Seeing various mode changes on cygwin

Seeing various mode changes on cygwin

[Jonas Fonseca]

Hi,

It seems that git on cygwin still have a few problems. I've experienced it both
when cloning with git and Cogito. It seems that cygwin overrides the previous
modes and sets the executable bit. git-reset doesn't fix it. Can this even be
fixed then?

A few examples below ...

jonas@cygwin /usr/local/dev/git/git
$ git reset
Documentation/sort_glossary.pl: needs update
t/lib-read-tree-m-3way.sh: needs update
t/t4109-apply-multifrag.sh: needs update
t/t4110-apply-scan.sh: needs update
t/t6000lib.sh: needs update
t/t6101-rev-parse-parents.sh: needs update
templates/hooks--applypatch-msg: needs update
templates/hooks--commit-msg: needs update
templates/hooks--post-commit: needs update
templates/hooks--post-update: needs update
templates/hooks--pre-applypatch: needs update
templates/hooks--pre-commit: needs update
templates/hooks--update: needs update

jonas@cygwin /usr/local/dev/git/git
$ git diff
diff --git a/Documentation/sort_glossary.pl b/Documentation/sort_glossary.pl
old mode 100644
new mode 100755
diff --git a/t/lib-read-tree-m-3way.sh b/t/lib-read-tree-m-3way.sh
old mode 100755
new mode 100644
diff --git a/t/t4109-apply-multifrag.sh b/t/t4109-apply-multifrag.sh
old mode 100644
new mode 100755
diff --git a/t/t4110-apply-scan.sh b/t/t4110-apply-scan.sh
old mode 100644
new mode 100755
diff --git a/t/t6000lib.sh b/t/t6000lib.sh
old mode 100755
new mode 100644
diff --git a/t/t6101-rev-parse-parents.sh b/t/t6101-rev-parse-parents.sh
old mode 100644
new mode 100755
diff --git a/templates/hooks--applypatch-msg b/templates/hooks--applypatch-msg
old mode 100644
new mode 100755
diff --git a/templates/hooks--commit-msg b/templates/hooks--commit-msg
old mode 100644
new mode 100755
diff --git a/templates/hooks--post-commit b/templates/hooks--post-commit
old mode 100644
new mode 100755
diff --git a/templates/hooks--post-update b/templates/hooks--post-update
old mode 100644
new mode 100755
diff --git a/templates/hooks--pre-applypatch b/templates/hooks--pre-applypatch
old mode 100644
new mode 100755
diff --git a/templates/hooks--pre-commit b/templates/hooks--pre-commit
old mode 100644
new mode 100755
diff --git a/templates/hooks--update b/templates/hooks--update
old mode 100644
new mode 100755

jonas@cygwin /usr/local/dev/git/cogito
$ cg diff debian/
diff --git a/debian/helper-scripts/make-orig.tgz
b/debian/helper-scripts/make-orig.tgz
old mode 100644
new mode 100755
diff --git a/debian/helper-scripts/make-package
b/debian/helper-scripts/make-package
old mode 100644
new mode 100755
diff --git a/debian/helper-scripts/make-test
b/debian/helper-scripts/make-test
old mode 100644
new mode 100755

jonas@cygwin /usr/local/dev/elinks/0.11
$ cg diff
diff --git a/config/config.guess b/config/config.guess
old mode 100644
new mode 100755
diff --git a/config/config.sub b/config/config.sub
old mode 100644
new mode 100755
diff --git a/contrib/conv/w3m2links.awk.in b/contrib/conv/w3m2links.awk.in
old mode 100644
new mode 100755
diff --git a/contrib/lua/bm-to-elinks-bookmarks.lua b/contrib/lua/bm-to-elinks-bookmarks.lua
old mode 100644
new mode 100755
diff --git a/contrib/wipe-out-ssl.awk b/contrib/wipe-out-ssl.awk
old mode 100644
new mode 100755
diff --git a/debian/elinks.postinst b/debian/elinks.postinst
old mode 100644
new mode 100755
diff --git a/debian/elinks.preinst b/debian/elinks.preinst
old mode 100644
new mode 100755
diff --git a/debian/elinks.prerm b/debian/elinks.prerm
old mode 100644
new mode 100755
diff --git a/po/gen_translations_stats.sh b/po/gen_translations_stats.sh
old mode 100644
new mode 100755

-- 
Jonas Fonseca

Re: Seeing various mode changes on cygwin

[Junio C Hamano]

Jonas Fonseca <fonseca@diku.dk> writes:

> ... It seems that cygwin overrides the previous
> modes and sets the executable bit. git-reset doesn't fix it. Can this even be
> fixed then?
>
> A few examples below ...
>
> jonas@cygwin /usr/local/dev/git/git
> $ git reset
> Documentation/sort_glossary.pl: needs update
> t/lib-read-tree-m-3way.sh: needs update

I do not have an access to Cygwin environment so cannot be of
help on this directly, but 'git reset' without flags defaults
"--mixed" and leaves the modified files intact.  Maybe hard
reset would help here, but the real solution is to figure out
why these files acquired the extra executable bits in the first
place.

