the commit summary message. However,
git-rebase--interactive tends to tell the user about the commits it
creates in the final history, if she wishes (cf. command line option
`--verbose`). The code parts handling non-root commits and squash
commits all output commit summary messages. Do not make the replay of
root commits an exception. Remove the option to make the report of
the rebased history complete. Do not forget to wrap the git-commit
command line in `output` so that the summary is shown if git-rebase
is called with the `--verbose` option but suppressed otherwise.

It is OK that the commit summary is still suppressed when git-commit
is used to initialize the authorship of the sentinel commit because
this additional commit is an implementation detail hidden from the
final history. The removed `-q` option was probably introduced as a
copy-and-paste error stemming from that part of the root commit
handling code.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 8e1730c..91ef0f7 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -510,8 +510,8 @@ do_pick () {
 		git commit --allow-empty --allow-empty-message --amend \
 			   --no-post-rewrite -n -q -C $1 &&
 			pick_one -n $1 &&
-			git commit --allow-empty --allow-empty-message \
-				   --amend --no-post-rewrite -n -q -C $1 \
+			output git commit --allow-empty --allow-empty-message \
+				   --amend --no-post-rewrite -n -C $1 \
 				   ${gpg_sign_opt:+"$gpg_sign_opt"} ||
 			die_with_patch $1 "Could not apply $1... $2"
 	else
-- 
2.0.1

[PATCH v2 12/23] rebase -i: root commits are replayed with an unnecessary option

[Fabian Ruch]

The command line used to recreate root commits uses `-C` to suppress
the log message editor. This is unnecessarily confusing, though,
because that suppression is a secondary effect of the option. The
main purpose of `-C` is to pull the metadata from another commit, but
here we know that this is a noop, since we are amending a commit just
created from the same data.

At the time `-C` was introduced, git-commit did not yet have a
documented `--no-edit`, and this was a reasonable way to get the
desired behavior. Switch it to use `--no-edit` to make the intended
effect more obvious.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 91ef0f7..71571c8 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -511,7 +511,7 @@ do_pick () {
 			   --no-post-rewrite -n -q -C $1 &&
 			pick_one -n $1 &&
 			output git commit --allow-empty --allow-empty-message \
-				   --amend --no-post-rewrite -n -C $1 \
+				   --amend --no-post-rewrite -n --no-edit \
 				   ${gpg_sign_opt:+"$gpg_sign_opt"} ||
 			die_with_patch $1 "Could not apply $1... $2"
 	else
-- 
2.0.1

[PATCH v2 13/23] rebase -i: commit only once when rewriting picks

[Fabian Ruch]

The options passed to `do_pick` determine whether the picked commit
will be rewritten or not. If the commit gets rewritten, because the
user requested to edit the commit message for instance, let
`pick_one` merely apply the changes introduced by the commit and do
not commit the resulting tree yet. If the commit is replayed as is,
leave it to `pick_one` to recreate the commit (possibly by
fast-forwarding the head). This makes it easier to combine git-commit
options like `--edit` and `--amend` in `do_pick` because
git-cherry-pick does not support `--amend`.

In the case of `--edit`, do not `exit_with_patch` but assign
`rewrite` to pick the changes with `-n`. If the pick conflicts, no
commit is created which we would have to amend when continuing the
rebase. To complete the pick after the conflicts are resolved the
user just resumes with `git rebase --continue`.

git-commit lets the user edit the commit log message by default. We
do not want that for the rewriting git-commit command line because
the default behaviour of git-rebase is exactly the opposite. Pass
`--no-edit` when rewriting a picked commit. An explicit `--edit`
passed to `do_pick` (for instance, when reword is executed) enables
the editor launch again. Similarly, pass `--allow-empty-message`
unless the log message is edited.

If `rebase--interactive` is used to rebase a complete branch onto
some head, `rebase` creates a sentinel commit that requires special
treatment by `do_pick`. Do not finalize the pick here either because
its commit message can be altered as for any other pick. Since the
orphaned root commit gets a temporary parent, it is always rewritten.
Safely use the rewrite infrastructure of `do_pick` to create the
final commit.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 35 ++++++++++++++++++++++-------------
 1 file changed, 22 insertions(+), 13 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 71571c8..b8c734e 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -63,7 +63,8 @@ msgnum="$state_dir"/msgnum
 author_script="$state_dir"/author-script
 
 # When an "edit" rebase command is being processed, the SHA1 of the
-# commit to be edited is recorded in this file.  When "git rebase
+# commit to be edited is recorded in this file.  The same happens when
+# rewriting a commit fails, for instance "reword".  When "git rebase
 # --continue" is executed, if there are any staged changes then they
 # will be amended to the HEAD commit, but only provided the HEAD
 # commit is still the commit to be edited.  When any other rebase
@@ -479,12 +480,17 @@ record_in_rewritten() {
 #     The commit message title of <commit>. Used for information
 #     purposes only.
 do_pick () {
-	edit=
+	allow_empty_message=y
+	rewrite=
+	rewrite_amend=
+	rewrite_edit=
 	while test $# -gt 0
 	do
 		case "$1" in
 		-e|--edit)
-			edit=y
+			rewrite=y
+			rewrite_edit=y
+			allow_empty_message=
 			;;
 		-*)
 			die "do_pick: unrecognized option -- $1"
@@ -499,6 +505,10 @@ do_pick () {
 
 	if test "$(git rev-parse HEAD)" = "$squash_onto"
 	then
+		rewrite=y
+		rewrite_amend=y
+		git rev-parse --verify HEAD >"$amend"
+
 		# Set the correct commit message and author info on the
 		# sentinel root before cherry-picking the original changes
 		# without committing (-n).  Finally, update the sentinel again
@@ -509,22 +519,21 @@ do_pick () {
 		# rebase --continue.
 		git commit --allow-empty --allow-empty-message --amend \
 			   --no-post-rewrite -n -q -C $1 &&
-			pick_one -n $1 &&
-			output git commit --allow-empty --allow-empty-message \
-				   --amend --no-post-rewrite -n --no-edit \
-				   ${gpg_sign_opt:+"$gpg_sign_opt"} ||
+			pick_one -n $1 ||
 			die_with_patch $1 "Could not apply $1... $2"
 	else
-		pick_one $1 ||
+		pick_one ${rewrite:+-n} $1 ||
 			die_with_patch $1 "Could not apply $1... $2"
 	fi
 
-	if test -n "$edit"
+	if test -n "$rewrite"
 	then
-		output git commit --allow-empty --amend --no-post-rewrite --no-pre-commit ${gpg_sign_opt:+"$gpg_sign_opt"} || {
-			warn "Could not amend commit after successfully picking $1... $2"
-			exit_with_patch $1 1
-		}
+		output git commit --allow-empty --no-post-rewrite -n --no-edit \
+			   ${allow_empty_message:+--allow-empty-message} \
+			   ${rewrite_amend:+--amend} \
+			   ${rewrite_edit:+--edit --commit-msg} \
+			   ${gpg_sign_opt:+"$gpg_sign_opt"} ||
+			die_with_patch $1 "Could not rewrite commit after successfully picking $1... $2"
 	fi
 }
 
-- 
2.0.1

[PATCH v2 14/23] rebase -i: do not die in do_pick

[Fabian Ruch]

Since `do_pick` might be executed in a sub-shell (a modified author
environment for instance), calling `die` in `do_pick` has no effect
but exiting the sub-shell with a failure exit status. The
git-rebase--interactive script is not terminated. Moreover, if
`do_pick` is called while a squash or fixup is in effect,
`die_with_patch` will discard `$squash_msg` as commit message.
Lastly, after a `die` in `do_pick` `do_next` has no chance to
reschedule tasks that failed before changes could be applied.

Indicate an error in `do_pick` using return statements and properly
kill the script at the call sites. Although possible in principle,
the issued error messages are no more indicating whether `do_pick`
failed while applying or while committing the changes. This reduces
code complexity at the call site and does not matter from a user's
point of view because a glance at the index reveals whether there are
conflicts or not and in-depth troubleshooting is still possible using
the `--verbose` option.

Remove the commit message title argument from `do_pick`'s interface,
which has become unused.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 34 +++++++++++++++++++---------------
 1 file changed, 19 insertions(+), 15 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index b8c734e..d812bad 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -464,7 +464,7 @@ record_in_rewritten() {
 
 # Apply the changes introduced by the given commit to the current head.
 #
-# do_pick [--edit] <commit> <title>
+# do_pick [--edit] <commit>
 #
 # Wrapper around git-cherry-pick.
 #
@@ -476,9 +476,11 @@ record_in_rewritten() {
 # <commit>
 #     The commit to cherry-pick.
 #
-# <title>
-#     The commit message title of <commit>. Used for information
-#     purposes only.
+# The return value is 1 if applying the changes resulted in a conflict
+# and 2 if the specified arguments were incorrect. If the changes could
+# be applied successfully but creating the commit failed, a value
+# greater than 2 is returned. No commit is created in either case and
+# the index is left with the (conflicting) changes in place.
 do_pick () {
 	allow_empty_message=y
 	rewrite=
@@ -493,7 +495,8 @@ do_pick () {
 			allow_empty_message=
 			;;
 		-*)
-			die "do_pick: unrecognized option -- $1"
+			warn "do_pick: unrecognized option -- $1"
+			return 2
 			;;
 		*)
 			break
@@ -501,7 +504,11 @@ do_pick () {
 		esac
 		shift
 	done
-	test $# -ne 2 && die "do_pick: wrong number of arguments"
+	if test $# -ne 1
+	then
+		warn "do_pick: wrong number of arguments"
+		return 2
+	fi
 
 	if test "$(git rev-parse HEAD)" = "$squash_onto"
 	then
@@ -519,11 +526,9 @@ do_pick () {
 		# rebase --continue.
 		git commit --allow-empty --allow-empty-message --amend \
 			   --no-post-rewrite -n -q -C $1 &&
-			pick_one -n $1 ||
-			die_with_patch $1 "Could not apply $1... $2"
+			pick_one -n $1 || return 1
 	else
-		pick_one ${rewrite:+-n} $1 ||
-			die_with_patch $1 "Could not apply $1... $2"
+		pick_one ${rewrite:+-n} $1 || return 1
 	fi
 
 	if test -n "$rewrite"
@@ -532,8 +537,7 @@ do_pick () {
 			   ${allow_empty_message:+--allow-empty-message} \
 			   ${rewrite_amend:+--amend} \
 			   ${rewrite_edit:+--edit --commit-msg} \
-			   ${gpg_sign_opt:+"$gpg_sign_opt"} ||
-			die_with_patch $1 "Could not rewrite commit after successfully picking $1... $2"
+			   ${gpg_sign_opt:+"$gpg_sign_opt"} || return 3
 	fi
 }
 
@@ -548,21 +552,21 @@ do_next () {
 		comment_for_reflog pick
 
 		mark_action_done
-		do_pick $sha1 "$rest"
+		do_pick $sha1 || die_with_patch $sha1 "Could not apply $sha1... $rest"
 		record_in_rewritten $sha1
 		;;
 	reword|r)
 		comment_for_reflog reword
 
 		mark_action_done
-		do_pick --edit $sha1 "$rest"
+		do_pick --edit $sha1 || die_with_patch $sha1 "Could not apply $sha1... $rest"
 		record_in_rewritten $sha1
 		;;
 	edit|e)
 		comment_for_reflog edit
 
 		mark_action_done
-		do_pick $sha1 "$rest"
+		do_pick $sha1 || die_with_patch $sha1 "Could not apply $sha1... $rest"
 		warn "Stopped at $sha1... $rest"
 		exit_with_patch $sha1 0
 		;;
-- 
2.0.1

[PATCH v2 15/23] rebase -i: teach do_pick the option --amend

[Fabian Ruch]

`do_pick` is the git-cherry-pick wrapper in git-rebase--interactive
that is used to implement the to-do list commands `pick`, `reword`
and `edit`. To cater for the different pick behaviours (like
`squash`), `do_pick` accepts several options not only from the
git-cherry-pick but also the git-commit interface.

Add the option `--amend` from the git-commit interface to the options
pool of `do_pick`. It creates a new commit for the changes introduced
by the picked commit and the previous one. The previous commit is
then replaced with the new commit. If no other options are specified,
the log message of the previous commit is used.

Be careful when `--amend` is used to pick a root commit because HEAD
might point to the sentinel commit but there is still nothing to
amend. Be sure to initialize `amend` so that commits are squashed
even when git-rebase--interactive is interrupted for resolving
conflicts. It is not a mistake to do the initialization regardless of
any conflicts because `amend` is always cleared before the next to-do
item is processed.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index d812bad..0871302 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -464,10 +464,16 @@ record_in_rewritten() {
 
 # Apply the changes introduced by the given commit to the current head.
 #
-# do_pick [--edit] <commit>
+# do_pick [--amend] [--edit] <commit>
 #
 # Wrapper around git-cherry-pick.
 #
+# --amend
+#     After picking <commit>, replace the current head commit with a new
+#     commit that also introduces the changes of <commit>.
+#
+#     _This is not a git-cherry-pick option._
+#
 # -e, --edit
 #     After picking <commit>, open an editor and let the user edit the
 #     commit message. The editor contents becomes the commit message of
@@ -489,6 +495,16 @@ do_pick () {
 	while test $# -gt 0
 	do
 		case "$1" in
+		--amend)
+			if test "$(git rev-parse HEAD)" = "$squash_onto" || ! git rev-parse -q --verify HEAD >/dev/null
+			then
+				warn "do_pick: nothing to amend"
+				return 2
+			fi
+			rewrite=y
+			rewrite_amend=y
+			git rev-parse --verify HEAD >"$amend"
+			;;
 		-e|--edit)
 			rewrite=y
 			rewrite_edit=y
-- 
2.0.1

[PATCH v2 16/23] rebase -i: teach do_pick the option --file

[Fabian Ruch]

`do_pick` is the git-cherry-pick wrapper in git-rebase--interactive
that is used to implement the to-do list command `pick`, `reword` and
`edit`. To cater for the different pick behaviours (like `squash`),
`do_pick` accepts several options not only from the git-cherry-pick
but also the git-commit interface.

Add the option `--file` from the git-commit interface to the options
pool of `do_pick`. It expects an argument itself which is interpreted
as a file path and takes the commit message from the given file. If
`--file` is passed to `do_pick`, assign the given file path to the
local variable `rewrite_message` and relay the option

    --file "$rewrite_message"

to the git-commit command line which creates the commit.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 0871302..0fbf773 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -464,7 +464,7 @@ record_in_rewritten() {
 
 # Apply the changes introduced by the given commit to the current head.
 #
-# do_pick [--amend] [--edit] <commit>
+# do_pick [--amend] [--file <file>] [--edit] <commit>
 #
 # Wrapper around git-cherry-pick.
 #
@@ -474,6 +474,12 @@ record_in_rewritten() {
 #
 #     _This is not a git-cherry-pick option._
 #
+# -F <file>, --file <file>
+#     Take the commit message from the given file. This creates a fresh
+#     commit.
+#
+#     _This is not a git-cherry-pick option._
+#
 # -e, --edit
 #     After picking <commit>, open an editor and let the user edit the
 #     commit message. The editor contents becomes the commit message of
@@ -492,6 +498,7 @@ do_pick () {
 	rewrite=
 	rewrite_amend=
 	rewrite_edit=
+	rewrite_message=
 	while test $# -gt 0
 	do
 		case "$1" in
@@ -505,6 +512,16 @@ do_pick () {
 			rewrite_amend=y
 			git rev-parse --verify HEAD >"$amend"
 			;;
+		-F|--file)
+			if test $# -eq 0
+			then
+				warn "do_pick: option --file specified but no <file> given"
+				return 2
+			fi
+			rewrite=y
+			rewrite_message=$2
+			shift
+			;;
 		-e|--edit)
 			rewrite=y
 			rewrite_edit=y
@@ -553,6 +570,7 @@ do_pick () {
 			   ${allow_empty_message:+--allow-empty-message} \
 			   ${rewrite_amend:+--amend} \
 			   ${rewrite_edit:+--edit --commit-msg} \
+			   ${rewrite_message:+--file "$rewrite_message"} \
 			   ${gpg_sign_opt:+"$gpg_sign_opt"} || return 3
 	fi
 }
-- 
2.0.1

[PATCH v2 17/23] rebase -i: prepare for squash in terms of do_pick --amend

[Fabian Ruch]

Rewrite `squash` and `fixup` handling in `do_next` using the sequence

    pick_one
    commit

in order to test the correctness of a single `do_squash` or
parameterised `do_pick` and make the subsequent patch reimplementing
`squash` in terms of such a single function more readable.

Do not call `rm -f "$GIT_DIR"/MERGE_MSG` since it has no effect on
the state after git-rebase--interactive terminates. The option `-F`
makes git-commit ignore `MERGE_MSG` for the log message. If
git-commit succeeds, `MERGE_MSG` is removed, and if it fails,
`MERGE_MSG` is overwritten by the error sequence `die_failed_squash`.
In summary, removing `MERGE_MSG` neither influences the squash commit
message nor the file state after git-commit returns.

Moreover, `pick_one` ignores `$GIT_DIR/SQUASH_MSG` and does not touch
`$squash_msg` so that it is correct to execute `pick_one` immediately
before git-commit.

Might be squashed into the subsequent commit.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 0fbf773..601a2ff 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -623,15 +623,15 @@ do_next () {
 		author_script_content=$(get_author_ident_from_commit HEAD)
 		echo "$author_script_content" > "$author_script"
 		eval "$author_script_content"
-		if ! pick_one -n $sha1
-		then
-			git rev-parse --verify HEAD >"$amend"
-			die_failed_squash $sha1 "$rest"
-		fi
 		case "$(peek_next_command)" in
 		squash|s|fixup|f)
 			# This is an intermediate commit; its message will only be
 			# used in case of trouble.  So use the long version:
+			if ! pick_one -n $sha1
+			then
+				git rev-parse --verify HEAD >"$amend"
+				die_failed_squash $sha1 "Could not apply $sha1... $rest"
+			fi
 			do_with_author output git commit --allow-empty-message --allow-empty \
 				--amend --no-verify -F "$squash_msg" \
 				${gpg_sign_opt:+"$gpg_sign_opt"} ||
@@ -641,13 +641,22 @@ do_next () {
 			# This is the final command of this squash/fixup group
 			if test -f "$fixup_msg"
 			then
+				if ! pick_one -n $sha1
+				then
+					git rev-parse --verify HEAD >"$amend"
+					die_failed_squash $sha1 "Could not apply $sha1... $rest"
+				fi
 				do_with_author output git commit --allow-empty-message --allow-empty \
 					--amend --no-verify -F "$fixup_msg" \
 					${gpg_sign_opt:+"$gpg_sign_opt"} ||
 					die_failed_squash $sha1 "$rest"
 			else
 				cp "$squash_msg" "$GIT_DIR"/SQUASH_MSG || exit
-				rm -f "$GIT_DIR"/MERGE_MSG
+				if ! pick_one -n $sha1
+				then
+					git rev-parse --verify HEAD >"$amend"
+					die_failed_squash $sha1 "Could not apply $sha1... $rest"
+				fi
 				do_with_author output git commit --allow-empty --amend --no-pre-commit -F "$GIT_DIR"/SQUASH_MSG -e \
 					${gpg_sign_opt:+"$gpg_sign_opt"} ||
 					die_failed_squash $sha1 "$rest"
-- 
2.0.1

[PATCH v2 18/23] rebase -i: implement squash in terms of do_pick

[Fabian Ruch]

The to-do list command `squash` and its close relative `fixup` replay
the changes of a commit like `pick` but do not recreate the commit.
Instead they replace the previous commit with a new commit that also
introduces the changes of the squashed commit. This is roughly like
cherry-picking without committing and using git-commit to amend the
previous commit.

The to-do list

    pick   a Some changes
    squash b Some more changes

gets translated into the sequence of git commands

    git cherry-pick a
    git cherry-pick -n b
    git commit --amend

and if git-cherry-pick supported `--amend` this would look even more
like the to-do list it is based on

    git cherry-pick a
    git cherry-pick --amend b.

Since `do_pick` takes care of `pick` entries and the above suggests
`squash` as an alias for `pick --amend`, reimplement `squash` in
terms of `do_pick --amend`. Introduce `$squash_msg` as the commit
message via the `--file` option. When the last commit of a squash
series is processed, the user is asked to review the log message.
Pass `--edit` as additional option in this case. The only difference
in the options passed to git-commit and `do_pick` is the omitted
`--no-verify`. However, `do_pick` does not execute the verification
hooks anyway because it solely replays commits and assumes that they
have been verified before.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 32 ++++++--------------------------
 1 file changed, 6 insertions(+), 26 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 601a2ff..29eca7e 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -627,39 +627,19 @@ do_next () {
 		squash|s|fixup|f)
 			# This is an intermediate commit; its message will only be
 			# used in case of trouble.  So use the long version:
-			if ! pick_one -n $sha1
-			then
-				git rev-parse --verify HEAD >"$amend"
-				die_failed_squash $sha1 "Could not apply $sha1... $rest"
-			fi
-			do_with_author output git commit --allow-empty-message --allow-empty \
-				--amend --no-verify -F "$squash_msg" \
-				${gpg_sign_opt:+"$gpg_sign_opt"} ||
-				die_failed_squash $sha1 "$rest"
+			do_with_author do_pick --amend -F "$squash_msg" $sha1 \
+				|| die_failed_squash $sha1 "$rest"
 			;;
 		*)
 			# This is the final command of this squash/fixup group
 			if test -f "$fixup_msg"
 			then
-				if ! pick_one -n $sha1
-				then
-					git rev-parse --verify HEAD >"$amend"
-					die_failed_squash $sha1 "Could not apply $sha1... $rest"
-				fi
-				do_with_author output git commit --allow-empty-message --allow-empty \
-					--amend --no-verify -F "$fixup_msg" \
-					${gpg_sign_opt:+"$gpg_sign_opt"} ||
-					die_failed_squash $sha1 "$rest"
+				do_with_author do_pick --amend -F "$fixup_msg" $sha1 \
+					|| die_failed_squash $sha1 "$rest"
 			else
 				cp "$squash_msg" "$GIT_DIR"/SQUASH_MSG || exit
-				if ! pick_one -n $sha1
-				then
-					git rev-parse --verify HEAD >"$amend"
-					die_failed_squash $sha1 "Could not apply $sha1... $rest"
-				fi
-				do_with_author output git commit --allow-empty --amend --no-pre-commit -F "$GIT_DIR"/SQUASH_MSG -e \
-					${gpg_sign_opt:+"$gpg_sign_opt"} ||
-					die_failed_squash $sha1 "$rest"
+				do_with_author do_pick --amend -F "$GIT_DIR"/SQUASH_MSG -e $sha1 \
+					|| die_failed_squash $sha1 "$rest"
 			fi
 			rm -f "$squash_msg" "$fixup_msg"
 			if test -z "$keep_empty" && is_empty_commit HEAD
-- 
2.0.1

[PATCH v2 19/23] rebase -i: explicitly distinguish replay commands and exec tasks

[Fabian Ruch]

There are two kinds of to-do list commands available. One kind
replays a commit (`pick`, `reword`, `edit`, `squash` and `fixup` that
is) and the other executes a shell command (`exec`). We will call the
first kind replay commands.

The two kinds of tasks are scheduled using different line formats.
Replay commands expect a commit hash argument following the command
name and exec concatenates all arguments to assemble a command line.

