[PATCH 0/5 v2] Introduce the .gitfile

[PATCH 0/5 v2] Introduce the .gitfile

[Lars Hjemli]

The patch-series has been reordered and updated according to comments on
the earlier series.

Shortlog:
 Simplify setup of $GIT_DIR in git-sh-setup.sh
 Add platform-independent .git "symlink"
 Teach resolve_gitlink_ref() about the .git file
 git-submodule: prepare for the .git-file
 Teach GIT-VERSION-GEN about the .git file

Diffstat:
 Documentation/repository-layout.txt |    5 ++-
 GIT-VERSION-GEN                     |    2 +-
 cache.h                             |    1 +
 environment.c                       |    2 +
 git-sh-setup.sh                     |    8 +---
 git-submodule.sh                    |    4 +-
 refs.c                              |   17 +++++++-
 setup.c                             |   47 ++++++++++++++++++++++
 t/t0002-gitfile.sh                  |   74 +++++++++++++++++++++++++++++++++++
 9 files changed, 146 insertions(+), 14 deletions(-)

[PATCH 1/5] Simplify setup of $GIT_DIR in git-sh-setup.sh

[Lars Hjemli]

Using 'git rev-parse --git-dir' makes the code shorter and more future-
proof.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
---
 git-sh-setup.sh |    8 +-------
 1 files changed, 1 insertions(+), 7 deletions(-)

diff --git a/git-sh-setup.sh b/git-sh-setup.sh
index f388275..a44b1c7 100755
--- a/git-sh-setup.sh
+++ b/git-sh-setup.sh
@@ -127,20 +127,14 @@ get_author_ident_from_commit () {
 # if we require to be in a git repository.
 if test -z "$NONGIT_OK"
 then
+	GIT_DIR=$(git rev-parse --git-dir) || exit
 	if [ -z "$SUBDIRECTORY_OK" ]
 	then
-		: ${GIT_DIR=.git}
 		test -z "$(git rev-parse --show-cdup)" || {
 			exit=$?
 			echo >&2 "You need to run this command from the toplevel of the working tree."
 			exit $exit
 		}
-	else
-		GIT_DIR=$(git rev-parse --git-dir) || {
-		    exit=$?
-		    echo >&2 "Failed to find a valid git directory."
-		    exit $exit
-		}
 	fi
 	test -n "$GIT_DIR" && GIT_DIR=$(cd "$GIT_DIR" && pwd) || {
 		echo >&2 "Unable to determine absolute path of git directory"
-- 
1.5.4.1.188.g3ea1f5

[PATCH 2/5] Add platform-independent .git "symlink"

[Lars Hjemli]

This patch allows .git to be a regular textfile containing the path of
the real git directory (prefixed with "gitdir: "), which can be useful on
platforms lacking support for real symlinks.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
---
 Documentation/repository-layout.txt |    5 ++-
 cache.h                             |    1 +
 environment.c                       |    2 +
 setup.c                             |   47 ++++++++++++++++++++++
 t/t0002-gitfile.sh                  |   74 +++++++++++++++++++++++++++++++++++
 5 files changed, 128 insertions(+), 1 deletions(-)
 create mode 100755 t/t0002-gitfile.sh

diff --git a/Documentation/repository-layout.txt b/Documentation/repository-layout.txt
index 6939130..bbaed2e 100644
--- a/Documentation/repository-layout.txt
+++ b/Documentation/repository-layout.txt
@@ -3,7 +3,10 @@ git repository layout
 
 You may find these things in your git repository (`.git`
 directory for a repository associated with your working tree, or
-`'project'.git` directory for a public 'bare' repository).
+`'project'.git` directory for a public 'bare' repository. It is
+also possible to have a working tree where `.git` is a plain
+ascii file containing `gitdir: <path>`, i.e. the path to the
+real git repository).
 
 objects::
 	Object store associated with this repository.  Usually
diff --git a/cache.h b/cache.h
index e1000bc..1ad822a 100644
--- a/cache.h
+++ b/cache.h
@@ -277,6 +277,7 @@ extern char *get_index_file(void);
 extern char *get_graft_file(void);
 extern int set_git_dir(const char *path);
 extern const char *get_git_work_tree(void);
+extern const char *read_gitfile_gently(const char *path);
 
 #define ALTERNATE_DB_ENVIRONMENT "GIT_ALTERNATE_OBJECT_DIRECTORIES"
 
diff --git a/environment.c b/environment.c
index 3527f16..8058e7b 100644
--- a/environment.c
+++ b/environment.c
@@ -49,6 +49,8 @@ static void setup_git_env(void)
 {
 	git_dir = getenv(GIT_DIR_ENVIRONMENT);
 	if (!git_dir)
+		git_dir = read_gitfile_gently(DEFAULT_GIT_DIR_ENVIRONMENT);
+	if (!git_dir)
 		git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
 	git_object_dir = getenv(DB_ENVIRONMENT);
 	if (!git_object_dir) {
diff --git a/setup.c b/setup.c
index 4509598..20502be 100644
--- a/setup.c
+++ b/setup.c
@@ -239,6 +239,44 @@ static int check_repository_format_gently(int *nongit_ok)
 }
 
 /*
+ * Try to read the location of the git directory from the .git file,
+ * return path to git directory if found.
+ */
+const char *read_gitfile_gently(const char *path)
+{
+	char *buf;
+	struct stat st;
+	int fd;
+	size_t len;
+
+	if (stat(path, &st))
+		return NULL;
+	if (!S_ISREG(st.st_mode))
+		return NULL;
+	fd = open(path, O_RDONLY);
+	if (fd < 0)
+		die("Error opening %s: %s", path, strerror(errno));
+	buf = xmalloc(st.st_size + 1);
+	len = read_in_full(fd, buf, st.st_size);
+	close(fd);
+	if (len != st.st_size)
+		die("Error reading %s", path);
+	buf[len] = '\0';
+	if (prefixcmp(buf, "gitdir: "))
+		die("Invalid gitfile format: %s", path);
+	while (buf[len - 1] == '\n' || buf[len - 1] == '\r')
+		len--;
+	if (len < 9)
+		die("No path in gitfile: %s", path);
+	buf[len] = '\0';
+	if (!is_git_directory(buf + 8))
+		die("Not a git repository: %s", buf + 8);
+	path = make_absolute_path(buf + 8);
+	free(buf);
+	return path;
+}
+
+/*
  * We cannot decide in this function whether we are in the work tree or
  * not, since the config can only be read _after_ this function was called.
  */
@@ -247,6 +285,7 @@ const char *setup_git_directory_gently(int *nongit_ok)
 	const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
 	static char cwd[PATH_MAX+1];
 	const char *gitdirenv;
+	const char *gitfile_dir;
 	int len, offset;
 
 	/*
@@ -293,8 +332,10 @@ const char *setup_git_directory_gently(int *nongit_ok)
 
