[PATCHv3 0/5] submodule embedgitdirs

[PATCHv3 0/5] submodule embedgitdirs

[Stefan Beller]

v3:
* have a slightly more generic function "relocate_gitdir".
  The recursion is strictly related to submodules, though.
* bail out if a submodule is using worktrees.
  This also lays the groundwork for later doing the proper thing,
  as worktree.h offers a function `get_submodule_worktrees(path)`
* nit by duy: use git_path instead of git_common_dir

* diff to v2 (as queued by Junio) below.

Stefan Beller (5):
  submodule: use absolute path for computing relative path connecting
  submodule helper: support super prefix
  test-lib-functions.sh: teach test_commit -C <dir>
  worktree: get worktrees from submodules
  submodule: add embed-git-dir function

 Documentation/git-submodule.txt   | 14 ++++++
 builtin/submodule--helper.c       | 68 ++++++++++++++++++++++++-----
 dir.c                             | 78 +++++++++++++++++++++++++++++++++
 dir.h                             |  4 ++
 git-submodule.sh                  |  7 ++-
 git.c                             |  2 +-
 submodule.c                       | 12 ++---
 submodule.h                       |  1 -
 t/t7412-submodule-embedgitdirs.sh | 92 +++++++++++++++++++++++++++++++++++++++
 t/test-lib-functions.sh           | 20 ++++++---
 worktree.c                        | 40 ++++++++++++-----
 worktree.h                        |  5 +++
 12 files changed, 309 insertions(+), 34 deletions(-)
 create mode 100755 t/t7412-submodule-embedgitdirs.sh

v2:
* fixed commit message for patch:
 "submodule: use absolute path for computing relative path connecting"
* a new patch "submodule helper: support super prefix"
* redid the final patch with more tests and fixing bugs along the way
* "test-lib-functions.sh: teach test_commit -C <dir>" unchanged

v1:
The discussion of the submodule checkout series revealed to me that a command
is needed to move the git directory from the submodules working tree to be
embedded into the superprojects git directory.

So I wrote the code to intern the submodules git dir into the superproject,
but whilst writing the code I realized this could be valueable for our use
in testing too. So I exposed it via the submodule--helper. But as the
submodule helper ought to be just an internal API, we could also
offer it via the proper submodule command.

The command as it is has little value to the end user for now, but
breaking it out of the submodule checkout series hopefully makes review easier.

Thanks,
Stefan

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 75cdbf45b8..f2df166d15 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -1081,11 +1081,14 @@ static int embed_git_dir(int argc, const char **argv, const char *prefix)
 	int i;
 	struct pathspec pathspec;
 	struct module_list list = MODULE_LIST_INIT;
+	unsigned flags = RELOCATE_GITDIR_RECURSE_SUBMODULES;
 
 	struct option embed_gitdir_options[] = {
 		OPT_STRING(0, "prefix", &prefix,
 			   N_("path"),
 			   N_("path into the working tree")),
+		OPT_BIT(0, "--recursive", &flags, N_("recurse into submodules"),
+			RELOCATE_GITDIR_RECURSE_SUBMODULES),
 		OPT_END()
 	};
 
@@ -1104,7 +1107,7 @@ static int embed_git_dir(int argc, const char **argv, const char *prefix)
 		return 1;
 
 	for (i = 0; i < list.nr; i++)
-		migrate_submodule_gitdir(prefix, list.entries[i]->name, 1);
+		relocate_gitdir(prefix, list.entries[i]->name, flags);
 
 	return 0;
 }
diff --git a/dir.c b/dir.c
index bfa8c8a9a5..7b3abc1340 100644
--- a/dir.c
+++ b/dir.c
@@ -15,6 +15,9 @@
 #include "utf8.h"
 #include "varint.h"
 #include "ewah/ewok.h"
+#include "submodule-config.h"
+#include "run-command.h"
+#include "worktree.h"
 