Adhere to the distinction of formats by not trying to parse the
`sha1` field unless we are dealing with a replay command. Move the
replay command handling code to a new function `do_replay` which
assumes the first argument to be a commit hash and make no more such
assumptions in `do_next`.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 42 ++++++++++++++++++++++++++++--------------
 1 file changed, 28 insertions(+), 14 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 29eca7e..6ecd4d7 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -575,13 +575,12 @@ do_pick () {
 	fi
 }
 
-do_next () {
-	rm -f "$msg" "$author_script" "$amend" || exit
-	read -r command sha1 rest < "$todo"
+do_replay () {
+	command=$1
+	sha1=$2
+	rest=$3
+
 	case "$command" in
-	"$comment_char"*|''|noop)
-		mark_action_done
-		;;
 	pick|p)
 		comment_for_reflog pick
 
@@ -660,6 +659,28 @@ do_next () {
 		esac
 		record_in_rewritten $sha1
 		;;
+	*)
+		read -r command <"$todo"
+		warn "Unknown command: $command"
+		fixtodo="Please fix this using 'git rebase --edit-todo'."
+		if git rev-parse --verify -q "$sha1" >/dev/null
+		then
+			die_with_patch $sha1 "$fixtodo"
+		else
+			die "$fixtodo"
+		fi
+		;;
+	esac
+}
+
+do_next () {
+	rm -f "$msg" "$author_script" "$amend" || exit
+	read -r command sha1 rest <"$todo"
+
+	case "$command" in
+	"$comment_char"*|''|noop)
+		mark_action_done
+		;;
 	x|"exec")
 		read -r command rest < "$todo"
 		mark_action_done
@@ -699,14 +720,7 @@ do_next () {
 		fi
 		;;
 	*)
-		warn "Unknown command: $command $sha1 $rest"
-		fixtodo="Please fix this using 'git rebase --edit-todo'."
-		if git rev-parse --verify -q "$sha1" >/dev/null
-		then
-			die_with_patch $sha1 "$fixtodo"
-		else
-			die "$fixtodo"
-		fi
+		do_replay $command $sha1 "$rest"
 		;;
 	esac
 	test -s "$todo" && return
-- 
2.0.1

[PATCH v2 20/23] rebase -i: parse to-do list command line options

[Fabian Ruch]

Read in to-do list lines as

    command args

instead of

    command sha1 rest

so that to-do list command lines can specify additional arguments
apart from the commit hash and the log message title, which become
the non-options in `args`. Loop over `args`, put all options (an
argument beginning with a dash) in `opts`, stop the loop on the first
non-option and assign it to `sha1`. The loop does not know the
options it parses so that options that take an argument themselves
are not supported at the moment. Neither are options that contain
spaces because the shell expansion of `args` in `do_next` interprets
white space characters as argument separator, that is a command line
like

    pick --author "A U Thor" fa1afe1 Some change

is parsed as the pick command

    pick --author

and the commit hash

    "A

which obviously results in an unknown revision error. For the sake of
completeness, in the example above the message title variable `rest`
is assigned the string 'U Thor" fa1afe1 Some change' (without the
single quotes).

Print an error message for unknown or unsupported command line
options, which means an error for all specified options at the
moment. Cleanly break the `do_next` loop by assigning the special
value 'unknown' to the local variable `command`, which triggers the
unknown command case in `do_cmd`.

The to-do list is also parsed when the commit hashes are translated
between long and short format before and after the to-do list is
edited. Apply the same procedure as in `do_cmd` with the exception
that we only care about where the options stop and the commit hash
begins. Do not reject any options when transforming the commit
hashes.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 49 ++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 41 insertions(+), 8 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 6ecd4d7..da435cb 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -577,8 +577,26 @@ do_pick () {
 
 do_replay () {
 	command=$1
-	sha1=$2
-	rest=$3
+	shift
+
+	opts=
+	while test $# -gt 0
+	do
+		case "$1" in
+		-*)
+			warn "Unknown option: $1"
+			command=unknown
+			;;
+		*)
+			break
+			;;
+		esac
+		opts="$opts $(git rev-parse --sq-quote "$1")"
+		shift
+	done
+	sha1=$1
+	shift
+	rest=$*
 
 	case "$command" in
 	pick|p)
@@ -675,7 +693,7 @@ do_replay () {
 
 do_next () {
 	rm -f "$msg" "$author_script" "$amend" || exit
-	read -r command sha1 rest <"$todo"
+	read -r command args <"$todo"
 
 	case "$command" in
 	"$comment_char"*|''|noop)
@@ -720,7 +738,7 @@ do_next () {
 		fi
 		;;
 	*)
-		do_replay $command $sha1 "$rest"
+		do_replay $command $args
 		;;
 	esac
 	test -s "$todo" && return
@@ -800,19 +818,34 @@ skip_unnecessary_picks () {
 }
 
 transform_todo_ids () {
-	while read -r command rest
+	while read -r command args
 	do
 		case "$command" in
 		"$comment_char"* | exec)
 			# Be careful for oddball commands like 'exec'
 			# that do not have a SHA-1 at the beginning of $rest.
+			newargs=\ $args
 			;;
 		*)
-			sha1=$(git rev-parse --verify --quiet "$@" ${rest%% *}) &&
-			rest="$sha1 ${rest#* }"
+			newargs=
+			sha1=
+			for arg in $args
+			do
+				case "$arg" in
+				-*)
+					newargs="$newargs $arg"
+					;;
+				*)
+					test -z "$sha1" &&
+						sha1=$(git rev-parse --verify --quiet "$@" $arg) &&
+						arg=$sha1
+					newargs="$newargs $arg"
+					;;
+				esac
+			done
 			;;
 		esac
-		printf '%s\n' "$command${rest:+ }$rest"
+		printf '%s\n' "$command$newargs"
 	done <"$todo" >"$todo.new" &&
 	mv -f "$todo.new" "$todo"
 }
-- 
2.0.1

Re: [PATCH v2 20/23] rebase -i: parse to-do list command line options

[Thomas Rast]

Fabian Ruch <bafain@gmail.com> writes:

[...]
> are not supported at the moment. Neither are options that contain
> spaces because the shell expansion of `args` in `do_next` interprets
> white space characters as argument separator, that is a command line
> like
>
>     pick --author "A U Thor" fa1afe1 Some change
>
> is parsed as the pick command
>
>     pick --author
>
> and the commit hash
>
>     "A
>
> which obviously results in an unknown revision error. For the sake of
> completeness, in the example above the message title variable `rest`
> is assigned the string 'U Thor" fa1afe1 Some change' (without the
> single quotes).

You could probably trim down the non-example a bit and instead give an
example :-)

> Print an error message for unknown or unsupported command line
> options, which means an error for all specified options at the
> moment.

Can you add a test that verifies we catch an obvious unknown option
(such as --unknown-option)?

> Cleanly break the `do_next` loop by assigning the special
> value 'unknown' to the local variable `command`, which triggers the
> unknown command case in `do_cmd`.
[...]
>  do_replay () {
>  	command=$1
> -	sha1=$2
> -	rest=$3
> +	shift
> +
> +	opts=
> +	while test $# -gt 0
> +	do
> +		case "$1" in
> +		-*)
> +			warn "Unknown option: $1"
> +			command=unknown
> +			;;
> +		*)
> +			break
> +			;;

This seems a rather hacky solution to me.  Doesn't this now print

  warning: Unknown option: --unknown-option
  warning: Unknown command: pick --unknown-option

?

It shouldn't claim the command is unknown if the command itself was
valid.

Also, you speak of do_cmd above, but the unknown command handling seems
to be part of do_replay?

-- 
Thomas Rast
tr@thomasrast.ch

Re: [PATCH v2 20/23] rebase -i: parse to-do list command line options

[Fabian Ruch]

Hi Thomas,

an updated patch is attached below.

Thomas Rast writes:> Fabian Ruch <bafain@gmail.com> writes:
> [...]
>> are not supported at the moment. Neither are options that contain
>> spaces because the shell expansion of `args` in `do_next` interprets
>> white space characters as argument separator, that is a command line
>> like
>>
>>     pick --author "A U Thor" fa1afe1 Some change
>>
>> is parsed as the pick command
>>
>>     pick --author
>>
>> and the commit hash
>>
>>     "A
>>
>> which obviously results in an unknown revision error. For the sake of
>> completeness, in the example above the message title variable `rest`
>> is assigned the string 'U Thor" fa1afe1 Some change' (without the
>> single quotes).
> 
> You could probably trim down the non-example a bit and instead give an
> example :-)

Done. The example "reword --signoff" is substituted for the
non-example and used for an error message example as well. I hope
that is not confusing.

>> Print an error message for unknown or unsupported command line
>> options, which means an error for all specified options at the
>> moment.
> 
> Can you add a test that verifies we catch an obvious unknown option
> (such as --unknown-option)?

Done. The test checks that git-rebase--interactive fails to execute
'pick --unknown-option' and that the rebase can be resumed after
removing the --unknown-option part.

>> Cleanly break the `do_next` loop by assigning the special
>> value 'unknown' to the local variable `command`, which triggers the
>> unknown command case in `do_cmd`.
> [...]
>>  do_replay () {
>>  	command=$1
>> -	sha1=$2
>> -	rest=$3
>> +	shift
>> +
>> +	opts=
>> +	while test $# -gt 0
>> +	do
>> +		case "$1" in
>> +		-*)
>> +			warn "Unknown option: $1"
>> +			command=unknown
>> +			;;
>> +		*)
>> +			break
>> +			;;
> 
> This seems a rather hacky solution to me.  Doesn't this now print
> 
>   warning: Unknown option: --unknown-option
>   warning: Unknown command: pick --unknown-option
> 
> ?
> 
> It shouldn't claim the command is unknown if the command itself was
> valid.

OK. "do_replay" now first checks for unknown commands and exits
immediately if that is the case, ignoring any options specified.

> Also, you speak of do_cmd above, but the unknown command handling seems
> to be part of do_replay?

Fixed.

   Fabian

-- >8 --
Subject: rebase -i: parse to-do list command line options

Read in to-do list lines as

    command args

instead of

    command sha1 rest

so that to-do list command lines can specify additional arguments
apart from the commit hash and the log message title, which become
the non-options in `args`. Loop over `args`, put all options (an
argument beginning with a dash) in `opts`, stop the loop on the first
non-option and assign it to `sha1`. For instance, the to-do list

    reword --signoff fa1afe1 Some change

is parsed as `command=reword`, `opts= '--signoff'` (including the
single quotes and the space for evaluation and concatenation of
options), `sha1=fa1afel` and `rest=Some change`. The loop does not
know the options it parses so that options that take an argument
themselves are not supported at the moment. Neither are options that
contain spaces because the shell expansion of `args` in `do_next`
interprets white space characters as argument separator.

Print an error message for unknown or unsupported command line
options, which means an error for all specified options at the
moment. Cleanly break the `do_next` loop by assigning a reason to the
local variable `malformed`, which triggers the unknown command code
in `do_replay`. Move the error code to the beginning of `do_replay`
so that unknown commands are reported before bad options are as only
the first error we come across is reported. For instance, the to-do
list from above produces the error

    Unknown 'reword' option: --signoff
    Please fix this using 'git rebase --edit-todo'.

The to-do list is also parsed when the commit hashes are translated
between long and short format before and after the to-do list is
edited. Apply the same procedure as in `do_replay` with the exception
that we only care about where the options stop and the commit hash
begins. Do not reject any options when transforming the commit
hashes.

Enable the specification of to-do list command line options in
`FAKE_LINES` the same way this is accomplished for command lines
passed to `exec`. Define a new `fake_editor.sh` that edits a static
to-do list instead of the one passed as argument when invoked by
git-rebase. Add a test case that checks that unknown options are
refused and can be corrected using `--edit-todo`.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh     | 80 ++++++++++++++++++++++++++++++++----------
 t/lib-rebase.sh                | 20 +++++++++--
 t/t3427-rebase-line-options.sh | 26 ++++++++++++++
 3 files changed, 105 insertions(+), 21 deletions(-)
 create mode 100755 t/t3427-rebase-line-options.sh

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 344d2cc..20636da 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -576,9 +576,47 @@ do_pick () {
 }
 
 do_replay () {
+	malformed=
 	command=$1
-	sha1=$2
-	rest=$3
+	shift
+	case "$command" in
+	pick|reword|edit|squash|fixup)
+		;;
+	*)
+		read -r command <"$todo"
+		malformed="Unknown command: $command"
+		;;
+	esac
+
+	opts=
+	while test $# -gt 0 && test -z "$malformed"
+	do
+		case "$1" in
+		-*)
+			malformed="Unknown '$command' option: $1"
+			;;
+		*)
+			break
+			;;
+		esac
+		opts="$opts $(git rev-parse --sq-quote "$1")"
+		shift
+	done
+	sha1=$1
+	shift
+	rest=$*
+
+	if test -n "$malformed"
+	then
+		warn "$malformed"
+		fixtodo="Please fix this using 'git rebase --edit-todo'."
+		if git rev-parse --verify -q "$sha1" >/dev/null
+		then
+			die_with_patch $sha1 "$fixtodo"
+		else
+			die "$fixtodo"
+		fi
+	fi
 
 	case "$command" in
 	pick|p)
@@ -659,23 +697,12 @@ do_replay () {
 		esac
 		record_in_rewritten $sha1
 		;;
-	*)
-		read -r command <"$todo"
-		warn "Unknown command: $command"
-		fixtodo="Please fix this using 'git rebase --edit-todo'."
-		if git rev-parse --verify -q "$sha1" >/dev/null
-		then
-			die_with_patch $sha1 "$fixtodo"
-		else
-			die "$fixtodo"
-		fi
-		;;
 	esac
 }
 
 do_next () {
 	rm -f "$msg" "$author_script" "$amend" || exit
-	read -r command sha1 rest <"$todo"
+	read -r command args <"$todo"
 
 	case "$command" in
 	"$comment_char"*|''|noop)
@@ -720,7 +747,7 @@ do_next () {
 		fi
 		;;
 	*)
-		do_replay $command $sha1 "$rest"
+		do_replay $command $args
 		;;
 	esac
 	test -s "$todo" && return
@@ -800,19 +827,34 @@ skip_unnecessary_picks () {
 }
 
 transform_todo_ids () {
-	while read -r command rest
+	while read -r command args
 	do
 		case "$command" in
 		"$comment_char"* | exec)
 			# Be careful for oddball commands like 'exec'
 			# that do not have a SHA-1 at the beginning of $rest.
+			newargs=\ $args
 			;;
 		*)
-			sha1=$(git rev-parse --verify --quiet "$@" ${rest%% *}) &&
-			rest="$sha1 ${rest#* }"
+			newargs=
+			sha1=
+			for arg in $args
+			do
+				case "$arg" in
+				-*)
+					newargs="$newargs $arg"
+					;;
+				*)
+					test -z "$sha1" &&
+						sha1=$(git rev-parse --verify --quiet "$@" $arg) &&
+						arg=$sha1
+					newargs="$newargs $arg"
+					;;
+				esac
+			done
 			;;
 		esac
-		printf '%s\n' "$command${rest:+ }$rest"
+		printf '%s\n' "$command$newargs"
 	done <"$todo" >"$todo.new" &&
 	mv -f "$todo.new" "$todo"
 }
diff --git a/t/lib-rebase.sh b/t/lib-rebase.sh
index 0cd1193..104f5bd 100644
--- a/t/lib-rebase.sh
+++ b/t/lib-rebase.sh
@@ -46,8 +46,8 @@ set_fake_editor () {
 	action=pick
 	for line in $FAKE_LINES; do
 		case $line in
-		squash|fixup|edit|reword)
-			action="$line";;
+		pick*|squash*|fixup*|edit*|reword*)
+			action=$(echo "$line" | sed 's/_/ /g');;
 		exec*)
 			echo "$line" | sed 's/_/ /g' >> "$1";;
 		"#")
@@ -80,6 +80,22 @@ set_cat_todo_editor () {
 	test_set_editor "$(pwd)/fake-editor.sh"
 }
 
+# set_fixed_todo_editor takes a file path as argument and installs an
+# editor script that, firstly, overwrites the file path argument with
+# the one specified during installation and, secondly, calls
+# fake-editor.sh for changing the contents as usual. This comes in
+# handy if it is easier to change some fixed file instead of the one
+# that will be passed when the editor is being invoked.
+
+set_fixed_todo_editor () {
+	set_fake_editor
+	write_script fake-editor-wrapper.sh <<-EOF
+	cp "$1" "\$1"
+	"$(pwd)"/fake-editor.sh "\$1"
+	EOF
+	test_set_editor "$(pwd)/fake-editor-wrapper.sh"
+}
+
 # checks that the revisions in "$2" represent a linear range with the
 # subjects in "$1"
 test_linear_range () {
diff --git a/t/t3427-rebase-line-options.sh b/t/t3427-rebase-line-options.sh
new file mode 100755
index 0000000..5881162
--- /dev/null
+++ b/t/t3427-rebase-line-options.sh
@@ -0,0 +1,26 @@
+#!/bin/sh
+
+test_description='git rebase -i with line options'
+
+. ./test-lib.sh
+
+. "$TEST_DIRECTORY"/lib-rebase.sh
+
+test_expect_success 'Set up repository' '
+	test_commit Initial &&
+	test_commit Commit1 &&
+	test_commit Commit2
+'
+
+test_expect_success 'Unknown option' '
+	git checkout -b unknown-option master &&
+	set_cat_todo_editor &&
+	test_must_fail git rebase -i HEAD^ >todo &&
+	set_fake_editor &&
+	test_must_fail env FAKE_LINES="1 pick_--unknown-option 2" git rebase -i HEAD~2 &&
+	set_fixed_todo_editor "$(pwd)"/todo &&
+	git rebase --edit-todo &&
+	git rebase --continue
+'
+
+test_done
-- 
2.0.1

[PATCH v2 21/23] rebase -i: teach do_pick the option --reset-author

[Fabian Ruch]

`do_pick` is the git-cherry-pick wrapper in git-rebase--interactive
that is used to implement many of the to-do list commands.
Eventually, the complete `do_pick` interface will be exposed to the
user in some form or another and those commands will become simple
aliases for the `do_pick` options now used to implement them.

Add the git-commit option `--reset-author` to the options pool of
`do_pick`. It rewrites the author date and name of the picked commit
to match the committer date and name.

If `--reset-author` is passed to `do_pick`, set the `rewrite` flag
and relay the option to the git-commit command line which creates the
final commit. If `--amend` is not passed as well, the fresh
authorship effect is achieved by the mere fact that we are creating a
new commit.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index da435cb..d6c99ea 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -464,10 +464,18 @@ record_in_rewritten() {
 
 # Apply the changes introduced by the given commit to the current head.
 #
-# do_pick [--amend] [--file <file>] [--edit] <commit>
+# do_pick [--reset-author] [--amend] [--file <file>] [--edit] <commit>
 #
 # Wrapper around git-cherry-pick.
 #
+# --reset-author
+#     Pretend the changes were made for the first time. Declare that the
+#     authorship of the resulting commit now belongs to the committer.
+#     This also renews the author timestamp. This creates a fresh
+#     commit.
+#
+#     _This is not a git-cherry-pick option._
+#
 # --amend
 #     After picking <commit>, replace the current head commit with a new
 #     commit that also introduces the changes of <commit>.
@@ -502,6 +510,10 @@ do_pick () {
 	while test $# -gt 0
 	do
 		case "$1" in
+		--reset-author)
+			rewrite=y
+			rewrite_author=y
+			;;
 		--amend)
 			if test "$(git rev-parse HEAD)" = "$squash_onto" || ! git rev-parse -q --verify HEAD >/dev/null
 			then
@@ -564,6 +576,14 @@ do_pick () {
 		pick_one ${rewrite:+-n} $1 || return 1
 	fi
 
+	if test -n "$rewrite_author" && test -z "$rewrite_amend"
+	then
+		# keep rewrite flag to create a new commit, rewrite
+		# without --reset-author though because it can only be
+		# used with -C, -c or --amend
+		rewrite_author=
+	fi
+
 	if test -n "$rewrite"
 	then
 		output git commit --allow-empty --no-post-rewrite -n --no-edit \
@@ -571,6 +591,7 @@ do_pick () {
 			   ${rewrite_amend:+--amend} \
 			   ${rewrite_edit:+--edit --commit-msg} \
 			   ${rewrite_message:+--file "$rewrite_message"} \
+			   ${rewrite_author:+--reset-author} \
 			   ${gpg_sign_opt:+"$gpg_sign_opt"} || return 3
 	fi
 }
-- 
2.0.1

[PATCH v2 22/23] rebase -i: teach do_pick the option --signoff

[Fabian Ruch]

`do_pick` is the git-cherry-pick wrapper in git-rebase--interactive
that is currently used to implement most of the to-do list commands
and offers additional options that will eventually find their way
onto to-do lists.

To extend the repertoire of available options, add the git-commit and
git-cherry-pick option `--signoff` to the `do_pick` interface. It
appends a Signed-off-by: line using the committer identity to the log
message of the picked commit.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index d6c99ea..a22459f 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -464,10 +464,15 @@ record_in_rewritten() {
 
 # Apply the changes introduced by the given commit to the current head.
 #
-# do_pick [--reset-author] [--amend] [--file <file>] [--edit] <commit>
+# do_pick [--signoff] [--reset-author] [--amend] [--file <file>]
+#         [--edit] <commit>
 #
 # Wrapper around git-cherry-pick.
 #
+# -s, --signoff
+#     Insert a Signed-off-by: line using the committer identity at the
+#     end of the commit log message. This creates a fresh commit.
+#
 # --reset-author
 #     Pretend the changes were made for the first time. Declare that the
 #     authorship of the resulting commit now belongs to the committer.
@@ -510,6 +515,10 @@ do_pick () {
 	while test $# -gt 0
 	do
 		case "$1" in
+		-s|--signoff)
+			rewrite=y
+			rewrite_signoff=y
+			;;
 		--reset-author)
 			rewrite=y
 			rewrite_author=y
@@ -588,6 +597,7 @@ do_pick () {
 	then
 		output git commit --allow-empty --no-post-rewrite -n --no-edit \
 			   ${allow_empty_message:+--allow-empty-message} \
+			   ${rewrite_signoff:+--signoff} \
 			   ${rewrite_amend:+--amend} \
 			   ${rewrite_edit:+--edit --commit-msg} \
 			   ${rewrite_message:+--file "$rewrite_message"} \
-- 
2.0.1

[PATCH v2 23/23] rebase -i: enable options --signoff, --reset-author for pick, reword

[Fabian Ruch]

pick and reword are atomic to-do list commands in the sense that they
open a new task which is closed after the respective command is
completed. squash and fixup are not atomic. They create a new task
which is not completed until the last squash or fixup is processed.

Lift the general unknown option blockade for the pick and reword
commands. If `do_cmd` comes across one of the options `--signoff` and
`--reset-author` while parsing a to-do entry and the scheduled
command is either `pick` or `reword`, relay the option to `do_pick`.

The `do_pick` options `--gpg-sign` and `--file` are not yet supported
because `do_cmd` cannot handle option arguments and options with
spaces at the moment. It is true that edit is one of the atomic
commands but it displays hash information when the rebase is stopped
and some options rewrite the picked commit which alters that
information. squash and fixup still do not accept user options as the
interplay of `--reset-author` and the author script are yet to be
determined.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index a22459f..4c05734 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -614,6 +614,16 @@ do_replay () {
 	while test $# -gt 0
 	do
 		case "$1" in
+		--signoff|--reset-author)
+			case "$command" in
+			pick|reword)
+				;;
+			*)
+				warn "Unsupported option: $1"
+				command=unknown
+				;;
+			esac
+			;;
 		-*)
 			warn "Unknown option: $1"
 			command=unknown
@@ -634,21 +644,24 @@ do_replay () {
 		comment_for_reflog pick
 
 		mark_action_done
-		do_pick $sha1 || die_with_patch $sha1 "Could not apply $sha1... $rest"
+		eval do_pick $opts $sha1 \
+			|| die_with_patch $sha1 "Could not apply $sha1... $rest"
 		record_in_rewritten $sha1
 		;;
 	reword|r)
 		comment_for_reflog reword
 
 		mark_action_done
-		do_pick --edit $sha1 || die_with_patch $sha1 "Could not apply $sha1... $rest"
+		eval do_pick --edit $opts $sha1 \
+			|| die_with_patch $sha1 "Could not apply $sha1... $rest"
 		record_in_rewritten $sha1
 		;;
 	edit|e)
 		comment_for_reflog edit
 
 		mark_action_done
-		do_pick $sha1 || die_with_patch $sha1 "Could not apply $sha1... $rest"
+		eval do_pick $opts $sha1 \
+			|| die_with_patch $sha1 "Could not apply $sha1... $rest"
 		warn "Stopped at $sha1... $rest"
 		exit_with_patch $sha1 0
 		;;
-- 
2.0.1

Re: [PATCH v2 23/23] rebase -i: enable options --signoff, --reset-author for pick, reword

[Thomas Rast]

Fabian Ruch <bafain@gmail.com> writes:

> @@ -634,21 +644,24 @@ do_replay () {
>  		comment_for_reflog pick
>  
>  		mark_action_done
> -		do_pick $sha1 || die_with_patch $sha1 "Could not apply $sha1... $rest"
> +		eval do_pick $opts $sha1 \
> +			|| die_with_patch $sha1 "Could not apply $sha1... $rest"

You had me a little puzzled at the switch to 'eval' here.  That is
necessary to match the quoting added in 20/23, not for any change in
this commit.  This commit is simply the first one to trigger this.
Also, are you sure $sha1 does not require quoting through an eval?


Please add tests to this patch.

-- 
Thomas Rast
tr@thomasrast.ch

Re: [PATCH v2 23/23] rebase -i: enable options --signoff, --reset-author for pick, reword

[Fabian Ruch]

Hi Thomas,

Thomas Rast writes:
> Fabian Ruch <bafain@gmail.com> writes:
>> @@ -634,21 +644,24 @@ do_replay () {
>>  		comment_for_reflog pick
>>  
>>  		mark_action_done
>> -		do_pick $sha1 || die_with_patch $sha1 "Could not apply $sha1... $rest"
>> +		eval do_pick $opts $sha1 \
>> +			|| die_with_patch $sha1 "Could not apply $sha1... $rest"
> 
> You had me a little puzzled at the switch to 'eval' here.  That is
> necessary to match the quoting added in 20/23, not for any change in
> this commit.  This commit is simply the first one to trigger this.