Re: Seeing various mode changes on cygwin

[Alex Riesen]

Junio C Hamano, Sat, Oct 08, 2005 20:51:55 +0200:
> > ... It seems that cygwin overrides the previous modes and sets the
> > executable bit. git-reset doesn't fix it. Can this even be fixed
> > then?
> >
> > A few examples below ...
> >
> > jonas@cygwin /usr/local/dev/git/git
> > $ git reset
> > Documentation/sort_glossary.pl: needs update
> > t/lib-read-tree-m-3way.sh: needs update
> 
> I do not have an access to Cygwin environment so cannot be of
> help on this directly, but 'git reset' without flags defaults
> "--mixed" and leaves the modified files intact.  Maybe hard
> reset would help here, but the real solution is to figure out
> why these files acquired the extra executable bits in the first
> place.

These are not real attributes, cygwin emulates them from the names,
like .exe will always be 0755, for example.

Re: Seeing various mode changes on cygwin

[Junio C Hamano]

Alex Riesen <raa.lkml@gmail.com> writes:

> These are not real attributes, cygwin emulates them from the names,
> like .exe will always be 0755, for example.

Ouch.  Is this true in general, or only on FAT-derived
filesystems?

We may need to worry about this on the core side after all.
Some people need to mount FAT even on Linux systems, 

Re: Seeing various mode changes on cygwin

[Linus Torvalds]

On Sat, 8 Oct 2005, Junio C Hamano wrote:
>
> Alex Riesen <raa.lkml@gmail.com> writes:
> > These are not real attributes, cygwin emulates them from the names,
> > like .exe will always be 0755, for example.
> 
> Ouch.  Is this true in general, or only on FAT-derived
> filesystems?
> 
> We may need to worry about this on the core side after all.
> Some people need to mount FAT even on Linux systems, 

I think we might want to have a flag that says "don't care about 
filesystem modes". That should be pretty easy, I think we'd get most of 
them by just adding some logic to "ce_match_stat()".

Then add a "git chmod" to set the mode in the index (which should end up 
being just a wrapper around the regular "git-update-index" using the 
"--cacheinfo" flag, I think).

Those parts should be trivial.

The more interesting issue is how to set the _flag_ that we should do 
this. We may have to add a config file, and it should be per-repository 
(ie something like ".git/config" or ".git/info/config"). Or do we just do 
yet another environment variable?

		Linus

Re: Seeing various mode changes on cygwin

[H. Peter Anvin]

Junio C Hamano wrote:
> Alex Riesen <raa.lkml@gmail.com> writes:
> 
>>These are not real attributes, cygwin emulates them from the names,
>>like .exe will always be 0755, for example.
> 
> Ouch.  Is this true in general, or only on FAT-derived
> filesystems?
> 
> We may need to worry about this on the core side after all.
> Some people need to mount FAT even on Linux systems, 
> 

At least on Cygwin/NTFS, you can do chmod just fine.

	-hpa

Re: Seeing various mode changes on cygwin

[Junio C Hamano]

Linus Torvalds <torvalds@osdl.org> writes:

> The more interesting issue is how to set the _flag_ that we should do 
> this. We may have to add a config file, and it should be per-repository 
> (ie something like ".git/config" or ".git/info/config"). Or do we just do 
> yet another environment variable?

Per-repository configuration file like .git/info/config sounds
like the way to go.  Long time ago, the core never read any
per-repository nor per-odb configuration file, but after grafts
and then now alternates, we started doing it, and there is no
reason to shy away from having an official configuration file
mechanism.  Maybe recent HTTP related environment variables
could also be folded into it.

While we are at it, we may want to move things around to
consolidate per-repository configuration into a single placek.
Specifically, I have moving .git/remotes/ in mind.

Re: Seeing various mode changes on cygwin

[Alex Riesen]

Junio C Hamano, Sun, Oct 09, 2005 01:36:17 +0200:
> > These are not real attributes, cygwin emulates them from the names,
> > like .exe will always be 0755, for example.
> 
> Ouch.  Is this true in general, or only on FAT-derived
> filesystems?
> 

Before they are chmod'ed by cygwin (with chmod): probably everywhere
on windows (I'm sure about vfat, were chmod wont help at all).  Even
if you can save user (unix) attributes somewhere, initial clone will
still always have this problem.

Re: Seeing various mode changes on cygwin

[Daniel Barkalow]

On Sat, 8 Oct 2005, Linus Torvalds wrote:

> I think we might want to have a flag that says "don't care about 
> filesystem modes". That should be pretty easy, I think we'd get most of 
> them by just adding some logic to "ce_match_stat()".
> 
> Then add a "git chmod" to set the mode in the index (which should end up 
> being just a wrapper around the regular "git-update-index" using the 
> "--cacheinfo" flag, I think).
> 
> Those parts should be trivial.
> 
> The more interesting issue is how to set the _flag_ that we should do 
> this. We may have to add a config file, and it should be per-repository 
> (ie something like ".git/config" or ".git/info/config"). Or do we just do 
> yet another environment variable?

Perhaps have a bit in the index mode for the file to say that the mode in 
the filesystem is unreliable, which gets set if a stat of the 
newly-written file doesn't match the mode it was supposed to have, or if 
git chmod is used to change it; then, if the bit is set, ignore the mode 
in the filesystem and just use the mode in the index.

This should prevent modes from magically changing, even if the user 
doesn't do anything special.

