[PATCH 0/4] Introduce the .git-file

[PATCH 0/4] Introduce the .git-file

[Lars Hjemli]

This is a resend of my previous patches + an update to make git-submodule
work with the .git-file + a litte documentation.

PS: Regarding the color of the bikeshed, it seems that everyone can live
with  "gitdir:" so that's what I ended up using.

Diffstat:
 Documentation/repository-layout.txt |    5 ++-
 git-submodule.sh                    |    4 +-
 setup.c                             |   40 +++++++++++++++++++
 t/t0002-gitfile.sh                  |   71 +++++++++++++++++++++++++++++++++++
 4 files changed, 117 insertions(+), 3 deletions(-)

[PATCH 1/4] 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>
---
 setup.c |   40 ++++++++++++++++++++++++++++++++++++++++
 1 files changed, 40 insertions(+), 0 deletions(-)

diff --git a/setup.c b/setup.c
index adede16..2cbda91 100644
--- a/setup.c
+++ b/setup.c
@@ -239,6 +239,40 @@ 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.
+ * Format of the .git file is
+ *    gitdir: <path>\n
+ */
+static 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);
+}
+
+/*
  * 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 +281,7 @@ 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;
 
 	/*
@@ -302,6 +337,11 @@ 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) {
+			setenv(GIT_DIR_ENVIRONMENT, gitfile_dir, 1);
+			break;
+		}
 		if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT))
 			break;
 		if (is_git_directory(".")) {
-- 
1.5.4.5.g25d066

[PATCH 2/4] Document the .git-file

[Lars Hjemli]

---
 Documentation/repository-layout.txt |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)

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
-- 
1.5.4.5.g25d066

[PATCH 3/4] Add tests for .git file

[Lars Hjemli]

Verify that the basic plumbing works when .git is a file pointing at
the real git directory.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
---
 t/t0002-gitfile.sh |   71 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 71 insertions(+), 0 deletions(-)
 create mode 100755 t/t0002-gitfile.sh

diff --git a/t/t0002-gitfile.sh b/t/t0002-gitfile.sh
new file mode 100755
index 0000000..f8f39e6
--- /dev/null
+++ b/t/t0002-gitfile.sh
@@ -0,0 +1,71 @@
+#!/bin/sh
+
+test_description='.git file
+
+Verify that plumbing commands work when .git is a file
+'
+. ./test-lib.sh
+
+chkfile() {
+	D=$(echo $1 | cut -b 1-2) &&
+	F=$(echo $1 | cut -b 3-40) &&
+	if test ! -f $REAL/objects/$D/$F
+	then
+		echo "Object not found: $REAL/objects/$D/$F"
+		false
+	fi
+}
+
+test_expect_success 'setup' '
+	REAL=$(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) &&
+	chkfile $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 -rf $REAL/objects/* &&
+	git update-index --add bar &&
+	if ! test -f $REAL/index
+	then
+		echo "$REAL/index not found"
+		false
+	fi &&
+	chkfile $SHA
+'
+
+test_expect_success 'check write-tree' '
+	SHA=$(git write-tree) &&
+	chkfile $SHA
+'
+
+test_expect_success 'check commit-tree' '
+	SHA=$(echo "commit bar" | git commit-tree $SHA) &&
+	chkfile $SHA
+'
+
+test_expect_success 'check rev-list' '
+	echo $SHA >$REAL/HEAD &&
+	test "$SHA" = "$(git rev-list HEAD)"
+'
+
+test_done
-- 
1.5.4.5.g25d066

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

[Lars Hjemli]

When git-submodule tried to detect 'active' submodules, it checked 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..220d64c 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -288,7 +288,7 @@ cmd_update()
 			continue
 		fi
 
-		if ! test -d "$path"/.git
+		if ! test -e "$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 "$path"/.git
+		if test -z "url" || ! test -e "$path"/.git
 		then
 			say "-$sha1 $path"
 			continue;
-- 
1.5.4.5.g25d066

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

[Mike Hommey]

On Mon, Feb 04, 2008 at 09:59:21PM +0100, Lars Hjemli wrote:
> -		if ! test -d "$path"/.git
> +		if ! test -e "$path"/.git

Is test -e supported by all shells we support ? I have some doubts...

Mike

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

[Lars Hjemli]

On Feb 4, 2008 11:23 PM, Mike Hommey <mh@glandium.org> wrote:
> On Mon, Feb 04, 2008 at 09:59:21PM +0100, Lars Hjemli wrote:
> > -             if ! test -d "$path"/.git
> > +             if ! test -e "$path"/.git
>
> Is test -e supported by all shells we support ? I have some doubts...
>

I dunno, but we already use it two other places in git-submodule.

I guess we can rewrite it to something like
  test -d $path || test -f $path || test -L $path || exist=0
if needed.

-- 
lh

Re: [PATCH 3/4] Add tests for .git file

[Junio C Hamano]

Lars Hjemli <hjemli@gmail.com> writes:

> Verify that the basic plumbing works when .git is a file pointing at
> the real git directory.
>
> Signed-off-by: Lars Hjemli <hjemli@gmail.com>
> ---
>  t/t0002-gitfile.sh |   71 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 files changed, 71 insertions(+), 0 deletions(-)
>  create mode 100755 t/t0002-gitfile.sh
>
> diff --git a/t/t0002-gitfile.sh b/t/t0002-gitfile.sh
> new file mode 100755
> index 0000000..f8f39e6
> --- /dev/null
> +++ b/t/t0002-gitfile.sh
> @@ -0,0 +1,71 @@
> +#!/bin/sh
> +
> +test_description='.git file
> +
> +Verify that plumbing commands work when .git is a file
> +'
> +. ./test-lib.sh
> +
> +chkfile() {
> +	D=$(echo $1 | cut -b 1-2) &&
> +	F=$(echo $1 | cut -b 3-40) &&
> +	if test ! -f $REAL/objects/$D/$F

	P=$(echo $1 | sed -e 's|\(..\)\(.*\)|\1/\2\|') &&
        if test ! -f "$REAL/objects/$P"
		...