This patch switches to 'eval' here because it is the first time
'opts' occurs. However, I agree that it might be confusing that
'opts' wasn't already added to the 'do_pick' lines by 20/23. By
"trigger" you mean that this commit is the first to actually fill
'opts' with contents? I will move these changes to 20/23 then.

> Also, are you sure $sha1 does not require quoting through an eval?

At least if we can assume that it is really a SHA-1 object name. As
such it does not contain characters interpreted by the shell, like
backslashes, quotes or whitespace.

> Please add tests to this patch.

The ones I had in mind are attached below the scissors line. The
current reroll fails the authorship checks and the 'git rebase
--continue' test cases. As the necessary changes would obfuscate this
sub-thread, they will be included in the next reroll.

   Fabian

-- >8 --
diff --git a/t/t3427-rebase-line-options.sh b/t/t3427-rebase-line-options.sh
index 5881162..a5a9e66 100755
--- a/t/t3427-rebase-line-options.sh
+++ b/t/t3427-rebase-line-options.sh
@@ -6,10 +6,32 @@ test_description='git rebase -i with line options'
 
 . "$TEST_DIRECTORY"/lib-rebase.sh
 
+commit_message () {
+	git cat-file commit "$1" | sed '1,/^$/d'
+}
+
+commit_authorship () {
+	git cat-file commit "$1" | sed -n '/^$/q;/^author /p'
+}
+
+authorship () {
+	echo "author $GIT_AUTHOR_NAME <$GIT_AUTHOR_EMAIL> $GIT_AUTHOR_DATE"
+}
+
+test_diff_file () {
+	if cmp "$1" "$2" >/dev/null
+	then
+		echo "'$1' and '$2' are the same"
+		return 1
+	fi
+}
+
 test_expect_success 'Set up repository' '
 	test_commit Initial &&
 	test_commit Commit1 &&
-	test_commit Commit2
+	test_commit Commit2 &&
+	git checkout -b branch Commit1 &&
+	test_commit Commit2_ Commit2.t
 '
 
 test_expect_success 'Unknown option' '
@@ -23,4 +45,137 @@ test_expect_success 'Unknown option' '
 	git rebase --continue
 '
 
+test_msg_author () {
+	set_fake_editor &&
+	FAKE_LINES="1 $1 2" git rebase -i HEAD~2 &&
+	commit_message HEAD >actual.msg &&
+	commit_authorship HEAD >actual.author &&
+	test_cmp expected.msg actual.msg &&
+	test_cmp expected.author actual.author
+}
+
+test_msg_author_misspelled () {
+	set_cat_todo_editor &&
+	test_must_fail git rebase -i HEAD^ >todo &&
+	set_fake_editor &&
+	test_must_fail env FAKE_LINES="1 $1-misspelled 2" git rebase -i HEAD~2 &&
+	set_fixed_todo_editor "$(pwd)"/todo &&
+	FAKE_LINES="$1 1" git rebase --edit-todo &&
+	git rebase --continue &&
+	commit_message HEAD >actual.msg &&
+	commit_authorship HEAD >actual.author &&
+	test_cmp expected.msg actual.msg &&
+	test_cmp expected.author actual.author
+}
+
+test_msg_author_conflicted () {
+	set_fake_editor &&
+	test_must_fail env FAKE_LINES="$1 1" git rebase -i master &&
+	git checkout --theirs Commit2.t &&
+	git add Commit2.t &&
+	git rebase --continue &&
+	commit_message HEAD >actual.msg &&
+	commit_authorship HEAD >actual.author &&
+	test_cmp expected.msg actual.msg &&
+	test_cmp expected.author actual.author
+}
+
+test_expect_success 'Misspelled pick --signoff' '
+	git checkout -b misspelled-pick--signoff master &&
+	cat >expected.msg <<-EOF &&
+	$(commit_message HEAD)
+
+	Signed-off-by: C O Mitter <committer@example.com>
+	EOF
+	commit_authorship HEAD >expected.author &&
+	test_msg_author_misspelled pick_--signoff
+'
+
+test_expect_success 'Conflicted pick --signoff' '
+	git checkout -b conflicted-pick--signoff branch &&
+	cat >expected.msg <<-EOF &&
+	$(commit_message HEAD)
+
+	Signed-off-by: C O Mitter <committer@example.com>
+	EOF
+	commit_authorship HEAD >expected.author &&
+	test_msg_author_conflicted pick_--signoff
+'
+
+test_expect_success 'pick --signoff' '
+	git checkout -b pick--signoff master &&
+	cat >expected.msg <<-EOF &&
+	$(commit_message HEAD)
+
+	Signed-off-by: C O Mitter <committer@example.com>
+	EOF
+	commit_authorship HEAD >expected.author &&
+	test_msg_author pick_--signoff
+'
+
+test_expect_success 'reword --signoff' '
+	git checkout -b reword--signoff master &&
+	cat >expected.msg <<-EOF &&
+	$(commit_message HEAD)
+
+	Signed-off-by: C O Mitter <committer@example.com>
+	EOF
+	commit_authorship HEAD >expected.author &&
+	test_msg_author reword_--signoff
+'
+
+test_expect_success 'Misspelled pick --reset-author' '
+	git checkout -b misspelled-pick--reset-author master &&
+	commit_message HEAD >expected.msg &&
+	test_tick &&
+	authorship >expected.author &&
+	commit_authorship HEAD >original.author &&
+	test_diff_file expected.author original.author &&
+	test_msg_author_misspelled pick_--reset-author
+'
+
+test_expect_success 'Conflicted pick --reset-author' '
+	git checkout -b conflicted-pick--reset-author branch &&
+	commit_message HEAD >expected.msg &&
+	test_tick &&
+	authorship >expected.author &&
+	commit_authorship HEAD >original.author &&
+	test_diff_file expected.author original.author &&
+	test_msg_author_conflicted pick_--reset-author
+'
+
+test_expect_success 'pick --reset-author' '
+	git checkout -b pick--reset-author master &&
+	commit_message HEAD >expected.msg &&
+	test_tick &&
+	authorship >expected.author &&
+	commit_authorship HEAD >original.author &&
+	test_diff_file expected.author original.author &&
+	test_msg_author pick_--reset-author
+'
+
+test_expect_success 'pick --reset-author --signoff' '
+	git checkout -b pick--reset-author--signoff master &&
+	cat >expected.msg <<-EOF &&
+	$(commit_message HEAD)
+
+	Signed-off-by: C O Mitter <committer@example.com>
+	EOF
+	test_tick &&
+	authorship >expected.author &&
+	commit_authorship HEAD >original.author &&
+	test_diff_file expected.author original.author &&
+	test_msg_author pick_--reset-author_--signoff
+'
+
+test_expect_success 'reword --reset-author' '
+	git checkout -b reword--reset-author master &&
+	commit_message HEAD >expected.msg &&
+	test_tick &&
+	authorship >expected.author &&
+	commit_authorship HEAD >original.author &&
+	test_diff_file expected.author original.author &&
+	test_msg_author reword_--reset-author
+'
+
 test_done

Re: [PATCH v2 23/23] rebase -i: enable options --signoff, --reset-author for pick, reword

[Michael Haggerty]

On 08/07/2014 01:59 AM, Fabian Ruch wrote:
> pick and reword are atomic to-do list commands in the sense that they
> open a new task which is closed after the respective command is
> completed. squash and fixup are not atomic. They create a new task
> which is not completed until the last squash or fixup is processed.

I don't understand the distinction that you are attempting to draw
between "atomic" and "non-atomic" commands.  For example, in the
following command list:

    pick 1111111
    squash 2222222
    fixup 3333333

the "pick" command doesn't seem very atomic, because the *end* result of
the three commands is a single commit that is affected by all three
commands.  Furthermore, if we change the example to

    pick 1111111
    squash --reset-author 2222222
    fixup --signoff 3333333

then isn't it clear that the user's intention was to apply both options,
"--reset-author" and "--signoff", to the resulting commit?  In other
words, it seems to me that any options on such a chain of lines should
be collected and applied to the final commit as a whole.

> Lift the general unknown option blockade for the pick and reword
> commands. If `do_cmd` comes across one of the options `--signoff` and
> `--reset-author` while parsing a to-do entry and the scheduled
> command is either `pick` or `reword`, relay the option to `do_pick`.

The new user-exposed options should be documented in the git-rebase(1)
manpage and probably also in the help text that is appended to every
"rebase -i" todo list.

> The `do_pick` options `--gpg-sign` and `--file` are not yet supported
> because `do_cmd` cannot handle option arguments and options with
> spaces at the moment. It is true that edit is one of the atomic
> commands but it displays hash information when the rebase is stopped
> and some options rewrite the picked commit which alters that
> information. squash and fixup still do not accept user options as the
> interplay of `--reset-author` and the author script are yet to be
> determined.
> [...]

Michael

-- 
Michael Haggerty
mhagger@alum.mit.edu

Re: [PATCH v2 23/23] rebase -i: enable options --signoff, --reset-author for pick, reword

[Fabian Ruch]

Hi,

Michael Haggerty writes:
> On 08/07/2014 01:59 AM, Fabian Ruch wrote:
>> Lift the general unknown option blockade for the pick and reword
>> commands. If `do_cmd` comes across one of the options `--signoff` and
>> `--reset-author` while parsing a to-do entry and the scheduled
>> command is either `pick` or `reword`, relay the option to `do_pick`.
> 
> The new user-exposed options should be documented in the git-rebase(1)
> manpage and probably also in the help text that is appended to every
> "rebase -i" todo list.

The next reroll will add the following paragraph to the git-rebase man
page right after the introduction of the 'reword' command in the section
"INTERACTIVE MODE":

> The commands "pick" and "reword" understand some well-known options.
> To add a Signed-off-by line at the end of the commit message, pass
> the `--signoff` option. The authorship can be renewed by specifying
> the `--reset-author` option. For instance, before you decide to
> publish a heavily edited commit you might want to reset the
> authorship and add your signature. You can do so on a per line basis:
> 
> -------------------------------------------
> pick deadbee The oneline of this commit
> pick --reset-author --signoff fa1afe1 The oneline of the next commit
> ...
> -------------------------------------------

By saying "heavily edited commit" I tried to describe a commit that has
been amended, reworded and reordered in such a way that the actual
author information has become meaningless.

The help text at the end of every to-do list would look like this:

> Commands:
>  p, pick = use commit
>  r, reword = use commit, but edit the commit message
>  e, edit = use commit, but stop for amending
>  s, squash = use commit, but meld into previous commit
>  f, fixup = like "squash", but discard this commit's log message
>  x, exec = run command (the rest of the line) using shell
> 
> Options:
>  [pick | reword] --signoff = add a Signed-off-by line
>  [pick | reword] --reset-author = renew authorship
> 
> These lines can be re-ordered; they are executed from top to bottom.
> 
> If you remove a line here THAT COMMIT WILL BE LOST.

New about this is the "Options" headline.

   Fabian

Re: [PATCH v2 23/23] rebase -i: enable options --signoff, --reset-author for pick, reword

[Fabian Ruch]

Hi Michael,

On 08/13/2014 02:47 PM, Michael Haggerty wrote:
> On 08/07/2014 01:59 AM, Fabian Ruch wrote:
>> pick and reword are atomic to-do list commands in the sense that they
>> open a new task which is closed after the respective command is
>> completed. squash and fixup are not atomic. They create a new task
>> which is not completed until the last squash or fixup is processed.
> 
> I don't understand the distinction that you are attempting to draw
> between "atomic" and "non-atomic" commands.  For example, in the
> following command list:
> 
>     pick 1111111
>     squash 2222222
>     fixup 3333333
> 
> the "pick" command doesn't seem very atomic, because the *end* result of
> the three commands is a single commit that is affected by all three
> commands.

Right, when I wrote the commit message I was thinking in abstract terms
so I implicitly thought of your example as a (single) squash/fixup
command. Now it has become obvious that I wasn't very thorough with the
implementation part. The git-rebase implementation is oblivious to the
context when it processes 'pick' lines and your example shows how 'pick'
lines can be part of squash/fixup command context. In conclusion, I
intended to keep options disabled for squash/fixup commands but failed
to do so because I neglected that a 'pick' line can initiate a
squash/fixup command.

> Furthermore, if we change the example to
> 
>     pick 1111111
>     squash --reset-author 2222222
>     fixup --signoff 3333333
> 
> then isn't it clear that the user's intention was to apply both options,
> "--reset-author" and "--signoff", to the resulting commit?

This seems to suggest an interpretation of todo lists similar to what I
was thinking of when writing the commit message, that is one in which
pick is not oblivious to the neighbouring commands. It might be a
problem that it forbids the (admittedly improbable) use case where
--reset-author is used to rewrite the authorship to something recent and
fixup to have an even more recent committership.

To reconcile this kind of vertical interpretation with the horizontal
specification of options one could introduce a todo list command taking
the list of commits to be squashed as an argument. However, that seems
to make it difficult to obtain the squash behaviour for some commits and
the fixup behaviour for others that are part of the same chain.

The alternative interpretation of todo lists as simplified batch scripts
for git commands would allow the intended behaviour (--reset-author and
--signoff applied to the resulting commit), not restrict the user
relatively to what she can already do on the command line and give
actually different meanings to the syntactically different todo lists

    pick 1111111
    squash --reset-author 2222222
    fixup --signoff 3333333

and

    pick 1111111
    squash --signoff 2222222
    fixup --reset-author 3333333

, which would be treated identically by an implementation that collects
the options. The current meaning of squash/fixup seems to be valid in
the batch interpretation.

> In other
> words, it seems to me that any options on such a chain of lines should
> be collected and applied to the final commit as a whole.

To summarise, I think line options might be confusing if we interpret

    pick 1111111
    squash --reset-author 2222222
    fixup --signoff 3333333

as

    combine the changes of 1111111, 2222222, 3333333
    concatenate the messages of 1111111 and 2222222
    edit the message
    reset the authorship to the committership
    add a Signed-off-by: line

and not as

    pick 1111111
    pick -n 2222222
    commit amend --reset-author -m $squash_msg
    pick -n 3333333
    commit amend --signoff --edit

.

Thanks for pointing me at these issues. "Atomic" and "non-atomic" are
really poorly-chosen terminology and the squash-initiating 'pick' might
not be implemented correctly.

   Fabian

[PATCH v3 00/27] Enable options --signoff, --reset-author for pick, reword, edit

[Fabian Ruch]

Hi,

this is the third reroll of the patch series that makes the
well-known commit options `--signoff` and `--reset-author` available
to be used with the to-do list commands `pick`, `reword` and `edit`.

What follows is a short changelog since the second reroll from almost
two weeks ago. The changes were mostly made in response to Thomas'
review.

- Merely a commit message comment: The `editor.sh` wrapper script is
  still necessary to use `output` with interactive to-do list
  commands because the `--quiet` option does not force all commands
  to be totally silent.

- `git-rebase--interactive.sh` now uses the quoting functionality of
  git-rev-parse when assigning the `editor.sh` path to the
  `GIT_EDITOR` environment variable, in case the path includes double
  quotes itself.

- The tests dealing with squash commits that violate either
  commit-msg or pre-commit now test `squash` and `fixup` sequences
  with more than two commits. This is important since the final
  commit is created on a different code path than the others.

- The `fake_editor.sh` change that prints the debug output on stderr
  instead of stdout is now a separate patch so that it can be
  referred to directly. The change might be considered a hack and
  needs revision.

- Since whitespace and shell quoting are not supported by line
  options, the `opts` variable does not need to be evaluated using
  `eval` anymore.

- Malformed to-do command lines either trigger an "unknown command"
  or an "unknown option" error message but not both.

- A test case that specifies that `git rebase --continue` only
  commits staged changes if the user has not committed on top of the
  last successfully replayed commit in the meantime. The rationale
  behind this is that `git rebase --continue` commits using the
  author information of the commit it tried to replay last. While it
  perfectly makes sense to assume that this information is correct
  when HEAD has not changed, it is probable that it is incorrect when
  the user has created commits herself because the rebase process was
  interrupted for conflict resolution only and one must know
  internals to intentionally make `git rebase --continue` commit
  changes on top of user-created commits using original author
  information.

- `do_pick` did not preserve the authorship of the original commit
  when it was asked to rewrite the commit, for instance using
  `reword`. This was fixed by applying the authorship of the named
  commit using `do_with_author`. That doesn't interfere with squash
  commits because `do_with_author` is a no-op when used with `git
  commit --amend`.

- `git rebase --continue` did not apply the line options after
  conflict resolution. This was added by remembering line options the
  way `git-rebase--interactive.sh` reminds itself of amending
  commits.

- The test suite `t3427-rebase-line-options.sh` is responsible for
  the specification of to-do lists that use line options.

- The two line options available are now documented both in the
  git-rebase man page and the to-do list help text.

Thanks for your time,
   Fabian

Fabian Ruch (27):
  rebase -i: allow replaying commits with empty log messages
  rebase -i: allow squashing empty commits without complaints
  rebase -i: allow rewording empty commits without complaints
  fake_editor: leave standard output unchanged
  rebase -i: hide interactive command messages in verbose mode
  rebase -i: discard redundant message when rewording fails
  commit: allow disabling pre-commit and commit-msg separately
  rebase -i: verify squash messages using commit-msg
  rebase -i: do not verify reworded patches using pre-commit
  rebase -i: teach do_pick the option --edit
  rebase -i: implement reword in terms of do_pick
  rebase -i: log the replay of root commits
  rebase -i: do not use -C when --no-edit is sufficient
  rebase -i: commit only once when rewriting picks
  rebase -i: do not die in do_pick
  rebase -i: teach do_pick the option --amend
  rebase -i: teach do_pick the option --file
  rebase -i: remove no-op do_with_author git commit --amend
  rebase -i: prepare for squash in terms of do_pick --amend
  rebase -i: implement squash in terms of do_pick
  rebase -i: explicitly distinguish replay commands and exec tasks
  rebase -i: parse to-do list command line options
  rebase -i: teach do_pick the option --reset-author
  rebase -i: teach do_pick the option --signoff
  rebase -i: do not overwrite user author information
  rebase -i: refuse to commit when resuming with updated head
  rebase -i: enable --signoff, --reset-author for pick, reword, edit

 Documentation/git-commit.txt   |   8 +-
 Documentation/git-rebase.txt   |  13 ++
 builtin/commit.c               |  32 +++-
 git-rebase--interactive.sh     | 370 ++++++++++++++++++++++++++++++++---------
 git-rebase.sh                  |  13 +-
 t/lib-rebase.sh                |  28 +++-
 t/t3404-rebase-interactive.sh  | 290 ++++++++++++++++++++++++++++++--
 t/t3406-rebase-message.sh      |  18 ++
 t/t3412-rebase-root.sh         |  16 ++
 t/t3427-rebase-line-options.sh | 216 ++++++++++++++++++++++++
 t/t7503-pre-commit-hook.sh     |  65 +++++++-
 t/t7504-commit-msg-hook.sh     |  85 ++++++++--
 t/test-lib-functions.sh        |  23 ++-
 13 files changed, 1044 insertions(+), 133 deletions(-)
 create mode 100755 t/t3427-rebase-line-options.sh

-- 
2.0.1

[PATCH v3 01/27] rebase -i: allow replaying commits with empty log messages

[Fabian Ruch]

git-rebase--interactive handles empty log messages inconsistently
between enabled and disabled fast-forwards. By default, commits with
empty log messages are rebased successfully like in non-interactive
mode. In contrast, the `--no-ff` option aborts the replay of such
commits.

In line with not verifying rebased commits and behaving like
git-rebase for `pick` lines, use the `--allow-empty-message` option
to replay commits. Root commits are replayed by recreating them in
`do_pick` using git-commit and all other commits are replayed using
git-cherry-pick in `pick_one`. Apply the option, understood by both
git-commit and git-cherry-pick, at the respective sites.

In case of `reword` and `squash`, continue to abort the rebase if the
_resulting_ commit would have no commit message. The rationale behind
this default is that patches and their log messages should be
verified at least once. For unchanged commits this is assumed to have
happened according to the author's standards when she created the
commits for the first time. While the empty log message can always be
kept in place by editing and resuming the aborted rebase, a debatable
alternative could be to teach git-rebase--interactive the option
`--allow-empty-message` for disabling complaints about empty log
messages even in changed commits.

The `fixup` case is different again because it throws away the second
commit's log message and uses the first log message for the changed
commit. Do not abort the rebase if that message is empty either since
it is assumed to have been verified already.

The remaining to-do list command `edit` is handled just like `pick`
for this matter, because git-rebase--interactive replays the named
commit without changes before the rebase is interrupted and the user
can make her changes to the replayed commit.

Add tests. In particular, design the `squash`-specific test case such
that it involves interim commits and `fixup` steps. Interim commits
should not trigger failures themselves and `fixup` steps should not
let git-rebase--interactive forget that it is still dealing with a
`squash` result.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh    | 10 ++++++----
 t/t3404-rebase-interactive.sh | 38 ++++++++++++++++++++++++++++++++++++++
 t/t3412-rebase-root.sh        | 16 ++++++++++++++++
 3 files changed, 60 insertions(+), 4 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index b64dd28..3222bf6 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -249,7 +249,7 @@ pick_one () {
 
 	test -d "$rewritten" &&
 		pick_one_preserving_merges "$@" && return
-	output eval git cherry-pick \
+	output eval git cherry-pick --allow-empty-message \
 			${gpg_sign_opt:+$(git rev-parse --sq-quote "$gpg_sign_opt")} \
 			"$strategy_args" $empty_args $ff "$@"
 }
@@ -363,7 +363,7 @@ pick_one_preserving_merges () {
 			echo "$sha1 $(git rev-parse HEAD^0)" >> "$rewritten_list"
 			;;
 		*)
-			output eval git cherry-pick \
+			output eval git cherry-pick --allow-empty-message \
 				${gpg_sign_opt:+$(git rev-parse --sq-quote "$gpg_sign_opt")} \
 				"$strategy_args" "$@" ||
 				die_with_patch $sha1 "Could not pick $sha1"
@@ -549,7 +549,8 @@ do_next () {
 		squash|s|fixup|f)
 			# This is an intermediate commit; its message will only be
 			# used in case of trouble.  So use the long version:
-			do_with_author output git commit --amend --no-verify -F "$squash_msg" \
+			do_with_author output git commit --allow-empty-message \
+				--amend --no-verify -F "$squash_msg" \
 				${gpg_sign_opt:+"$gpg_sign_opt"} ||
 				die_failed_squash $sha1 "$rest"
 			;;
@@ -557,7 +558,8 @@ do_next () {
 			# This is the final command of this squash/fixup group
 			if test -f "$fixup_msg"
 			then
-				do_with_author git commit --amend --no-verify -F "$fixup_msg" \
+				do_with_author git commit --allow-empty-message \
+					--amend --no-verify -F "$fixup_msg" \
 					${gpg_sign_opt:+"$gpg_sign_opt"} ||
 					die_failed_squash $sha1 "$rest"
 			else
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index 8197ed2..9c71835 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -1039,4 +1039,42 @@ test_expect_success 'short SHA-1 collide' '
 	)
 '
 
+test_expect_success 'setup commits with empty commit log messages' '
+	git checkout -b empty-log-messages master &&
+	test_commit no-msg-commit-1 &&
+	git commit --amend --allow-empty-message -F - </dev/null &&
+	test_commit no-msg-commit-2 &&
+	git commit --amend --allow-empty-message -F - </dev/null &&
+	test_commit no-msg-commit-3 &&
+	git commit --amend --allow-empty-message -F - </dev/null
+'
+
+test_expect_success 'rebase commits with empty commit log messages' '
+	git checkout -b rebase-empty-log-messages empty-log-messages &&
+	set_fake_editor &&
+	test_expect_code 0 env FAKE_LINES="1" git rebase -i master &&
+	test_expect_code 0 env FAKE_LINES="1" git rebase -i --no-ff master
+'
+
+test_expect_success 'reword commits with empty commit log messages' '
+	git checkout -b reword-empty-log-messages empty-log-messages &&
+	test_when_finished reset_rebase &&
+	set_fake_editor &&
+	test_must_fail env FAKE_LINES="reword 1" git rebase -i master
+'
+
+test_expect_success 'squash commits with empty commit log messages' '
+	git checkout -b squash-empty-log-messages empty-log-messages &&
+	set_fake_editor &&
+	test_must_fail env FAKE_LINES="1 squash 2 fixup 3" git rebase -i master &&
+	git commit --allow-empty-message --amend &&
+	git rebase --continue
+'
+
+test_expect_success 'fixup commits with empty commit log messages' '
+	git checkout -b fixup-empty-log-messages empty-log-messages &&
+	set_fake_editor &&
+	env FAKE_LINES="1 fixup 2" git rebase -i master
+'
+
 test_done
diff --git a/t/t3412-rebase-root.sh b/t/t3412-rebase-root.sh
index 0b52105..7add7a1 100755
--- a/t/t3412-rebase-root.sh
+++ b/t/t3412-rebase-root.sh
@@ -278,4 +278,20 @@ test_expect_success 'rebase -i -p --root with conflict (second part)' '
 	test_cmp expect-conflict-p out
 '
 
+test_expect_success 'rebase --root root with empty log message' '
+	git checkout --orphan empty-log-messages-root master &&
+	test_commit no-msg-root-commit &&
+	git commit --amend --allow-empty-message -F - </dev/null &&
+	test_expect_code 0 git rebase --root &&
+	test_expect_code 0 git rebase --root --no-ff
+'
+
+test_expect_success 'rebase --root commits with empty log messages' '
+	git checkout -b empty-log-messages master &&
+	test_commit no-msg-commit &&
+	git commit --amend --allow-empty-message -F - </dev/null &&
+	test_expect_code 0 git rebase --root &&
+	test_expect_code 0 git rebase --root --no-ff
+'
+
 test_done
-- 
2.0.1

[PATCH v3 02/27] rebase -i: allow squashing empty commits without complaints

[Fabian Ruch]

The to-do list commands `squash` and `fixup` apply the changes
introduced by the named commit to the tree but instead of creating
a new commit on top of the current head it replaces the previous
commit with a new commit that records the updated tree. If the
result is an empty commit git-rebase stops with the error message

   You asked to amend the most recent commit, but doing so would make
   it empty. You can repeat your command with --allow-empty, or you can
   remove the commit entirely with "git reset HEAD^".