 	/*
 	 * Test in the following order (relative to the cwd):
+	 * - .git (file containing "gitdir: <path>")
 	 * - .git/
 	 * - ./ (bare)
+	 * - ../.git
 	 * - ../.git/
 	 * - ../ (bare)
 	 * - ../../.git/
@@ -302,6 +343,12 @@ const char *setup_git_directory_gently(int *nongit_ok)
 	 */
 	offset = len = strlen(cwd);
 	for (;;) {
+		gitfile_dir = read_gitfile_gently(DEFAULT_GIT_DIR_ENVIRONMENT);
+		if (gitfile_dir) {
+			if (set_git_dir(gitfile_dir))
+				die("Repository setup failed");
+			break;
+		}
 		if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT))
 			break;
 		if (is_git_directory(".")) {
diff --git a/t/t0002-gitfile.sh b/t/t0002-gitfile.sh
new file mode 100755
index 0000000..d280663
--- /dev/null
+++ b/t/t0002-gitfile.sh
@@ -0,0 +1,74 @@
+#!/bin/sh
+
+test_description='.git file
+
+Verify that plumbing commands work when .git is a file
+'
+. ./test-lib.sh
+
+objpath() {
+    echo "$1" | sed -e 's|\(..\)|\1/|'
+}
+
+objck() {
+	p=$(objpath "$1")
+	if test ! -f "$REAL/objects/$p"
+	then
+		echo "Object not found: $REAL/objects/$p"
+		false
+	fi
+}
+
+test_expect_success 'setup' '
+	REAL="$(pwd)/.real" &&
+	mv .git "$REAL" &&
+	echo "gitdir: $REAL" >.git
+'
+
+test_expect_success 'check rev-parse --git-dir' '
+	test "$REAL" = "$(git rev-parse --git-dir)"
+'
+
+test_expect_success 'check hash-object' '
+	echo "foo" >bar &&
+	SHA=$(cat bar | git hash-object -w --stdin) &&
+	objck $SHA
+'
+
+test_expect_success 'check cat-file' '
+	git cat-file blob $SHA >actual &&
+	diff -u bar actual
+'
+
+test_expect_success 'check update-index' '
+	if test -f "$REAL/index"
+	then
+		echo "Hmm, $REAL/index exists?"
+		false
+	fi &&
+	rm -f "$REAL/objects/$(objpath $SHA)" &&
+	git update-index --add bar &&
+	if ! test -f "$REAL/index"
+	then
+		echo "$REAL/index not found"
+		false
+	fi &&
+	objck $SHA
+'
+
+test_expect_success 'check write-tree' '
+	SHA=$(git write-tree) &&
+	objck $SHA
+'
+
+test_expect_success 'check commit-tree' '
+	SHA=$(echo "commit bar" | git commit-tree $SHA) &&
+	objck $SHA
+'
+
+test_expect_success 'check rev-list' '
+	echo $SHA >"$REAL/HEAD" &&
+	test "$SHA" = "$(git rev-list HEAD)"
+'
+
+test_done
-- 
1.5.4.1.188.g3ea1f5

[PATCH 3/5] Teach resolve_gitlink_ref() about the .git file

[Lars Hjemli]

When .git in a submodule is a file, resolve_gitlink_ref() needs to pick up
the real GIT_DIR of the submodule from that file.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
---
 refs.c |   17 ++++++++++++++---
 1 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/refs.c b/refs.c
index 67d2a50..56de5cf 100644
--- a/refs.c
+++ b/refs.c
@@ -351,6 +351,7 @@ int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *re
 {
 	int len = strlen(path), retval;
 	char *gitdir;
+	const char *tmp;
 
 	while (len && path[len-1] == '/')
 		len--;
@@ -358,9 +359,19 @@ int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *re
 		return -1;
 	gitdir = xmalloc(len + MAXREFLEN + 8);
 	memcpy(gitdir, path, len);
-	memcpy(gitdir + len, "/.git/", 7);
-
-	retval = resolve_gitlink_ref_recursive(gitdir, len+6, refname, result, 0);
+	memcpy(gitdir + len, "/.git", 6);
+	len += 5;
+
+	tmp = read_gitfile_gently(gitdir);
+	if (tmp) {
+		free(gitdir);
+		len = strlen(tmp);
+		gitdir = xmalloc(len + MAXREFLEN + 3);
+		memcpy(gitdir, tmp, len);
+	}
+	gitdir[len] = '/';
+	gitdir[++len] = '\0';
+	retval = resolve_gitlink_ref_recursive(gitdir, len, refname, result, 0);
 	free(gitdir);
 	return retval;
 }
-- 
1.5.4.1.188.g3ea1f5

[PATCH 4/5] git-submodule: prepare for the .git-file

[Lars Hjemli]

When git-submodule tries to detect 'active' submodules, it checks for the
existence of a directory named '.git'. This isn't good enough now that .git
can be a file pointing to the real $GIT_DIR so the tests are changed to
reflect this.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
---
 git-submodule.sh |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/git-submodule.sh b/git-submodule.sh
index a6aaf40..e7c08b5 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -288,7 +288,7 @@ cmd_update()
 			continue
 		fi
 
-		if ! test -d "$path"/.git
+		if ! test -d "$path"/.git -o -f "$path"/.git
 		then
 			module_clone "$path" "$url" || exit
 			subsha1=
@@ -362,7 +362,7 @@ cmd_status()
 	do
 		name=$(module_name "$path") || exit
 		url=$(git config submodule."$name".url)
-		if test -z "url" || ! test -d "$path"/.git
+		if test -z "url" || ! test -d "$path"/.git -o -f "$path"/.git
 		then
 			say "-$sha1 $path"
 			continue;
-- 
1.5.4.1.188.g3ea1f5

[PATCH 5/5] Teach GIT-VERSION-GEN about the .git file

[Lars Hjemli]

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
---
 GIT-VERSION-GEN |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/GIT-VERSION-GEN b/GIT-VERSION-GEN
index 38a3273..2432a4f 100755
--- a/GIT-VERSION-GEN
+++ b/GIT-VERSION-GEN
@@ -11,7 +11,7 @@ LF='
 if test -f version
 then
 	VN=$(cat version) || VN="$DEF_VER"
-elif test -d .git &&
+elif test -d .git -o -f .git &&
 	VN=$(git describe --abbrev=4 HEAD 2>/dev/null) &&
 	case "$VN" in
 	*$LF*) (exit 1) ;;
-- 
1.5.4.1.188.g3ea1f5

Re: [PATCH 2/5] Add platform-independent .git "symlink"

[Johannes Schindelin]

Hi,

On Mon, 18 Feb 2008, Lars Hjemli wrote:

> diff --git a/environment.c b/environment.c
> index 3527f16..8058e7b 100644
> --- a/environment.c
> +++ b/environment.c
> @@ -49,6 +49,8 @@ static void setup_git_env(void)
>  {
>  	git_dir = getenv(GIT_DIR_ENVIRONMENT);
>  	if (!git_dir)
> +		git_dir = read_gitfile_gently(DEFAULT_GIT_DIR_ENVIRONMENT);
> +	if (!git_dir)
>  		git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;