 struct path_simplify {
 	int len;
@@ -2748,3 +2751,78 @@ void untracked_cache_add_to_index(struct index_state *istate,
 {
 	untracked_cache_invalidate_path(istate, path);
 }
+
+/*
+ * Migrate the given submodule (and all its submodules recursively) from
+ * having its git directory within the working tree to the git dir nested
+ * in its superprojects git dir under modules/.
+ */
+void relocate_gitdir(const char *prefix, const char *path, unsigned flags)
+{
+	char *old_git_dir;
+	const char *new_git_dir;
+	const struct submodule *sub;
+	struct worktree **worktrees;
+	int i;
+
+	worktrees = get_submodule_worktrees(path);
+	for (i = 0; worktrees[i]; i++)
+		;
+	if (i > 1)
+		die(_("relocate_gitdir for submodule with more than one worktree not supported"));
+
+	old_git_dir = xstrfmt("%s/.git", path);
+	if (read_gitfile(old_git_dir))
+		/* If it is an actual gitfile, it doesn't need migration. */
+		goto out;
+
+	sub = submodule_from_path(null_sha1, path);
+	if (!sub)
+		die(_("Could not lookup name for submodule '%s'"),
+		      path);
+
+	new_git_dir = git_path("modules/%s", sub->name);
+	if (safe_create_leading_directories_const(new_git_dir) < 0)
+		die(_("could not create directory '%s'"), new_git_dir);
+
+	if (!prefix)
+		prefix = get_super_prefix();
+	printf("Migrating git directory of %s%s from\n'%s' to\n'%s'\n",
+		prefix ? prefix : "", path,
+		real_path(old_git_dir), new_git_dir);
+
+	if (rename(old_git_dir, new_git_dir) < 0)
+		die_errno(_("Could not migrate git directory from '%s' to '%s'"),
+			old_git_dir, new_git_dir);
+
+	connect_work_tree_and_git_dir(path, new_git_dir);
+
+out:
+	if (flags & RELOCATE_GITDIR_RECURSE_SUBMODULES) {
+		struct child_process cp = CHILD_PROCESS_INIT;
+		struct strbuf sb = STRBUF_INIT;
+
+		if (flags & ~RELOCATE_GITDIR_RECURSE_SUBMODULES)
+			die("BUG: we don't know how to pass the flags down?");
+
+		if (get_super_prefix())
+			strbuf_addstr(&sb, get_super_prefix());
+		strbuf_addstr(&sb, path);
+		strbuf_addch(&sb, '/');
+
+		cp.dir = path;
+		cp.git_cmd = 1;
+		cp.no_stdin = 1;
+		argv_array_pushl(&cp.args, "--super-prefix", sb.buf,
+					    "submodule--helper",
+					   "embed-git-dirs", NULL);
+		prepare_submodule_repo_env(&cp.env_array);
+		if (run_command(&cp))
+			die(_("Could not migrate git directory in submodule '%s'"),
+			    path);
+
+		strbuf_release(&sb);
+	}
+
+	free(old_git_dir);
+}
diff --git a/dir.h b/dir.h
index 97c83bb383..0b5e99b21d 100644
--- a/dir.h
+++ b/dir.h
@@ -335,4 +335,8 @@ struct untracked_cache *read_untracked_extension(const void *data, unsigned long
 void write_untracked_extension(struct strbuf *out, struct untracked_cache *untracked);
 void add_untracked_cache(struct index_state *istate);
 void remove_untracked_cache(struct index_state *istate);
+
+#define RELOCATE_GITDIR_RECURSE_SUBMODULES (1<<0)
+extern void relocate_gitdir(const char *prefix, const char *path, unsigned flags);
+
 #endif
diff --git a/submodule.c b/submodule.c
index d330b567a3..66c5ce5a24 100644
--- a/submodule.c
+++ b/submodule.c
@@ -1263,68 +1263,3 @@ void prepare_submodule_repo_env(struct argv_array *out)
 	}
 	argv_array_push(out, "GIT_DIR=.git");
 }
-
-/*
- * Migrate the given submodule (and all its submodules recursively) from
- * having its git directory within the working tree to the git dir nested
- * in its superprojects git dir under modules/.
- */
-void migrate_submodule_gitdir(const char *prefix, const char *path,
-			      int recursive)
-{
-	char *old_git_dir;
-	const char *new_git_dir;
-	const struct submodule *sub;
-
-	old_git_dir = xstrfmt("%s/.git", path);
-	if (read_gitfile(old_git_dir))
-		/* If it is an actual gitfile, it doesn't need migration. */
-		goto out;
-
-	sub = submodule_from_path(null_sha1, path);
-	if (!sub)
-		die(_("Could not lookup name for submodule '%s'"),
-		      path);
-
-	new_git_dir = git_common_path("modules/%s", sub->name);
-	if (safe_create_leading_directories_const(new_git_dir) < 0)
-		die(_("could not create directory '%s'"), new_git_dir);
-
-	if (!prefix)
-		prefix = get_super_prefix();
-	printf("Migrating git directory of %s%s from\n'%s' to\n'%s'\n",
-		prefix ? prefix : "", path,
-		real_path(old_git_dir), new_git_dir);
-
-	if (rename(old_git_dir, new_git_dir) < 0)
-		die_errno(_("Could not migrate git directory from '%s' to '%s'"),
-			old_git_dir, new_git_dir);
-
-	connect_work_tree_and_git_dir(path, new_git_dir);
-
-out:
-	if (recursive) {
-		struct child_process cp = CHILD_PROCESS_INIT;
-		struct strbuf sb = STRBUF_INIT;
-
-		if (get_super_prefix())
-			strbuf_addstr(&sb, get_super_prefix());
-		strbuf_addstr(&sb, path);
-		strbuf_addch(&sb, '/');
-
-		cp.dir = path;
-		cp.git_cmd = 1;
-		cp.no_stdin = 1;
-		argv_array_pushl(&cp.args, "--super-prefix", sb.buf,
-					    "submodule--helper",
-					   "embed-git-dirs", NULL);
-		prepare_submodule_repo_env(&cp.env_array);
-		if (run_command(&cp))
-			die(_("Could not migrate git directory in submodule '%s'"),
-			    path);
-
-		strbuf_release(&sb);
-	}
-
-	free(old_git_dir);
-}
diff --git a/submodule.h b/submodule.h
index e5975d1f3d..1e42222cff 100644
--- a/submodule.h
+++ b/submodule.h
@@ -74,7 +74,4 @@ int parallel_submodules(void);
  * retaining any config in the environment.
  */
 void prepare_submodule_repo_env(struct argv_array *out);
-
-extern void migrate_submodule_gitdir(const char *prefix,
-				     const char *path, int recursive);
 #endif
diff --git a/t/t7412-submodule-embedgitdirs.sh b/t/t7412-submodule-embedgitdirs.sh
index 1cf5d4b4af..e3443b88cd 100755
--- a/t/t7412-submodule-embedgitdirs.sh
+++ b/t/t7412-submodule-embedgitdirs.sh
@@ -74,4 +74,19 @@ test_expect_success 'embedding the git dir fails for incomplete submodules' '
 	test_cmp expect.2 actual.2
 '
 