	-Daniel
*This .sig left intentionally blank*

Re: Seeing various mode changes on cygwin

[Junio C Hamano]

Daniel Barkalow <barkalow@iabervon.org> writes:

> Perhaps have a bit in the index mode for the file to say that the mode in 
> the filesystem is unreliable, which gets set if a stat of the 
> newly-written file doesn't match the mode it was supposed to have, or if 
> git chmod is used to change it; then, if the bit is set, ignore the mode 
> in the filesystem and just use the mode in the index.

In effect, you are making the "per-repo configuration" Linus
mentioned a non configuration but a property recorded in the
index file.  I think this is a clever solution which is very
helpful to the end user.  I have to think about this a bit, but
my gut feeling tells me that it is the right direction if it
works.

I do not think you have to necessarily record it in the "index
mode" -- which implies this is per path -- nor even in the index
file itself.  We might even be able to get away with doing this
check at git-init-db time just once, and record it in a file,
say ".git/fs-mode-unreliable".

Re: Seeing various mode changes on cygwin

[Daniel Barkalow]

On Mon, 10 Oct 2005, Junio C Hamano wrote:

> Daniel Barkalow <barkalow@iabervon.org> writes:
> 
> > Perhaps have a bit in the index mode for the file to say that the mode in 
> > the filesystem is unreliable, which gets set if a stat of the 
> > newly-written file doesn't match the mode it was supposed to have, or if 
> > git chmod is used to change it; then, if the bit is set, ignore the mode 
> > in the filesystem and just use the mode in the index.
> 
> In effect, you are making the "per-repo configuration" Linus
> mentioned a non configuration but a property recorded in the
> index file.  I think this is a clever solution which is very
> helpful to the end user.  I have to think about this a bit, but
> my gut feeling tells me that it is the right direction if it
> works.
> 
> I do not think you have to necessarily record it in the "index
> mode" -- which implies this is per path -- nor even in the index
> file itself.  We might even be able to get away with doing this
> check at git-init-db time just once, and record it in a file,
> say ".git/fs-mode-unreliable".

Actually, you're right; it is information about the behavior of the 
working tree, and is also needed if you want to compare the working tree 
against a tree object, in which case you aren't using the index at all.

	-Daniel
*This .sig left intentionally blank*

Re: Seeing various mode changes on cygwin

[Linus Torvalds]

On Mon, 10 Oct 2005, Daniel Barkalow wrote:
> 
> Actually, you're right; it is information about the behavior of the 
> working tree, and is also needed if you want to compare the working tree 
> against a tree object, in which case you aren't using the index at all.

Git _always_ uses the index for working tree operations.

It may take the actual file _data_ from the working tree, but it will take 
the list of files from the index, so it's certainly possible to link the 
index to the working tree.

That said, I don't think it's necessarily a good idea. You can have 
temporary indexes for various operations that ignore the main one (ie any 
random

	GIT_INDEX_FILE=tmp git-read-tree ...

will create a new index).

So I think it's much better to have a config file.

I'll write something up. Make it extensible while at it.

		Linus

Add ".git/config" file parser

[Linus Torvalds]

This is a first cut at a very simple parser for a git config file.

The format of the file is a simple ini-file like thing, with simple 
variable/value pairs. You can (and should) make the variables have a 
simple single-level scope, ie a valid file looks something like this:

	#
	# This is the config file, and
	# a '#' or ';' character indicates
	# a comment
	#

	; core variables
	[core]
		; Don't trust file modes
		filemode = false

	; Our diff algorithm 
	[diff]
		external = "/usr/local/bin/gnu-diff -u"
		renames = true

which parses into two variables: "core.filemode" is associated with the 
string "false", and "diff.external" gets the appropriate quoted value.

Right now we only react to one variable: "core.filemode" is a boolean that 
decides if we should care about the 0100 (user-execute) bit of the stat 
information. Even that is just a parsing demonstration - this doesn't 
actually implement that st_mode compare logic itself.

Different programs can react to different config options, although they 
should always fall back to calling "git_default_config()" on any config 
option name that they don't recognize.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
----

Ok, so it's stupid. But quite frankly, I think the Windows ini-file format 
is a hell of a lot more readable than something over-engineered like XML 
files or other crap.

The interface is really easy to use, imho. You can do things like

	static int enable_renames = 0;

	static int my_options(const char *var, const char *value)
	{
		if (!strcmp("diff.renames", var)) {
			enable_renames = git_config_bool(var, value);
			return 0;
		}

		/*
		 * Put other local option parsing for this program
		 * here .. 
		 */

		/* Fall back on the default ones */
		return git_default_config(var, value);
	}

and then in the "main()" routine you just do

		git_config(my_options);

at the top (or, more precisely, just after the "git_setup_directory()" if 
you have one).

And as usual, it's not like this has gotten a whole lot of testing.

Flames, comments, whatever? The code is actually written so that the 
config file parsing should really be pretty neutral. It doesn't even have 
any git-specific in it, except for the naming and the actual initial 
"fopen()" pathname used, I think.