I still maintain that the code (maybe not the diff) is easier to read like 
this:

  	if (!git_dir) {
		git_dir = read_gitfile_gently(DEFAULT_GIT_DIR_ENVIRONMENT);
		if (!git_dir)
  			git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
	}

> diff --git a/setup.c b/setup.c
> index 4509598..20502be 100644
> --- a/setup.c
> +++ b/setup.c
> @@ -239,6 +239,44 @@ static int check_repository_format_gently(int *nongit_ok)
>  }
>  
>  /*
> + * Try to read the location of the git directory from the .git file,
> + * return path to git directory if found.
> + */
> +const char *read_gitfile_gently(const char *path)
> +{
> +	char *buf;
> +	struct stat st;
> +	int fd;
> +	size_t len;
> +
> +	if (stat(path, &st))
> +		return NULL;
> +	if (!S_ISREG(st.st_mode))
> +		return NULL;
> +	fd = open(path, O_RDONLY);
> +	if (fd < 0)
> +		die("Error opening %s: %s", path, strerror(errno));

Hmm.  Like I said, in the "gently" case, we might want to just print a 
warning and return NULL.

However, since you have 5 die()s in this function that would clutter the 
code tremendously.  I briefly considered (shut your eyes now if you do 
not like ugly code):

	int (*show_error)(const char *format, ...) = nongit_ok ?
		error : (int (*)(const char *format, ...))die;

but now I think a better method would be

static int show_error(int die_on_error, const char *format, ...)
{
        va_list params;

        va_start(params, err);
	if (die_on_error)
		die_routine(err, params);
	else
	        error_routine(err, params);
        va_end(params);
        return -1;
}

This would even be a candidate for a global function die_or_error().

Then you could use it like this:

	if (fd < 0 && die("Error opening %s: %s", path, strerror(errno))
		return NULL;

Hmm.  Seeing what I wrote, it does not really feel elegant.

So maybe we can just scratch all that, and I agree that an invalid .git 
file means "no repository" (as opposed to "no valid repository").

In that case, you might want to test for that, too...

Speaking about tests:

> +test_expect_success 'setup' '
> +       REAL="$(pwd)/.real" &&
> +       mv .git "$REAL" &&
> +       echo "gitdir: $REAL" >.git
> +'

Let's not do this.  It would clutter the t/ directory unnecessarily.  
Instead, do something like this:

test_expect_success setup '

	REAL="$(pwd)/.real" &&
	mkdir test &&
	cd test &&
	echo "gitdir: $REAL" > .git

'

Hmm?

Ciao,
Dscho "who likes to write 'Hmm' three times in a mail"

Re: [PATCH 2/5] Add platform-independent .git "symlink"

[Lars Hjemli]

On Feb 18, 2008 1:34 PM, Johannes Schindelin <Johannes.Schindelin@gmx.de> wrote:
> Hi,
>
> On Mon, 18 Feb 2008, Lars Hjemli wrote:
>
> > diff --git a/environment.c b/environment.c
> > index 3527f16..8058e7b 100644
> > --- a/environment.c
> > +++ b/environment.c
> > @@ -49,6 +49,8 @@ static void setup_git_env(void)
> >  {
> >       git_dir = getenv(GIT_DIR_ENVIRONMENT);
> >       if (!git_dir)
> > +             git_dir = read_gitfile_gently(DEFAULT_GIT_DIR_ENVIRONMENT);
> > +     if (!git_dir)
> >               git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
>
> I still maintain that the code (maybe not the diff) is easier to read like
> this:
>
>         if (!git_dir) {
>                 git_dir = read_gitfile_gently(DEFAULT_GIT_DIR_ENVIRONMENT);
>                 if (!git_dir)
>                         git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
>         }

IMHO such constructs are butt ugly, but if there's consensus for your
way, I'll abide...


> [* snip *]
>
> So maybe we can just scratch all that, and I agree that an invalid .git
> file means "no repository" (as opposed to "no valid repository").
>
> In that case, you might want to test for that, too...

I think I do, did you find a loophole in the testing?


>
> Speaking about tests:
>
> > +test_expect_success 'setup' '
> > +       REAL="$(pwd)/.real" &&
> > +       mv .git "$REAL" &&
> > +       echo "gitdir: $REAL" >.git
> > +'
>
> Let's not do this.  It would clutter the t/ directory unnecessarily.

What do you mean? The test just moves t/trash/.git to t/trash/.real...

--
larsh

Re: [PATCH 2/5] Add platform-independent .git "symlink"

[Jakub Narebski]

Lars Hjemli wrote:
> On Feb 18, 2008 1:34 PM, Johannes Schindelin wrote:
>> On Mon, 18 Feb 2008, Lars Hjemli wrote:
>>
>> > diff --git a/environment.c b/environment.c
>> > index 3527f16..8058e7b 100644
>> > --- a/environment.c
>> > +++ b/environment.c
>> > @@ -49,6 +49,8 @@ static void setup_git_env(void)
>> >  {
>> >       git_dir = getenv(GIT_DIR_ENVIRONMENT);
>> >       if (!git_dir)
>> > +             git_dir = read_gitfile_gently(DEFAULT_GIT_DIR_ENVIRONMENT);
>> > +     if (!git_dir)
>> >               git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
>>
>> I still maintain that the code (maybe not the diff) is easier to read like
>> this:
>>
>>         if (!git_dir) {
>>                 git_dir = read_gitfile_gently(DEFAULT_GIT_DIR_ENVIRONMENT);
>>                 if (!git_dir)
>>                         git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
>>         }
> 
> IMHO such constructs are butt ugly, but if there's consensus for your
> way, I'll abide...

I prefer the original variant. It is IMHO no less, and perhaps even
more readable, and it is not soo deeply nested.

-- 
Jakub Narebski
Warsaw, Poland
ShadeHawk on #git

Re: [PATCH 2/5] Add platform-independent .git "symlink"

[Johannes Schindelin]

Hi,

On Mon, 18 Feb 2008, Lars Hjemli wrote:

> On Feb 18, 2008 1:34 PM, Johannes Schindelin 
> <Johannes.Schindelin@gmx.de> wrote:
> >
> > [* snip *]
> >
> > So maybe we can just scratch all that, and I agree that an invalid 
> > .git file means "no repository" (as opposed to "no valid repository").
> >
> > In that case, you might want to test for that, too...
> 
> I think I do, did you find a loophole in the testing?

I meant writing a readable, but invalid .git file.  Then testing that Git 
die()s with the correct message.

> > Speaking about tests:
> >
> > > +test_expect_success 'setup' '
> > > +       REAL="$(pwd)/.real" &&
> > > +       mv .git "$REAL" &&
> > > +       echo "gitdir: $REAL" >.git
> > > +'
> >
> > Let's not do this.  It would clutter the t/ directory unnecessarily.
> 
> What do you mean? The test just moves t/trash/.git to t/trash/.real...