+test_expect_success 'setup a submodule with multiple worktrees' '
+	# first create another unembedded git dir in a new submodule
+	git init sub3 &&
+	test_commit -C sub3 first &&
+	git submodule add ./sub3 &&
+	test_tick &&
+	git commit -m "add another submodule" &&
+	git -C sub3 worktree add ../sub3_second_work_tree
+'
+
+test_expect_success 'embed a submodule with multiple worktrees' '
+	test_must_fail git submodule embedgitdirs sub3 2>error &&
+	test_i18ngrep "not supported" error
+'
+
 test_done
diff --git a/worktree.c b/worktree.c
index f7869f8d60..fb1f72bbf3 100644
--- a/worktree.c
+++ b/worktree.c
@@ -72,7 +72,7 @@ static void add_head_info(struct strbuf *head_ref, struct worktree *worktree)
 /**
  * get the main worktree
  */
-static struct worktree *get_main_worktree(void)
+static struct worktree *get_main_worktree(const char *git_common_dir)
 {
 	struct worktree *worktree = NULL;
 	struct strbuf path = STRBUF_INIT;
@@ -81,12 +81,12 @@ static struct worktree *get_main_worktree(void)
 	int is_bare = 0;
 	int is_detached = 0;
 
-	strbuf_add_absolute_path(&worktree_path, get_git_common_dir());
+	strbuf_add_absolute_path(&worktree_path, git_common_dir);
 	is_bare = !strbuf_strip_suffix(&worktree_path, "/.git");
 	if (is_bare)
 		strbuf_strip_suffix(&worktree_path, "/.");
 
-	strbuf_addf(&path, "%s/HEAD", get_git_common_dir());
+	strbuf_addf(&path, "%s/HEAD", git_common_dir);
 
 	if (parse_ref(path.buf, &head_ref, &is_detached) < 0)
 		goto done;
@@ -109,7 +109,8 @@ static struct worktree *get_main_worktree(void)
 	return worktree;
 }
 
-static struct worktree *get_linked_worktree(const char *id)
+static struct worktree *get_linked_worktree(const char *git_common_dir,
+					    const char *id)
 {
 	struct worktree *worktree = NULL;
 	struct strbuf path = STRBUF_INIT;
@@ -120,7 +121,7 @@ static struct worktree *get_linked_worktree(const char *id)
 	if (!id)
 		die("Missing linked worktree name");
 
-	strbuf_git_common_path(&path, "worktrees/%s/gitdir", id);
+	strbuf_addf(&path, "%s/worktrees/%s/gitdir", git_common_dir, id);
 	if (strbuf_read_file(&worktree_path, path.buf, 0) <= 0)
 		/* invalid gitdir file */
 		goto done;
@@ -133,7 +134,7 @@ static struct worktree *get_linked_worktree(const char *id)
 	}
 
 	strbuf_reset(&path);
-	strbuf_addf(&path, "%s/worktrees/%s/HEAD", get_git_common_dir(), id);
+	strbuf_addf(&path, "%s/worktrees/%s/HEAD", git_common_dir, id);
 
 	if (parse_ref(path.buf, &head_ref, &is_detached) < 0)
 		goto done;
@@ -173,7 +174,7 @@ static void mark_current_worktree(struct worktree **worktrees)
 	free(git_dir);
 }
 
-struct worktree **get_worktrees(void)
+struct worktree **get_worktrees_internal(const char *git_common_dir)
 {
 	struct worktree **list = NULL;
 	struct strbuf path = STRBUF_INIT;
@@ -183,10 +184,10 @@ struct worktree **get_worktrees(void)
 
 	list = xmalloc(alloc * sizeof(struct worktree *));
 
-	if ((list[counter] = get_main_worktree()))
+	if ((list[counter] = get_main_worktree(git_common_dir)))
 		counter++;
 
-	strbuf_addf(&path, "%s/worktrees", get_git_common_dir());
+	strbuf_addf(&path, "%s/worktrees", git_common_dir);
 	dir = opendir(path.buf);
 	strbuf_release(&path);
 	if (dir) {
@@ -195,7 +196,7 @@ struct worktree **get_worktrees(void)
 			if (is_dot_or_dotdot(d->d_name))
 				continue;
 
-			if ((linked = get_linked_worktree(d->d_name))) {
+			if ((linked = get_linked_worktree(git_common_dir, d->d_name))) {
 				ALLOC_GROW(list, counter + 1, alloc);
 				list[counter++] = linked;
 			}
@@ -209,6 +210,25 @@ struct worktree **get_worktrees(void)
 	return list;
 }
 
+struct worktree **get_worktrees(void)
+{
+	return get_worktrees_internal(get_git_common_dir());
+}
+
+struct worktree **get_submodule_worktrees(const char *path)
+{
+	const char *submodule_common_dir;
+	struct strbuf sb = STRBUF_INIT;
+	struct worktree **ret;
+	strbuf_addf(&sb, "%s/.git", path);
+	submodule_common_dir = resolve_gitdir(sb.buf);
+
+	ret = get_worktrees_internal(submodule_common_dir);
+
+	strbuf_release(&sb);
+	return ret;
+}
+
 const char *get_worktree_git_dir(const struct worktree *wt)
 {
 	if (!wt)
diff --git a/worktree.h b/worktree.h
index 90e1311fa7..c93845516c 100644
--- a/worktree.h
+++ b/worktree.h
@@ -25,6 +25,11 @@ struct worktree {
  */
 extern struct worktree **get_worktrees(void);
 
+/*
+ * Get the worktrees of a submodule named by `path`.
+ */
+extern struct worktree **get_submodule_worktrees(const char *path);
+
 /*
  * Return git dir of the worktree. Note that the path may be relative.
  * If wt is NULL, git dir of current worktree is returned.


