[PATCHv4 0/3] submodule--helper: Have some refactoring only patches first

@@ -33,7 +33,7 @@ static int module_list_compute(int argc, const char **argv,
 		ps_matched = xcalloc(pathspec->nr, 1);
 
 	if (read_cache() < 0)
-		die("index file corrupt");
+		die(_("index file corrupt"));
 
 	for (i = 0; i < active_nr; i++) {
 		const struct cache_entry *ce = active_cache[i];

@@ -79,7 +79,7 @@ static int module_list(int argc, const char **argv, const char *prefix)
 	};
 
 	const char *const git_submodule_helper_usage[] = {
-		N_("git submodule--helper module_list [--prefix=<path>] [<path>...]"),
+		N_("git submodule--helper list [--prefix=<path>] [<path>...]"),
 		NULL
 	};
 

@@ -110,21 +110,20 @@ static int module_name(int argc, const char **argv, const char *prefix)
 {
 	const struct submodule *sub;
 
-	if (argc != 1)
+	if (argc != 2)
 		usage("git submodule--helper module_name <path>\n");
 
 	gitmodules_config();
-	sub = submodule_from_path(null_sha1, argv[0]);
+	sub = submodule_from_path(null_sha1, argv[1]);
 
 	if (!sub)
 		die(N_("No submodule mapping found in .gitmodules for path '%s'"),
-		    argv[0]);
+		    argv[1]);
 
 	printf("%s\n", sub->name);
 
 	return 0;
 }
-
 static int clone_submodule(const char *path, const char *gitdir, const char *url,
 			   const char *depth, const char *reference, int quiet)
 {

@@ -166,7 +165,7 @@ static int module_clone(int argc, const char **argv, const char *prefix)
 	struct strbuf rel_path = STRBUF_INIT;
 	struct strbuf sb = STRBUF_INIT;
 
-	struct option module_update_options[] = {
+	struct option module_clone_options[] = {
 		OPT_STRING(0, "prefix", &alternative_path,
 			   N_("path"),
 			   N_("alternative anchor for relative paths")),

@@ -189,38 +188,41 @@ static int module_clone(int argc, const char **argv, const char *prefix)
 		OPT_END()
 	};
 
-	static const char * const git_submodule_helper_usage[] = {
-		N_("git submodule--helper update [--prefix=<path>] [--quiet] [--remote] [-N|--no-fetch]"
-		   "[-f|--force] [--rebase|--merge] [--reference <repository>]"
-		   "[--depth <depth>] [--recursive] [--] [<path>...]"),
+	const char * const git_submodule_helper_usage[] = {
+		N_("git submodule--helper clone [--prefix=<path>] [--quiet] "
+		   "[--reference <repository>] [--name <name>] [--url <url>]"
+		   "[--depth <depth>] [--] [<path>...]"),
 		NULL
 	};
 
-	argc = parse_options(argc, argv, prefix, module_update_options,
+	argc = parse_options(argc, argv, prefix, module_clone_options,
 			     git_submodule_helper_usage, 0);
 
 	strbuf_addf(&sb, "%s/modules/%s", get_git_dir(), name);
 	sm_gitdir = strbuf_detach(&sb, NULL);
 
 	if (!file_exists(sm_gitdir)) {
-		safe_create_leading_directories_const(sm_gitdir);
+		if (safe_create_leading_directories_const(sm_gitdir) < 0)
+			die(_("could not create directory '%s'"), sm_gitdir);
 		if (clone_submodule(path, sm_gitdir, url, depth, reference, quiet))
-			die(N_("Clone of '%s' into submodule path '%s' failed"),
+			die(N_("clone of '%s' into submodule path '%s' failed"),
 			    url, path);
 	} else {
-		safe_create_leading_directories_const(path);
-		unlink(sm_gitdir);
+		if (safe_create_leading_directories_const(path) < 0)
+			die(_("could not create directory '%s'"), path);
+		if (unlink(sm_gitdir) < 0)
+			die_errno(_("failed to delete '%s'"), sm_gitdir);
 	}
 
 	/* Write a .git file in the submodule to redirect to the superproject. */
-	if (alternative_path && !strcmp(alternative_path, "")) {
+	if (alternative_path && *alternative_path)) {
 		p = relative_path(path, alternative_path, &sb);
 		strbuf_reset(&sb);
 	} else
 		p = path;
 
 	if (safe_create_leading_directories_const(p) < 0)
-		die("Could not create directory '%s'", p);
+		die(_("could not create directory '%s'"), p);
 
 	strbuf_addf(&sb, "%s/.git", p);
 