---
diff --git a/Makefile b/Makefile
index a201187..e8b46f1 100644
--- a/Makefile
+++ b/Makefile
@@ -158,7 +158,7 @@ LIB_OBJS = \
 	object.o pack-check.o patch-delta.o path.o pkt-line.o \
 	quote.o read-cache.o refs.o run-command.o \
 	server-info.o setup.o sha1_file.o sha1_name.o strbuf.o \
-	tag.o tree.o usage.o $(DIFF_OBJS)
+	tag.o tree.o usage.o config.o $(DIFF_OBJS)
 
 LIBS = $(LIB_FILE)
 LIBS += -lz
diff --git a/cache.h b/cache.h
index 5987d4c..0571282 100644
--- a/cache.h
+++ b/cache.h
@@ -178,6 +178,8 @@ extern int hold_index_file_for_update(st
 extern int commit_index_file(struct cache_file *);
 extern void rollback_index_file(struct cache_file *);
 
+extern int trust_executable_bit;
+
 #define MTIME_CHANGED	0x0001
 #define CTIME_CHANGED	0x0002
 #define OWNER_CHANGED	0x0004
@@ -372,4 +374,10 @@ extern int gitfakemunmap(void *start, si
 
 #endif
 
+typedef int (*config_fn_t)(const char *, const char *);
+extern int git_default_config(const char *, const char *);
+extern int git_config(config_fn_t fn);
+extern int git_config_int(const char *, const char *);
+extern int git_config_bool(const char *, const char *);
+
 #endif /* CACHE_H */
diff --git a/config.c b/config.c
new file mode 100644
index 0000000..f3c4fa4
--- /dev/null
+++ b/config.c
@@ -0,0 +1,222 @@
+#include <ctype.h>
+
+#include "cache.h"
+
+#define MAXNAME (256)
+
+static FILE *config_file;
+static int config_linenr;
+static int get_next_char(void)
+{
+	int c;
+	FILE *f;
+
+	c = '\n';
+	if ((f = config_file) != NULL) {
+		c = fgetc(f);
+		if (c == '\n')
+			config_linenr++;
+		if (c == EOF) {
+			config_file = NULL;
+			c = '\n';
+		}
+	}
+	return c;
+}
+
+static char *parse_value(void)
+{
+	static char value[1024];
+	int quote = 0, comment = 0, len = 0, space = 0;
+
+	for (;;) {
+		int c = get_next_char();
+		if (len >= sizeof(value))
+			return NULL;
+		if (c == '\n') {
+			if (quote)
+				return NULL;
+			value[len] = 0;
+			return value;
+		}
+		if (comment)
+			continue;
+		if (isspace(c) && !quote) {
+			space = 1;
+			continue;
+		}
+		if (space) {
+			if (len)
+				value[len++] = ' ';
+			space = 0;
+		}
+		if (c == '\\') {
+			c = get_next_char();
+			switch (c) {
+			case '\n':
+				continue;
+			case 't':
+				c = '\t';
+				break;
+			case 'b':
+				c = '\b';
+				break;
+			case 'n':
+				c = '\n';
+				break;
+			return NULL;
+			}
+			value[len++] = c;
+			continue;
+		}
+		if (c == '"') {
+			quote = 1-quote;
+			continue;
+		}
+		if (!quote) {
+			if (c == ';' || c == '#') {
+				comment = 1;
+				continue;
+			}
+		}
+		value[len++] = c;
+	}
+}
+
+static int get_value(config_fn_t fn, char *name, unsigned int len)
+{
+	int c;
+	char *value;
+
+	/* Get the full name */
+	for (;;) {
+		c = get_next_char();
+		if (c == EOF)
+			break;
+		if (!isalnum(c))
+			break;
+		name[len++] = tolower(c);
+		if (len >= MAXNAME)
+			return -1;
+	}
+	name[len] = 0;
+	while (c == ' ' || c == '\t')
+		c = get_next_char();
+
+	value = NULL;
+	if (c != '\n') {
+		if (c != '=')
+			return -1;
+		value = parse_value();
+		if (!value)
+			return -1;
+	}
+	return fn(name, value);
+}
+
+static int get_base_var(char *name)
+{
+	int baselen = 0;
+
+	for (;;) {
+		int c = get_next_char();
+		if (c == EOF)
+			return -1;
+		if (c == ']')
+			return baselen;
+		if (!isalnum(c))
+			return -1;
+		if (baselen > MAXNAME / 2)
+			return -1;
+		name[baselen++] = tolower(c);
+	}
+}
+
+static int git_parse_file(config_fn_t fn)
+{
+	int comment = 0;
+	int baselen = 0;
+	static char var[MAXNAME];
+
+	for (;;) {
+		int c = get_next_char();
+		if (c == '\n') {
+			/* EOF? */
+			if (!config_file)
+				return 0;
+			comment = 0;
+			continue;
+		}
+		if (comment || isspace(c))
+			continue;
+		if (c == '#' || c == ';') {
+			comment = 1;
+			continue;
+		}
+		if (c == '[') {
+			baselen = get_base_var(var);
+			if (baselen <= 0)
+				break;
+			var[baselen++] = '.';
+			var[baselen] = 0;
+			continue;
+		}
+		if (!isalpha(c))
+			break;
+		var[baselen] = c;
+		if (get_value(fn, var, baselen+1) < 0)
+			break;
+	}
+	die("bad config file line %d", config_linenr);
+}
+
+int git_config_int(const char *name, const char *value)
+{
+	if (value && *value) {
+		char *end;
+		int val = strtol(value, &end, 0);
+		if (!*end)
+			return val;
+	}
+	die("bad config value for '%s'", name);
+}
+
+int git_config_bool(const char *name, const char *value)
+{
+	if (!value)
+		return 1;
+	if (!*value)
+		return 0;
+	if (!strcasecmp(value, "true"))
+		return 1;
+	if (!strcasecmp(value, "false"))
+		return 0;
+	return git_config_int(name, value) != 0;
+}
+
+int git_default_config(const char *var, const char *value)
+{
+	/* This needs a better name */
+	if (!strcmp(var, "core.filemode")) {
+		trust_executable_bit = git_config_bool(var, value);
+		return 0;
+	}
+
+	/* Add other config variables here.. */
+	return 0;
+}
+
+int git_config(config_fn_t fn)
+{
+	int ret;
+	FILE *f = fopen(git_path("config"), "r");
+
+	ret = -1;
+	if (f) {
+		config_file = f;
+		config_linenr = 1;
+		ret = git_parse_file(fn);
+		fclose(f);
+	}
+	return ret;
+}
diff --git a/diff-files.c b/diff-files.c
index 5e59832..96d2c7f 100644
--- a/diff-files.c
+++ b/diff-files.c
@@ -38,6 +38,7 @@ int main(int argc, const char **argv)
 	const char *prefix = setup_git_directory();
 	int entries, i;
 