This message is not very helpful because neither does git-rebase
support an option `--allow-empty` nor does the messages say how to
resume the rebase. Firstly, change the error message to

   The squash result is empty and --keep-empty was not specified.

   You can remove the squash commit now with

     git reset HEAD^

   Once you are done, run

     git rebase --continue

If the user wishes to squash a sequence of commits into one
commit, f. i.

   pick A
   squash Revert "A"
   squash A'

, it does not matter for the end result that the first squash
result, or any sub-sequence in general, is going to be empty. The
squash message is not affected at all by which commits are created
and only the commit created by the last line in the sequence will
end up in the final history. Secondly, print the error message
only if the whole squash sequence produced an empty commit.

Lastly, since an empty squash commit is not a failure to rewrite
the history as planned, issue the message above as a mere warning
and interrupt the rebase with the return value zero. The
interruption should be considered as a notification with the
chance to undo it on the spot. Specifying the `--keep-empty`
option tells git-rebase to keep empty squash commits in the
rebased history without notification.

Add tests.

Reported-by: Peter Krefting <peter@softwolves.pp.se>
Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh    | 20 +++++++++++---
 t/t3404-rebase-interactive.sh | 62 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 79 insertions(+), 3 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 3222bf6..ada340c 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -549,7 +549,7 @@ do_next () {
 		squash|s|fixup|f)
 			# This is an intermediate commit; its message will only be
 			# used in case of trouble.  So use the long version:
-			do_with_author output git commit --allow-empty-message \
+			do_with_author output git commit --allow-empty-message --allow-empty \
 				--amend --no-verify -F "$squash_msg" \
 				${gpg_sign_opt:+"$gpg_sign_opt"} ||
 				die_failed_squash $sha1 "$rest"
@@ -558,18 +558,32 @@ do_next () {
 			# This is the final command of this squash/fixup group
 			if test -f "$fixup_msg"
 			then
-				do_with_author git commit --allow-empty-message \
+				do_with_author git commit --allow-empty-message --allow-empty \
 					--amend --no-verify -F "$fixup_msg" \
 					${gpg_sign_opt:+"$gpg_sign_opt"} ||
 					die_failed_squash $sha1 "$rest"
 			else
 				cp "$squash_msg" "$GIT_DIR"/SQUASH_MSG || exit
 				rm -f "$GIT_DIR"/MERGE_MSG
-				do_with_author git commit --amend --no-verify -F "$GIT_DIR"/SQUASH_MSG -e \
+				do_with_author git commit --allow-empty --amend --no-verify -F "$GIT_DIR"/SQUASH_MSG -e \
 					${gpg_sign_opt:+"$gpg_sign_opt"} ||
 					die_failed_squash $sha1 "$rest"
 			fi
 			rm -f "$squash_msg" "$fixup_msg"
+			if test -z "$keep_empty" && is_empty_commit HEAD
+			then
+				echo "$sha1" >"$state_dir"/stopped-sha
+				warn "The squash result is empty and --keep-empty was not specified."
+				warn
+				warn "You can remove the squash commit now with"
+				warn
+				warn "  git reset HEAD^"
+				warn
+				warn "Once you are done, run"
+				warn
+				warn "  git rebase --continue"
+				exit 0
+			fi
 			;;
 		esac
 		record_in_rewritten $sha1
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index 9c71835..a95cb2a 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -237,6 +237,68 @@ test_expect_success 'retain authorship' '
 	git show HEAD | grep "^Author: Twerp Snog"
 '
 
+test_expect_success 'setup squash/fixup reverted and fixed feature' '
+	git checkout -b reverted-feature master &&
+	test_commit feature &&
+	git revert feature &&
+	git checkout -b fixed-feature reverted-feature &&
+	test_commit featurev2
+'
+
+test_expect_success 'fixup fixed feature (empty interim commit)' '
+	git checkout -b fixup-fixed-feature fixed-feature &&
+	set_fake_editor &&
+	FAKE_LINES="1 fixup 2 fixup 3" git rebase -i master &&
+	git log --oneline master.. >actual &&
+	test_line_count = 1 actual &&
+	git diff --exit-code featurev2
+'
+
+test_expect_success 'squash fixed feature (empty interim commit)' '
+	git checkout -b squash-fixed-feature fixed-feature &&
+	set_fake_editor &&
+	FAKE_LINES="1 squash 2 squash 3" git rebase -i master &&
+	git log --oneline master.. >actual &&
+	test_line_count = 1 actual &&
+	git diff --exit-code featurev2
+'
+
+test_expect_success 'fixup reverted feature (empty final commit)' '
+	git checkout -b fixup-reverted-feature reverted-feature &&
+	set_fake_editor &&
+	FAKE_LINES="1 fixup 2" git rebase -i master &&
+	git reset HEAD^ &&
+	git rebase --continue &&
+	test_cmp_rev master HEAD
+'
+
+test_expect_success 'squash reverted feature (empty final commit)' '
+	git checkout -b squash-reverted-feature reverted-feature &&
+	set_fake_editor &&
+	FAKE_LINES="1 squash 2" git rebase -i master &&
+	git reset HEAD^ &&
+	git rebase --continue &&
+	test_cmp_rev master HEAD
+'
+
+test_expect_success 'fixup reverted feature (empty final commit with --keep-empty)' '
+	git checkout -b fixup-keep-reverted-feature reverted-feature &&
+	set_fake_editor &&
+	FAKE_LINES="1 fixup 2" git rebase -i --keep-empty master &&
+	git log --oneline master.. >actual &&
+	test_line_count = 1 actual &&
+	git diff --exit-code master
+'
+
+test_expect_success 'squash reverted feature (empty final commit with --keep-empty)' '
+	git checkout -b squash-keep-reverted-feature reverted-feature &&
+	set_fake_editor &&
+	FAKE_LINES="1 squash 2" git rebase -i --keep-empty master &&
+	git log --oneline master.. >actual &&
+	test_line_count = 1 actual &&
+	git diff --exit-code master
+'
+
 test_expect_success 'squash' '
 	git reset --hard twerp &&
 	echo B > file7 &&
-- 
2.0.1

[PATCH v3 03/27] rebase -i: allow rewording empty commits without complaints

[Fabian Ruch]

The to-do list command `reword` replays a commit like `pick` but lets
the user also edit the commit's log message. If `--keep-empty` is
passed as option to git-rebase--interactive, empty commits ought to
be replayed without complaints. However, if the users chooses to
reword an empty commit by changing the respective to-do list entry
from

    pick fa1afe1 Empty commit

to

    reword fa1afe1 Empty commit

, then git-rebase--interactive suddenly fails to replay the empty
commit. This is especially counterintuitive because `reword` is
thought of as a `pick` that alters the log message in some way but
nothing more and the unchanged to-do list entry would not fail.

Handle `reword` by cherry-picking the named commit and editing the
log message using

    git commit --allow-empty --amend

instead of

    git commit --amend.

Add test.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh    |  2 +-
 t/t3404-rebase-interactive.sh | 33 +++++++++++++++++++++++++++++++++
 2 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index ada340c..eb1dcda 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -504,7 +504,7 @@ do_next () {
 
 		mark_action_done
 		do_pick $sha1 "$rest"
-		git commit --amend --no-post-rewrite ${gpg_sign_opt:+"$gpg_sign_opt"} || {
+		git commit --allow-empty --amend --no-post-rewrite ${gpg_sign_opt:+"$gpg_sign_opt"} || {
 			warn "Could not amend commit after successfully picking $sha1... $rest"
 			warn "This is most likely due to an empty commit message, or the pre-commit hook"
 			warn "failed. If the pre-commit hook failed, you may need to resolve the issue before"
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index a95cb2a..f4e886f 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -75,6 +75,39 @@ test_expect_success 'rebase --keep-empty' '
 	test_line_count = 6 actual
 '
 
+test_expect_success 'rebase --keep-empty (reword)' '
+	git checkout -b reword-emptybranch emptybranch &&
+	set_fake_editor &&
+	FAKE_LINES="1 reword 2" git rebase --keep-empty -i HEAD~2 &&
+	git log --oneline >actual &&
+	test_line_count = 6 actual
+'
+
+test_expect_success 'rebase --keep-empty (edit)' '
+	git checkout -b edit-emptybranch emptybranch &&
+	set_fake_editor &&
+	FAKE_LINES="1 edit 2" git rebase --keep-empty -i HEAD~2 &&
+	git rebase --continue &&
+	git log --oneline >actual &&
+	test_line_count = 6 actual
+'
+
+test_expect_success 'rebase --keep-empty (fixup)' '
+	git checkout -b fixup-emptybranch emptybranch &&
+	set_fake_editor &&
+	FAKE_LINES="1 fixup 2" git rebase --keep-empty -i HEAD~2 &&
+	git log --oneline >actual &&
+	test_line_count = 5 actual
+'
+
+test_expect_success 'rebase --keep-empty (squash)' '
+	git checkout -b squash-emptybranch emptybranch &&
+	set_fake_editor &&
+	FAKE_LINES="1 squash 2" git rebase --keep-empty -i HEAD~2 &&
+	git log --oneline >actual &&
+	test_line_count = 5 actual
+'
+
 test_expect_success 'rebase -i with the exec command' '
 	git checkout master &&
 	(
-- 
2.0.1

[PATCH v3 04/27] fake_editor: leave standard output unchanged

[Fabian Ruch]

The helper function `set_fake_editor` installs a script as
`GIT_EDITOR` that applies pre-defined editing rules to the files it
is called with, which is a quite powerful tool when writing test
cases for git-rebase--interactive. To aid in debugging the changes it
makes, the installed script dumps the file contents to stdout before
and after editing. That interferes with the output from
git-rebase--interactive, however, and the debug information has to be
removed from stdout in a error-prone way. Print the editor contents
on stderr instead.

When a test case wants to analyse stderr, we need to come up with a
different solution. The less convenient possibility that always
remains is to store the debug output in a file in the "trash"
directory or even keeping copies of the edited files before and after
editing.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 t/lib-rebase.sh               |  8 ++++----
 t/t3404-rebase-interactive.sh | 18 ++++++------------
 2 files changed, 10 insertions(+), 16 deletions(-)

diff --git a/t/lib-rebase.sh b/t/lib-rebase.sh
index 6bd2522..0cd1193 100644
--- a/t/lib-rebase.sh
+++ b/t/lib-rebase.sh
@@ -41,8 +41,8 @@ set_fake_editor () {
 	test -z "$FAKE_LINES" && exit
 	grep -v '^#' < "$1" > "$1".tmp
 	rm -f "$1"
-	echo 'rebase -i script before editing:'
-	cat "$1".tmp
+	echo 'rebase -i script before editing:' >&2
+	cat "$1".tmp >&2
 	action=pick
 	for line in $FAKE_LINES; do
 		case $line in
@@ -59,8 +59,8 @@ set_fake_editor () {
 			action=pick;;
 		esac
 	done
-	echo 'rebase -i script after editing:'
-	cat "$1"
+	echo 'rebase -i script after editing:' >&2
+	cat "$1" >&2
 	EOF
 
 	test_set_editor "$(pwd)/fake-editor.sh"
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index f4e886f..7cc6ebf 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -882,9 +882,8 @@ test_expect_success 'running "git rebase -i --exec git show HEAD"' '
 	(
 		FAKE_LINES="1 exec_git_show_HEAD 2 exec_git_show_HEAD" &&
 		export FAKE_LINES &&
-		git rebase -i HEAD~2 >expect
+		git rebase -i HEAD~2 >expected
 	) &&
-	sed -e "1,9d" expect >expected &&
 	test_cmp expected actual
 '
 
@@ -896,9 +895,8 @@ test_expect_success 'running "git rebase --exec git show HEAD -i"' '
 	(
 		FAKE_LINES="1 exec_git_show_HEAD 2 exec_git_show_HEAD" &&
 		export FAKE_LINES &&
-		git rebase -i HEAD~2 >expect
+		git rebase -i HEAD~2 >expected
 	) &&
-	sed -e "1,9d" expect >expected &&
 	test_cmp expected actual
 '
 
@@ -910,9 +908,8 @@ test_expect_success 'running "git rebase -ix git show HEAD"' '
 	(
 		FAKE_LINES="1 exec_git_show_HEAD 2 exec_git_show_HEAD" &&
 		export FAKE_LINES &&
-		git rebase -i HEAD~2 >expect
+		git rebase -i HEAD~2 >expected
 	) &&
-	sed -e "1,9d" expect >expected &&
 	test_cmp expected actual
 '
 
@@ -924,9 +921,8 @@ test_expect_success 'rebase -ix with several <CMD>' '
 	(
 		FAKE_LINES="1 exec_git_show_HEAD;_pwd 2 exec_git_show_HEAD;_pwd" &&
 		export FAKE_LINES &&
-		git rebase -i HEAD~2 >expect
+		git rebase -i HEAD~2 >expected
 	) &&
-	sed -e "1,9d" expect >expected &&
 	test_cmp expected actual
 '
 
@@ -939,9 +935,8 @@ test_expect_success 'rebase -ix with several instances of --exec' '
 		FAKE_LINES="1 exec_git_show_HEAD exec_pwd 2
 				exec_git_show_HEAD exec_pwd" &&
 		export FAKE_LINES &&
-		git rebase -i HEAD~2 >expect
+		git rebase -i HEAD~2 >expected
 	) &&
-	sed -e "1,11d" expect >expected &&
 	test_cmp expected actual
 '
 
@@ -965,9 +960,8 @@ test_expect_success 'rebase -ix with --autosquash' '
 		git checkout -b autosquash_expected &&
 		FAKE_LINES="1 fixup 3 fixup 4 exec_git_show_HEAD 2 exec_git_show_HEAD" &&
 		export FAKE_LINES &&
-		git rebase -i HEAD~4 >expect
+		git rebase -i HEAD~4 >expected
 	) &&
-	sed -e "1,13d" expect >expected &&
 	test_cmp expected actual
 '
 
-- 
2.0.1

[PATCH v3 05/27] rebase -i: hide interactive command messages in verbose mode

[Fabian Ruch]

git-rebase--interactive prints summary messages of the commits it
creates in the final history only if the `--verbose` option is
specified by the user and suppresses them otherwise. This behaviour
is implemented by wrapping git-commit calls in a shell function named
`output` which redirects stderr to stdout, captures stdout in a shell
variable and ignores its contents unless the command exits with an
error status.

The command lines used to implement the to-do list commands `reword`
and `squash` print diagnostic messages even in non-verbose mode. The
reason for this inconsistency is that both commands launch the log
message editor `GIT_EDITOR` which usually requires a working terminal
attached to stdin. Wrapping the `reword` and `squash` command lines
in `output` would seemingly freeze the terminal (see commit 7725cb5,
"rebase -i: fix reword when using a terminal editor"). Temporarily
redirect the `GIT_EDITOR` output to a third file descriptor in order
to ship it around the capture stream. Wrap the remaining git-commit
command lines in the new `output`. At the moment, it is still no
alternative to pass the `--quiet` option in non-verbose mode because
git-merge-recursive for instance prints some messages regardless of
the verbosity level.

In order to temporarily redirect the editor output, the new
definition of `output` creates a wrapper script in the state
directory to be used as `GIT_EDITOR`. Make sure the state directory
exists before `output` is called for the first time.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh |  9 +++++----
 git-rebase.sh              | 13 +++++++++++--
 t/t3406-rebase-message.sh  | 18 ++++++++++++++++++
 3 files changed, 34 insertions(+), 6 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index eb1dcda..cebe742 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -504,7 +504,7 @@ do_next () {
 
 		mark_action_done
 		do_pick $sha1 "$rest"
-		git commit --allow-empty --amend --no-post-rewrite ${gpg_sign_opt:+"$gpg_sign_opt"} || {
+		output git commit --allow-empty --amend --no-post-rewrite ${gpg_sign_opt:+"$gpg_sign_opt"} || {
 			warn "Could not amend commit after successfully picking $sha1... $rest"
 			warn "This is most likely due to an empty commit message, or the pre-commit hook"
 			warn "failed. If the pre-commit hook failed, you may need to resolve the issue before"
@@ -558,14 +558,14 @@ do_next () {
 			# This is the final command of this squash/fixup group
 			if test -f "$fixup_msg"
 			then
-				do_with_author git commit --allow-empty-message --allow-empty \
+				do_with_author output git commit --allow-empty-message --allow-empty \
 					--amend --no-verify -F "$fixup_msg" \
 					${gpg_sign_opt:+"$gpg_sign_opt"} ||
 					die_failed_squash $sha1 "$rest"
 			else
 				cp "$squash_msg" "$GIT_DIR"/SQUASH_MSG || exit
 				rm -f "$GIT_DIR"/MERGE_MSG
-				do_with_author git commit --allow-empty --amend --no-verify -F "$GIT_DIR"/SQUASH_MSG -e \
+				do_with_author output git commit --allow-empty --amend --no-verify -F "$GIT_DIR"/SQUASH_MSG -e \
 					${gpg_sign_opt:+"$gpg_sign_opt"} ||
 					die_failed_squash $sha1 "$rest"
 			fi
@@ -923,6 +923,8 @@ EOF
 	;;
 esac
 
+mkdir -p "$state_dir" || die "Could not create temporary $state_dir"
+
 git var GIT_COMMITTER_IDENT >/dev/null ||
 	die "You need to set your committer info first"
 
@@ -938,7 +940,6 @@ then
 fi
 
 orig_head=$(git rev-parse --verify HEAD) || die "No HEAD?"
-mkdir -p "$state_dir" || die "Could not create temporary $state_dir"
 
 : > "$state_dir"/interactive || die "Could not mark as interactive"
 write_basic_state
diff --git a/git-rebase.sh b/git-rebase.sh
index 55da9db..46141b8 100755
--- a/git-rebase.sh
+++ b/git-rebase.sh
@@ -131,9 +131,18 @@ write_basic_state () {
 output () {
 	case "$verbose" in
 	'')
-		output=$("$@" 2>&1 )
+		cat >"$state_dir"/editor.sh <<-EOF
+		#!/bin/sh
+		$(git var GIT_EDITOR) "\$@" >&3
+		EOF
+		chmod +x "$state_dir"/editor.sh
+		(
+			GIT_EDITOR=$(git rev-parse --sq-quote "$state_dir"/editor.sh)
+			export GIT_EDITOR
+			"$@" 3>&1 1>"$state_dir"/output 2>&1
+		)
 		status=$?
-		test $status != 0 && printf "%s\n" "$output"
+		test $status != 0 && cat "$state_dir"/output
 		return $status
 		;;
 	*)
diff --git a/t/t3406-rebase-message.sh b/t/t3406-rebase-message.sh
index 0392e36..d7003a9 100755
--- a/t/t3406-rebase-message.sh
+++ b/t/t3406-rebase-message.sh
@@ -4,6 +4,8 @@ test_description='messages from rebase operation'
 
 . ./test-lib.sh
 
+. "$TEST_DIRECTORY"/lib-rebase.sh
+
 test_expect_success 'setup' '
 	test_commit O fileO &&
 	test_commit X fileX &&
@@ -84,4 +86,20 @@ test_expect_success 'rebase --onto outputs the invalid ref' '
 	test_i18ngrep "invalid-ref" err
 '
 
+test_expect_success 'commit summary is suppressed in non-verbose mode' '
+	git checkout --detach Y &&
+	cat >expected.out <<-EOF &&
+	Rebasing (1/5)\r
+	Rebasing (2/5)\r
+	Rebasing (3/5)\r
+	Rebasing (4/5)\r
+	Rebasing (5/5)\r
+	EOF
+	set_fake_editor &&
+	FAKE_LINES="reword 1 fixup 2 fixup 3 4 squash 5" \
+	git rebase -i --root >actual.out.tmp &&
+	sed -e "s/\r/\\\\r\n/g" <actual.out.tmp >actual.out &&
+	test_cmp expected.out actual.out
+'
+
 test_done
-- 
2.0.1

[PATCH v3 06/27] rebase -i: discard redundant message when rewording fails

[Fabian Ruch]

The to-do list command `reword` replays a commit like `pick` but lets
the user also edit the commit's log message. If the edited log
message is empty or is found ill-formatted by one of the commit
hooks, git-rebase--interactive prints three error messages to the
console.

    1. The git-commit output, which contains all the output from hook
       scripts.
    2. A rebase diagnosis saying at which task on the to-do list it
       got stuck.
    3. Generic presumptions about what could have triggered the
       error.

The third message contains redundant information and does not add any
enlightenment either, which makes the output unnecessarily longish
and different from the other commands' output. For instance, this is
what the output looks like if the log message is empty (contains
duplicate Signed-off-by lines).

    (1.) Aborting commit due to empty commit message. (Duplicate Signed-off-by lines.)
    (2.) Could not amend commit after successfully picking fa1afe1... Some change
    (3.) This is most likely due to an empty commit message, or the pre-commit hook
         failed. If the pre-commit hook failed, you may need to resolve the issue before
         you are able to reword the commit.

Discard the third message.

It is true that a failed hook script might not output any diagnosis
but then the generic message is not of much help either. Since this
lack of information affects the built-in git commands for commit,
merge and cherry-pick first, the solution would be to keep track of
the failed hooks in their output so that the user knows which of her
hooks require improvement.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index cebe742..cf62daa 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -506,9 +506,6 @@ do_next () {
 		do_pick $sha1 "$rest"
 		output git commit --allow-empty --amend --no-post-rewrite ${gpg_sign_opt:+"$gpg_sign_opt"} || {
 			warn "Could not amend commit after successfully picking $sha1... $rest"
-			warn "This is most likely due to an empty commit message, or the pre-commit hook"
-			warn "failed. If the pre-commit hook failed, you may need to resolve the issue before"
-			warn "you are able to reword the commit."
 			exit_with_patch $sha1 1
 		}
 		record_in_rewritten $sha1
-- 
2.0.1

[PATCH v3 07/27] commit: allow disabling pre-commit and commit-msg separately

[Fabian Ruch]

Introduce the git-commit command line options `--no-pre-commit` and
`--no-commit-msg` to disable the pre-commit and commit-msg hooks,
respectively. Make `--no-verify` a synonym for specifying both at the
same time.

This change is motivated by an internal usage of git-commit in
git-rebase--interactive to disable pre-commit while keeping
commit-msg enabled when rewording a commit.

Make `test_commit` forward unknown options to git-commit instead of
teaching it all possible options. In order to support leading double
dashes in `<message>`, stop interpreting `test_commit` arguments
following a `--` argument as options. This wasn't a problem before
because the first unknown option would be used as `<message>`.

Allow disabling tag creation to avoid name clashes when using
`test_commit` with the same arguments several times from the same
test suite. By default, `test_commit` tags successful commits using
git-tag for easy reference. The `--notag` option skips this step.

Add tests.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 Documentation/git-commit.txt |  8 ++++-
 builtin/commit.c             | 32 ++++++++++++++---
 t/t7503-pre-commit-hook.sh   | 65 ++++++++++++++++++++++++++++-----
 t/t7504-commit-msg-hook.sh   | 85 ++++++++++++++++++++++++++++++++++----------
 t/test-lib-functions.sh      | 23 ++++++++----
 5 files changed, 176 insertions(+), 37 deletions(-)

diff --git a/Documentation/git-commit.txt b/Documentation/git-commit.txt
index 0bbc8f5..28a2c5c 100644
--- a/Documentation/git-commit.txt
+++ b/Documentation/git-commit.txt
@@ -158,7 +158,7 @@ OPTIONS
 
 -n::
 --no-verify::
-	This option bypasses the pre-commit and commit-msg hooks.
+	A synonym for `--no-pre-commit --no-commit-msg`.
 	See also linkgit:githooks[5].
 