@@ -228,31 +230,32 @@ static int module_clone(int argc, const char **argv, const char *prefix)
 		die(_("could not create leading directories of '%s'"), sb.buf);
 	submodule_dot_git = fopen(sb.buf, "w");
 	if (!submodule_dot_git)
-		die ("Cannot open file '%s': %s", sb.buf, strerror(errno));
+		die (_("cannot open file '%s': %s"), sb.buf, strerror(errno));
 
 	fprintf(submodule_dot_git, "gitdir: %s\n",
 		relative_path(sm_gitdir, path, &rel_path));
 	if (fclose(submodule_dot_git))
-		die("Could not close file %s", sb.buf);
+		die(_("could not close file %s"), sb.buf);
 	strbuf_reset(&sb);
 
-	/* Redirect the worktree of the submodule in the superprojects config */
+	/* Redirect the worktree of the submodule in the superproject's config */
+	if (strbuf_getcwd(&sb))
+		die_errno(_("unable to get current working directory"));
+
 	if (!is_absolute_path(sm_gitdir)) {
-		char *s = (char*)sm_gitdir;
 		if (strbuf_getcwd(&sb))
-			die_errno("unable to get current working directory");
+			die_errno(_("unable to get current working directory"));
 		strbuf_addf(&sb, "/%s", sm_gitdir);
+		free(sm_gitdir);
 		sm_gitdir = strbuf_detach(&sb, NULL);
-		free(s);
 	}
 
-	if (strbuf_getcwd(&sb))
-		die_errno("unable to get current working directory");
+
 	strbuf_addf(&sb, "/%s", path);
 
 	p = git_pathdup_submodule(path, "config");
 	if (!p)
-		die("Could not get submodule directory for '%s'", path);
+		die(_("could not get submodule directory for '%s'"), path);
 	git_config_set_in_file(p, "core.worktree",
 			       relative_path(sb.buf, sm_gitdir, &rel_path));
 	strbuf_release(&sb);

@@ -260,23 +263,37 @@ static int module_clone(int argc, const char **argv, const char *prefix)
 	return 0;
 }
 
+struct cmd_struct {
+	const char *cmd;
+	int (*fct)(int, const char **, const char *);
+};
+
+static struct cmd_struct commands[] = {
+	{"list", module_list},
+	{"name", module_name},
+	{"clone", module_clone},
+};
+
 int cmd_submodule__helper(int argc, const char **argv, const char *prefix)
 {
+	int i;
 	if (argc < 2)
-		die(N_("fatal: submodule--helper subcommand must be called with "
-		       "a subcommand, which are module-list, module-name, "
-		       "module-clone\n"));
+		goto out;
 
-	if (!strcmp(argv[1], "module-list"))
-		return module_list(argc - 1, argv + 1, prefix);
+	for (i = 0; i < ARRAY_SIZE(commands); i++)
+		if (!strcmp(argv[1], commands[i].cmd))
+			return commands[i].fct(argc - 1, argv + 1, prefix);
 
-	if (!strcmp(argv[1], "module-name"))
-		return module_name(argc - 2, argv + 2, prefix);
+out:
+	if (argc > 1)
+		fprintf(stderr, _("fatal: '%s' is not a valid submodule--helper "
+				  "subcommand, which are:\n"), argv[1]);
+	else
+		fprintf(stderr, _("fatal: submodule--helper subcommand must be "
+				  "called with a subcommand, which are:\n"));
 
-	if (!strcmp(argv[1], "module-clone"))
-		return module_clone(argc - 1, argv + 1, prefix);
+	for (i = 0; i < ARRAY_SIZE(commands); i++)
+		fprintf(stderr, "\t%s\n", commands[i].cmd);
 
-	die(N_("fatal: '%s' is not a valid submodule--helper subcommand, "
-	       "which are module-list, module-name, module-clone\n"),
-	    argv[1]);
+	exit(129);
 }

@@ -338,7 +338,7 @@ Use -f if you really want to add it." >&2
 				echo "$(eval_gettext "Reactivating local git directory for submodule '\$sm_name'.")"
 			fi
 		fi
-		git submodule--helper module-clone ${GIT_QUIET:+--quiet} --prefix "$wt_prefix" --path "$sm_path" --name "$sm_name" --url "$realrepo" "$reference" "$depth" || exit
+		git submodule--helper clone ${GIT_QUIET:+--quiet} --prefix "$wt_prefix" --path "$sm_path" --name "$sm_name" --url "$realrepo" "$reference" "$depth" || exit
 		(
 			clear_local_git_env
 			cd "$sm_path" &&

@@ -398,7 +398,7 @@ cmd_foreach()
 	# command in the subshell (and a recursive call to this function)
 	exec 3<&0
 
-	git submodule--helper module-list --prefix "$wt_prefix"|
+	git submodule--helper list --prefix "$wt_prefix"|
 	while read mode sha1 stage sm_path
 	do
 		die_if_unmatched "$mode"