-- 
2.10.2.613.g22f2156

[PATCHv3 1/5] submodule: use absolute path for computing relative path connecting

[Stefan Beller]

The current caller of connect_work_tree_and_git_dir passes
an absolute path for the `git_dir` parameter. In the future patch
we will also pass in relative path for `git_dir`. Extend the functionality
of connect_work_tree_and_git_dir to take relative paths for parameters.

We could work around this in the future patch by computing the absolute
path for the git_dir in the calling site, however accepting relative
paths for either parameter makes the API for this function much harder
to misuse.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 submodule.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/submodule.c b/submodule.c
index 6f7d883de9..66c5ce5a24 100644
--- a/submodule.c
+++ b/submodule.c
@@ -1227,23 +1227,25 @@ void connect_work_tree_and_git_dir(const char *work_tree, const char *git_dir)
 {
 	struct strbuf file_name = STRBUF_INIT;
 	struct strbuf rel_path = STRBUF_INIT;
-	const char *real_work_tree = xstrdup(real_path(work_tree));
+	char *real_git_dir = xstrdup(real_path(git_dir));
+	char *real_work_tree = xstrdup(real_path(work_tree));
 
 	/* Update gitfile */
 	strbuf_addf(&file_name, "%s/.git", work_tree);
 	write_file(file_name.buf, "gitdir: %s",
-		   relative_path(git_dir, real_work_tree, &rel_path));
+		   relative_path(real_git_dir, real_work_tree, &rel_path));
 
 	/* Update core.worktree setting */
 	strbuf_reset(&file_name);
-	strbuf_addf(&file_name, "%s/config", git_dir);
+	strbuf_addf(&file_name, "%s/config", real_git_dir);
 	git_config_set_in_file(file_name.buf, "core.worktree",
-			       relative_path(real_work_tree, git_dir,
+			       relative_path(real_work_tree, real_git_dir,
 					     &rel_path));
 
 	strbuf_release(&file_name);
 	strbuf_release(&rel_path);
-	free((void *)real_work_tree);
+	free(real_work_tree);
+	free(real_git_dir);
 }
 
 int parallel_submodules(void)
-- 
2.10.2.613.g22f2156

[PATCHv3 2/5] submodule helper: support super prefix

[Stefan Beller]

Just like main commands in Git, the submodule helper needs
access to the superproject prefix. Enable this in the git.c
but have its own fuse in the helper code by having a flag to
turn on the super prefix.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin/submodule--helper.c | 31 ++++++++++++++++++++-----------
 git.c                       |  2 +-
 2 files changed, 21 insertions(+), 12 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 4beeda5f9f..806e29ce4e 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -1076,21 +1076,24 @@ static int resolve_remote_submodule_branch(int argc, const char **argv,
 	return 0;
 }
 
+#define SUPPORT_SUPER_PREFIX (1<<0)
+
 struct cmd_struct {
 	const char *cmd;
 	int (*fn)(int, const char **, const char *);
+	int option;
 };
 
 static struct cmd_struct commands[] = {
-	{"list", module_list},
-	{"name", module_name},
-	{"clone", module_clone},
-	{"update-clone", update_clone},
-	{"relative-path", resolve_relative_path},
-	{"resolve-relative-url", resolve_relative_url},
-	{"resolve-relative-url-test", resolve_relative_url_test},
-	{"init", module_init},
-	{"remote-branch", resolve_remote_submodule_branch}
+	{"list", module_list, 0},
+	{"name", module_name, 0},
+	{"clone", module_clone, 0},
+	{"update-clone", update_clone, 0},
+	{"relative-path", resolve_relative_path, 0},
+	{"resolve-relative-url", resolve_relative_url, 0},
+	{"resolve-relative-url-test", resolve_relative_url_test, 0},
+	{"init", module_init, 0},
+	{"remote-branch", resolve_remote_submodule_branch, 0}
 };
 
 int cmd_submodule__helper(int argc, const char **argv, const char *prefix)
@@ -1100,9 +1103,15 @@ int cmd_submodule__helper(int argc, const char **argv, const char *prefix)
 		die(_("submodule--helper subcommand must be "
 		      "called with a subcommand"));
 
