[PATCH/RFC v2 2/2] submodule: modify clone command to recursively shallow clone submodules

[Cole Minnaar <cole.minnaar@gmail.com>]

When cloning a repository that contains submodules and specifying the
`--depth` option to the 'git clone' command, the top level repository will be
cloned with the specified depth, but all submodules within the
repository will be cloned in their entirety.

Modified 'git clone' to pass the `--depth` option, if specified, to any
submodule clone commands.
Modified 'git clone' to pass the `--no-single-branch`, if specified, to any
submodule clone commands.

Signed-off-by: Cole Minnaar <cole.minnaar@gmail.com>
---
 Documentation/git-clone.txt |  5 ++++-
 builtin/clone.c             | 15 +++++++++------
 2 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/Documentation/git-clone.txt b/Documentation/git-clone.txt
index 0363d00..7621251 100644
--- a/Documentation/git-clone.txt
+++ b/Documentation/git-clone.txt
@@ -178,7 +178,8 @@ objects from the source repository into a pack in the cloned repository.
 
 --depth <depth>::
 	Create a 'shallow' clone with a history truncated to the
-	specified number of revisions.
+	specified number of revisions. If `--recursive` was also specified
+	the depth value will be passed to all submodules within when cloning.
 
 --[no-]single-branch::
 	Clone only the history leading to the tip of a single branch,
@@ -192,6 +193,8 @@ objects from the source repository into a pack in the cloned repository.
 	initial cloning.  If the HEAD at the remote did not point at any
 	branch when `--single-branch` clone was made, no remote-tracking
 	branch is created.
+	If `--recursive` was also specified, this option will be passed to
+	all submodules when cloning.
 
 --recursive::
 --recurse-submodules::
diff --git a/builtin/clone.c b/builtin/clone.c
index dd4092b..b27917c 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -48,6 +48,7 @@ static int option_verbosity;
 static int option_progress = -1;
 static struct string_list option_config;
 static struct string_list option_reference;
+static struct argv_array argv_submodule_cmd = ARGV_ARRAY_INIT;
 
 static int opt_parse_reference(const struct option *opt, const char *arg, int unset)
 {
@@ -100,10 +101,6 @@ static struct option builtin_clone_options[] = {
 	OPT_END()
 };
 
-static const char *argv_submodule[] = {
-	"submodule", "update", "--init", "--recursive", NULL
-};
-
 static char *get_repo_path(const char *repo, int *is_bundle)
 {
 	static char *suffix[] = { "/.git", "", ".git/.git", ".git" };
@@ -663,8 +660,14 @@ static int checkout(void)
 	err |= run_hook_le(NULL, "post-checkout", sha1_to_hex(null_sha1),
 			   sha1_to_hex(sha1), "1", NULL);
 
-	if (!err && option_recursive)
-		err = run_command_v_opt(argv_submodule, RUN_GIT_CMD);
+	if (!err && option_recursive) {
+		argv_array_pushl(&argv_submodule_cmd, "submodule", "update", "--init", "--recursive", NULL);
+		if (option_depth)
+			argv_array_pushf(&argv_submodule_cmd, "--depth=%d", atoi(option_depth));
+		if (!option_single_branch)
+			argv_array_pushl(&argv_submodule_cmd, "--no-single-branch", NULL);
+		err = run_command_v_opt(argv_submodule_cmd.argv, RUN_GIT_CMD);
+	}
 
 	return err;
 }
-- 
2.1.0.240.g8a0e823