 --allow-empty::
@@ -238,6 +238,12 @@ You should understand the implications of rewriting history if you
 amend a commit that has already been published.  (See the "RECOVERING
 FROM UPSTREAM REBASE" section in linkgit:git-rebase[1].)
 
+--no-pre-commit::
+	This option bypasses the pre-commit hook.
+
+--no-commit-msg::
+	This option bypasses the commit-msg hook.
+
 --no-post-rewrite::
 	Bypass the post-rewrite hook.
 
diff --git a/builtin/commit.c b/builtin/commit.c
index 5ed6036..dfd354e 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -98,12 +98,27 @@ static char *edit_message, *use_message;
 static char *fixup_message, *squash_message;
 static int all, also, interactive, patch_interactive, only, amend, signoff;
 static int edit_flag = -1; /* unspecified */
-static int quiet, verbose, no_verify, allow_empty, dry_run, renew_authorship;
+static int quiet, verbose, allow_empty, dry_run, renew_authorship;
 static int no_post_rewrite, allow_empty_message;
 static char *untracked_files_arg, *force_date, *ignore_submodule_arg;
 static char *sign_commit;
 
 /*
+ * The verify variable is interpreted as a bitmap of enabled commit
+ * verification hooks according to the legend below.
+ *
+ * By default, the pre-commit and commit-msg hooks are enabled. This
+ * is represented by both the PRE_COMMIT and COMMIT_MSG bits being
+ * set.
+ *
+ * The bitmap is changed through the command line options
+ * --no-verify, --no-pre-commit and --no-commit-msg.
+ */
+#define PRE_COMMIT (1<<0)
+#define COMMIT_MSG (1<<1)
+static int verify = PRE_COMMIT | COMMIT_MSG;
+
+/*
  * The default commit message cleanup mode will remove the lines
  * beginning with # (shell comments) and leading and trailing
  * whitespaces (empty lines or containing only whitespaces)
@@ -661,7 +676,8 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
 	/* This checks and barfs if author is badly specified */
 	determine_author_info(author_ident);
 
-	if (!no_verify && run_commit_hook(use_editor, index_file, "pre-commit", NULL))
+	if (verify & PRE_COMMIT &&
+	    run_commit_hook(use_editor, index_file, "pre-commit", NULL))
 		return 0;
 
 	if (squash_message) {
@@ -962,7 +978,7 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
 		}
 	}
 
-	if (!no_verify &&
+	if (verify & COMMIT_MSG &&
 	    run_commit_hook(use_editor, index_file, "commit-msg", git_path(commit_editmsg), NULL)) {
 		return 0;
 	}
@@ -1590,7 +1606,9 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
 		OPT_BOOL(0, "interactive", &interactive, N_("interactively add files")),
 		OPT_BOOL('p', "patch", &patch_interactive, N_("interactively add changes")),
 		OPT_BOOL('o', "only", &only, N_("commit only specified files")),
-		OPT_BOOL('n', "no-verify", &no_verify, N_("bypass pre-commit hook")),
+		OPT_NEGBIT('n', "no-verify", &verify,
+			   N_("synonym for --no-pre-commit --no-commit-msg"),
+			   PRE_COMMIT | COMMIT_MSG),
 		OPT_BOOL(0, "dry-run", &dry_run, N_("show what would be committed")),
 		OPT_SET_INT(0, "short", &status_format, N_("show status concisely"),
 			    STATUS_FORMAT_SHORT),
@@ -1603,6 +1621,12 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
 		OPT_BOOL('z', "null", &s.null_termination,
 			 N_("terminate entries with NUL")),
 		OPT_BOOL(0, "amend", &amend, N_("amend previous commit")),
+		OPT_NEGBIT(0, "no-pre-commit", &verify,
+			   N_("bypass pre-commit hook"),
+			   PRE_COMMIT),
+		OPT_NEGBIT(0, "no-commit-msg", &verify,
+			   N_("bypass commit-msg hook"),
+			   COMMIT_MSG),
 		OPT_BOOL(0, "no-post-rewrite", &no_post_rewrite, N_("bypass post-rewrite hook")),
 		{ OPTION_STRING, 'u', "untracked-files", &untracked_files_arg, N_("mode"), N_("show untracked files, optional modes: all, normal, no. (Default: all)"), PARSE_OPT_OPTARG, NULL, (intptr_t)"all" },
 		/* end commit contents options */
diff --git a/t/t7503-pre-commit-hook.sh b/t/t7503-pre-commit-hook.sh
index 984889b..db5de1c 100755
--- a/t/t7503-pre-commit-hook.sh
+++ b/t/t7503-pre-commit-hook.sh
@@ -12,11 +12,11 @@ test_expect_success 'with no hook' '
 
 '
 
-test_expect_success '--no-verify with no hook' '
+test_expect_success '--no-pre-commit with no hook' '
 
 	echo "bar" > file &&
 	git add file &&
-	git commit --no-verify -m "bar"
+	git commit --no-pre-commit -m "bar"
 
 '
 
@@ -38,11 +38,11 @@ test_expect_success 'with succeeding hook' '
 
 '
 
-test_expect_success '--no-verify with succeeding hook' '
+test_expect_success '--no-pre-commit with succeeding hook' '
 
 	echo "even more" >> file &&
 	git add file &&
-	git commit --no-verify -m "even more"
+	git commit --no-pre-commit -m "even more"
 
 '
 
@@ -60,11 +60,11 @@ test_expect_success 'with failing hook' '
 
 '
 
-test_expect_success '--no-verify with failing hook' '
+test_expect_success '--no-pre-commit with failing hook' '
 
 	echo "stuff" >> file &&
 	git add file &&
-	git commit --no-verify -m "stuff"
+	git commit --no-pre-commit -m "stuff"
 
 '
 
@@ -77,15 +77,64 @@ test_expect_success POSIXPERM 'with non-executable hook' '
 
 '
 
-test_expect_success POSIXPERM '--no-verify with non-executable hook' '
+test_expect_success POSIXPERM '--no-pre-commit with non-executable hook' '
 
 	echo "more content" >> file &&
 	git add file &&
-	git commit --no-verify -m "more content"
+	git commit --no-pre-commit -m "more content"
 
 '
 chmod +x "$HOOK"
 
+test_hook_enabled () {
+	git checkout --detach master &&
+	output="running failing pre-commit hook with ${*:-(none)}..." &&
+	>actual.output &&
+	cat >"$HOOK" <<-EOF &&
+	#!/bin/sh
+	echo "$output" >>actual.output
+	exit 1
+	EOF
+	chmod +x "$HOOK" &&
+	echo "$output" >expected.output &&
+	test_must_fail test_commit $* file &&
+	test_cmp expected.output actual.output
+}
+
+test_hook_disabled () {
+	git checkout --detach master &&
+	output="running failing pre-commit hook with ${*:-(none)}..." &&
+	>actual.output &&
+	cat >"$HOOK" <<-EOF &&
+	#!/bin/sh
+	echo "$output" >>actual.output
+	exit 1
+	EOF
+	chmod +x "$HOOK" &&
+	test_commit --notag $* file &&
+	test_must_be_empty actual.output
+}
+
+test_expect_success 'command line options combinations' '
+	test_hook_enabled &&
+	test_hook_enabled --pre-commit &&
+	test_hook_enabled --no-pre-commit --pre-commit &&
+	test_hook_enabled --no-verify --pre-commit &&
+	test_hook_enabled --verify &&
+	test_hook_enabled --no-pre-commit --verify &&
+	test_hook_enabled --no-verify --verify &&
+	test_hook_enabled --verify --no-commit-msg &&
+	test_hook_enabled --verify --commit-msg &&
+	test_hook_disabled --no-pre-commit &&
+	test_hook_disabled --pre-commit --no-pre-commit &&
+	test_hook_disabled --pre-commit --no-verify &&
+	test_hook_disabled --no-verify &&
+	test_hook_disabled --verify --no-pre-commit &&
+	test_hook_disabled --verify --no-verify &&
+	test_hook_disabled --no-verify --no-commit-msg &&
+	test_hook_disabled --no-verify --commit-msg
+'
+
 # a hook that checks $GIT_PREFIX and succeeds inside the
 # success/ subdirectory only
 cat > "$HOOK" <<EOF
diff --git a/t/t7504-commit-msg-hook.sh b/t/t7504-commit-msg-hook.sh
index 1f53ea8..59642a3 100755
--- a/t/t7504-commit-msg-hook.sh
+++ b/t/t7504-commit-msg-hook.sh
@@ -34,20 +34,20 @@ test_expect_success 'with no hook (editor)' '
 
 '
 
-test_expect_success '--no-verify with no hook' '
+test_expect_success '--no-commit-msg with no hook' '
 
 	echo "bar" > file &&
 	git add file &&
-	git commit --no-verify -m "bar"
+	git commit --no-commit-msg -m "bar"
 
 '
 
-test_expect_success '--no-verify with no hook (editor)' '
+test_expect_success '--no-commit-msg with no hook (editor)' '
 
 	echo "more bar" > file &&
 	git add file &&
 	echo "more bar" > FAKE_MSG &&
-	GIT_EDITOR="\"\$FAKE_EDITOR\"" git commit --no-verify
+	GIT_EDITOR="\"\$FAKE_EDITOR\"" git commit --no-commit-msg
 
 '
 
@@ -78,20 +78,20 @@ test_expect_success 'with succeeding hook (editor)' '
 
 '
 
-test_expect_success '--no-verify with succeeding hook' '
+test_expect_success '--no-commit-msg with succeeding hook' '
 
 	echo "even more" >> file &&
 	git add file &&
-	git commit --no-verify -m "even more"
+	git commit --no-commit-msg -m "even more"
 
 '
 
-test_expect_success '--no-verify with succeeding hook (editor)' '
+test_expect_success '--no-commit-msg with succeeding hook (editor)' '
 
 	echo "even more more" >> file &&
 	git add file &&
 	echo "even more more" > FAKE_MSG &&
-	GIT_EDITOR="\"\$FAKE_EDITOR\"" git commit --no-verify
+	GIT_EDITOR="\"\$FAKE_EDITOR\"" git commit --no-commit-msg
 
 '
 
@@ -118,20 +118,20 @@ test_expect_success 'with failing hook (editor)' '
 
 '
 
-test_expect_success '--no-verify with failing hook' '
+test_expect_success '--no-commit-msg with failing hook' '
 
 	echo "stuff" >> file &&
 	git add file &&
-	git commit --no-verify -m "stuff"
+	git commit --no-commit-msg -m "stuff"
 
 '
 
-test_expect_success '--no-verify with failing hook (editor)' '
+test_expect_success '--no-commit-msg with failing hook (editor)' '
 
 	echo "more stuff" >> file &&
 	git add file &&
 	echo "more stuff" > FAKE_MSG &&
-	GIT_EDITOR="\"\$FAKE_EDITOR\"" git commit --no-verify
+	GIT_EDITOR="\"\$FAKE_EDITOR\"" git commit --no-commit-msg
 
 '
 
@@ -153,23 +153,72 @@ test_expect_success POSIXPERM 'with non-executable hook (editor)' '
 
 '
 
-test_expect_success POSIXPERM '--no-verify with non-executable hook' '
+test_expect_success POSIXPERM '--no-commit-msg with non-executable hook' '
 
 	echo "more content" >> file &&
 	git add file &&
-	git commit --no-verify -m "more content"
+	git commit --no-commit-msg -m "more content"
 
 '
 
-test_expect_success POSIXPERM '--no-verify with non-executable hook (editor)' '
+test_expect_success POSIXPERM '--no-commit-msg with non-executable hook (editor)' '
 
 	echo "even more content" >> file &&
 	git add file &&
 	echo "even more content" > FAKE_MSG &&
-	GIT_EDITOR="\"\$FAKE_EDITOR\"" git commit --no-verify
+	GIT_EDITOR="\"\$FAKE_EDITOR\"" git commit --no-commit-msg
 
 '
 
+test_hook_enabled () {
+	git checkout --detach master &&
+	output="running failing commit-msg hook with ${*:-(none)}..." &&
+	>actual.output &&
+	cat >"$HOOK" <<-EOF &&
+	#!/bin/sh
+	echo "$output" >>actual.output
+	exit 1
+	EOF
+	chmod +x "$HOOK" &&
+	echo "$output" >expected.output &&
+	test_must_fail test_commit $* file &&
+	test_cmp expected.output actual.output
+}
+
+test_hook_disabled () {
+	git checkout --detach master &&
+	output="running failing commit-msg hook with ${*:-(none)}..." &&
+	>actual.output &&
+	cat >"$HOOK" <<-EOF &&
+	#!/bin/sh
+	echo "$output" >>actual.output
+	exit 1
+	EOF
+	chmod +x "$HOOK" &&
+	test_commit --notag $* file &&
+	test_must_be_empty actual.output
+}
+
+test_expect_success 'command line options combinations' '
+	test_hook_enabled &&
+	test_hook_enabled --commit-msg &&
+	test_hook_enabled --no-commit-msg --commit-msg &&
+	test_hook_enabled --no-verify --commit-msg &&
+	test_hook_enabled --verify &&
+	test_hook_enabled --no-commit-msg --verify &&
+	test_hook_enabled --no-verify --verify &&
+	test_hook_enabled --verify --no-pre-commit &&
+	test_hook_enabled --verify --pre-commit &&
+	test_hook_disabled --no-commit-msg &&
+	test_hook_disabled --commit-msg --no-commit-msg &&
+	test_hook_disabled --commit-msg --no-verify &&
+	test_hook_disabled --no-verify &&
+	test_hook_disabled --verify --no-commit-msg &&
+	test_hook_disabled --verify --no-verify &&
+	test_hook_disabled --no-verify --no-pre-commit &&
+	test_hook_disabled --no-verify --pre-commit
+'
+
 # now a hook that edits the commit message
 cat > "$HOOK" <<'EOF'
 #!/bin/sh
@@ -205,7 +254,7 @@ test_expect_success "hook doesn't edit commit message" '
 
 	echo "plus" >> file &&
 	git add file &&
-	git commit --no-verify -m "plus" &&
+	git commit --no-commit-msg -m "plus" &&
 	commit_msg_is "plus"
 
 '
@@ -215,7 +264,7 @@ test_expect_success "hook doesn't edit commit message (editor)" '
 	echo "more plus" >> file &&
 	git add file &&
 	echo "more plus" > FAKE_MSG &&
-	GIT_EDITOR="\"\$FAKE_EDITOR\"" git commit --no-verify &&
+	GIT_EDITOR="\"\$FAKE_EDITOR\"" git commit --no-commit-msg &&
 	commit_msg_is "more plus"
 
 '
diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
index dafd6ad..a107073 100644
--- a/t/test-lib-functions.sh
+++ b/t/test-lib-functions.sh
@@ -154,20 +154,28 @@ test_pause () {
 
 test_commit () {
 	notick= &&
-	signoff= &&
+	notag= &&
+	commit_opts= &&
 	while test $# != 0
 	do
 		case "$1" in
 		--notick)
 			notick=yes
 			;;
-		--signoff)
-			signoff="$1"
+		--notag)
+			notag=yes
+			;;
+		--)
+			shift &&
+			break
+			;;
+		-*)
+			commit_opts="$commit_opts $1"
 			;;
 		*)
 			break
 			;;
-		esac
+		esac &&
 		shift
 	done &&
 	file=${2:-"$1.t"} &&
@@ -177,8 +185,11 @@ test_commit () {
 	then
 		test_tick
 	fi &&
-	git commit $signoff -m "$1" &&
-	git tag "${4:-$1}"
+	git commit $commit_opts -m "$1" &&
+	if test -z "$notag"
+	then
+		git tag "${4:-$1}"
+	fi
 }
 
 # Call test_merge with the arguments "<message> <commit>", where <commit>
-- 
2.0.1

[PATCH v3 08/27] rebase -i: verify squash messages using commit-msg

[Fabian Ruch]

Using the to-do list command `squash` the user can specify two or
more commits and git-rebase creates one commit that introduces all
their changes combined. The authorship for the created commit is
taken from the first commit specified and the user can edit the log
message. There is a variant of `squash` available named `fixup` which
also takes the first log message without asking for user input.

While it is reasonable to not verify replayed changes twice or
rejecting some other author's changes in her name, it is insufficient
to not verify the user input used as log message in the case of
`squash`. Specify the git-commit option `--no-pre-commit` instead of
`--no-verify` when committing the squash result, but not before, to
let the commit-msg hook verify the final squash message. For the same
reasons the pre-commit hook is disabled in all replay modes, the
commit-msg hook is disabled in `fixup` mode.

Add tests. In addition to the existing test checking that the
pre-commit hook is disabled when simply picking a commit, provide a
test checking that the commit-msg hook is disabled as well.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh    |  2 +-
 t/t3404-rebase-interactive.sh | 80 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 81 insertions(+), 1 deletion(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index cf62daa..54c4614 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -562,7 +562,7 @@ do_next () {
 			else
 				cp "$squash_msg" "$GIT_DIR"/SQUASH_MSG || exit
 				rm -f "$GIT_DIR"/MERGE_MSG
-				do_with_author output git commit --allow-empty --amend --no-verify -F "$GIT_DIR"/SQUASH_MSG -e \
+				do_with_author output git commit --allow-empty --amend --no-pre-commit -F "$GIT_DIR"/SQUASH_MSG -e \
 					${gpg_sign_opt:+"$gpg_sign_opt"} ||
 					die_failed_squash $sha1 "$rest"
 			fi
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index 7cc6ebf..abb829e 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -664,6 +664,86 @@ test_expect_success 'rebase a commit violating pre-commit' '
 
 '
 
+test_expect_success 'setup failing pre-commit' '
+	HOOKDIR="$(git rev-parse --git-dir)"/hooks &&
+	mkdir -p "$HOOKDIR" &&
+	PRE_COMMIT="$HOOKDIR"/pre-commit &&
+	cat >"$PRE_COMMIT" <<-EOF &&
+	#!/bin/sh
+	echo running failing pre-commit...
+	exit 1
+	EOF
+	chmod +x "$PRE_COMMIT" &&
+	git checkout -b violating-pre-commit master &&
+	test_must_fail test_commit pre-commit-violated-1 &&
+	test_commit --no-verify pre-commit-violated-1 &&
+	test_must_fail test_commit pre-commit-violated-2 &&
+	test_commit --no-verify pre-commit-violated-2 &&
+	test_must_fail test_commit pre-commit-violated-3 &&
+	test_commit --no-verify pre-commit-violated-3
+'
+
+test_expect_success 'squash commits violating pre-commit' '
+	git checkout -b squash-violating-pre-commit violating-pre-commit &&
+	test_when_finished reset_rebase &&
+	set_fake_editor &&
+	env FAKE_LINES="1 squash 2 squash 3" git rebase -i master
+'
+
+test_expect_success 'fixup commits violating pre-commit' '
+	git checkout -b fixup-violating-pre-commit violating-pre-commit &&
+	test_when_finished reset_rebase &&
+	set_fake_editor &&
+	env FAKE_LINES="1 fixup 2 fixup 3" git rebase -i master
+'
+
+test_expect_success 'clean up failing pre-commit' '
+	rm "$PRE_COMMIT"
+'
+
+test_expect_success 'setup failing commit-msg' '
+	HOOKDIR="$(git rev-parse --git-dir)"/hooks &&
+	mkdir -p "$HOOKDIR" &&
+	COMMIT_MSG="$HOOKDIR"/commit-msg &&
+	cat >"$COMMIT_MSG" <<-EOF &&
+	#!/bin/sh
+	echo running failing commit-msg...
+	exit 1
+	EOF
+	chmod +x "$COMMIT_MSG" &&
+	git checkout -b violating-commit-msg master &&
+	test_must_fail test_commit commit-msg-violated-1 &&
+	test_commit --no-verify commit-msg-violated-1 &&
+	test_must_fail test_commit commit-msg-violated-2 &&
+	test_commit --no-verify commit-msg-violated-2 &&
+	test_must_fail test_commit commit-msg-violated-3 &&
+	test_commit --no-verify commit-msg-violated-3
+'
+
+test_expect_success 'rebase a commit violating commit-msg' '
+	git checkout -b rebase-violating-commit-msg violating-commit-msg &&
+	set_fake_editor &&
+	FAKE_LINES="1" git rebase -i master
+'
+
+test_expect_success 'squash commits violating commit-msg' '
+	git checkout -b squash-violating-commit-msg violating-commit-msg &&
+	set_fake_editor &&
+	test_must_fail env FAKE_LINES="1 squash 2 squash 3" git rebase -i master &&
+	git commit --no-verify --amend &&
+	git rebase --continue
+'
+
+test_expect_success 'fixup commits violating commit-msg' '
+	git checkout -b fixup-violating-commit-msg violating-commit-msg &&
+	set_fake_editor &&
+	env FAKE_LINES="1 fixup 2 fixup 3" git rebase -i master
+'
+
+test_expect_success 'clean up failing commit-msg' '
+	rm "$COMMIT_MSG"
+'
+
 test_expect_success 'rebase with a file named HEAD in worktree' '
 
 	rm -fr .git/hooks &&
-- 
2.0.1

[PATCH v3 09/27] rebase -i: do not verify reworded patches using pre-commit

[Fabian Ruch]

The to-do list command `reword` replays a commit like `pick` but lets
the user also edit the commit's log message. This happens in two
steps. Firstly, the named commit is cherry-picked. Secondly, the
commit created in the first step is amended using an unchanged index
to edit the log message. The pre-commit hook is meant to verify the
changes introduced by a commit (for instance, catching inserted
trailing white space). Since the committed tree is not changed
between the two steps and we do not verify rebased patches, do not
execute the pre-commit hook in the second step.

Specify the git-commit option `--no-pre-commit` to disable the
pre-commit hook when editing the log message. The commit-msg hook
will still be executed to verify the edited commit log message. As
before, if the hook finds the new log message ill-formatted, the
rebase will be interrupted with the unchanged commit replayed and the
new log message in `$GIT_DIR/COMMIT_EDITMSG`.

Add tests.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh    |  2 +-
 t/t3404-rebase-interactive.sh | 14 ++++++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 54c4614..570c4e9 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -504,7 +504,7 @@ do_next () {
 
 		mark_action_done
 		do_pick $sha1 "$rest"
-		output git commit --allow-empty --amend --no-post-rewrite ${gpg_sign_opt:+"$gpg_sign_opt"} || {
+		output git commit --allow-empty --amend --no-post-rewrite --no-pre-commit ${gpg_sign_opt:+"$gpg_sign_opt"} || {
 			warn "Could not amend commit after successfully picking $sha1... $rest"
 			exit_with_patch $sha1 1
 		}
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index abb829e..ecdab11 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -683,6 +683,13 @@ test_expect_success 'setup failing pre-commit' '
 	test_commit --no-verify pre-commit-violated-3
 '
 
+test_expect_success 'reword a commit violating pre-commit' '
+	git checkout -b reword-violating-pre-commit violating-pre-commit &&
+	test_when_finished reset_rebase &&
+	set_fake_editor &&
+	env FAKE_LINES="reword 1" git rebase -i master
+'
+
 test_expect_success 'squash commits violating pre-commit' '
 	git checkout -b squash-violating-pre-commit violating-pre-commit &&
 	test_when_finished reset_rebase &&
@@ -726,6 +733,13 @@ test_expect_success 'rebase a commit violating commit-msg' '
 	FAKE_LINES="1" git rebase -i master
 '
 
+test_expect_success 'reword a commit violating commit-msg' '
+	git checkout -b reword-violating-commit-msg violating-commit-msg &&
+	test_when_finished reset_rebase &&
+	set_fake_editor &&
+	test_must_fail env FAKE_LINES="reword 1" git rebase -i master
+'
+
 test_expect_success 'squash commits violating commit-msg' '
 	git checkout -b squash-violating-commit-msg violating-commit-msg &&
 	set_fake_editor &&
-- 
2.0.1

[PATCH v3 10/27] rebase -i: teach do_pick the option --edit

[Fabian Ruch]

`do_pick` is the git-cherry-pick wrapper in git-rebase--interactive
that is used to implement the to-do list command `pick`. To cater for
the different pick behaviours (like `reword`), `do_pick` accepts
several options not only from the git-cherry-pick but also the
git-commit interface. Add the common option `--edit` to let the user
edit the log message of the named commit.

Loop over `$@` to parse the `do_pick` arguments. Assign the local
variable `edit` if one of the options is `--edit` so that the
remainder of `do_pick` can easily check whether the client code asked
to edit the commit message. If one of the options is unknown, mention
it on the console and `die`. Break the loop on the first non-option
and do some sanity checking to ensure that there exactly two
non-options, which are interpreted by the remainder as `<commit>` and
`<title>` like before.