+	git_config(git_default_config);
 	diff_setup(&diff_options);
 	while (1 < argc && argv[1][0] == '-') {
 		if (!strcmp(argv[1], "-q"))
diff --git a/diff-tree.c b/diff-tree.c
index b2d74eb..2203fa5 100644
--- a/diff-tree.c
+++ b/diff-tree.c
@@ -408,6 +408,7 @@ int main(int argc, const char **argv)
 	unsigned char sha1[2][20];
 	const char *prefix = setup_git_directory();
 
+	git_config(git_default_config);
 	nr_sha1 = 0;
 	diff_setup(&diff_options);
 
diff --git a/read-cache.c b/read-cache.c
index d2aebdd..c7f3b26 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -5,6 +5,7 @@
  */
 #include "cache.h"
 
+int trust_executable_bit = 1;
 struct cache_entry **active_cache = NULL;
 unsigned int active_nr = 0, active_alloc = 0, active_cache_changed = 0;
 

Re: Add ".git/config" file parser

[Linus Torvalds]

On Mon, 10 Oct 2005, Linus Torvalds wrote:
> 
> 	; core variables
> 	[core]
> 		; Don't trust file modes
> 		filemode = false
> 
> 	; Our diff algorithm 
> 	[diff]
> 		external = "/usr/local/bin/gnu-diff -u"
> 		renames = true
> 
> which parses into two variables: "core.filemode" is associated with the 
> string "false", and "diff.external" gets the appropriate quoted value.

_Three_ variables. Duh. I added the "renames" thing later, as I was 
looking at what kinds of default flags the "git-diff-xyz" family might be 
interested in having.

		Linus

Re: Add ".git/config" file parser

[H. Peter Anvin]

Linus Torvalds wrote:
> 
> On Mon, 10 Oct 2005, Linus Torvalds wrote:
> 
>>	; core variables
>>	[core]
>>		; Don't trust file modes
>>		filemode = false
>>
>>	; Our diff algorithm 
>>	[diff]
>>		external = "/usr/local/bin/gnu-diff -u"
>>		renames = true
>>
>>which parses into two variables: "core.filemode" is associated with the 
>>string "false", and "diff.external" gets the appropriate quoted value.
>  
> _Three_ variables. Duh. I added the "renames" thing later, as I was 
> looking at what kinds of default flags the "git-diff-xyz" family might be 
> interested in having.
> 

A suggestion: if you make your basic types (integer, string, boolean) 
recognizable by the parser, you can present them in that way.  This 
pretty much means strings will have to always be double-quoted, but that 
avoids a bunch of ambiguities.

	-hpa

Re: Add ".git/config" file parser

[Linus Torvalds]

On Mon, 10 Oct 2005, H. Peter Anvin wrote:
> 
> A suggestion: if you make your basic types (integer, string, boolean)
> recognizable by the parser, you can present them in that way.  This pretty
> much means strings will have to always be double-quoted, but that avoids a
> bunch of ambiguities.

Well, the parser is already pretty unambiguous, purely by virtue of being 
stupid as hell.

In particular, the only thing quoting does is to actually make whitespace 
meaningful, and as a way to allow comments inside strings (otherwise a "#" 
or ";" is always a "comment starts here" marker).

Outside of quotes, any whitespace will just collapse to a single space 
(and be removed from beginning and end).

And quite frankly, always keeping the things as strings just makes things 
so much easier and the interfaces very simple. And if/when you want to 
turn the string into a boolean or a regular integer, there are two helper 
functions that do exactly that, so it's not very hard.

I considered using some "smart" parser (ie using something like 
flex/bison), but the thing is, I didn't want smart. I personally think 
it's a lot more important for the file format to be _nice_, and there I 
think it's fine if

	[diff]
		external=/usr/local/bin/gnu-diff

doesn't need quotes, even if it's obviously a string. Simplicity is a 
virtue (both in parsing and in the "language" parsed).