-	for (i = 0; i < ARRAY_SIZE(commands); i++)
-		if (!strcmp(argv[1], commands[i].cmd))
+	for (i = 0; i < ARRAY_SIZE(commands); i++) {
+		if (!strcmp(argv[1], commands[i].cmd)) {
+			if (get_super_prefix() &&
+			    !(commands[i].option & SUPPORT_SUPER_PREFIX))
+				die("%s doesn't support --super-prefix",
+				    commands[i].cmd);
 			return commands[i].fn(argc - 1, argv + 1, prefix);
+		}
+	}
 
 	die(_("'%s' is not a valid submodule--helper "
 	      "subcommand"), argv[1]);
diff --git a/git.c b/git.c
index efa1059fe0..98dcf6c518 100644
--- a/git.c
+++ b/git.c
@@ -493,7 +493,7 @@ static struct cmd_struct commands[] = {
 	{ "stage", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 	{ "status", cmd_status, RUN_SETUP | NEED_WORK_TREE },
 	{ "stripspace", cmd_stripspace },
-	{ "submodule--helper", cmd_submodule__helper, RUN_SETUP },
+	{ "submodule--helper", cmd_submodule__helper, RUN_SETUP | SUPPORT_SUPER_PREFIX},
 	{ "symbolic-ref", cmd_symbolic_ref, RUN_SETUP },
 	{ "tag", cmd_tag, RUN_SETUP },
 	{ "unpack-file", cmd_unpack_file, RUN_SETUP },
-- 
2.10.2.613.g22f2156

[PATCHv3 3/5] test-lib-functions.sh: teach test_commit -C <dir>

[Stefan Beller]

Specifically when setting up submodule tests, it comes in handy if
we can create commits in repositories that are not at the root of
the tested trash dir. Add "-C <dir>" similar to gits -C parameter
that will perform the operation in the given directory.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 t/test-lib-functions.sh | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
index fdaeb3a96b..579e812506 100644
--- a/t/test-lib-functions.sh
+++ b/t/test-lib-functions.sh
@@ -157,16 +157,21 @@ debug () {
 	 GIT_TEST_GDB=1 "$@"
 }
 
-# Call test_commit with the arguments "<message> [<file> [<contents> [<tag>]]]"
+# Call test_commit with the arguments
+# [-C <directory>] <message> [<file> [<contents> [<tag>]]]"
 #
 # This will commit a file with the given contents and the given commit
 # message, and tag the resulting commit with the given tag name.
 #
 # <file>, <contents>, and <tag> all default to <message>.
+#
+# If the first argument is "-C", the second argument is used as a path for
+# the git invocations.
 
 test_commit () {
 	notick= &&
 	signoff= &&
+	indir= &&
 	while test $# != 0
 	do
 		case "$1" in
@@ -176,21 +181,26 @@ test_commit () {
 		--signoff)
 			signoff="$1"
 			;;
+		-C)
+			indir="$2"
+			shift
+			;;
 		*)
 			break
 			;;
 		esac
 		shift
 	done &&
+	indir=${indir:+"$indir"/} &&
 	file=${2:-"$1.t"} &&
-	echo "${3-$1}" > "$file" &&
-	git add "$file" &&
+	echo "${3-$1}" > "$indir$file" &&
+	git ${indir:+ -C "$indir"} add "$file" &&
 	if test -z "$notick"
 	then
 		test_tick
 	fi &&
-	git commit $signoff -m "$1" &&
-	git tag "${4:-$1}"
+	git ${indir:+ -C "$indir"} commit $signoff -m "$1" &&
+	git ${indir:+ -C "$indir"} tag "${4:-$1}"
 }
 
 # Call test_merge with the arguments "<message> <commit>", where <commit>
-- 
2.10.2.613.g22f2156

[PATCHv3 4/5] worktree: get worktrees from submodules

[Stefan Beller]

In a later patch we want to move around the the git directory of
a submodule. Both submodules as well as worktrees are involved in
placing git directories at unusual places, so their functionality
may collide. To react appropriately to situations where worktrees
in submodules are in use, offer a new function to query the
worktrees for submodules.

Signed-off-by: Stefan Beller <sbeller@google.com>
---
 worktree.c | 40 ++++++++++++++++++++++++++++++----------
 worktree.h |  5 +++++
 2 files changed, 35 insertions(+), 10 deletions(-)

diff --git a/worktree.c b/worktree.c
index f7869f8d60..fb1f72bbf3 100644
--- a/worktree.c
+++ b/worktree.c
@@ -72,7 +72,7 @@ static void add_head_info(struct strbuf *head_ref, struct worktree *worktree)
 /**
  * get the main worktree
  */
-static struct worktree *get_main_worktree(void)
+static struct worktree *get_main_worktree(const char *git_common_dir)
 {
 	struct worktree *worktree = NULL;
 	struct strbuf path = STRBUF_INIT;
@@ -81,12 +81,12 @@ static struct worktree *get_main_worktree(void)
 	int is_bare = 0;
 	int is_detached = 0;
 
-	strbuf_add_absolute_path(&worktree_path, get_git_common_dir());
+	strbuf_add_absolute_path(&worktree_path, git_common_dir);
 	is_bare = !strbuf_strip_suffix(&worktree_path, "/.git");
 	if (is_bare)
 		strbuf_strip_suffix(&worktree_path, "/.");
 
-	strbuf_addf(&path, "%s/HEAD", get_git_common_dir());
+	strbuf_addf(&path, "%s/HEAD", git_common_dir);
 
 	if (parse_ref(path.buf, &head_ref, &is_detached) < 0)
 		goto done;
@@ -109,7 +109,8 @@ static struct worktree *get_main_worktree(void)
 	return worktree;
 }
 
-static struct worktree *get_linked_worktree(const char *id)
+static struct worktree *get_linked_worktree(const char *git_common_dir,
+					    const char *id)
 {
 	struct worktree *worktree = NULL;
 	struct strbuf path = STRBUF_INIT;
@@ -120,7 +121,7 @@ static struct worktree *get_linked_worktree(const char *id)
 	if (!id)
 		die("Missing linked worktree name");
 