`do_pick` ought to act as a wrapper around `cherry-pick`.
Unfortunately, it cannot just forward `--edit` to the `cherry-pick`
command line. The assembled command line is executed within a command
substitution for controlling the verbosity of `rebase--interactive`.
Passing `--edit` would either hang the terminal or clutter the
substituted command output with control sequences. Execute the
`reword` code from `do_next` instead if the option `--edit` is
specified.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 43 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 570c4e9..8a89ced 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -461,7 +461,42 @@ record_in_rewritten() {
 	esac
 }
 
+# Apply the changes introduced by the given commit to the current head.
+#
+# do_pick [--edit] <commit> <title>
+#
+# Wrapper around git-cherry-pick.
+#
+# -e, --edit
+#     After picking <commit>, open an editor and let the user edit the
+#     commit message. The editor contents becomes the commit message of
+#     the new head. This creates a fresh commit.
+#
+# <commit>
+#     The commit to cherry-pick.
+#
+# <title>
+#     The commit message title of <commit>. Used for information
+#     purposes only.
 do_pick () {
+	edit=
+	while test $# -gt 0
+	do
+		case "$1" in
+		-e|--edit)
+			edit=y
+			;;
+		-*)
+			die "do_pick: unrecognized option -- $1"
+			;;
+		*)
+			break
+			;;
+		esac
+		shift
+	done
+	test $# -ne 2 && die "do_pick: wrong number of arguments"
+
 	if test "$(git rev-parse HEAD)" = "$squash_onto"
 	then
 		# Set the correct commit message and author info on the
@@ -483,6 +518,14 @@ do_pick () {
 		pick_one $1 ||
 			die_with_patch $1 "Could not apply $1... $2"
 	fi
+
+	if test -n "$edit"
+	then
+		output git commit --allow-empty --amend --no-post-rewrite --no-pre-commit ${gpg_sign_opt:+"$gpg_sign_opt"} || {
+			warn "Could not amend commit after successfully picking $1... $2"
+			exit_with_patch $1 1
+		}
+	fi
 }
 
 do_next () {
-- 
2.0.1

[PATCH v3 11/27] rebase -i: implement reword in terms of do_pick

[Fabian Ruch]

The to-do list command `reword` replays a commit like `pick` but lets
the user also edit the commit's log message. If one thinks of `pick`
entries as scheduled `cherry-pick` command lines, then `reword`
becomes an alias for the command line `cherry-pick --edit`. The
porcelain `rebase--interactive` defines a function `do_pick` for
processing the `pick` entries on to-do lists. Reimplement `reword` in
terms of `do_pick --edit`.

If the user picks a commit using the to-do list line

    reword fa1afe1 Some change

execute the command `do_pick --edit fa1afe1 "Some change"` which
carries out exactly the same steps as the case arm for `reword` in
`do_next` so far.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 8a89ced..2d768b3 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -546,11 +546,7 @@ do_next () {
 		comment_for_reflog reword
 
 		mark_action_done
-		do_pick $sha1 "$rest"
-		output git commit --allow-empty --amend --no-post-rewrite --no-pre-commit ${gpg_sign_opt:+"$gpg_sign_opt"} || {
-			warn "Could not amend commit after successfully picking $sha1... $rest"
-			exit_with_patch $sha1 1
-		}
+		do_pick --edit $sha1 "$rest"
 		record_in_rewritten $sha1
 		;;
 	edit|e)
-- 
2.0.1

[PATCH v3 12/27] rebase -i: log the replay of root commits

[Fabian Ruch]

The command line used to recreate root commits specifies the option
`-q` which suppresses the commit summary message. However,
git-rebase--interactive tends to tell the user about the commits it
creates in the final history, if she wishes (cf. command line option
`--verbose`). The code parts handling non-root commits and squash
commits all output commit summary messages. Do not make the replay of
root commits an exception. Remove the option to make the report of
the rebased history complete. Do not forget to wrap the git-commit
command line in `output` so that the summary is shown if git-rebase
is called with the `--verbose` option but suppressed otherwise.

It is OK that the commit summary is still suppressed when git-commit
is used to initialize the authorship of the sentinel commit because
this additional commit is an implementation detail hidden from the
final history. The removed `-q` option was probably introduced as a
copy-and-paste error stemming from that part of the root commit
handling code.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 2d768b3..f4bb822 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -510,8 +510,8 @@ do_pick () {
 		git commit --allow-empty --allow-empty-message --amend \
 			   --no-post-rewrite -n -q -C $1 &&
 			pick_one -n $1 &&
-			git commit --allow-empty --allow-empty-message \
-				   --amend --no-post-rewrite -n -q -C $1 \
+			output git commit --allow-empty --allow-empty-message \
+				   --amend --no-post-rewrite -n -C $1 \
 				   ${gpg_sign_opt:+"$gpg_sign_opt"} ||
 			die_with_patch $1 "Could not apply $1... $2"
 	else
-- 
2.0.1

[PATCH v3 13/27] rebase -i: do not use -C when --no-edit is sufficient

[Fabian Ruch]

The command line used to recreate root commits uses `-C` to suppress
the log message editor. This is unnecessarily confusing, though,
because that suppression is a secondary effect of the option. The
main purpose of `-C` is to pull the metadata from another commit, but
here we know that this is a no-op, since we are amending a commit
just created from the same data.

At the time `-C` was introduced, git-commit did not yet have a
documented `--no-edit`, and this was a reasonable way to get the
desired behavior. Switch it to use `--no-edit` to make the intended
effect more obvious.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index f4bb822..6561831 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -511,7 +511,7 @@ do_pick () {
 			   --no-post-rewrite -n -q -C $1 &&
 			pick_one -n $1 &&
 			output git commit --allow-empty --allow-empty-message \
-				   --amend --no-post-rewrite -n -C $1 \
+				   --amend --no-post-rewrite -n --no-edit \
 				   ${gpg_sign_opt:+"$gpg_sign_opt"} ||
 			die_with_patch $1 "Could not apply $1... $2"
 	else
-- 
2.0.1

[PATCH v3 14/27] rebase -i: commit only once when rewriting picks

[Fabian Ruch]

The options passed to `do_pick` determine whether the picked commit
will be rewritten or not. If the commit gets rewritten, because the
user requested to edit the commit message for instance, let
`pick_one` merely apply the changes introduced by the commit and do
not commit the resulting tree yet. If the commit is replayed as is,
leave it to `pick_one` to recreate the commit (possibly by
fast-forwarding the head). This makes it easier to combine git-commit
options like `--edit` and `--amend` in `do_pick` because
git-cherry-pick does not support `--amend`.

In the case of `--edit`, do not `exit_with_patch` but assign
`rewrite` to pick the changes with `-n`. If the pick conflicts, no
commit is created which we would have to amend when continuing the
rebase. To complete the pick after the conflicts are resolved the
user just resumes with `git rebase --continue`.

git-commit lets the user edit the commit log message by default. We
do not want that for the rewriting git-commit command line because
the default behaviour of git-rebase is exactly the opposite. Pass
`--no-edit` when rewriting a picked commit. An explicit `--edit`
passed to `do_pick` (for instance, when reword is executed) enables
the editor launch again. Similarly, pass `--allow-empty-message`
unless the log message is edited.

If `rebase--interactive` is used to rebase a complete branch onto
some head, `rebase` creates a sentinel commit that requires special
treatment by `do_pick`. Do not finalize the pick here either because
its commit message can be altered as for any other pick. Since the
orphaned root commit gets a temporary parent, it is always rewritten.
Safely use the rewrite infrastructure of `do_pick` to create the
final commit.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh    | 41 ++++++++++++++++++++++++++---------------
 t/t3404-rebase-interactive.sh | 10 ++++++++++
 2 files changed, 36 insertions(+), 15 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 6561831..181e06a 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -63,9 +63,10 @@ msgnum="$state_dir"/msgnum
 author_script="$state_dir"/author-script
 
 # When an "edit" rebase command is being processed, the SHA1 of the
-# commit to be edited is recorded in this file.  When "git rebase
-# --continue" is executed, if there are any staged changes then they
-# will be amended to the HEAD commit, but only provided the HEAD
+# commit to be edited is recorded in this file.  The same happens when
+# rewriting a root commit fails, for instance "reword".  When "git
+# rebase --continue" is executed, if there are any staged changes then
+# they will be amended to the HEAD commit, but only provided the HEAD
 # commit is still the commit to be edited.  When any other rebase
 # command is processed, this file is deleted.
 amend="$state_dir"/amend
@@ -479,12 +480,17 @@ record_in_rewritten() {
 #     The commit message title of <commit>. Used for information
 #     purposes only.
 do_pick () {
-	edit=
+	allow_empty_message=y
+	rewrite=
+	rewrite_amend=
+	rewrite_edit=
 	while test $# -gt 0
 	do
 		case "$1" in
 		-e|--edit)
-			edit=y
+			rewrite=y
+			rewrite_edit=y
+			allow_empty_message=
 			;;
 		-*)
 			die "do_pick: unrecognized option -- $1"
@@ -499,6 +505,10 @@ do_pick () {
 
 	if test "$(git rev-parse HEAD)" = "$squash_onto"
 	then
+		rewrite=y
+		rewrite_amend=y
+		git rev-parse --verify HEAD >"$amend"
+
 		# Set the correct commit message and author info on the
 		# sentinel root before cherry-picking the original changes
 		# without committing (-n).  Finally, update the sentinel again
@@ -509,22 +519,23 @@ do_pick () {
 		# rebase --continue.
 		git commit --allow-empty --allow-empty-message --amend \
 			   --no-post-rewrite -n -q -C $1 &&
-			pick_one -n $1 &&
-			output git commit --allow-empty --allow-empty-message \
-				   --amend --no-post-rewrite -n --no-edit \
-				   ${gpg_sign_opt:+"$gpg_sign_opt"} ||
+			pick_one -n $1 ||
 			die_with_patch $1 "Could not apply $1... $2"
 	else
-		pick_one $1 ||
+		pick_one ${rewrite:+-n} $1 ||
 			die_with_patch $1 "Could not apply $1... $2"
 	fi
 
-	if test -n "$edit"
+	if test -n "$rewrite"
 	then
-		output git commit --allow-empty --amend --no-post-rewrite --no-pre-commit ${gpg_sign_opt:+"$gpg_sign_opt"} || {
-			warn "Could not amend commit after successfully picking $1... $2"
-			exit_with_patch $1 1
-		}
+		eval $(get_author_ident_from_commit $1)
+		do_with_author output git commit \
+			   --allow-empty --no-post-rewrite -n --no-edit \
+			   ${allow_empty_message:+--allow-empty-message} \
+			   ${rewrite_amend:+--amend} \
+			   ${rewrite_edit:+--edit --commit-msg} \
+			   ${gpg_sign_opt:+"$gpg_sign_opt"} ||
+			die_with_patch $1 "Could not rewrite commit after successfully picking $1... $2"
 	fi
 }
 
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index ecdab11..8de7a39 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -270,6 +270,16 @@ test_expect_success 'retain authorship' '
 	git show HEAD | grep "^Author: Twerp Snog"
 '
 
+test_expect_success 'retain authorship (reword)' '
+	echo A > file8 &&
+	git add file8 &&
+	test_tick &&
+	GIT_AUTHOR_NAME="Twerp Snog" git commit -m "different author" &&
+	set_fake_editor &&
+	FAKE_LINES="reword 1" git rebase -i --onto master HEAD^ &&
+	git show HEAD | grep "^Author: Twerp Snog"
+'
+
 test_expect_success 'setup squash/fixup reverted and fixed feature' '
 	git checkout -b reverted-feature master &&
 	test_commit feature &&
-- 
2.0.1

[PATCH v3 15/27] rebase -i: do not die in do_pick

[Fabian Ruch]

Since `do_pick` might be executed in a sub-shell (a modified author
environment for instance), calling `die` in `do_pick` has no effect
but exiting the sub-shell with a failure exit status. The
git-rebase--interactive script is not terminated. Moreover, if
`do_pick` is called while a squash or fixup is in effect,
`die_with_patch` will discard `$squash_msg` as commit message.
Lastly, after a `die` in `do_pick` `do_next` has no chance to
reschedule tasks that failed before changes could be applied.

Indicate an error in `do_pick` using return statements and properly
kill the script at the call sites. Although possible in principle,
the issued error messages are no more indicating whether `do_pick`
failed while applying or while committing the changes. This reduces
code complexity at the call site and does not matter from a user's
point of view because a glance at the index reveals whether there are
conflicts or not and in-depth troubleshooting is still possible using
the `--verbose` option.

Remove the commit message title argument from `do_pick`'s interface,
which has become unused.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 34 +++++++++++++++++++---------------
 1 file changed, 19 insertions(+), 15 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 181e06a..a5a8aa3 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -464,7 +464,7 @@ record_in_rewritten() {
 
 # Apply the changes introduced by the given commit to the current head.
 #
-# do_pick [--edit] <commit> <title>
+# do_pick [--edit] <commit>
 #
 # Wrapper around git-cherry-pick.
 #
@@ -476,9 +476,11 @@ record_in_rewritten() {
 # <commit>
 #     The commit to cherry-pick.
 #
-# <title>
-#     The commit message title of <commit>. Used for information
-#     purposes only.
+# The return value is 1 if applying the changes resulted in a conflict
+# and 2 if the specified arguments were incorrect. If the changes could
+# be applied successfully but creating the commit failed, a value
+# greater than 2 is returned. No commit is created in either case and
+# the index is left with the (conflicting) changes in place.
 do_pick () {
 	allow_empty_message=y
 	rewrite=
@@ -493,7 +495,8 @@ do_pick () {
 			allow_empty_message=
 			;;
 		-*)
-			die "do_pick: unrecognized option -- $1"
+			warn "do_pick: unrecognized option -- $1"
+			return 2
 			;;
 		*)
 			break
@@ -501,7 +504,11 @@ do_pick () {
 		esac
 		shift
 	done
-	test $# -ne 2 && die "do_pick: wrong number of arguments"
+	if test $# -ne 1
+	then
+		warn "do_pick: wrong number of arguments"
+		return 2
+	fi
 
 	if test "$(git rev-parse HEAD)" = "$squash_onto"
 	then
@@ -519,11 +526,9 @@ do_pick () {
 		# rebase --continue.
 		git commit --allow-empty --allow-empty-message --amend \
 			   --no-post-rewrite -n -q -C $1 &&
-			pick_one -n $1 ||
-			die_with_patch $1 "Could not apply $1... $2"
+			pick_one -n $1 || return 1
 	else
-		pick_one ${rewrite:+-n} $1 ||
-			die_with_patch $1 "Could not apply $1... $2"
+		pick_one ${rewrite:+-n} $1 || return 1
 	fi
 
 	if test -n "$rewrite"
@@ -534,8 +539,7 @@ do_pick () {
 			   ${allow_empty_message:+--allow-empty-message} \
 			   ${rewrite_amend:+--amend} \
 			   ${rewrite_edit:+--edit --commit-msg} \
-			   ${gpg_sign_opt:+"$gpg_sign_opt"} ||
-			die_with_patch $1 "Could not rewrite commit after successfully picking $1... $2"
+			   ${gpg_sign_opt:+"$gpg_sign_opt"} || return 3
 	fi
 }
 
@@ -550,21 +554,21 @@ do_next () {
 		comment_for_reflog pick
 
 		mark_action_done
-		do_pick $sha1 "$rest"
+		do_pick $sha1 || die_with_patch $sha1 "Could not apply $sha1... $rest"
 		record_in_rewritten $sha1
 		;;
 	reword|r)
 		comment_for_reflog reword
 
 		mark_action_done
-		do_pick --edit $sha1 "$rest"
+		do_pick --edit $sha1 || die_with_patch $sha1 "Could not apply $sha1... $rest"
 		record_in_rewritten $sha1
 		;;
 	edit|e)
 		comment_for_reflog edit
 
 		mark_action_done
-		do_pick $sha1 "$rest"
+		do_pick $sha1 || die_with_patch $sha1 "Could not apply $sha1... $rest"
 		warn "Stopped at $sha1... $rest"
 		exit_with_patch $sha1 0
 		;;
-- 
2.0.1

[PATCH v3 16/27] rebase -i: teach do_pick the option --amend

[Fabian Ruch]

`do_pick` is the git-cherry-pick wrapper in git-rebase--interactive
that is used to implement the to-do list commands `pick`, `reword`
and `edit`. To cater for the different pick behaviours (like
`squash`), `do_pick` accepts several options not only from the
git-cherry-pick but also the git-commit interface.

Add the option `--amend` from the git-commit interface to the options
pool of `do_pick`. It creates a new commit for the changes introduced
by the picked commit and the previous one. The previous commit is
then replaced with the new commit. If no other options are specified,
the log message of the previous commit is used.

Be careful when `--amend` is used to pick a root commit because HEAD
might point to the sentinel commit but there is still nothing to
amend. Be sure to initialize `amend` so that commits are squashed
even when git-rebase--interactive is interrupted for resolving
conflicts. It is not a mistake to do the initialization regardless of
any conflicts because `amend` is always cleared before the next to-do
item is processed.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index a5a8aa3..20a637a 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -464,10 +464,16 @@ record_in_rewritten() {
 
 # Apply the changes introduced by the given commit to the current head.
 #
-# do_pick [--edit] <commit>
+# do_pick [--amend] [--edit] <commit>
 #
 # Wrapper around git-cherry-pick.
 #
+# --amend
+#     After picking <commit>, replace the current head commit with a new
+#     commit that also introduces the changes of <commit>.
+#
+#     _This is not a git-cherry-pick option._
+#
 # -e, --edit
 #     After picking <commit>, open an editor and let the user edit the
 #     commit message. The editor contents becomes the commit message of
@@ -489,6 +495,16 @@ do_pick () {
 	while test $# -gt 0
 	do
 		case "$1" in
+		--amend)
+			if test "$(git rev-parse HEAD)" = "$squash_onto" || ! git rev-parse -q --verify HEAD >/dev/null
+			then
+				warn "do_pick: nothing to amend"
+				return 2
+			fi
+			rewrite=y
+			rewrite_amend=y
+			git rev-parse --verify HEAD >"$amend"
+			;;
 		-e|--edit)
 			rewrite=y
 			rewrite_edit=y
-- 
2.0.1

[PATCH v3 17/27] rebase -i: teach do_pick the option --file

[Fabian Ruch]

`do_pick` is the git-cherry-pick wrapper in git-rebase--interactive
that is used to implement the to-do list command `pick`, `reword` and
`edit`. To cater for the different pick behaviours (like `squash`),
`do_pick` accepts several options not only from the git-cherry-pick
but also the git-commit interface.

Add the option `--file` from the git-commit interface to the options
pool of `do_pick`. It expects an argument itself which is interpreted
as a file path and takes the commit message from the given file. If
`--file` is passed to `do_pick`, assign the given file path to the
local variable `rewrite_message` and relay the option

    --file "$rewrite_message"

to the git-commit command line which creates the commit.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 20a637a..f8be238 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -464,7 +464,7 @@ record_in_rewritten() {
 
 # Apply the changes introduced by the given commit to the current head.
 #
-# do_pick [--amend] [--edit] <commit>
+# do_pick [--amend] [--file <file>] [--edit] <commit>
 #
 # Wrapper around git-cherry-pick.
 #
@@ -474,6 +474,12 @@ record_in_rewritten() {
 #
 #     _This is not a git-cherry-pick option._
 #
+# -F <file>, --file <file>
+#     Take the commit message from the given file. This creates a fresh
+#     commit.
+#
+#     _This is not a git-cherry-pick option._
+#
 # -e, --edit
 #     After picking <commit>, open an editor and let the user edit the
 #     commit message. The editor contents becomes the commit message of
@@ -492,6 +498,7 @@ do_pick () {
 	rewrite=
 	rewrite_amend=
 	rewrite_edit=
+	rewrite_message=
 	while test $# -gt 0
 	do
 		case "$1" in
@@ -505,6 +512,16 @@ do_pick () {
 			rewrite_amend=y
 			git rev-parse --verify HEAD >"$amend"
 			;;
+		-F|--file)
+			if test $# -eq 0
+			then
+				warn "do_pick: option --file specified but no <file> given"
+				return 2
+			fi
+			rewrite=y
+			rewrite_message=$2
+			shift
+			;;
 		-e|--edit)
 			rewrite=y
 			rewrite_edit=y
@@ -555,6 +572,7 @@ do_pick () {
 			   ${allow_empty_message:+--allow-empty-message} \
 			   ${rewrite_amend:+--amend} \
 			   ${rewrite_edit:+--edit --commit-msg} \
+			   ${rewrite_message:+--file "$rewrite_message"} \
 			   ${gpg_sign_opt:+"$gpg_sign_opt"} || return 3
 	fi
 }
-- 
2.0.1

[PATCH v3 18/27] rebase -i: remove no-op do_with_author git commit --amend

[Fabian Ruch]

The author script is a file in the state directory that contains
assignments of the environment variables

    GIT_AUTHOR_NAME
    GIT_AUTHOR_EMAIL
    GIT_AUTHOR_DATE

to be evaluated by the shell. It is used to store author information
and has two applications in `git-rebase--interactive.sh`. Firstly,
the authorship of squash commits is read from it while the squash
commit is being amended step by step. Secondly, after conflict
resolution `git rebase --continue` restores the author information of
the original commit by sourcing the author script. For the
assignments of the git environment variables to take effect,
git-rebase--interactive executes the respective git-commit commands
wrapped in `do_with_author`. That shell function executes the named
command in a subshell that exports the git environment variables.

Since

    git commit --amend

has been used instead of

    git reset --soft HEAD^
    git commit

to amend squash commits, wrapping git-commit in `do_with_author` has
become a no-op because, unless the `--reset-author` option is
specified, `git commit --amend` ignores the user environment and
reuses the authorship of the commit it amends. To make the code
clearer and until we decide to use other authorships for squash
commits than the one of the first commit, unwrap `git commit
--amend`.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh    | 17 +++++++----------
 t/t3404-rebase-interactive.sh | 23 +++++++++++++++++++++++
 2 files changed, 30 insertions(+), 10 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index f8be238..ab807e5 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -622,9 +622,6 @@ do_next () {
 
 		mark_action_done
 		update_squash_messages $squash_style $sha1
-		author_script_content=$(get_author_ident_from_commit HEAD)
-		echo "$author_script_content" > "$author_script"
-		eval "$author_script_content"
 		if ! pick_one -n $sha1
 		then
 			git rev-parse --verify HEAD >"$amend"
@@ -634,7 +631,7 @@ do_next () {
 		squash|s|fixup|f)
 			# This is an intermediate commit; its message will only be
 			# used in case of trouble.  So use the long version:
-			do_with_author output git commit --allow-empty-message --allow-empty \
+			output git commit --allow-empty-message --allow-empty \
 				--amend --no-verify -F "$squash_msg" \
 				${gpg_sign_opt:+"$gpg_sign_opt"} ||
 				die_failed_squash $sha1 "$rest"
@@ -643,14 +640,14 @@ do_next () {
 			# This is the final command of this squash/fixup group
 			if test -f "$fixup_msg"
 			then
-				do_with_author output git commit --allow-empty-message --allow-empty \
+				output git commit --allow-empty-message --allow-empty \
 					--amend --no-verify -F "$fixup_msg" \
 					${gpg_sign_opt:+"$gpg_sign_opt"} ||
 					die_failed_squash $sha1 "$rest"
 			else
 				cp "$squash_msg" "$GIT_DIR"/SQUASH_MSG || exit
 				rm -f "$GIT_DIR"/MERGE_MSG
-				do_with_author output git commit --allow-empty --amend --no-pre-commit -F "$GIT_DIR"/SQUASH_MSG -e \
+				output git commit --allow-empty --amend --no-pre-commit -F "$GIT_DIR"/SQUASH_MSG -e \
 					${gpg_sign_opt:+"$gpg_sign_opt"} ||
 					die_failed_squash $sha1 "$rest"
 			fi
@@ -939,7 +936,7 @@ continue)
 	then
 		: Nothing to commit -- skip this
 	else
-		if ! test -f "$author_script"
+		if ! test -f "$author_script" && ! test -f "$amend"
 		then
 			gpg_sign_opt_quoted=${gpg_sign_opt:+$(git rev-parse --sq-quote "$gpg_sign_opt")}
 			die "You have staged changes in your working tree. If these changes are meant to be
@@ -956,8 +953,6 @@ In both case, once you're done, continue with:
   git rebase --continue
 "
 		fi
-		. "$author_script" ||
-			die "Error trying to find the author identity to amend commit"
 		if test -f "$amend"
 		then
 			current_head=$(git rev-parse --verify HEAD)
@@ -965,10 +960,12 @@ In both case, once you're done, continue with:
 			die "\
 You have uncommitted changes in your working tree. Please, commit them
 first and then run 'git rebase --continue' again."
-			do_with_author git commit --amend --no-verify -F "$msg" -e \
+			git commit --amend --no-verify -F "$msg" -e \
 				${gpg_sign_opt:+"$gpg_sign_opt"} ||
 				die "Could not commit staged changes."
 		else
+			. "$author_script" ||
+				die "Error trying to find the author identity to amend commit"
 			do_with_author git commit --no-verify -F "$msg" -e \
 				${gpg_sign_opt:+"$gpg_sign_opt"} ||
 				die "Could not commit staged changes."
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index 8de7a39..c037a07 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -1270,4 +1270,27 @@ test_expect_success 'fixup commits with empty commit log messages' '
 	env FAKE_LINES="1 fixup 2" git rebase -i master
 '
 
+test_expect_success 'squash commits have authorship of the first commit' '
+	git checkout -b squash-authorship master &&
+	git cat-file commit HEAD~3 | sed -n -e "/^$/q" -e "/^author /p" >expected.author &&
+	test_tick &&
+	set_fake_editor &&
+	FAKE_LINES="1 squash 2 squash 3 fixup 4" git rebase -i HEAD~4 &&
+	git cat-file commit HEAD | sed -n -e "/^$/q" -e "/^author /p" >actual.author &&
+	test_cmp expected.author actual.author
+'
+
+test_expect_success 'squash commits have authorship of the first commit after conflict' '
+	git checkout -b squash-authorship-conflict conflict-branch &&
+	git cat-file commit HEAD~3 | sed -n -e "/^$/q" -e "/^author /p" >expected.author &&
+	test_tick &&
+	set_fake_editor &&
+	test_must_fail env FAKE_LINES="1 squash 2 squash 4 fixup 3" git rebase -i HEAD~4 &&
+	git checkout --ours conflict &&
+	git add conflict &&
+	git rebase --continue &&
+	git cat-file commit HEAD | sed -n -e "/^$/q" -e "/^author /p" >actual.author &&
+	test_cmp expected.author actual.author
+'
+
 test_done
-- 
2.0.1

[PATCH v3 19/27] rebase -i: prepare for squash in terms of do_pick --amend

[Fabian Ruch]

Rewrite `squash` and `fixup` handling in `do_next` using the sequence

    pick_one
    commit

in order to test the correctness of a single `do_squash` or
parameterised `do_pick` and make the subsequent patch reimplementing
`squash` in terms of such a single function more readable.