Oh, well.  I'll go and buy me some new glasses.

Thanks,
Dscho

Re: [PATCH 2/5] Add platform-independent .git "symlink"

[Lars Hjemli]

On Feb 18, 2008 2:35 PM, Johannes Schindelin <Johannes.Schindelin@gmx.de> wrote:
> Hi,
>
> On Mon, 18 Feb 2008, Lars Hjemli wrote:
>
> > On Feb 18, 2008 1:34 PM, Johannes Schindelin wrote:
> > >
> > > [* snip *]
> > >
> > > So maybe we can just scratch all that, and I agree that an invalid
> > > .git file means "no repository" (as opposed to "no valid repository").
> > >
> > > In that case, you might want to test for that, too...
> >
> > I think I do, did you find a loophole in the testing?
>
> I meant writing a readable, but invalid .git file.  Then testing that Git
> die()s with the correct message.

Ah, sorry for being slow, that's an excellent suggestion. I'll update
the test-script and resend 2/5.

--
larsh

[PATCH 2/5] Add platform-independent .git "symlink"

[Lars Hjemli]

This patch allows .git to be a regular textfile containing the path of
the real git directory (prefixed with "gitdir: "), which can be useful on
platforms lacking support for real symlinks.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
---

On Feb 18, 2008 2:35 PM, Johannes Schindelin wrote:
> I meant writing a readable, but invalid .git file.  Then testing that Git
> die()s with the correct message.

Something like this?


 Documentation/repository-layout.txt |    5 ++-
 cache.h                             |    1 +
 environment.c                       |    2 +
 setup.c                             |   47 ++++++++++++++++
 t/t0002-gitfile.sh                  |  103 +++++++++++++++++++++++++++++++++++
 5 files changed, 157 insertions(+), 1 deletions(-)
 create mode 100755 t/t0002-gitfile.sh

diff --git a/Documentation/repository-layout.txt b/Documentation/repository-layout.txt
index 6939130..bbaed2e 100644
--- a/Documentation/repository-layout.txt
+++ b/Documentation/repository-layout.txt
@@ -3,7 +3,10 @@ git repository layout
 
 You may find these things in your git repository (`.git`
 directory for a repository associated with your working tree, or
-`'project'.git` directory for a public 'bare' repository).
+`'project'.git` directory for a public 'bare' repository. It is
+also possible to have a working tree where `.git` is a plain
+ascii file containing `gitdir: <path>`, i.e. the path to the
+real git repository).
 
 objects::
 	Object store associated with this repository.  Usually
diff --git a/cache.h b/cache.h
index e1000bc..1ad822a 100644
--- a/cache.h
+++ b/cache.h
@@ -277,6 +277,7 @@ extern char *get_index_file(void);
 extern char *get_graft_file(void);
 extern int set_git_dir(const char *path);
 extern const char *get_git_work_tree(void);
+extern const char *read_gitfile_gently(const char *path);
 
 #define ALTERNATE_DB_ENVIRONMENT "GIT_ALTERNATE_OBJECT_DIRECTORIES"
 
diff --git a/environment.c b/environment.c
index 3527f16..8058e7b 100644
--- a/environment.c
+++ b/environment.c
@@ -49,6 +49,8 @@ static void setup_git_env(void)
 {
 	git_dir = getenv(GIT_DIR_ENVIRONMENT);
 	if (!git_dir)
+		git_dir = read_gitfile_gently(DEFAULT_GIT_DIR_ENVIRONMENT);
+	if (!git_dir)
 		git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
 	git_object_dir = getenv(DB_ENVIRONMENT);
 	if (!git_object_dir) {
diff --git a/setup.c b/setup.c
index 4509598..20502be 100644
--- a/setup.c
+++ b/setup.c
@@ -239,6 +239,44 @@ static int check_repository_format_gently(int *nongit_ok)
 }
 
 /*
+ * Try to read the location of the git directory from the .git file,
+ * return path to git directory if found.
+ */
+const char *read_gitfile_gently(const char *path)
+{
+	char *buf;
+	struct stat st;
+	int fd;
+	size_t len;
+
+	if (stat(path, &st))
+		return NULL;
+	if (!S_ISREG(st.st_mode))
+		return NULL;
+	fd = open(path, O_RDONLY);
+	if (fd < 0)
+		die("Error opening %s: %s", path, strerror(errno));
+	buf = xmalloc(st.st_size + 1);
+	len = read_in_full(fd, buf, st.st_size);
+	close(fd);
+	if (len != st.st_size)
+		die("Error reading %s", path);
+	buf[len] = '\0';
+	if (prefixcmp(buf, "gitdir: "))
+		die("Invalid gitfile format: %s", path);
+	while (buf[len - 1] == '\n' || buf[len - 1] == '\r')
+		len--;
+	if (len < 9)
+		die("No path in gitfile: %s", path);
+	buf[len] = '\0';
+	if (!is_git_directory(buf + 8))
+		die("Not a git repository: %s", buf + 8);
+	path = make_absolute_path(buf + 8);
+	free(buf);
+	return path;
+}
+
+/*
  * We cannot decide in this function whether we are in the work tree or
  * not, since the config can only be read _after_ this function was called.
  */
@@ -247,6 +285,7 @@ const char *setup_git_directory_gently(int *nongit_ok)
 	const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
 	static char cwd[PATH_MAX+1];
 	const char *gitdirenv;
+	const char *gitfile_dir;
 	int len, offset;
 
 	/*
@@ -293,8 +332,10 @@ const char *setup_git_directory_gently(int *nongit_ok)
 