-	strbuf_git_common_path(&path, "worktrees/%s/gitdir", id);
+	strbuf_addf(&path, "%s/worktrees/%s/gitdir", git_common_dir, id);
 	if (strbuf_read_file(&worktree_path, path.buf, 0) <= 0)
 		/* invalid gitdir file */
 		goto done;
@@ -133,7 +134,7 @@ static struct worktree *get_linked_worktree(const char *id)
 	}
 
 	strbuf_reset(&path);
-	strbuf_addf(&path, "%s/worktrees/%s/HEAD", get_git_common_dir(), id);
+	strbuf_addf(&path, "%s/worktrees/%s/HEAD", git_common_dir, id);
 
 	if (parse_ref(path.buf, &head_ref, &is_detached) < 0)
 		goto done;
@@ -173,7 +174,7 @@ static void mark_current_worktree(struct worktree **worktrees)
 	free(git_dir);
 }
 
-struct worktree **get_worktrees(void)
+struct worktree **get_worktrees_internal(const char *git_common_dir)
 {
 	struct worktree **list = NULL;
 	struct strbuf path = STRBUF_INIT;
@@ -183,10 +184,10 @@ struct worktree **get_worktrees(void)
 
 	list = xmalloc(alloc * sizeof(struct worktree *));
 
-	if ((list[counter] = get_main_worktree()))
+	if ((list[counter] = get_main_worktree(git_common_dir)))
 		counter++;
 
-	strbuf_addf(&path, "%s/worktrees", get_git_common_dir());
+	strbuf_addf(&path, "%s/worktrees", git_common_dir);
 	dir = opendir(path.buf);
 	strbuf_release(&path);
 	if (dir) {
@@ -195,7 +196,7 @@ struct worktree **get_worktrees(void)
 			if (is_dot_or_dotdot(d->d_name))
 				continue;
 
-			if ((linked = get_linked_worktree(d->d_name))) {
+			if ((linked = get_linked_worktree(git_common_dir, d->d_name))) {
 				ALLOC_GROW(list, counter + 1, alloc);
 				list[counter++] = linked;
 			}
@@ -209,6 +210,25 @@ struct worktree **get_worktrees(void)
 	return list;
 }
 
+struct worktree **get_worktrees(void)
+{
+	return get_worktrees_internal(get_git_common_dir());
+}
+
+struct worktree **get_submodule_worktrees(const char *path)
+{
+	const char *submodule_common_dir;
+	struct strbuf sb = STRBUF_INIT;
+	struct worktree **ret;
+	strbuf_addf(&sb, "%s/.git", path);
+	submodule_common_dir = resolve_gitdir(sb.buf);
+
+	ret = get_worktrees_internal(submodule_common_dir);
+
+	strbuf_release(&sb);
+	return ret;
+}
+
 const char *get_worktree_git_dir(const struct worktree *wt)
 {
 	if (!wt)
diff --git a/worktree.h b/worktree.h
index 90e1311fa7..c93845516c 100644
--- a/worktree.h
+++ b/worktree.h
@@ -25,6 +25,11 @@ struct worktree {
  */
 extern struct worktree **get_worktrees(void);
 
+/*
+ * Get the worktrees of a submodule named by `path`.
+ */
+extern struct worktree **get_submodule_worktrees(const char *path);
+
 /*
  * Return git dir of the worktree. Note that the path may be relative.
  * If wt is NULL, git dir of current worktree is returned.
-- 
2.10.2.613.g22f2156

[PATCHv3 5/5] submodule: add embed-git-dir function

[Stefan Beller]

When a submodule has its git dir inside the working dir, the submodule
support for checkout that we plan to add in a later patch will fail.

Add functionality to migrate the git directory to be embedded
into the superprojects git directory.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 Documentation/git-submodule.txt   | 14 ++++++
 builtin/submodule--helper.c       | 39 ++++++++++++++++-
 dir.c                             | 78 +++++++++++++++++++++++++++++++++
 dir.h                             |  4 ++
 git-submodule.sh                  |  7 ++-
 submodule.h                       |  1 -
 t/t7412-submodule-embedgitdirs.sh | 92 +++++++++++++++++++++++++++++++++++++++
 7 files changed, 232 insertions(+), 3 deletions(-)
 create mode 100755 t/t7412-submodule-embedgitdirs.sh

diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index d841573475..34791cfc65 100644
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -22,6 +22,7 @@ SYNOPSIS
 	      [commit] [--] [<path>...]
 'git submodule' [--quiet] foreach [--recursive] <command>
 'git submodule' [--quiet] sync [--recursive] [--] [<path>...]
+'git submodule' [--quiet] embedgitdirs [--] [<path>...]
 
 
 DESCRIPTION
@@ -245,6 +246,19 @@ sync::
 If `--recursive` is specified, this command will recurse into the
 registered submodules, and sync any nested submodules within.
 