Do not call `rm -f "$GIT_DIR"/MERGE_MSG` since it has no effect on
the state after git-rebase--interactive terminates. The option `-F`
makes git-commit ignore `MERGE_MSG` for the log message. If
git-commit succeeds, `MERGE_MSG` is removed, and if it fails,
`MERGE_MSG` is overwritten by the error sequence `die_failed_squash`.
In summary, removing `MERGE_MSG` neither influences the squash commit
message nor the file state after git-commit returns.

Moreover, `pick_one` ignores `$GIT_DIR/SQUASH_MSG` and does not touch
`$squash_msg` so that it is correct to execute `pick_one` immediately
before git-commit.

Might be squashed into the subsequent commit.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index ab807e5..614579c 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -622,15 +622,15 @@ do_next () {
 
 		mark_action_done
 		update_squash_messages $squash_style $sha1
-		if ! pick_one -n $sha1
-		then
-			git rev-parse --verify HEAD >"$amend"
-			die_failed_squash $sha1 "$rest"
-		fi
 		case "$(peek_next_command)" in
 		squash|s|fixup|f)
 			# This is an intermediate commit; its message will only be
 			# used in case of trouble.  So use the long version:
+			if ! pick_one -n $sha1
+			then
+				git rev-parse --verify HEAD >"$amend"
+				die_failed_squash $sha1 "Could not apply $sha1... $rest"
+			fi
 			output git commit --allow-empty-message --allow-empty \
 				--amend --no-verify -F "$squash_msg" \
 				${gpg_sign_opt:+"$gpg_sign_opt"} ||
@@ -640,13 +640,22 @@ do_next () {
 			# This is the final command of this squash/fixup group
 			if test -f "$fixup_msg"
 			then
+				if ! pick_one -n $sha1
+				then
+					git rev-parse --verify HEAD >"$amend"
+					die_failed_squash $sha1 "Could not apply $sha1... $rest"
+				fi
 				output git commit --allow-empty-message --allow-empty \
 					--amend --no-verify -F "$fixup_msg" \
 					${gpg_sign_opt:+"$gpg_sign_opt"} ||
 					die_failed_squash $sha1 "$rest"
 			else
 				cp "$squash_msg" "$GIT_DIR"/SQUASH_MSG || exit
-				rm -f "$GIT_DIR"/MERGE_MSG
+				if ! pick_one -n $sha1
+				then
+					git rev-parse --verify HEAD >"$amend"
+					die_failed_squash $sha1 "Could not apply $sha1... $rest"
+				fi
 				output git commit --allow-empty --amend --no-pre-commit -F "$GIT_DIR"/SQUASH_MSG -e \
 					${gpg_sign_opt:+"$gpg_sign_opt"} ||
 					die_failed_squash $sha1 "$rest"
-- 
2.0.1

[PATCH v3 20/27] rebase -i: implement squash in terms of do_pick

[Fabian Ruch]

The to-do list command `squash` and its close relative `fixup` replay
the changes of a commit like `pick` but do not recreate the commit.
Instead they replace the previous commit with a new commit that also
introduces the changes of the squashed commit. This is roughly like
cherry-picking without committing and using git-commit to amend the
previous commit.

The to-do list

    pick   a Some changes
    squash b Some more changes

gets translated into the sequence of git commands

    git cherry-pick a
    git cherry-pick -n b
    git commit --amend

and if git-cherry-pick supported `--amend` this would look even more
like the to-do list it is based on

    git cherry-pick a
    git cherry-pick --amend b.

Since `do_pick` takes care of `pick` entries and the above suggests
`squash` as an alias for `pick --amend`, reimplement `squash` in
terms of `do_pick --amend`. Introduce `$squash_msg` as the commit
message via the `--file` option. When the last commit of a squash
series is processed, the user is asked to review the log message.
Pass `--edit` as additional option in this case. The only difference
in the options passed to git-commit and `do_pick` is the omitted
`--no-verify`. However, `do_pick` does not execute the verification
hooks anyway because it solely replays commits and assumes that they
have been verified before.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 32 ++++++--------------------------
 1 file changed, 6 insertions(+), 26 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 614579c..6a123f0 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -626,39 +626,19 @@ do_next () {
 		squash|s|fixup|f)
 			# This is an intermediate commit; its message will only be
 			# used in case of trouble.  So use the long version:
-			if ! pick_one -n $sha1
-			then
-				git rev-parse --verify HEAD >"$amend"
-				die_failed_squash $sha1 "Could not apply $sha1... $rest"
-			fi
-			output git commit --allow-empty-message --allow-empty \
-				--amend --no-verify -F "$squash_msg" \
-				${gpg_sign_opt:+"$gpg_sign_opt"} ||
-				die_failed_squash $sha1 "$rest"
+			do_pick --amend -F "$squash_msg" $sha1 \
+				|| die_failed_squash $sha1 "$rest"
 			;;
 		*)
 			# This is the final command of this squash/fixup group
 			if test -f "$fixup_msg"
 			then
-				if ! pick_one -n $sha1
-				then
-					git rev-parse --verify HEAD >"$amend"
-					die_failed_squash $sha1 "Could not apply $sha1... $rest"
-				fi
-				output git commit --allow-empty-message --allow-empty \
-					--amend --no-verify -F "$fixup_msg" \
-					${gpg_sign_opt:+"$gpg_sign_opt"} ||
-					die_failed_squash $sha1 "$rest"
+				do_pick --amend -F "$fixup_msg" $sha1 \
+					|| die_failed_squash $sha1 "$rest"
 			else
 				cp "$squash_msg" "$GIT_DIR"/SQUASH_MSG || exit
-				if ! pick_one -n $sha1
-				then
-					git rev-parse --verify HEAD >"$amend"
-					die_failed_squash $sha1 "Could not apply $sha1... $rest"
-				fi
-				output git commit --allow-empty --amend --no-pre-commit -F "$GIT_DIR"/SQUASH_MSG -e \
-					${gpg_sign_opt:+"$gpg_sign_opt"} ||
-					die_failed_squash $sha1 "$rest"
+				do_pick --amend -F "$GIT_DIR"/SQUASH_MSG -e $sha1 \
+					|| die_failed_squash $sha1 "$rest"
 			fi
 			rm -f "$squash_msg" "$fixup_msg"
 			if test -z "$keep_empty" && is_empty_commit HEAD
-- 
2.0.1

[PATCH v3 21/27] rebase -i: explicitly distinguish replay commands and exec tasks

[Fabian Ruch]

There are two kinds of to-do list commands available. One kind
replays a commit (`pick`, `reword`, `edit`, `squash` and `fixup` that
is) and the other executes a shell command (`exec`). We will call the
first kind replay commands.

The two kinds of tasks are scheduled using different line formats.
Replay commands expect a commit hash argument following the command
name and exec concatenates all arguments to assemble a command line.

Adhere to the distinction of formats by not trying to parse the
`sha1` field unless we are dealing with a replay command. Move the
replay command handling code to a new function `do_replay` which
assumes the first argument to be a commit hash and make no more such
assumptions in `do_next`.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 42 ++++++++++++++++++++++++++++--------------
 1 file changed, 28 insertions(+), 14 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 6a123f0..e140bf0 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -577,13 +577,12 @@ do_pick () {
 	fi
 }
 
-do_next () {
-	rm -f "$msg" "$author_script" "$amend" || exit
-	read -r command sha1 rest < "$todo"
+do_replay () {
+	command=$1
+	sha1=$2
+	rest=$3
+
 	case "$command" in
-	"$comment_char"*|''|noop)
-		mark_action_done
-		;;
 	pick|p)
 		comment_for_reflog pick
 
@@ -659,6 +658,28 @@ do_next () {
 		esac
 		record_in_rewritten $sha1
 		;;
+	*)
+		read -r command <"$todo"
+		warn "Unknown command: $command"
+		fixtodo="Please fix this using 'git rebase --edit-todo'."
+		if git rev-parse --verify -q "$sha1" >/dev/null
+		then
+			die_with_patch $sha1 "$fixtodo"
+		else
+			die "$fixtodo"
+		fi
+		;;
+	esac
+}
+
+do_next () {
+	rm -f "$msg" "$author_script" "$amend" || exit
+	read -r command sha1 rest <"$todo"
+
+	case "$command" in
+	"$comment_char"*|''|noop)
+		mark_action_done
+		;;
 	x|"exec")
 		read -r command rest < "$todo"
 		mark_action_done
@@ -698,14 +719,7 @@ do_next () {
 		fi
 		;;
 	*)
-		warn "Unknown command: $command $sha1 $rest"
-		fixtodo="Please fix this using 'git rebase --edit-todo'."
-		if git rev-parse --verify -q "$sha1" >/dev/null
-		then
-			die_with_patch $sha1 "$fixtodo"
-		else
-			die "$fixtodo"
-		fi
+		do_replay $command $sha1 "$rest"
 		;;
 	esac
 	test -s "$todo" && return
-- 
2.0.1

[PATCH v3 22/27] rebase -i: parse to-do list command line options

[Fabian Ruch]

Read in to-do list lines as

    command args

instead of

    command sha1 rest

so that to-do list command lines can specify additional arguments
apart from the commit hash and the log message title, which become
the non-options in `args`. Loop over `args`, put all options (an
argument beginning with a dash) in `opts`, stop the loop on the first
non-option and assign it to `sha1`. For instance, the to-do list

    reword --signoff fa1afe1 Some change

is parsed as `command=reword`, `opts= '--signoff'` (including the
single quotes and the space for evaluation and concatenation of
options), `sha1=fa1afel` and `rest=Some change`. The loop does not
know the options it parses so that options that take an argument
themselves are not supported at the moment. Neither are options that
contain spaces because the shell expansion of `args` in `do_next`
interprets white space characters as argument separator.

Print an error message for unknown or unsupported command line
options, which means an error for all specified options at the
moment. Cleanly break the `do_next` loop by assigning a reason to the
local variable `malformed`, which triggers the unknown command code
in `do_replay`. Move the error code to the beginning of `do_replay`
so that unknown commands are reported before bad options are as only
the first error we come across is reported. For instance, the to-do
list from above produces the error

    Unknown 'reword' option: --signoff
    Please fix this using 'git rebase --edit-todo'.

The to-do list is also parsed when the commit hashes are translated
between long and short format before and after the to-do list is
edited. Apply the same procedure as in `do_replay` with the exception
that we only care about where the options stop and the commit hash
begins. Do not reject any options when transforming the commit
hashes.

Enable the specification of to-do list command line options in
`FAKE_LINES` the same way this is accomplished for command lines
passed to `exec`. Define a new `fake_editor.sh` that edits a static
to-do list instead of the one passed as argument when invoked by
git-rebase. Add a test case that checks that unknown options are
refused and can be corrected using `--edit-todo`.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh     | 95 +++++++++++++++++++++++++++++++-----------
 t/lib-rebase.sh                | 20 ++++++++-
 t/t3427-rebase-line-options.sh | 26 ++++++++++++
 3 files changed, 114 insertions(+), 27 deletions(-)
 create mode 100755 t/t3427-rebase-line-options.sh

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index e140bf0..8b39f2d 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -578,30 +578,71 @@ do_pick () {
 }
 
 do_replay () {
+	malformed=
 	command=$1
-	sha1=$2
-	rest=$3
+	shift
+	case "$command" in
+	pick|reword|edit|squash|fixup)
+		;;
+	*)
+		read -r command <"$todo"
+		malformed="Unknown command: $command"
+		;;
+	esac
+
+	opts=
+	while test $# -gt 0 && test -z "$malformed"
+	do
+		case "$1" in
+		-*)
+			malformed="Unknown '$command' option: $1"
+			;;
+		*)
+			break
+			;;
+		esac
+		opts="$opts $1"
+		shift
+	done
+	sha1=$1
+	shift
+	rest=$*
+
+	if test -n "$malformed"
+	then
+		warn "$malformed"
+		fixtodo="Please fix this using 'git rebase --edit-todo'."
+		if git rev-parse --verify -q "$sha1" >/dev/null
+		then
+			die_with_patch $sha1 "$fixtodo"
+		else
+			die "$fixtodo"
+		fi
+	fi
 
 	case "$command" in
 	pick|p)
 		comment_for_reflog pick
 
 		mark_action_done
-		do_pick $sha1 || die_with_patch $sha1 "Could not apply $sha1... $rest"
+		do_pick $opts $sha1 \
+			|| die_with_patch $sha1 "Could not apply $sha1... $rest"
 		record_in_rewritten $sha1
 		;;
 	reword|r)
 		comment_for_reflog reword
 
 		mark_action_done
-		do_pick --edit $sha1 || die_with_patch $sha1 "Could not apply $sha1... $rest"
+		do_pick --edit $opts $sha1 \
+			|| die_with_patch $sha1 "Could not apply $sha1... $rest"
 		record_in_rewritten $sha1
 		;;
 	edit|e)
 		comment_for_reflog edit
 
 		mark_action_done
-		do_pick $sha1 || die_with_patch $sha1 "Could not apply $sha1... $rest"
+		do_pick $opts $sha1 \
+			|| die_with_patch $sha1 "Could not apply $sha1... $rest"
 		warn "Stopped at $sha1... $rest"
 		exit_with_patch $sha1 0
 		;;
@@ -625,18 +666,18 @@ do_replay () {
 		squash|s|fixup|f)
 			# This is an intermediate commit; its message will only be
 			# used in case of trouble.  So use the long version:
-			do_pick --amend -F "$squash_msg" $sha1 \
+			do_pick --amend -F "$squash_msg" $opts $sha1 \
 				|| die_failed_squash $sha1 "$rest"
 			;;
 		*)
 			# This is the final command of this squash/fixup group
 			if test -f "$fixup_msg"
 			then
-				do_pick --amend -F "$fixup_msg" $sha1 \
+				do_pick --amend -F "$fixup_msg" $opts $sha1 \
 					|| die_failed_squash $sha1 "$rest"
 			else
 				cp "$squash_msg" "$GIT_DIR"/SQUASH_MSG || exit
-				do_pick --amend -F "$GIT_DIR"/SQUASH_MSG -e $sha1 \
+				do_pick --amend -F "$GIT_DIR"/SQUASH_MSG -e $opts $sha1 \
 					|| die_failed_squash $sha1 "$rest"
 			fi
 			rm -f "$squash_msg" "$fixup_msg"
@@ -658,23 +699,12 @@ do_replay () {
 		esac
 		record_in_rewritten $sha1
 		;;
-	*)
-		read -r command <"$todo"
-		warn "Unknown command: $command"
-		fixtodo="Please fix this using 'git rebase --edit-todo'."
-		if git rev-parse --verify -q "$sha1" >/dev/null
-		then
-			die_with_patch $sha1 "$fixtodo"
-		else
-			die "$fixtodo"
-		fi
-		;;
 	esac
 }
 
 do_next () {
 	rm -f "$msg" "$author_script" "$amend" || exit
-	read -r command sha1 rest <"$todo"
+	read -r command args <"$todo"
 
 	case "$command" in
 	"$comment_char"*|''|noop)
@@ -719,7 +749,7 @@ do_next () {
 		fi
 		;;
 	*)
-		do_replay $command $sha1 "$rest"
+		do_replay $command $args
 		;;
 	esac
 	test -s "$todo" && return
@@ -799,19 +829,34 @@ skip_unnecessary_picks () {
 }
 
 transform_todo_ids () {
-	while read -r command rest
+	while read -r command args
 	do
 		case "$command" in
 		"$comment_char"* | exec)
 			# Be careful for oddball commands like 'exec'
 			# that do not have a SHA-1 at the beginning of $rest.
+			newargs=\ $args
 			;;
 		*)
-			sha1=$(git rev-parse --verify --quiet "$@" ${rest%% *}) &&
-			rest="$sha1 ${rest#* }"
+			newargs=
+			sha1=
+			for arg in $args
+			do
+				case "$arg" in
+				-*)
+					newargs="$newargs $arg"
+					;;
+				*)
+					test -z "$sha1" &&
+						sha1=$(git rev-parse --verify --quiet "$@" $arg) &&
+						arg=$sha1
+					newargs="$newargs $arg"
+					;;
+				esac
+			done
 			;;
 		esac
-		printf '%s\n' "$command${rest:+ }$rest"
+		printf '%s\n' "$command$newargs"
 	done <"$todo" >"$todo.new" &&
 	mv -f "$todo.new" "$todo"
 }
diff --git a/t/lib-rebase.sh b/t/lib-rebase.sh
index 0cd1193..104f5bd 100644
--- a/t/lib-rebase.sh
+++ b/t/lib-rebase.sh
@@ -46,8 +46,8 @@ set_fake_editor () {
 	action=pick
 	for line in $FAKE_LINES; do
 		case $line in
-		squash|fixup|edit|reword)
-			action="$line";;
+		pick*|squash*|fixup*|edit*|reword*)
+			action=$(echo "$line" | sed 's/_/ /g');;
 		exec*)
 			echo "$line" | sed 's/_/ /g' >> "$1";;
 		"#")
@@ -80,6 +80,22 @@ set_cat_todo_editor () {
 	test_set_editor "$(pwd)/fake-editor.sh"
 }
 
+# set_fixed_todo_editor takes a file path as argument and installs an
+# editor script that, firstly, overwrites the file path argument with
+# the one specified during installation and, secondly, calls
+# fake-editor.sh for changing the contents as usual. This comes in
+# handy if it is easier to change some fixed file instead of the one
+# that will be passed when the editor is being invoked.
+
+set_fixed_todo_editor () {
+	set_fake_editor
+	write_script fake-editor-wrapper.sh <<-EOF
+	cp "$1" "\$1"
+	"$(pwd)"/fake-editor.sh "\$1"
+	EOF
+	test_set_editor "$(pwd)/fake-editor-wrapper.sh"
+}
+
 # checks that the revisions in "$2" represent a linear range with the
 # subjects in "$1"
 test_linear_range () {
diff --git a/t/t3427-rebase-line-options.sh b/t/t3427-rebase-line-options.sh
new file mode 100755
index 0000000..5881162
--- /dev/null
+++ b/t/t3427-rebase-line-options.sh
@@ -0,0 +1,26 @@
+#!/bin/sh
+
+test_description='git rebase -i with line options'
+
+. ./test-lib.sh
+
+. "$TEST_DIRECTORY"/lib-rebase.sh
+
+test_expect_success 'Set up repository' '
+	test_commit Initial &&
+	test_commit Commit1 &&
+	test_commit Commit2
+'
+
+test_expect_success 'Unknown option' '
+	git checkout -b unknown-option master &&
+	set_cat_todo_editor &&
+	test_must_fail git rebase -i HEAD^ >todo &&
+	set_fake_editor &&
+	test_must_fail env FAKE_LINES="1 pick_--unknown-option 2" git rebase -i HEAD~2 &&
+	set_fixed_todo_editor "$(pwd)"/todo &&
+	git rebase --edit-todo &&
+	git rebase --continue
+'
+
+test_done
-- 
2.0.1

[PATCH v3 23/27] rebase -i: teach do_pick the option --reset-author

[Fabian Ruch]

`do_pick` is the git-cherry-pick wrapper in git-rebase--interactive
that is used to implement many of the to-do list commands.
Eventually, the complete `do_pick` interface will be exposed to the
user in some form or another and those commands will become simple
aliases for the `do_pick` options now used to implement them.

Add the git-commit option `--reset-author` to the options pool of
`do_pick`. It rewrites the author date and name of the picked commit
to match the committer date and name.

If `--reset-author` is passed to `do_pick`, set the `rewrite` flag
and relay the option to the git-commit command line which creates the
final commit. If `--amend` is not passed as well, the fresh
authorship effect is achieved by the mere fact that we are creating a
new commit. Do not even source the ident information in that case
because the user shell might have already exported the respective
environment variables.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 26 ++++++++++++++++++++++----
 1 file changed, 22 insertions(+), 4 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 8b39f2d..6c75bc5 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -464,10 +464,18 @@ record_in_rewritten() {
 
 # Apply the changes introduced by the given commit to the current head.
 #
-# do_pick [--amend] [--file <file>] [--edit] <commit>
+# do_pick [--reset-author] [--amend] [--file <file>] [--edit] <commit>
 #
 # Wrapper around git-cherry-pick.
 #
+# --reset-author
+#     Pretend the changes were made for the first time. Declare that the
+#     authorship of the resulting commit now belongs to the committer.
+#     This also renews the author timestamp. This creates a fresh
+#     commit.
+#
+#     _This is not a git-cherry-pick option._
+#
 # --amend
 #     After picking <commit>, replace the current head commit with a new
 #     commit that also introduces the changes of <commit>.
@@ -496,12 +504,17 @@ record_in_rewritten() {
 do_pick () {
 	allow_empty_message=y
 	rewrite=
+	rewrite_reset_author=
 	rewrite_amend=
 	rewrite_edit=
 	rewrite_message=
 	while test $# -gt 0
 	do
 		case "$1" in
+		--reset-author)
+			rewrite=y
+			rewrite_reset_author=y
+			;;
 		--amend)
 			if test "$(git rev-parse HEAD)" = "$squash_onto" || ! git rev-parse -q --verify HEAD >/dev/null
 			then
@@ -566,11 +579,16 @@ do_pick () {
 
 	if test -n "$rewrite"
 	then
-		eval $(get_author_ident_from_commit $1)
-		do_with_author output git commit \
+		do_with_author=
+		if test -z "$rewrite_reset_author" && test -z "$rewrite_amend"
+		then
+			eval $(get_author_ident_from_commit $1)
+			do_with_author=do_with_author
+		fi
+		$do_with_author output git commit \
 			   --allow-empty --no-post-rewrite -n --no-edit \
 			   ${allow_empty_message:+--allow-empty-message} \
-			   ${rewrite_amend:+--amend} \
+			   ${rewrite_amend:+--amend ${rewrite_reset_author:+--reset-author}} \
 			   ${rewrite_edit:+--edit --commit-msg} \
 			   ${rewrite_message:+--file "$rewrite_message"} \
 			   ${gpg_sign_opt:+"$gpg_sign_opt"} || return 3
-- 
2.0.1

[PATCH v3 24/27] rebase -i: teach do_pick the option --signoff

[Fabian Ruch]

`do_pick` is the git-cherry-pick wrapper in git-rebase--interactive
that is currently used to implement most of the to-do list commands
and offers additional options that will eventually find their way
onto to-do lists.