Although it probably is more efficient to do this with one
process, s/cut/sed/ is mostly a style issue.

Be careful with quoting.  $REAL might contain a $IFS whitespace
as you grabbed it from $(pwd)...

> +test_expect_success 'setup' '
> +	REAL=$(pwd)/.real &&
> +	mv .git $REAL &&
> +	echo "gitdir: $REAL" >.git
> +'
> ...
> +test_expect_success 'check update-index' '
> +	if test -f $REAL/index
> +	then
> +		echo "Hmm, $REAL/index exists?"
> +		false
> +	fi &&
> +	rm -rf $REAL/objects/* &&

... and it matters especially if you do this ;-)

[PATCH 3/4 v2] Add tests for .git file

[Lars Hjemli]

Verify that the basic plumbing works when .git is a file pointing at
the real git directory.

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

This updated patch replaces cut with sed and tries to do proper quoting.


 t/t0002-gitfile.sh |   74 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 74 insertions(+), 0 deletions(-)
 create mode 100755 t/t0002-gitfile.sh

diff --git a/t/t0002-gitfile.sh b/t/t0002-gitfile.sh
new file mode 100755
index 0000000..7f8ee2f
--- /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 $1 | sed -re 's|(..)(.+)|\1/\2|'
+}
+
+objck() {
+	p=$(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
-- 
1.5.4.6.g6627

Re: [PATCH 3/4 v2] Add tests for .git file

[Junio C Hamano]

Lars Hjemli <hjemli@gmail.com> writes:

> Verify that the basic plumbing works when .git is a file pointing at
> the real git directory.
>
> Signed-off-by: Lars Hjemli <hjemli@gmail.com>
> ---
>
> This updated patch replaces cut with sed and tries to do proper quoting.
>
>
>  t/t0002-gitfile.sh |   74 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 files changed, 74 insertions(+), 0 deletions(-)
>  create mode 100755 t/t0002-gitfile.sh
>
> diff --git a/t/t0002-gitfile.sh b/t/t0002-gitfile.sh
> new file mode 100755
> index 0000000..7f8ee2f
> --- /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 -re 's|(..)(.+)|\1/\2|'
> +}

"sed -r"???  Please limit ourselves to the basics.

> +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)"
> +'

Nicely done.

Re: [PATCH 3/4 v2] Add tests for .git file

[Lars Hjemli]

On Feb 6, 2008 9:40 AM, Junio C Hamano <gitster@pobox.com> wrote:
> Lars Hjemli <hjemli@gmail.com> writes:
> > +objpath() {
> > +    echo $1 | sed -re 's|(..)(.+)|\1/\2|'
> > +}
>
> "sed -r"???  Please limit ourselves to the basics.

Sorry, I didn't realize 'sed -r' wasn't kosher. Should I resend or is
this something you'd --amend?

--
larsh

Re: [PATCH 3/4 v2] Add tests for .git file

[Junio C Hamano]

"Lars Hjemli" <hjemli@gmail.com> writes:

> On Feb 6, 2008 9:40 AM, Junio C Hamano <gitster@pobox.com> wrote:
>> Lars Hjemli <hjemli@gmail.com> writes:
>> > +objpath() {
>> > +    echo $1 | sed -re 's|(..)(.+)|\1/\2|'
>> > +}
>>
>> "sed -r"???  Please limit ourselves to the basics.
>
> Sorry, I didn't realize 'sed -r' wasn't kosher. Should I resend or is
> this something you'd --amend?

If we live in POSIX only world it is fine, but I try to be
conservative when I am able.

No need to resend; I've done something like this (there are
other minor amends).

    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/|'
    +}
    + ...

But the result won't be pushed out til tomorrow morning.

Re: [PATCH 3/4 v2] Add tests for .git file

[Lars Hjemli]

On Feb 6, 2008 11:13 AM, Junio C Hamano <gitster@pobox.com> wrote:
> "Lars Hjemli" <hjemli@gmail.com> writes:
>
> > On Feb 6, 2008 9:40 AM, Junio C Hamano <gitster@pobox.com> wrote:
> >> Lars Hjemli <hjemli@gmail.com> writes:
> >> > +objpath() {
> >> > +    echo $1 | sed -re 's|(..)(.+)|\1/\2|'
> >> > +}
> >>
> >> "sed -r"???  Please limit ourselves to the basics.
> >
> > Sorry, I didn't realize 'sed -r' wasn't kosher. Should I resend or is
> > this something you'd --amend?
>
> If we live in POSIX only world it is fine, but I try to be
> conservative when I am able.

Ok, good to know that my lack of experience doesn't pollute the codebase ;-)

> No need to resend; I've done something like this (there are
> other minor amends).
>...
>     +objpath() {
>     +    echo "$1" | sed -e 's|\(..\)|\1/|'
>     +}

Thanks.
--
larsh