+embedgitdirs::
+	Move the git directory of submodules into its superprojects
+	`$GIT_DIR/modules` path and then connect the git directory and
+	its working directory by setting the `core.worktree` and adding
+	a .git file pointing to the git directory interned into the
+	superproject.
++
+A repository that was cloned independently and later added as a submodule or
+old setups have the submodules git directory inside the submodule instead of
+embedded into the superprojects git directory.
++
+This command is recursive by default.
+
 OPTIONS
 -------
 -q::
diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 806e29ce4e..f2df166d15 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -1076,6 +1076,42 @@ static int resolve_remote_submodule_branch(int argc, const char **argv,
 	return 0;
 }
 
+static int embed_git_dir(int argc, const char **argv, const char *prefix)
+{
+	int i;
+	struct pathspec pathspec;
+	struct module_list list = MODULE_LIST_INIT;
+	unsigned flags = RELOCATE_GITDIR_RECURSE_SUBMODULES;
+
+	struct option embed_gitdir_options[] = {
+		OPT_STRING(0, "prefix", &prefix,
+			   N_("path"),
+			   N_("path into the working tree")),
+		OPT_BIT(0, "--recursive", &flags, N_("recurse into submodules"),
+			RELOCATE_GITDIR_RECURSE_SUBMODULES),
+		OPT_END()
+	};
+
+	const char *const git_submodule_helper_usage[] = {
+		N_("git submodule--helper embed-git-dir [<path>...]"),
+		NULL
+	};
+
+	argc = parse_options(argc, argv, prefix, embed_gitdir_options,
+			     git_submodule_helper_usage, 0);
+
+	gitmodules_config();
+	git_config(submodule_config, NULL);
+
+	if (module_list_compute(argc, argv, prefix, &pathspec, &list) < 0)
+		return 1;
+
+	for (i = 0; i < list.nr; i++)
+		relocate_gitdir(prefix, list.entries[i]->name, flags);
+
+	return 0;
+}
+
 #define SUPPORT_SUPER_PREFIX (1<<0)
 
 struct cmd_struct {
@@ -1093,7 +1129,8 @@ static struct cmd_struct commands[] = {
 	{"resolve-relative-url", resolve_relative_url, 0},
 	{"resolve-relative-url-test", resolve_relative_url_test, 0},
 	{"init", module_init, 0},
-	{"remote-branch", resolve_remote_submodule_branch, 0}
+	{"remote-branch", resolve_remote_submodule_branch, 0},
+	{"embed-git-dirs", embed_git_dir, SUPPORT_SUPER_PREFIX}
 };
 
 int cmd_submodule__helper(int argc, const char **argv, const char *prefix)
diff --git a/dir.c b/dir.c
index bfa8c8a9a5..7b3abc1340 100644
--- a/dir.c
+++ b/dir.c
@@ -15,6 +15,9 @@
 #include "utf8.h"
 #include "varint.h"
 #include "ewah/ewok.h"
+#include "submodule-config.h"
+#include "run-command.h"
+#include "worktree.h"
 
 struct path_simplify {
 	int len;
@@ -2748,3 +2751,78 @@ void untracked_cache_add_to_index(struct index_state *istate,
 {
 	untracked_cache_invalidate_path(istate, path);
 }
+
+/*
+ * Migrate the given submodule (and all its submodules recursively) from
+ * having its git directory within the working tree to the git dir nested
+ * in its superprojects git dir under modules/.
+ */
+void relocate_gitdir(const char *prefix, const char *path, unsigned flags)
+{
+	char *old_git_dir;
+	const char *new_git_dir;
+	const struct submodule *sub;
+	struct worktree **worktrees;
+	int i;
+
+	worktrees = get_submodule_worktrees(path);
+	for (i = 0; worktrees[i]; i++)
+		;
+	if (i > 1)
+		die(_("relocate_gitdir for submodule with more than one worktree not supported"));
+
+	old_git_dir = xstrfmt("%s/.git", path);
+	if (read_gitfile(old_git_dir))
+		/* If it is an actual gitfile, it doesn't need migration. */
+		goto out;
+
+	sub = submodule_from_path(null_sha1, path);
+	if (!sub)
+		die(_("Could not lookup name for submodule '%s'"),
+		      path);
+
+	new_git_dir = git_path("modules/%s", sub->name);
+	if (safe_create_leading_directories_const(new_git_dir) < 0)
+		die(_("could not create directory '%s'"), new_git_dir);
+
+	if (!prefix)
+		prefix = get_super_prefix();
+	printf("Migrating git directory of %s%s from\n'%s' to\n'%s'\n",
+		prefix ? prefix : "", path,
+		real_path(old_git_dir), new_git_dir);
+
+	if (rename(old_git_dir, new_git_dir) < 0)
+		die_errno(_("Could not migrate git directory from '%s' to '%s'"),
+			old_git_dir, new_git_dir);
+
+	connect_work_tree_and_git_dir(path, new_git_dir);
+
+out:
+	if (flags & RELOCATE_GITDIR_RECURSE_SUBMODULES) {
+		struct child_process cp = CHILD_PROCESS_INIT;
+		struct strbuf sb = STRBUF_INIT;
+
+		if (flags & ~RELOCATE_GITDIR_RECURSE_SUBMODULES)
+			die("BUG: we don't know how to pass the flags down?");
+
+		if (get_super_prefix())
+			strbuf_addstr(&sb, get_super_prefix());
+		strbuf_addstr(&sb, path);
+		strbuf_addch(&sb, '/');
+
+		cp.dir = path;
+		cp.git_cmd = 1;
+		cp.no_stdin = 1;
+		argv_array_pushl(&cp.args, "--super-prefix", sb.buf,
+					    "submodule--helper",
+					   "embed-git-dirs", NULL);
+		prepare_submodule_repo_env(&cp.env_array);
+		if (run_command(&cp))
+			die(_("Could not migrate git directory in submodule '%s'"),
+			    path);
+
+		strbuf_release(&sb);
+	}
+
+	free(old_git_dir);
+}
diff --git a/dir.h b/dir.h
index 97c83bb383..0b5e99b21d 100644
--- a/dir.h
+++ b/dir.h
@@ -335,4 +335,8 @@ struct untracked_cache *read_untracked_extension(const void *data, unsigned long
 void write_untracked_extension(struct strbuf *out, struct untracked_cache *untracked);
 void add_untracked_cache(struct index_state *istate);
 void remove_untracked_cache(struct index_state *istate);
+
+#define RELOCATE_GITDIR_RECURSE_SUBMODULES (1<<0)
+extern void relocate_gitdir(const char *prefix, const char *path, unsigned flags);
+
 #endif
diff --git a/git-submodule.sh b/git-submodule.sh
index a024a135d6..b7e124f340 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -1131,6 +1131,11 @@ cmd_sync()
 	done
 }
 