 	/*
 	 * Test in the following order (relative to the cwd):
+	 * - .git (file containing "gitdir: <path>")
 	 * - .git/
 	 * - ./ (bare)
+	 * - ../.git
 	 * - ../.git/
 	 * - ../ (bare)
 	 * - ../../.git/
@@ -302,6 +343,12 @@ const char *setup_git_directory_gently(int *nongit_ok)
 	 */
 	offset = len = strlen(cwd);
 	for (;;) {
+		gitfile_dir = read_gitfile_gently(DEFAULT_GIT_DIR_ENVIRONMENT);
+		if (gitfile_dir) {
+			if (set_git_dir(gitfile_dir))
+				die("Repository setup failed");
+			break;
+		}
 		if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT))
 			break;
 		if (is_git_directory(".")) {
diff --git a/t/t0002-gitfile.sh b/t/t0002-gitfile.sh
new file mode 100755
index 0000000..c5dbc72
--- /dev/null
+++ b/t/t0002-gitfile.sh
@@ -0,0 +1,103 @@
+#!/bin/sh
+
+test_description='.git file
+
+Verify that plumbing commands work when .git is a file
+'
+. ./test-lib.sh
+
+objpath() {
+    echo "$1" | sed -e 's|\(..\)|\1/|'
+}
+
+objck() {
+	p=$(objpath "$1")
+	if test ! -f "$REAL/objects/$p"
+	then
+		echo "Object not found: $REAL/objects/$p"
+		false
+	fi
+}
+
+
+test_expect_success 'initial setup' '
+	REAL="$(pwd)/.real" &&
+	mv .git "$REAL"
+'
+
+test_expect_success 'bad setup: invalid .git file format' '
+	echo "gitdir $REAL" >.git &&
+	if git rev-parse 2>.err
+	then
+		echo "git rev-parse accepted an invalid .git file"
+		false
+	fi &&
+	if ! grep -qe "Invalid gitfile format" .err
+	then
+		echo "git rev-parse returned wrong error"
+		false
+	fi
+'
+
+test_expect_success 'bad setup: invalid .git file path' '
+	echo "gitdir: $REAL.not" >.git &&
+	if git rev-parse 2>.err
+	then
+		echo "git rev-parse accepted an invalid .git file path"
+		false
+	fi &&
+	if ! grep -qe "Not a git repository" .err
+	then
+		echo "git rev-parse returned wrong error"
+		false
+	fi
+'
+
+test_expect_success 'final setup + check rev-parse --git-dir' '
+	echo "gitdir: $REAL" >.git &&
+	test "$REAL" = "$(git rev-parse --git-dir)"
+'
+
+test_expect_success 'check hash-object' '
+	echo "foo" >bar &&
+	SHA=$(cat bar | git hash-object -w --stdin) &&
+	objck $SHA
+'
+
+test_expect_success 'check cat-file' '
+	git cat-file blob $SHA >actual &&
+	diff -u bar actual
+'
+
+test_expect_success 'check update-index' '
+	if test -f "$REAL/index"
+	then
+		echo "Hmm, $REAL/index exists?"
+		false
+	fi &&
+	rm -f "$REAL/objects/$(objpath $SHA)" &&
+	git update-index --add bar &&
+	if ! test -f "$REAL/index"
+	then
+		echo "$REAL/index not found"
+		false
+	fi &&
+	objck $SHA
+'
+
+test_expect_success 'check write-tree' '
+	SHA=$(git write-tree) &&
+	objck $SHA
+'
+
+test_expect_success 'check commit-tree' '
+	SHA=$(echo "commit bar" | git commit-tree $SHA) &&
+	objck $SHA
+'
+
+test_expect_success 'check rev-list' '
+	echo $SHA >"$REAL/HEAD" &&
+	test "$SHA" = "$(git rev-list HEAD)"
+'
+
+test_done
-- 
1.5.4.1.188.g3ea1f5

Re: [PATCH 2/5] Add platform-independent .git "symlink"

[Johannes Schindelin]

Hi,

On Mon, 18 Feb 2008, Lars Hjemli wrote:

> On Feb 18, 2008 2:35 PM, Johannes Schindelin wrote:
> > I meant writing a readable, but invalid .git file.  Then testing that 
> > Git die()s with the correct message.
> 
> Something like this?

Sure.

Ciao,
Dscho

Re: [PATCH 0/5 v2] Introduce the .gitfile

[Johannes Schindelin]

Hi,

On Mon, 18 Feb 2008, Lars Hjemli wrote:

> The patch-series has been reordered and updated according to comments on 
> the earlier series.

It would be easier on a stupid reviewer like me, if you summarised what 
you changed.  In the case of patch "1/5 => 2/5", I would even have 
appreciated an interdiff...

Oh, and I was kind of surprised to learn that it is the ".gitfile", not 
the ".git file"... I ran to your patch straight away, and was relieved 
when I found out that you still call it ".git".

Ciao,
Dscho

Re: [PATCH 0/5 v2] Introduce the .gitfile

[Lars Hjemli]

On Feb 18, 2008 1:17 PM, Johannes Schindelin <Johannes.Schindelin@gmx.de> wrote:
> On Mon, 18 Feb 2008, Lars Hjemli wrote:
>
> > The patch-series has been reordered and updated according to comments on
> > the earlier series.
>
> It would be easier on a stupid reviewer like me, if you summarised what
> you changed.

Ok, I'll keep that in mind next time, and here's a quick summary (from
the top of my head) of this series vs. the previous:
* patch 1 and 2 are swapped, since the changes to git-sh-setup.sh can
be applied onto master regardless of the rest of the patch series
(while the other patches still rely on 1/5).
* git-sh-setup.sh is simplified even further, and relies on
git-rev-parse to produce the error message when no gitdir can be
found.
* read_gitfile_gently() is moved from environment.c into setup.c since
it now invokes is_git_directory().
* read_gitfile_gently() will gently ignore a 'missing' .git or a .git
which isn't a regular file, but die()s on all other errors.


> In the case of patch "1/5 => 2/5", I would even have
> appreciated an interdiff...

Sorry, but I don't think I understand what you mean by interdiff.


>
> Oh, and I was kind of surprised to learn that it is the ".gitfile", not
> the ".git file"... I ran to your patch straight away, and was relieved
> when I found out that you still call it ".git".

Yeah, I suck really bad on consistency ;-)


--
lh

Re: [PATCH 0/5 v2] Introduce the .gitfile

[Johannes Schindelin]

Hi,

On Mon, 18 Feb 2008, Lars Hjemli wrote:

> On Feb 18, 2008 1:17 PM, Johannes Schindelin 
> <Johannes.Schindelin@gmx.de> wrote:
> > On Mon, 18 Feb 2008, Lars Hjemli wrote:
> >
> > > The patch-series has been reordered and updated according to 
> > > comments on the earlier series.
> >
> > It would be easier on a stupid reviewer like me, if you summarised 
> > what you changed.
> 
> Ok, I'll keep that in mind next time, and here's a quick summary (from
> the top of my head) of this series vs. the previous:
> * patch 1 and 2 are swapped, since the changes to git-sh-setup.sh can
> be applied onto master regardless of the rest of the patch series
> (while the other patches still rely on 1/5).
> * git-sh-setup.sh is simplified even further, and relies on
> git-rev-parse to produce the error message when no gitdir can be
> found.
> * read_gitfile_gently() is moved from environment.c into setup.c since
> it now invokes is_git_directory().
> * read_gitfile_gently() will gently ignore a 'missing' .git or a .git
> which isn't a regular file, but die()s on all other errors.

Thanks.

> > In the case of patch "1/5 => 2/5", I would even have appreciated an 
> > interdiff...
> 
> Sorry, but I don't think I understand what you mean by interdiff.

The tool interdiff of patchutils is really nice: you can visualise what 
would be the diff between the state after applying the first patch, and 
the state after applying the second patch, without applying anything at 
all:

	$ interdiff <patch1> <patch2>

Ciao,
Dscho

Re: [PATCH 0/5 v2] Introduce the .gitfile

[Lars Hjemli]

On Feb 18, 2008 2:31 PM, Johannes Schindelin <Johannes.Schindelin@gmx.de> wrote:
> Hi,
>
> On Mon, 18 Feb 2008, Lars Hjemli wrote:
>
> > On Feb 18, 2008 1:17 PM, Johannes Schindelin wrote:
> > > In the case of patch "1/5 => 2/5", I would even have appreciated an
> > > interdiff...
> >
> > Sorry, but I don't think I understand what you mean by interdiff.
>
> The tool interdiff of patchutils is really nice: you can visualise what
> would be the diff between the state after applying the first patch, and
> the state after applying the second patch, without applying anything at
> all:
>
>         $ interdiff <patch1> <patch2>

Ok, that sounds useful (I was kind of confused since 'man interdiff'
gave me nothing: being on slackware I'm so spoiled with preinstalled
dev-tools that I see no point in consulting google ;).