In fact, even the example I had - with a space and an argument - doesn't 
need quotes (since the single space will be collapsed to a single space), 
I just put that as an example.

Side note: the design is meant to allow different programs to share the 
same config file without having to know about each others config 
variables. Anything they don't recognize is just ignored. The downside is 
that if you mistype an option name, nobody will recognize it, and nobody 
will complain either. 

That was one of the reasons for the "scoping". It not only allows grouping 
of variables, but it means that the "git-diff-xyz" family of programs 
might decide that they'll report anything that starts with "diff." but 
that they don't understand as a warning (but preferably not error, since 
it might be a newer option that an older version of git just doesn't 
understand).

		Linus

Re: Add ".git/config" file parser

[Junio C Hamano]

This is a WIP to implement update-index that does not care the
filesystem mode change.  When you have the following in
.git/config:

        [core]
                filemode = false

the following things happen:

 * "git-update-index --refresh" does not consider the executable
   bit change significant.

 * "git-update-index" on an existing path takes executable bit
   from the existing index entry, if the blob types are the
   same.

 * "git-diff-files" pretends the path on the filesystem has the
   same executable bit as the existing index entry, if the blob
   types are the same.

Yet to be done items are:

 * Other programs from diff-* family that compares with the
   filesystem needs to be covered.

 * "git-update-index --chmod=+x" and "--chmod=-x".

 * Refector code that takes the executable bit change from an
   existing index entry.

WIP-not-worth-signing-off-yet-by: Junio C Hamano <junkio.cox.net>
---
cd /opt/packrat/playpen/public/in-place/git/git.junio/
git diff HEAD
diff --git a/diff-files.c b/diff-files.c
index 96d2c7f..014f74e 100644
--- a/diff-files.c
+++ b/diff-files.c
@@ -81,7 +81,7 @@ int main(int argc, const char **argv)
 
 	for (i = 0; i < entries; i++) {
 		struct stat st;
-		unsigned int oldmode;
+		unsigned int oldmode, newmode;
 		struct cache_entry *ce = active_cache[i];
 		int changed;
 
@@ -111,7 +111,12 @@ int main(int argc, const char **argv)
 		if (!changed && !diff_options.find_copies_harder)
 			continue;
 		oldmode = ntohl(ce->ce_mode);
-		show_modified(oldmode, DIFF_FILE_CANON_MODE(st.st_mode),
+
+		newmode = DIFF_FILE_CANON_MODE(st.st_mode);
+		if (!trust_executable_bit &&
+		    S_ISREG(newmode) && ((newmode ^ oldmode) == 0111))
+			newmode = oldmode;
+		show_modified(oldmode, newmode,
 			      ce->sha1, (changed ? null_sha1 : ce->sha1),
 			      ce->name);
 	}
diff --git a/read-cache.c b/read-cache.c
index c7f3b26..4ed369a 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -36,8 +36,11 @@ int ce_match_stat(struct cache_entry *ce
 	switch (ntohl(ce->ce_mode) & S_IFMT) {
 	case S_IFREG:
 		changed |= !S_ISREG(st->st_mode) ? TYPE_CHANGED : 0;
-		/* We consider only the owner x bit to be relevant for "mode changes" */
-		if (0100 & (ntohl(ce->ce_mode) ^ st->st_mode))
+		/* We consider only the owner x bit to be relevant for
+		 * "mode changes"
+		 */
+		if (trust_executable_bit &&
+		    (0100 & (ntohl(ce->ce_mode) ^ st->st_mode)))
 			changed |= MODE_CHANGED;
 		break;
 	case S_IFLNK:
@@ -393,7 +396,7 @@ int add_cache_entry(struct cache_entry *
 	int skip_df_check = option & ADD_CACHE_SKIP_DFCHECK;
 	pos = cache_name_pos(ce->name, ntohs(ce->ce_flags));
 
-	/* existing match? Just replace it */
+	/* existing match? Just replace it. */
 	if (pos >= 0) {
 		active_cache_changed = 1;
 		active_cache[pos] = ce;
@@ -416,7 +419,8 @@ int add_cache_entry(struct cache_entry *
 	if (!ok_to_add)
 		return -1;
 
-	if (!skip_df_check && check_file_directory_conflict(ce, pos, ok_to_replace)) {
+	if (!skip_df_check &&
+	    check_file_directory_conflict(ce, pos, ok_to_replace)) {
 		if (!ok_to_replace)
 			return -1;
 		pos = cache_name_pos(ce->name, ntohs(ce->ce_flags));
diff --git a/update-index.c b/update-index.c
index 01b4088..fd3a882 100644
--- a/update-index.c
+++ b/update-index.c
@@ -67,13 +67,23 @@ static int add_file_to_cache(const char 
 			return error("lstat(\"%s\"): %s", path,
 				     strerror(errno));
 	}
+
 	namelen = strlen(path);
 	size = cache_entry_size(namelen);
 	ce = xmalloc(size);
 	memset(ce, 0, size);
 	memcpy(ce->name, path, namelen);
 	fill_stat_cache_info(ce, &st);
+
 	ce->ce_mode = create_ce_mode(st.st_mode);
+	if (!trust_executable_bit) {
+		/* If there is an existing entry, pick the mode bits
+		 * from it.
+		 */
+		int pos = cache_name_pos(path, namelen);
+		if (0 <= pos)
+			ce->ce_mode = active_cache[pos]->ce_mode;
+	}
 	ce->ce_flags = htons(namelen);
 
 	if (index_path(ce->sha1, path, &st, !info_only))
@@ -328,6 +338,8 @@ int main(int argc, const char **argv)
 	const char *prefix = setup_git_directory();
 	int prefix_length = prefix ? strlen(prefix) : 0;
 
+	git_config(git_default_config);
+
 	newfd = hold_index_file_for_update(&cache_file, get_index_file());
 	if (newfd < 0)
 		die("unable to create new cachefile");

[PATCH] Use core.filemode.