+cmd_embedgitdirs()
+{
+	git submodule--helper embed-git-dirs --prefix "$wt_prefix" "$@"
+}
+
 # This loop parses the command line arguments to find the
 # subcommand name to dispatch.  Parsing of the subcommand specific
 # options are primarily done by the subcommand implementations.
@@ -1140,7 +1145,7 @@ cmd_sync()
 while test $# != 0 && test -z "$command"
 do
 	case "$1" in
-	add | foreach | init | deinit | update | status | summary | sync)
+	add | foreach | init | deinit | update | status | summary | sync | embedgitdirs)
 		command=$1
 		;;
 	-q|--quiet)
diff --git a/submodule.h b/submodule.h
index d9e197a948..1e42222cff 100644
--- a/submodule.h
+++ b/submodule.h
@@ -74,5 +74,4 @@ int parallel_submodules(void);
  * retaining any config in the environment.
  */
 void prepare_submodule_repo_env(struct argv_array *out);
-
 #endif
diff --git a/t/t7412-submodule-embedgitdirs.sh b/t/t7412-submodule-embedgitdirs.sh
new file mode 100755
index 0000000000..e3443b88cd
--- /dev/null
+++ b/t/t7412-submodule-embedgitdirs.sh
@@ -0,0 +1,92 @@
+#!/bin/sh
+
+test_description='Test submodule embedgitdirs
+
+This test verifies that `git submodue embedgitdirs` moves a submodules git
+directory into the superproject.
+'
+
+. ./test-lib.sh
+
+test_expect_success 'setup a real submodule' '
+	git init sub1 &&
+	test_commit -C sub1 first &&
+	git submodule add ./sub1 &&
+	test_tick &&
+	git commit -m superproject
+'
+
+test_expect_success 'embed the git dir' '
+	>expect.1 &&
+	>expect.2 &&
+	>actual.1 &&
+	>actual.2 &&
+	git status >expect.1 &&
+	git -C sub1 rev-parse HEAD >expect.2 &&
+	git submodule embedgitdirs &&
+	git fsck &&
+	test -f sub1/.git &&
+	test -d .git/modules/sub1 &&
+	git status >actual.1 &&
+	git -C sub1 rev-parse HEAD >actual.2 &&
+	test_cmp expect.1 actual.1 &&
+	test_cmp expect.2 actual.2
+'
+
+test_expect_success 'setup nested submodule' '
+	git init sub1/nested &&
+	test_commit -C sub1/nested first_nested &&
+	git -C sub1 submodule add ./nested &&
+	test_tick &&
+	git -C sub1 commit -m "add nested" &&
+	git add sub1 &&
+	git commit -m "sub1 to include nested submodule"
+'
+
+test_expect_success 'embed the git dir in a nested submodule' '
+	git status >expect.1 &&
+	git -C sub1/nested rev-parse HEAD >expect.2 &&
+	git submodule embedgitdirs &&
+	test -f sub1/nested/.git &&
+	test -d .git/modules/sub1/modules/nested &&
+	git status >actual.1 &&
+	git -C sub1/nested rev-parse HEAD >actual.2 &&
+	test_cmp expect.1 actual.1 &&
+	test_cmp expect.2 actual.2
+'
+
+test_expect_success 'setup a gitlink with missing .gitmodules entry' '
+	git init sub2 &&
+	test_commit -C sub2 first &&
+	git add sub2 &&
+	git commit -m superproject
+'
+
+test_expect_success 'embedding the git dir fails for incomplete submodules' '
+	git status >expect.1 &&
+	git -C sub2 rev-parse HEAD >expect.2 &&
+	test_must_fail git submodule embedgitdirs &&
+	git -C sub2 fsck &&
+	test -d sub2/.git &&
+	git status >actual &&
+	git -C sub2 rev-parse HEAD >actual.2 &&
+	test_cmp expect.1 actual.1 &&
+	test_cmp expect.2 actual.2
+'
+
+test_expect_success 'setup a submodule with multiple worktrees' '
+	# first create another unembedded git dir in a new submodule
+	git init sub3 &&
+	test_commit -C sub3 first &&
+	git submodule add ./sub3 &&
+	test_tick &&
+	git commit -m "add another submodule" &&
+	git -C sub3 worktree add ../sub3_second_work_tree
+'
+
+test_expect_success 'embed a submodule with multiple worktrees' '
+	test_must_fail git submodule embedgitdirs sub3 2>error &&
+	test_i18ngrep "not supported" error
+'
+
+test_done
-- 
2.10.2.613.g22f2156