Something like this (possibly mangled by gmail)?

$ interdiff prev-patch-2 curr-patch-1
diff -u b/git-sh-setup.sh b/git-sh-setup.sh
--- b/git-sh-setup.sh
+++ b/git-sh-setup.sh
@@ -127,11 +127,7 @@
 # if we require to be in a git repository.
 if test -z "$NONGIT_OK"
 then
-       GIT_DIR=$(git rev-parse --git-dir) || {
-               exit=$?
-               echo >&2 "Failed to find a valid git directory."
-               exit $exit
-       }
+       GIT_DIR=$(git rev-parse --git-dir) || exit
        if [ -z "$SUBDIRECTORY_OK" ]
        then
                test -z "$(git rev-parse --show-cdup)" || {

$ interdiff prev-patch-1 curr-patch-2
diff -u b/Documentation/repository-layout.txt
b/Documentation/repository-layout.txt
--- b/Documentation/repository-layout.txt
+++ b/Documentation/repository-layout.txt
@@ -5,7 +5,7 @@
 directory for a repository associated with your working tree, or
 `'project'.git` directory for a public 'bare' repository. It is
 also possible to have a working tree where `.git` is a plain
-ascii file containing `gitdir: <path>\n`, i.e. the path to the
+ascii file containing `gitdir: <path>`, i.e. the path to the
 real git repository).

 objects::
diff -u b/environment.c b/environment.c
--- b/environment.c
+++ b/environment.c
@@ -45,42 +45,6 @@
 static const char *git_dir;
 static char *git_object_dir, *git_index_file, *git_refs_dir, *git_graft_file;

-/*
- * Try to read the location of the git directory from the .git file,
- * return path to git directory if found.
- * Format of the .git file is
- *    gitdir: <path>\n
- */
-const char *read_gitfile_gently(const char *path)
-{
-       static char buf[PATH_MAX + 9];  /* "gitdir: " + "\n" */
-       struct stat st;
-       int fd;
-       size_t len;
-
-       if (stat(path, &st))
-               return NULL;
-       if (!S_ISREG(st.st_mode) || st.st_size >= sizeof(buf))
-               return NULL;
-       fd = open(path, O_RDONLY);
-       if (fd < 0)
-               return NULL;
-       len = read_in_full(fd, buf, sizeof(buf));
-       close(fd);
-       if (len != st.st_size)
-               return NULL;
-       if (!len || buf[len - 1] != '\n')
-               return NULL;
-       buf[len - 1] = '\0';
-       if (prefixcmp(buf, "gitdir: "))
-               return NULL;
-/*
-       if (!is_git_directory(buf + 8))
-               return NULL;
-*/
-       return make_absolute_path(buf + 8);
-}
-
 static void setup_git_env(void)
 {
        git_dir = getenv(GIT_DIR_ENVIRONMENT);
diff -u b/setup.c b/setup.c
--- b/setup.c
+++ b/setup.c
@@ -239,6 +239,44 @@
 }

 /*
+ * Try to read the location of the git directory from the .git file,
+ * return path to git directory if found.
+ */
+const char *read_gitfile_gently(const char *path)
+{
+       char *buf;
+       struct stat st;
+       int fd;
+       size_t len;
+
+       if (stat(path, &st))
+               return NULL;
+       if (!S_ISREG(st.st_mode))
+               return NULL;
+       fd = open(path, O_RDONLY);
+       if (fd < 0)
+               die("Error opening %s: %s", path, strerror(errno));
+       buf = xmalloc(st.st_size + 1);
+       len = read_in_full(fd, buf, st.st_size);
+       close(fd);
+       if (len != st.st_size)
+               die("Error reading %s", path);
+       buf[len] = '\0';
+       if (prefixcmp(buf, "gitdir: "))
+               die("Invalid gitfile format: %s", path);
+       while (buf[len - 1] == '\n' || buf[len - 1] == '\r')
+               len--;
+       if (len < 9)
+               die("No path in gitfile: %s", path);
+       buf[len] = '\0';
+       if (!is_git_directory(buf + 8))
+               die("Not a git repository: %s", buf + 8);
+       path = make_absolute_path(buf + 8);
+       free(buf);
+       return path;
+}
+
+/*
  * We cannot decide in this function whether we are in the work tree or
  * not, since the config can only be read _after_ this function was called.
  */
@@ -294,10 +332,10 @@

        /*
         * Test in the following order (relative to the cwd):
-        * - .git (file containing "gitdir: <path>\n")
+        * - .git (file containing "gitdir: <path>")
         * - .git/
         * - ./ (bare)
-        * - ../.git (file containing "gitdir: <path>\n")
+        * - ../.git
         * - ../.git/
         * - ../ (bare)
         * - ../../.git/
@@ -306,9 +344,9 @@
        offset = len = strlen(cwd);
        for (;;) {
                gitfile_dir = read_gitfile_gently(DEFAULT_GIT_DIR_ENVIRONMENT);
-               if (gitfile_dir && is_git_directory(gitfile_dir)) {
+               if (gitfile_dir) {
                        if (set_git_dir(gitfile_dir))
-                               return NULL;
+                               die("Repository setup failed");
                        break;
                }
                if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT))


--
larsh

Re: [PATCH 0/5 v2] Introduce the .gitfile

[Johannes Schindelin]

Hi,

On Mon, 18 Feb 2008, Lars Hjemli wrote:

> On Feb 18, 2008 2:31 PM, Johannes Schindelin <Johannes.Schindelin@gmx.de> wrote:
>
> > On Mon, 18 Feb 2008, Lars Hjemli wrote:
> >
> > > On Feb 18, 2008 1:17 PM, Johannes Schindelin wrote:
> > > > In the case of patch "1/5 => 2/5", I would even have appreciated 
> > > > an interdiff...
> > >
> > > Sorry, but I don't think I understand what you mean by interdiff.
> >
> > The tool interdiff of patchutils is really nice: you can visualise 
> > what would be the diff between the state after applying the first 
> > patch, and the state after applying the second patch, without applying 
> > anything at all:
> >
> >         $ interdiff <patch1> <patch2>
> 
> Ok, that sounds useful (I was kind of confused since 'man interdiff' 
> gave me nothing: being on slackware I'm so spoiled with preinstalled 
> dev-tools that I see no point in consulting google ;).
> 
> Something like this (possibly mangled by gmail)?