[Junio C Hamano]

Junio C Hamano <junkio@cox.net> writes:

> This is a WIP to implement update-index that does not care the
> filesystem mode change...

I finished this one and have it in the master branch.  I'd
appreciate feedback from folks on affected platforms, most
notably Cygwin.

It might not be a bad idea to populate a new repository with a
default .git/config file that sets "core.filemode = false" on
Cygwin platform, using the templates mechanism.  People on NTFS
might not like that -- I do not know.

Anyway, that is a separate topic.

 -- >8 -- cut here -- >8 --

With "[core] filemode = false", you can tell git to ignore
differences in the working tree file only in executable bit.

 * "git-update-index --refresh" does not say "needs update" if index
   entry and working tree file differs only in executable bit.

 * "git-update-index" on an existing path takes executable bit
   from the existing index entry, if the path and index entry are
   both regular files.

 * "git-diff-files" and "git-diff-index" without --cached flag
   pretend the path on the filesystem has the same executable
   bit as the existing index entry, if the path and index entry
   are both regular files.

If you are on a filesystem with unreliable mode bits, you may need to
force the executable bit after registering the path in the index.

 * "git-update-index --chmod=+x foo" flips the executable bit of the
   index file entry for path "foo" on.  Use "--chmod=-x" to flip it
   off.

Note that --chmod only works in index file and does not look at nor
update the working tree.

So if you are on a filesystem and do not have working executable bit,
you would do:

 1. set the appropriate .git/config option;

 2. "git-update-index --add new-file.c"

 3. "git-ls-files --stage new-file.c" to see if it has the desired
   mode bits.  If not, e.g. to drop executable bit picked up from the
   filesystem, say "git-update-index --chmod=-x new-file.c".

Signed-off-by: Junio C Hamano <junkio@cox.net>

---

 diff-files.c   |   10 ++++++++--
 diff-index.c   |   11 +++++++++--
 read-cache.c   |   12 ++++++++----
 update-index.c |   46 +++++++++++++++++++++++++++++++++++++++++++++-
 4 files changed, 70 insertions(+), 9 deletions(-)

applies-to: 8c8a7c6987bcb0eeab559a58170fccd767ce0218
3e09cdfd114651fc61656dbd45d5ec3d9352cb2b
diff --git a/diff-files.c b/diff-files.c
index 96d2c7f..8a8f9b6 100644
--- a/diff-files.c
+++ b/diff-files.c
@@ -81,7 +81,7 @@ int main(int argc, const char **argv)
 
 	for (i = 0; i < entries; i++) {
 		struct stat st;
-		unsigned int oldmode;
+		unsigned int oldmode, newmode;
 		struct cache_entry *ce = active_cache[i];
 		int changed;
 
@@ -111,7 +111,13 @@ int main(int argc, const char **argv)
 		if (!changed && !diff_options.find_copies_harder)
 			continue;
 		oldmode = ntohl(ce->ce_mode);
-		show_modified(oldmode, DIFF_FILE_CANON_MODE(st.st_mode),
+
+		newmode = DIFF_FILE_CANON_MODE(st.st_mode);
+		if (!trust_executable_bit &&
+		    S_ISREG(newmode) && S_ISREG(oldmode) &&
+		    ((newmode ^ oldmode) == 0111))
+			newmode = oldmode;
+		show_modified(oldmode, newmode,
 			      ce->sha1, (changed ? null_sha1 : ce->sha1),
 			      ce->name);
 	}
diff --git a/diff-index.c b/diff-index.c
index 62b36cc..c9a9f4c 100644
--- a/diff-index.c
+++ b/diff-index.c
@@ -15,7 +15,7 @@ static void show_file(const char *prefix
 }
 
 static int get_stat_data(struct cache_entry *ce,
-			 unsigned char **sha1p, unsigned int *modep)
+			 unsigned char ** sha1p, unsigned int *modep)
 {
 	unsigned char *sha1 = ce->sha1;
 	unsigned int mode = ce->ce_mode;
@@ -35,6 +35,10 @@ static int get_stat_data(struct cache_en
 		changed = ce_match_stat(ce, &st);
 		if (changed) {
 			mode = create_ce_mode(st.st_mode);
+			if (!trust_executable_bit &&
+			    S_ISREG(mode) && S_ISREG(ce->ce_mode) &&
+			    ((mode ^ ce->ce_mode) == 0111))
+				mode = ce->ce_mode;
 			sha1 = no_sha1;
 		}
 	}
@@ -49,7 +53,9 @@ static void show_new_file(struct cache_e
 	unsigned char *sha1;
 	unsigned int mode;
 
