fetch/pull: Add the --recurse-submodules option

Until now you had to call "git submodule update" (without -N|--no-fetch
option) or something like "git submodule foreach git fetch" to fetch
new commits in populated submodules from their remote.

This could lead to "(commits not present)" messages in the output of
"git diff --submodule" (which is used by "git gui" and "gitk") after
fetching or pulling new commits in the superproject and is an obstacle for
implementing recursive checkout of submodules. Also "git submodule
update" cannot fetch changes when disconnected, so it was very easy to
forget to fetch the submodule changes before disconnecting only to
discover later that they are needed.

This patch adds the "--recurse-submodules" option to recursively fetch
each populated submodule from the url configured in the .git/config of the
submodule at the end of each "git fetch" or during "git pull" in the
superproject. The submodule paths are taken from the index.

The hidden option "--submodule-prefix" is added to "git fetch" to be able
to print out the full paths of nested submodules.

Signed-off-by: Jens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 65 insertions, 1 deletions

diff --git a/submodule.c b/submodule.c
index 91a4758747..4d9b774cd1 100644
--- a/submodule.c
+++ b/submodule.c
@@ -63,7 +63,7 @@ void set_diffopt_flags_from_submodule_config(struct diff_options *diffopt,
 	}
 }
 
-static int submodule_config(const char *var, const char *value, void *cb)
+int submodule_config(const char *var, const char *value, void *cb)
 {
 	if (!prefixcmp(var, "submodule."))
 		return parse_submodule_config_option(var, value);
@@ -229,6 +229,70 @@ void show_submodule_summary(FILE *f, const char *path,
 	strbuf_release(&sb);
 }
 
+int fetch_populated_submodules(int num_options, const char **options,
+			       const char *prefix, int quiet)
+{
+	int i, result = 0, argc = 0;
+	struct child_process cp;
+	const char **argv;
+	struct string_list_item *name_for_path;
+	const char *work_tree = get_git_work_tree();
+	if (!work_tree)
+		return 0;
+
+	if (!the_index.initialized)
+		if (read_cache() < 0)
+			die("index file corrupt");
+
+	argv = xcalloc(num_options + 5, sizeof(const char *));
+	argv[argc++] = "fetch";
+	for (i = 0; i < num_options; i++)
+		argv[argc++] = options[i];
+	argv[argc++] = "--submodule-prefix";
+
+	memset(&cp, 0, sizeof(cp));
+	cp.argv = argv;
+	cp.env = local_repo_env;
+	cp.git_cmd = 1;
+	cp.no_stdin = 1;
+
+	for (i = 0; i < active_nr; i++) {
+		struct strbuf submodule_path = STRBUF_INIT;
+		struct strbuf submodule_git_dir = STRBUF_INIT;
+		struct strbuf submodule_prefix = STRBUF_INIT;
+		struct cache_entry *ce = active_cache[i];
+		const char *git_dir, *name;
+
+		if (!S_ISGITLINK(ce->ce_mode))
+			continue;
+
+		name = ce->name;
+		name_for_path = unsorted_string_list_lookup(&config_name_for_path, ce->name);
+		if (name_for_path)
+			name = name_for_path->util;
+
+		strbuf_addf(&submodule_path, "%s/%s", work_tree, ce->name);
+		strbuf_addf(&submodule_git_dir, "%s/.git", submodule_path.buf);
+		strbuf_addf(&submodule_prefix, "%s%s/", prefix, ce->name);
+		git_dir = read_gitfile_gently(submodule_git_dir.buf);
+		if (!git_dir)
+			git_dir = submodule_git_dir.buf;
+		if (is_directory(git_dir)) {
+			if (!quiet)
+				printf("Fetching submodule %s%s\n", prefix, ce->name);
+			cp.dir = submodule_path.buf;
+			argv[argc] = submodule_prefix.buf;
+			if (run_command(&cp))
+				result = 1;
+		}
+		strbuf_release(&submodule_path);
+		strbuf_release(&submodule_git_dir);
+		strbuf_release(&submodule_prefix);
+	}
+	free(argv);
+	return result;
+}
+
 unsigned is_submodule_modified(const char *path, int ignore_untracked)
 {
 	ssize_t len;