Heh, thank you!  The mangling does not matter, since this is purely for 
reviewing pleasure.

Thanks,
Dscho

Intoducing the .git file (again)

[Lars Hjemli]

These patches enables .git to be a textfile containing the path to the git
directory proper. It passes all the tests so hopefully there are no
regressions, but there may be bugs and omissions lurking when this feature
is actually used; I've exercised it in my git, cgit and dayjob repos but git
is big and has many codepaths so I wouldn't be suprised if there still are
some git commands left which fails to obey the .git file.

PS: These patches could certainly be squashed into a single patch, but I've
left them as is to make each one easier to review.

PPS: If included, the .git file should probably be used by git-submodule to
clone submodule repositories into something like $GIT_DIR/submodules/<name>,
as that would make local submodule changes more resistant to dataloss due to
checkout/reset in the containing repository.

Shortlog:
 Add platform-independent .git "symlink"
 Fix setup of $GIT_DIR in git-sh-setup.sh
 Teach resolve_gitlink_ref() about the .git file
 git-submodule: prepare for the .git-file
 Teach GIT-VERSION-GEN about the .git file

Diffstat:
 Documentation/repository-layout.txt |    5 ++-
 GIT-VERSION-GEN                     |    2 +-
 cache.h                             |    1 +
 environment.c                       |   38 ++++++++++++++++++
 git-sh-setup.sh                     |   12 ++---
 git-submodule.sh                    |    4 +-
 refs.c                              |   17 +++++++-
 setup.c                             |    9 ++++
 t/t0002-gitfile.sh                  |   74 +++++++++++++++++++++++++++++++++++
 9 files changed, 148 insertions(+), 14 deletions(-)

[PATCH 1/5] Add platform-independent .git "symlink"

[Lars Hjemli]

This patch allows .git to be a regular textfile containing the path of
the real git directory (formatted like "gitdir: <path>\n"), which is
useful on platforms lacking support for real symlinks.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
---
 Documentation/repository-layout.txt |    5 ++-
 cache.h                             |    1 +
 environment.c                       |   38 ++++++++++++++++++
 setup.c                             |    9 ++++
 t/t0002-gitfile.sh                  |   74 +++++++++++++++++++++++++++++++++++
 5 files changed, 126 insertions(+), 1 deletions(-)
 create mode 100755 t/t0002-gitfile.sh

diff --git a/Documentation/repository-layout.txt b/Documentation/repository-layout.txt
index 6939130..e9db3a1 100644
--- a/Documentation/repository-layout.txt
+++ b/Documentation/repository-layout.txt
@@ -3,7 +3,10 @@ git repository layout
 
 You may find these things in your git repository (`.git`
 directory for a repository associated with your working tree, or
-`'project'.git` directory for a public 'bare' repository).
+`'project'.git` directory for a public 'bare' repository. It is
+also possible to have a working tree where `.git` is a plain
+ascii file containing `gitdir: <path>\n`, i.e. the path to the
+real git repository).
 
 objects::
 	Object store associated with this repository.  Usually
diff --git a/cache.h b/cache.h
index e1000bc..1ad822a 100644
--- a/cache.h
+++ b/cache.h
@@ -277,6 +277,7 @@ extern char *get_index_file(void);
 extern char *get_graft_file(void);
 extern int set_git_dir(const char *path);
 extern const char *get_git_work_tree(void);
+extern const char *read_gitfile_gently(const char *path);
 
 #define ALTERNATE_DB_ENVIRONMENT "GIT_ALTERNATE_OBJECT_DIRECTORIES"
 
diff --git a/environment.c b/environment.c
index 3527f16..d120e8f 100644
--- a/environment.c
+++ b/environment.c
@@ -45,10 +45,48 @@ static const char *work_tree;
 static const char *git_dir;
 static char *git_object_dir, *git_index_file, *git_refs_dir, *git_graft_file;
 
+/*
+ * Try to read the location of the git directory from the .git file,
+ * return path to git directory if found.
+ * Format of the .git file is
+ *    gitdir: <path>\n
+ */
+const char *read_gitfile_gently(const char *path)
+{
+	static char buf[PATH_MAX + 9];  /* "gitdir: " + "\n" */
+	struct stat st;
+	int fd;
+	size_t len;
+
+	if (stat(path, &st))
+		return NULL;
+	if (!S_ISREG(st.st_mode) || st.st_size >= sizeof(buf))
+		return NULL;
+	fd = open(path, O_RDONLY);
+	if (fd < 0)
+		return NULL;
+	len = read_in_full(fd, buf, sizeof(buf));
+	close(fd);
+	if (len != st.st_size)
+		return NULL;
+	if (!len || buf[len - 1] != '\n')
+		return NULL;
+	buf[len - 1] = '\0';
+	if (prefixcmp(buf, "gitdir: "))
+		return NULL;
+/*
+	if (!is_git_directory(buf + 8))
+		return NULL;
+*/
+	return make_absolute_path(buf + 8);
+}
+
 static void setup_git_env(void)
 {
 	git_dir = getenv(GIT_DIR_ENVIRONMENT);
 	if (!git_dir)
+		git_dir = read_gitfile_gently(DEFAULT_GIT_DIR_ENVIRONMENT);
+	if (!git_dir)
 		git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
 	git_object_dir = getenv(DB_ENVIRONMENT);
 	if (!git_object_dir) {
diff --git a/setup.c b/setup.c
index 4509598..ebdf64b 100644
--- a/setup.c
+++ b/setup.c
@@ -247,6 +247,7 @@ const char *setup_git_directory_gently(int *nongit_ok)
 	const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
 	static char cwd[PATH_MAX+1];
 	const char *gitdirenv;
+	const char *gitfile_dir;
 	int len, offset;
 
 	/*
@@ -293,8 +294,10 @@ const char *setup_git_directory_gently(int *nongit_ok)
 