-	/* New file in the index: it might actually be different in the working copy */
+	/* New file in the index: it might actually be different in
+	 * the working copy.
+	 */
 	if (get_stat_data(new, &sha1, &mode) < 0)
 		return;
 
@@ -174,6 +180,7 @@ int main(int argc, const char **argv)
 	int allow_options = 1;
 	int i;
 
+	git_config(git_default_config);
 	diff_setup(&diff_options);
 	for (i = 1; i < argc; i++) {
 		const char *arg = argv[i];
diff --git a/read-cache.c b/read-cache.c
index c7f3b26..4ed369a 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -36,8 +36,11 @@ int ce_match_stat(struct cache_entry *ce
 	switch (ntohl(ce->ce_mode) & S_IFMT) {
 	case S_IFREG:
 		changed |= !S_ISREG(st->st_mode) ? TYPE_CHANGED : 0;
-		/* We consider only the owner x bit to be relevant for "mode changes" */
-		if (0100 & (ntohl(ce->ce_mode) ^ st->st_mode))
+		/* We consider only the owner x bit to be relevant for
+		 * "mode changes"
+		 */
+		if (trust_executable_bit &&
+		    (0100 & (ntohl(ce->ce_mode) ^ st->st_mode)))
 			changed |= MODE_CHANGED;
 		break;
 	case S_IFLNK:
@@ -393,7 +396,7 @@ int add_cache_entry(struct cache_entry *
 	int skip_df_check = option & ADD_CACHE_SKIP_DFCHECK;
 	pos = cache_name_pos(ce->name, ntohs(ce->ce_flags));
 
-	/* existing match? Just replace it */
+	/* existing match? Just replace it. */
 	if (pos >= 0) {
 		active_cache_changed = 1;
 		active_cache[pos] = ce;
@@ -416,7 +419,8 @@ int add_cache_entry(struct cache_entry *
 	if (!ok_to_add)
 		return -1;
 
-	if (!skip_df_check && check_file_directory_conflict(ce, pos, ok_to_replace)) {
+	if (!skip_df_check &&
+	    check_file_directory_conflict(ce, pos, ok_to_replace)) {
 		if (!ok_to_replace)
 			return -1;
 		pos = cache_name_pos(ce->name, ntohs(ce->ce_flags));
diff --git a/update-index.c b/update-index.c
index 01b4088..1eeb45d 100644
--- a/update-index.c
+++ b/update-index.c
@@ -67,13 +67,23 @@ static int add_file_to_cache(const char 
 			return error("lstat(\"%s\"): %s", path,
 				     strerror(errno));
 	}
+
 	namelen = strlen(path);
 	size = cache_entry_size(namelen);
 	ce = xmalloc(size);
 	memset(ce, 0, size);
 	memcpy(ce->name, path, namelen);
 	fill_stat_cache_info(ce, &st);
+
 	ce->ce_mode = create_ce_mode(st.st_mode);
+	if (!trust_executable_bit) {
+		/* If there is an existing entry, pick the mode bits
+		 * from it.
+		 */
+		int pos = cache_name_pos(path, namelen);
+		if (0 <= pos)
+			ce->ce_mode = active_cache[pos]->ce_mode;
+	}
 	ce->ce_flags = htons(namelen);
 
 	if (index_path(ce->sha1, path, &st, !info_only))
@@ -253,8 +263,32 @@ static int add_cacheinfo(const char *arg
 	return add_cache_entry(ce, option);
 }
 
-static struct cache_file cache_file;
+static int chmod_path(int flip, const char *path)
+{
+	int pos;
+	struct cache_entry *ce;
+	unsigned int mode;
+
+	pos = cache_name_pos(path, strlen(path));
+	if (pos < 0)
+		return -1;
+	ce = active_cache[pos];
+	mode = ntohl(ce->ce_mode);
+	if (!S_ISREG(mode))
+		return -1;
+	switch (flip) {
+	case '+':
+		ce->ce_mode |= htonl(0111); break;
+	case '-':
+		ce->ce_mode &= htonl(~0111); break;
+	default:
+		return -1;
+	}
+	active_cache_changed = 1;
+	return 0;
+}
 
+static struct cache_file cache_file;
 
 static void update_one(const char *path, const char *prefix, int prefix_length)
 {
@@ -328,6 +362,8 @@ int main(int argc, const char **argv)
 	const char *prefix = setup_git_directory();
 	int prefix_length = prefix ? strlen(prefix) : 0;
 
+	git_config(git_default_config);
+
 	newfd = hold_index_file_for_update(&cache_file, get_index_file());
 	if (newfd < 0)
 		die("unable to create new cachefile");
@@ -376,6 +412,14 @@ int main(int argc, const char **argv)
 				i += 3;
 				continue;
 			}
+			if (!strcmp(path, "--chmod=-x") ||
+			    !strcmp(path, "--chmod=+x")) {
+				if (argc <= i+1)
+					die("git-update-index: %s <path>", path);
+				if (chmod_path(path[8], argv[++i]))
+					die("git-update-index: %s cannot chmod %s", path, argv[i]);
+				continue;
+			}
 			if (!strcmp(path, "--info-only")) {
 				info_only = 1;
 				continue;
---
0.99.8.GIT