To extend the repertoire of available options, add the git-commit and
git-cherry-pick option `--signoff` to the `do_pick` interface. It
appends a Signed-off-by: line using the committer identity to the log
message of the picked commit.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 6c75bc5..73c97a1 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -464,10 +464,15 @@ record_in_rewritten() {
 
 # Apply the changes introduced by the given commit to the current head.
 #
-# do_pick [--reset-author] [--amend] [--file <file>] [--edit] <commit>
+# do_pick [--signoff] [--reset-author] [--amend] [--file <file>]
+#         [--edit] <commit>
 #
 # Wrapper around git-cherry-pick.
 #
+# -s, --signoff
+#     Insert a Signed-off-by: line using the committer identity at the
+#     end of the commit log message. This creates a fresh commit.
+#
 # --reset-author
 #     Pretend the changes were made for the first time. Declare that the
 #     authorship of the resulting commit now belongs to the committer.
@@ -504,6 +509,7 @@ record_in_rewritten() {
 do_pick () {
 	allow_empty_message=y
 	rewrite=
+	rewrite_signoff=
 	rewrite_reset_author=
 	rewrite_amend=
 	rewrite_edit=
@@ -511,6 +517,10 @@ do_pick () {
 	while test $# -gt 0
 	do
 		case "$1" in
+		-s|--signoff)
+			rewrite=y
+			rewrite_signoff=y
+			;;
 		--reset-author)
 			rewrite=y
 			rewrite_reset_author=y
@@ -588,6 +598,7 @@ do_pick () {
 		$do_with_author output git commit \
 			   --allow-empty --no-post-rewrite -n --no-edit \
 			   ${allow_empty_message:+--allow-empty-message} \
+			   ${rewrite_signoff:+--signoff} \
 			   ${rewrite_amend:+--amend ${rewrite_reset_author:+--reset-author}} \
 			   ${rewrite_edit:+--edit --commit-msg} \
 			   ${rewrite_message:+--file "$rewrite_message"} \
-- 
2.0.1

[PATCH v3 25/27] rebase -i: do not overwrite user author information

[Fabian Ruch]

The shell function `get_author_ident_from_commit` defined by
git-sh-setup retrieves the author information from the named commit
and returns assignments of the environment variables

    GIT_AUTHOR_NAME
    GIT_AUTHOR_EMAIL
    GIT_AUTHOR_DATE

ready for evaluation by the shell.

This interface is used in conjunction with the so-called author
script which is a git-rebase--interactive state file that contains
the `get_author_ident_from_commit` output. It is sourced when `git
rebase --continue` is executed after conflict resolution to retain
the original commit authorship.

The variable assignments are only exported by the subshell that
executes the git-commit command line that commits the resolved
conflicts. That is taken care of by wrapping the git-commit call in
`do_with_author`. However, this is not enough protection from
modifying the git environment variables unintentionally because the
user running git-rebase could have already exported those herself.
And therefore, a bare git-commit could result in an authorship that
is neither intended by the user nor by git-rebase--interactive.

While it is not an issue now (either `do_with_author`,
git-cherry-pick or `--amend` are used to create commits), the
unnecessary loss of the author name and e-mail copied from the user
environment, and the unneeded fixing of the author date might become
a problem when we decide to support something similar to
`--reset-author` or `--ignore-date in interactive git-rebase.

Do not assign the git environment variables until in the
`do_with_author` subshell.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 73c97a1..8fbfe6d 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -166,7 +166,7 @@ make_patch () {
 	test -f "$msg" ||
 		commit_message "$1" > "$msg"
 	test -f "$author_script" ||
-		get_author_ident_from_commit "$1" > "$author_script"
+		echo "$1" > "$author_script"
 }
 
 die_with_patch () {
@@ -215,9 +215,13 @@ is_merge_commit()
 }
 
 # Run command with GIT_AUTHOR_NAME, GIT_AUTHOR_EMAIL, and
-# GIT_AUTHOR_DATE exported from the current environment.
+# GIT_AUTHOR_DATE assigned the author information extracted from the
+# named commit and exported.
 do_with_author () {
 	(
+		sha1=$1
+		shift
+		eval $(get_author_ident_from_commit $sha1)
 		export GIT_AUTHOR_NAME GIT_AUTHOR_EMAIL GIT_AUTHOR_DATE
 		"$@"
 	)
@@ -348,13 +352,11 @@ pick_one_preserving_merges () {
 			test "a$1" = a-n && die "Refusing to squash a merge: $sha1"
 
 			# redo merge
-			author_script_content=$(get_author_ident_from_commit $sha1)
-			eval "$author_script_content"
 			msg_content="$(commit_message $sha1)"
 			# No point in merging the first parent, that's HEAD
 			new_parents=${new_parents# $first_parent}
 			merge_args="--no-log --no-ff"
-			if ! do_with_author output eval \
+			if ! do_with_author $sha1 output eval \
 			'git merge ${gpg_sign_opt:+"$gpg_sign_opt"} \
 				$merge_args $strategy_args -m "$msg_content" $new_parents'
 			then
@@ -592,8 +594,7 @@ do_pick () {
 		do_with_author=
 		if test -z "$rewrite_reset_author" && test -z "$rewrite_amend"
 		then
-			eval $(get_author_ident_from_commit $1)
-			do_with_author=do_with_author
+			do_with_author="do_with_author $1"
 		fi
 		$do_with_author output git commit \
 			   --allow-empty --no-post-rewrite -n --no-edit \
@@ -1041,9 +1042,9 @@ first and then run 'git rebase --continue' again."
 				${gpg_sign_opt:+"$gpg_sign_opt"} ||
 				die "Could not commit staged changes."
 		else
-			. "$author_script" ||
+			test -r "$author_script" ||
 				die "Error trying to find the author identity to amend commit"
-			do_with_author git commit --no-verify -F "$msg" -e \
+			do_with_author $(cat "$author_script") git commit --no-verify -F "$msg" -e \
 				${gpg_sign_opt:+"$gpg_sign_opt"} ||
 				die "Could not commit staged changes."
 		fi
-- 
2.0.1

[PATCH v3 26/27] rebase -i: refuse to commit when resuming with updated head

[Fabian Ruch]

If git-rebase--interactive fails to apply the changes introduced by a
commit due to conflicts, it interrupts the rebase process and gives
the user a shell to resolve the conflicts manually. The process is
resumed when the user executes `git rebase --continue`. If the index
has changes, the script assumes that those are to be committed under
the authorship and with the log message of the commit it tried to
replay last. However, that assumption is most likely incorrect if the
user has already committed the resolved changes herself. To prevent
committing unrelated changes under the wrong authorship and with the
wrong log message, at least check that HEAD is still at the same
commit by tracking the hash of the last replayed commit. A similar
check already happens before `git rebase --continue` amends the
previous commit after an `edit` or a conflicted `squash` command.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 git-rebase--interactive.sh    | 35 +++++++++++++++++++++--------------
 t/t3404-rebase-interactive.sh | 12 ++++++++++++
 2 files changed, 33 insertions(+), 14 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 8fbfe6d..51ee80c 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -62,13 +62,18 @@ msgnum="$state_dir"/msgnum
 # being rebased.
 author_script="$state_dir"/author-script
 
-# When an "edit" rebase command is being processed, the SHA1 of the
-# commit to be edited is recorded in this file.  The same happens when
-# rewriting a root commit fails, for instance "reword".  When "git
-# rebase --continue" is executed, if there are any staged changes then
-# they will be amended to the HEAD commit, but only provided the HEAD
-# commit is still the commit to be edited.  When any other rebase
-# command is processed, this file is deleted.
+# This file keeps track of the SHA1 of the last replayed commit, the
+# new parent of the next commit being replayed. It is used to make
+# sure that "git rebase --continue" only commits resolved conflicts
+# or "edit" changes automatically.
+last_head="$state_dir"/last_head
+
+# When an "edit" or a "squash" rebase command is being processed, the
+# file 'amend' is created. When "git rebase --continue" is executed,
+# if there are any staged changes then they will be amended to the
+# HEAD commit, but only provided the HEAD commit is still the commit
+# to be edited or the squash commit. When any other rebase command is
+# processed, these files are deleted.
 amend="$state_dir"/amend
 
 # For the post-rewrite hook, we make a list of rewritten commits and
@@ -179,7 +184,8 @@ die_with_patch () {
 exit_with_patch () {
 	echo "$1" > "$state_dir"/stopped-sha
 	make_patch $1
-	git rev-parse --verify HEAD > "$amend"
+	>"$amend"
+	git rev-parse --verify HEAD >"$last_head"
 	gpg_sign_opt_quoted=${gpg_sign_opt:+$(git rev-parse --sq-quote "$gpg_sign_opt")}
 	warn "You can amend the commit now, with"
 	warn
@@ -535,7 +541,7 @@ do_pick () {
 			fi
 			rewrite=y
 			rewrite_amend=y
-			git rev-parse --verify HEAD >"$amend"
+			>"$amend"
 			;;
 		-F|--file)
 			if test $# -eq 0
@@ -572,7 +578,7 @@ do_pick () {
 	then
 		rewrite=y
 		rewrite_amend=y
-		git rev-parse --verify HEAD >"$amend"
+		>"$amend"
 
 		# Set the correct commit message and author info on the
 		# sentinel root before cherry-picking the original changes
@@ -734,6 +740,7 @@ do_replay () {
 
 do_next () {
 	rm -f "$msg" "$author_script" "$amend" || exit
+	git rev-parse --verify HEAD >"$last_head" || exit
 	read -r command args <"$todo"
 
 	case "$command" in
@@ -1031,13 +1038,13 @@ In both case, once you're done, continue with:
   git rebase --continue
 "
 		fi
-		if test -f "$amend"
-		then
-			current_head=$(git rev-parse --verify HEAD)
-			test "$current_head" = $(cat "$amend") ||
+		current_head=$(git rev-parse --verify HEAD)
+		test "$current_head" = $(cat "$last_head") ||
 			die "\
 You have uncommitted changes in your working tree. Please, commit them
 first and then run 'git rebase --continue' again."
+		if test -f "$amend"
+		then
 			git commit --amend --no-verify -F "$msg" -e \
 				${gpg_sign_opt:+"$gpg_sign_opt"} ||
 				die "Could not commit staged changes."
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index c037a07..5955bd8 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -444,6 +444,18 @@ test_expect_success '--continue tries to commit' '
 	git show HEAD | grep chouette
 '
 
+test_expect_success '--continue does not commit after head is moved' '
+	git reset --hard to-be-rebased@{1} &&
+	test_must_fail git rebase -i --onto new-branch1 HEAD^ &&
+	echo resolved >file1 &&
+	git add file1 &&
+	git commit &&
+	echo dirty >file1 &&
+	test_must_fail git rebase --continue &&
+	git checkout file1 &&
+	git rebase --continue
+'
+
 test_expect_success 'verbose flag is heeded, even after --continue' '
 	git reset --hard master@{1} &&
 	test_tick &&
-- 
2.0.1

[PATCH v3 27/27] rebase -i: enable --signoff, --reset-author for pick, reword, edit

[Fabian Ruch]

Lift the general unknown option blockade for the `pick`, `reword` and
`edit` commands. If `do_cmd` comes across one of the options
`--signoff` and `--reset-author` while parsing a to-do entry and the
scheduled command is either `pick` or `reword`, relay the option to
`do_pick`.

Remember to add Signed-off-by: and to reset the authorship even when
the rebase is interrupted for conflict resolution and `git rebase
--continue` creates the commit. Employ the same mechanism that is
used to remember amending an interim squash commit after conflict
resolution or a commit after editing. If a line option was specified,
create the files `signoff` and `resetauthor` respectively in the
state directory. While `signoff` is handled by simply specifying the
`--signoff` option when creating the commit, the `resetauthor` case
is somewhat more involved. The author script contains the author
information of the replayed commit. Renewing the authorship means
using the user environment for the authorship so that we need to skip
the author script if `resetauthor` exists and we are not amending. If
we are amending, `--reset-author` must be passed to git-commit
because otherwise the authorship of HEAD would be used.

`do_pick` options like `--gpg-sign` and `--file` are not yet
supported because `do_cmd` cannot handle option arguments and options
with spaces at the moment. `squash` and `fixup` still do not accept
user options as the interplay of `--reset-author` and the author
script is yet to be determined.

Document the new options by listing them in the to-do help and giving
a usage example in the "INTERACTIVE MODE" section of the git-rebase
man page.

Add tests.

Signed-off-by: Fabian Ruch <bafain@gmail.com>
---
 Documentation/git-rebase.txt   |  13 +++
 git-rebase--interactive.sh     |  38 +++++++-
 t/t3427-rebase-line-options.sh | 192 ++++++++++++++++++++++++++++++++++++++++-
 3 files changed, 240 insertions(+), 3 deletions(-)

diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt
index 2a93c64..10c0fd2 100644
--- a/Documentation/git-rebase.txt
+++ b/Documentation/git-rebase.txt
@@ -508,6 +508,19 @@ rebasing.
 If you just want to edit the commit message for a commit, replace the
 command "pick" with the command "reword".
 
+The commands "pick", "reword" and "edit" understand some well-known
+options. To add a Signed-off-by line at the end of the commit
+message, pass the `--signoff` option. The authorship can be renewed
+by specifying the `--reset-author` option. For instance, before you
+decide to publish a heavily edited commit you might want to reset the
+authorship and add your signature. You can do so on a per line basis:
+
+-------------------------------------------
+pick deadbee The oneline of this commit
+pick --reset-author --signoff fa1afe1 The oneline of the next commit
+...
+-------------------------------------------
+
 If you want to fold two or more commits into one, replace the command
 "pick" for the second and subsequent commits with "squash" or "fixup".
 If the commits had different authors, the folded commit will be
diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 51ee80c..0db5001 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -72,9 +72,15 @@ last_head="$state_dir"/last_head
 # file 'amend' is created. When "git rebase --continue" is executed,
 # if there are any staged changes then they will be amended to the
 # HEAD commit, but only provided the HEAD commit is still the commit
-# to be edited or the squash commit. When any other rebase command is
+# to be edited or the squash commit. Similarly, when a Signed-off-by:
+# should be added to a log message or the authorship should be
+# renewed, the files 'signoff' and 'resetauthor' are created
+# respectively, and "git rebase --continue" carries out the changes
+# after conflict resolution. When any other rebase command is
 # processed, these files are deleted.
 amend="$state_dir"/amend
+signoff="$state_dir"/signoff
+resetauthor="$state_dir"/resetauthor
 
 # For the post-rewrite hook, we make a list of rewritten commits and
 # their new sha1s.  The rewritten-pending list keeps the sha1s of
@@ -149,6 +155,10 @@ Commands:
  f, fixup = like "squash", but discard this commit's log message
  x, exec = run command (the rest of the line) using shell
 
+Options:
+ [pick | reword | edit] --signoff = add a Signed-off-by line
+ [pick | reword | edit] --reset-author = renew authorship
+
 These lines can be re-ordered; they are executed from top to bottom.
 
 If you remove a line here THAT COMMIT WILL BE LOST.
@@ -528,10 +538,12 @@ do_pick () {
 		-s|--signoff)
 			rewrite=y
 			rewrite_signoff=y
+			>"$signoff"
 			;;
 		--reset-author)
 			rewrite=y
 			rewrite_reset_author=y
+			>"$resetauthor"
 			;;
 		--amend)
 			if test "$(git rev-parse HEAD)" = "$squash_onto" || ! git rev-parse -q --verify HEAD >/dev/null
@@ -630,6 +642,15 @@ do_replay () {
 	while test $# -gt 0 && test -z "$malformed"
 	do
 		case "$1" in
+		--signoff|--reset-author)
+			case "$command" in
+			pick|reword|edit)
+				;;
+			*)
+				malformed="Unsupported '$command' option: $1"
+				;;
+			esac
+			;;
 		-*)
 			malformed="Unknown '$command' option: $1"
 			;;
@@ -739,7 +760,7 @@ do_replay () {
 }
 
 do_next () {
-	rm -f "$msg" "$author_script" "$amend" || exit
+	rm -f "$msg" "$author_script" "$amend" "$signoff" "$resetauthor" || exit
 	git rev-parse --verify HEAD >"$last_head" || exit
 	read -r command args <"$todo"
 
@@ -1043,15 +1064,28 @@ In both case, once you're done, continue with:
 			die "\
 You have uncommitted changes in your working tree. Please, commit them
 first and then run 'git rebase --continue' again."
+		rewrite_reset_author=
+		rewrite_signoff=
+		test -f "$resetauthor" && rewrite_reset_author=y
+		test -f "$signoff" && rewrite_signoff=y
 		if test -f "$amend"
 		then
 			git commit --amend --no-verify -F "$msg" -e \
+				${rewrite_signoff:+--signoff} \
+				${rewrite_reset_author:+--reset-author} \
+				${gpg_sign_opt:+"$gpg_sign_opt"} ||
+				die "Could not commit staged changes."
+		elif test -n "$rewrite_reset_author"
+		then
+			git commit --no-verify -F "$msg" -e \
+				${rewrite_signoff:+--signoff} \
 				${gpg_sign_opt:+"$gpg_sign_opt"} ||
 				die "Could not commit staged changes."
 		else
 			test -r "$author_script" ||
 				die "Error trying to find the author identity to amend commit"
 			do_with_author $(cat "$author_script") git commit --no-verify -F "$msg" -e \
+				${rewrite_signoff:+--signoff} \
 				${gpg_sign_opt:+"$gpg_sign_opt"} ||
 				die "Could not commit staged changes."
 		fi
diff --git a/t/t3427-rebase-line-options.sh b/t/t3427-rebase-line-options.sh
index 5881162..9c9501a 100755
--- a/t/t3427-rebase-line-options.sh
+++ b/t/t3427-rebase-line-options.sh
@@ -6,10 +6,32 @@ test_description='git rebase -i with line options'
 
 . "$TEST_DIRECTORY"/lib-rebase.sh
 
+commit_message () {
+	git cat-file commit "$1" | sed '1,/^$/d'
+}
+
+commit_authorship () {
+	git cat-file commit "$1" | sed -n '/^$/q;/^author /p'
+}
+
+authorship () {
+	echo "author $GIT_AUTHOR_NAME <$GIT_AUTHOR_EMAIL> $GIT_AUTHOR_DATE"
+}
+
+test_diff_file () {
+	if cmp "$1" "$2" >/dev/null
+	then
+		echo "'$1' and '$2' are the same"
+		return 1
+	fi
+}
+
 test_expect_success 'Set up repository' '
 	test_commit Initial &&
 	test_commit Commit1 &&
-	test_commit Commit2
+	test_commit Commit2 &&
+	git checkout -b branch Commit1 &&
+	test_commit Commit2_ Commit2.t
 '
 
 test_expect_success 'Unknown option' '
@@ -23,4 +45,172 @@ test_expect_success 'Unknown option' '
 	git rebase --continue
 '
 
+test_msg_author () {
+	set_fake_editor &&
+	FAKE_LINES="1 $1 2" git rebase -i HEAD~2 &&
+	commit_message HEAD >actual.msg &&
+	commit_authorship HEAD >actual.author &&
+	test_cmp expected.msg actual.msg &&
+	test_cmp expected.author actual.author
+}
+
+test_msg_author_misspelled () {
+	set_cat_todo_editor &&
+	test_must_fail git rebase -i HEAD^ >todo &&
+	set_fake_editor &&
+	test_must_fail env FAKE_LINES="1 $1-misspelled 2" git rebase -i HEAD~2 &&
+	set_fixed_todo_editor "$(pwd)"/todo &&
+	FAKE_LINES="$1 1" git rebase --edit-todo &&
+	git rebase --continue &&
+	commit_message HEAD >actual.msg &&
+	commit_authorship HEAD >actual.author &&
+	test_cmp expected.msg actual.msg &&
+	test_cmp expected.author actual.author
+}
+
+test_msg_author_conflicted () {
+	set_fake_editor &&
+	test_must_fail env FAKE_LINES="$1 1" git rebase -i master &&
+	git checkout --theirs Commit2.t &&
+	git add Commit2.t &&
+	git rebase --continue &&
+	commit_message HEAD >actual.msg &&
+	commit_authorship HEAD >actual.author &&
+	test_cmp expected.msg actual.msg &&
+	test_cmp expected.author actual.author
+}
+
+test_expect_success 'Misspelled pick --signoff' '
+	git checkout -b misspelled-pick--signoff master &&
+	cat >expected.msg <<-EOF &&
+	$(commit_message HEAD)
+
+	Signed-off-by: C O Mitter <committer@example.com>
+	EOF
+	commit_authorship HEAD >expected.author &&
+	test_msg_author_misspelled pick_--signoff
+'
+
+test_expect_success 'Conflicted pick --signoff' '
+	git checkout -b conflicted-pick--signoff branch &&
+	cat >expected.msg <<-EOF &&
+	$(commit_message HEAD)
+
+	Signed-off-by: C O Mitter <committer@example.com>
+	EOF
+	commit_authorship HEAD >expected.author &&
+	test_msg_author_conflicted pick_--signoff
+'
+
+test_expect_success 'pick --signoff' '
+	git checkout -b pick--signoff master &&
+	cat >expected.msg <<-EOF &&
+	$(commit_message HEAD)
+
+	Signed-off-by: C O Mitter <committer@example.com>
+	EOF
+	commit_authorship HEAD >expected.author &&
+	test_msg_author pick_--signoff
+'
+
+test_expect_success 'reword --signoff' '
+	git checkout -b reword--signoff master &&
+	cat >expected.msg <<-EOF &&
+	$(commit_message HEAD)
+
+	Signed-off-by: C O Mitter <committer@example.com>
+	EOF
+	commit_authorship HEAD >expected.author &&
+	test_msg_author reword_--signoff
+'
+
+test_expect_success 'edit --signoff' '
+	git checkout -b edit--signoff master &&
+	cat >expected.msg <<-EOF &&
+	$(commit_message HEAD)
+
+	Signed-off-by: C O Mitter <committer@example.com>
+	EOF
+	commit_authorship HEAD >expected.author &&
+	set_fake_editor &&
+	FAKE_LINES="1 edit_--signoff 2" git rebase -i HEAD~2 &&
+	git rebase --continue &&
+	commit_message HEAD >actual.msg &&
+	commit_authorship HEAD >actual.author &&
+	test_cmp expected.msg actual.msg &&
+	test_cmp expected.author actual.author
+'
+
+test_expect_success 'Misspelled pick --reset-author' '
+	git checkout -b misspelled-pick--reset-author master &&
+	commit_message HEAD >expected.msg &&
+	test_tick &&
+	authorship >expected.author &&
+	commit_authorship HEAD >original.author &&
+	test_diff_file expected.author original.author &&
+	test_msg_author_misspelled pick_--reset-author
+'
+
+test_expect_success 'Conflicted pick --reset-author' '
+	git checkout -b conflicted-pick--reset-author branch &&
+	commit_message HEAD >expected.msg &&
+	test_tick &&
+	authorship >expected.author &&
+	commit_authorship HEAD >original.author &&
+	test_diff_file expected.author original.author &&
+	test_msg_author_conflicted pick_--reset-author
+'
+
+test_expect_success 'pick --reset-author' '
+	git checkout -b pick--reset-author master &&
+	commit_message HEAD >expected.msg &&
+	test_tick &&
+	authorship >expected.author &&
+	commit_authorship HEAD >original.author &&
+	test_diff_file expected.author original.author &&
+	test_msg_author pick_--reset-author
+'
+
+test_expect_success 'pick --reset-author --signoff' '
+	git checkout -b pick--reset-author--signoff master &&
+	cat >expected.msg <<-EOF &&
+	$(commit_message HEAD)
+
+	Signed-off-by: C O Mitter <committer@example.com>
+	EOF
+	test_tick &&
+	authorship >expected.author &&
+	commit_authorship HEAD >original.author &&
+	test_diff_file expected.author original.author &&
+	test_msg_author pick_--reset-author_--signoff
+'
+
+test_expect_success 'reword --reset-author' '
+	git checkout -b reword--reset-author master &&
+	commit_message HEAD >expected.msg &&
+	test_tick &&
+	authorship >expected.author &&
+	commit_authorship HEAD >original.author &&
+	test_diff_file expected.author original.author &&
+	test_msg_author reword_--reset-author
+'
+
+test_expect_success 'edit --reset-author' '
+	git checkout -b edit--reset-author master &&
+	commit_message HEAD >expected.msg &&
+	commit_authorship HEAD >original.author &&
+	test_diff_file expected.author original.author &&
+	set_fake_editor &&
+	FAKE_LINES="1 edit_--reset-author 2" git rebase -i HEAD~2 &&
+	>Commit2.t &&
+	git add Commit2.t &&
+	test_tick &&
+	authorship >expected.author &&
+	git rebase --continue &&
+	commit_message HEAD >actual.msg &&
+	commit_authorship HEAD >actual.author &&
+	test_cmp expected.msg actual.msg &&
+	test_cmp expected.author actual.author
+'
+
 test_done
-- 
2.0.1