 	/*
 	 * Test in the following order (relative to the cwd):
+	 * - .git (file containing "gitdir: <path>\n")
 	 * - .git/
 	 * - ./ (bare)
+	 * - ../.git (file containing "gitdir: <path>\n")
 	 * - ../.git/
 	 * - ../ (bare)
 	 * - ../../.git/
@@ -302,6 +305,12 @@ const char *setup_git_directory_gently(int *nongit_ok)
 	 */
 	offset = len = strlen(cwd);
 	for (;;) {
+		gitfile_dir = read_gitfile_gently(DEFAULT_GIT_DIR_ENVIRONMENT);
+		if (gitfile_dir && is_git_directory(gitfile_dir)) {
+			if (set_git_dir(gitfile_dir))
+				return NULL;
+			break;
+		}
 		if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT))
 			break;
 		if (is_git_directory(".")) {
diff --git a/t/t0002-gitfile.sh b/t/t0002-gitfile.sh
new file mode 100755
index 0000000..d280663
--- /dev/null
+++ b/t/t0002-gitfile.sh
@@ -0,0 +1,74 @@
+#!/bin/sh
+
+test_description='.git file
+
+Verify that plumbing commands work when .git is a file
+'
+. ./test-lib.sh
+
+objpath() {
+    echo "$1" | sed -e 's|\(..\)|\1/|'
+}
+
+objck() {
+	p=$(objpath "$1")
+	if test ! -f "$REAL/objects/$p"
+	then
+		echo "Object not found: $REAL/objects/$p"
+		false
+	fi
+}
+
+test_expect_success 'setup' '
+	REAL="$(pwd)/.real" &&
+	mv .git "$REAL" &&
+	echo "gitdir: $REAL" >.git
+'
+
+test_expect_success 'check rev-parse --git-dir' '
+	test "$REAL" = "$(git rev-parse --git-dir)"
+'
+
+test_expect_success 'check hash-object' '
+	echo "foo" >bar &&
+	SHA=$(cat bar | git hash-object -w --stdin) &&
+	objck $SHA
+'
+
+test_expect_success 'check cat-file' '
+	git cat-file blob $SHA >actual &&
+	diff -u bar actual
+'
+
+test_expect_success 'check update-index' '
+	if test -f "$REAL/index"
+	then
+		echo "Hmm, $REAL/index exists?"
+		false
+	fi &&
+	rm -f "$REAL/objects/$(objpath $SHA)" &&
+	git update-index --add bar &&
+	if ! test -f "$REAL/index"
+	then
+		echo "$REAL/index not found"
+		false
+	fi &&
+	objck $SHA
+'
+
+test_expect_success 'check write-tree' '
+	SHA=$(git write-tree) &&
+	objck $SHA
+'
+
+test_expect_success 'check commit-tree' '
+	SHA=$(echo "commit bar" | git commit-tree $SHA) &&
+	objck $SHA
+'
+
+test_expect_success 'check rev-list' '
+	echo $SHA >"$REAL/HEAD" &&
+	test "$SHA" = "$(git rev-list HEAD)"
+'
+
+test_done
-- 
1.5.4.1.188.gdfa6c

[PATCH 2/5] Fix setup of $GIT_DIR in git-sh-setup.sh

[Lars Hjemli]

Since .git can be a file refering to the real GIT_DIR, git-sh-setup needs
to use 'git rev-parse --git-dir' to obtain the location of the git
repository.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
---
 git-sh-setup.sh |   12 +++++-------
 1 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/git-sh-setup.sh b/git-sh-setup.sh
index f388275..a7dbce2 100755
--- a/git-sh-setup.sh
+++ b/git-sh-setup.sh
@@ -127,20 +127,18 @@ get_author_ident_from_commit () {
 # if we require to be in a git repository.
 if test -z "$NONGIT_OK"
 then
+	GIT_DIR=$(git rev-parse --git-dir) || {
+		exit=$?
+		echo >&2 "Failed to find a valid git directory."
+		exit $exit
+	}
 	if [ -z "$SUBDIRECTORY_OK" ]
 	then
-		: ${GIT_DIR=.git}
 		test -z "$(git rev-parse --show-cdup)" || {
 			exit=$?
 			echo >&2 "You need to run this command from the toplevel of the working tree."
 			exit $exit
 		}
-	else
-		GIT_DIR=$(git rev-parse --git-dir) || {
-		    exit=$?
-		    echo >&2 "Failed to find a valid git directory."
-		    exit $exit
-		}
 	fi
 	test -n "$GIT_DIR" && GIT_DIR=$(cd "$GIT_DIR" && pwd) || {
 		echo >&2 "Unable to determine absolute path of git directory"
-- 
1.5.4.1.188.gdfa6c

[PATCH 3/5] Teach resolve_gitlink_ref() about the .git file

[Lars Hjemli]

When .git in a submodule is a file, resolve_gitlink_ref() needs to pick up
the real GIT_DIR of the submodule from that file.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
---
 refs.c |   17 ++++++++++++++---
 1 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/refs.c b/refs.c
index 67d2a50..56de5cf 100644
--- a/refs.c
+++ b/refs.c
@@ -351,6 +351,7 @@ int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *re
 {
 	int len = strlen(path), retval;
 	char *gitdir;
+	const char *tmp;
 
 	while (len && path[len-1] == '/')
 		len--;
@@ -358,9 +359,19 @@ int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *re
 		return -1;
 	gitdir = xmalloc(len + MAXREFLEN + 8);
 	memcpy(gitdir, path, len);
-	memcpy(gitdir + len, "/.git/", 7);
-
-	retval = resolve_gitlink_ref_recursive(gitdir, len+6, refname, result, 0);
+	memcpy(gitdir + len, "/.git", 6);
+	len += 5;
+
+	tmp = read_gitfile_gently(gitdir);
+	if (tmp) {
+		free(gitdir);
+		len = strlen(tmp);
+		gitdir = xmalloc(len + MAXREFLEN + 3);
+		memcpy(gitdir, tmp, len);
+	}
+	gitdir[len] = '/';
+	gitdir[++len] = '\0';
+	retval = resolve_gitlink_ref_recursive(gitdir, len, refname, result, 0);
 	free(gitdir);
 	return retval;
 }
-- 
1.5.4.1.188.gdfa6c

[PATCH 4/5] git-submodule: prepare for the .git-file

[Lars Hjemli]

When git-submodule tries to detect 'active' submodules, it checks for the
existence of a directory named '.git'. This isn't good enough now that .git
can be a file pointing to the real $GIT_DIR so the tests are changed to
reflect this.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
---
 git-submodule.sh |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/git-submodule.sh b/git-submodule.sh
index a6aaf40..e7c08b5 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -288,7 +288,7 @@ cmd_update()
 			continue
 		fi
 
-		if ! test -d "$path"/.git
+		if ! test -d "$path"/.git -o -f "$path"/.git
 		then
 			module_clone "$path" "$url" || exit
 			subsha1=
@@ -362,7 +362,7 @@ cmd_status()
 	do
 		name=$(module_name "$path") || exit
 		url=$(git config submodule."$name".url)
-		if test -z "url" || ! test -d "$path"/.git
+		if test -z "url" || ! test -d "$path"/.git -o -f "$path"/.git
 		then
 			say "-$sha1 $path"
 			continue;
-- 
1.5.4.1.188.gdfa6c

[PATCH 5/5] Teach GIT-VERSION-GEN about the .git file

[Lars Hjemli]

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
---
 GIT-VERSION-GEN |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/GIT-VERSION-GEN b/GIT-VERSION-GEN
index 38a3273..2432a4f 100755
--- a/GIT-VERSION-GEN
+++ b/GIT-VERSION-GEN
@@ -11,7 +11,7 @@ LF='
 if test -f version
 then
 	VN=$(cat version) || VN="$DEF_VER"
-elif test -d .git &&
+elif test -d .git -o -f .git &&
 	VN=$(git describe --abbrev=4 HEAD 2>/dev/null) &&
 	case "$VN" in
 	*$LF*) (exit 1) ;;
-- 
1.5.4.1.188.gdfa6c