@@ -406,7 +406,7 @@ cmd_foreach()
 		then
 			displaypath=$(relative_path "$sm_path")
 			say "$(eval_gettext "Entering '\$prefix\$displaypath'")"
-			name=$(git submodule--helper module-name "$sm_path")
+			name=$(git submodule--helper name "$sm_path")
 			(
 				prefix="$prefix$sm_path/"
 				clear_local_git_env

@@ -458,11 +458,11 @@ cmd_init()
 		shift
 	done
 
-	git submodule--helper module-list --prefix "$wt_prefix" "$@" |
+	git submodule--helper list --prefix "$wt_prefix" "$@" |
 	while read mode sha1 stage sm_path
 	do
 		die_if_unmatched "$mode"
-		name=$(git submodule--helper module-name "$sm_path") || exit
+		name=$(git submodule--helper name "$sm_path") || exit
 
 		displaypath=$(relative_path "$sm_path")
 

@@ -540,11 +540,11 @@ cmd_deinit()
 		die "$(eval_gettext "Use '.' if you really want to deinitialize all submodules")"
 	fi
 
-	git submodule--helper module-list --prefix "$wt_prefix" "$@" |
+	git submodule--helper list --prefix "$wt_prefix" "$@" |
 	while read mode sha1 stage sm_path
 	do
 		die_if_unmatched "$mode"
-		name=$(git submodule--helper module-name "$sm_path") || exit
+		name=$(git submodule--helper name "$sm_path") || exit
 
 		displaypath=$(relative_path "$sm_path")
 

@@ -656,7 +656,7 @@ cmd_update()
 	fi
 
 	cloned_modules=
-	git submodule--helper module-list --prefix "$wt_prefix" "$@" | {
+	git submodule--helper list --prefix "$wt_prefix" "$@" | {
 	err=
 	while read mode sha1 stage sm_path
 	do

@@ -666,7 +666,7 @@ cmd_update()
 			echo >&2 "Skipping unmerged submodule $prefix$sm_path"
 			continue
 		fi
-		name=$(git submodule--helper module-name "$sm_path") || exit
+		name=$(git submodule--helper name "$sm_path") || exit
 		url=$(git config submodule."$name".url)
 		branch=$(get_submodule_config "$name" branch master)
 		if ! test -z "$update"

@@ -700,7 +700,7 @@ Maybe you want to use 'update --init'?")"
 
 		if ! test -d "$sm_path"/.git && ! test -f "$sm_path"/.git
 		then
-			git submodule--helper module-clone ${GIT_QUIET:+--quiet} --prefix "$prefix" --path "$sm_path" --name "$name" --url "$url" "$reference" "$depth" || exit
+			git submodule--helper clone ${GIT_QUIET:+--quiet} --prefix "$prefix" --path "$sm_path" --name "$name" --url "$url" "$reference" "$depth" || exit
 			cloned_modules="$cloned_modules;$name"
 			subsha1=
 		else

@@ -930,7 +930,7 @@ cmd_summary() {
 			# Respect the ignore setting for --for-status.
 			if test -n "$for_status"
 			then
-				name=$(git submodule--helper module-name "$sm_path")
+				name=$(git submodule--helper name "$sm_path")
 				ignore_config=$(get_submodule_config "$name" ignore none)
 				test $status != A && test $ignore_config = all && continue
 			fi

@@ -1088,11 +1088,11 @@ cmd_status()
 		shift
 	done
 
-	git submodule--helper module-list --prefix "$wt_prefix" "$@" |
+	git submodule--helper list --prefix "$wt_prefix" "$@" |
 	while read mode sha1 stage sm_path
 	do
 		die_if_unmatched "$mode"
-		name=$(git submodule--helper module-name "$sm_path") || exit
+		name=$(git submodule--helper name "$sm_path") || exit
 		url=$(git config submodule."$name".url)
 		displaypath=$(relative_path "$prefix$sm_path")
 		if test "$stage" = U

@@ -1165,11 +1165,11 @@ cmd_sync()
 		esac
 	done
 	cd_to_toplevel
-	git submodule--helper module-list --prefix "$wt_prefix" "$@" |
+	git submodule--helper list --prefix "$wt_prefix" "$@" |
 	while read mode sha1 stage sm_path
 	do
 		die_if_unmatched "$mode"
-		name=$(git submodule--helper module-name "$sm_path")
+		name=$(git submodule--helper name "$sm_path")
 		url=$(git config -f .gitmodules --get submodule."$name".url)
 
 		# Possibly a url relative to parent

@@ -8,6 +8,7 @@
 #include "submodule.h"
 #include "submodule-config.h"
 #include "string-list.h"
+#include "run-command.h"
 
 static const struct cache_entry **ce_entries;
 static int ce_alloc, ce_used;

@@ -123,6 +124,144 @@ static int module_name(int argc, const char **argv, const char *prefix)
 
 	return 0;
 }
+static int clone_submodule(const char *path, const char *gitdir, const char *url,
+			   const char *depth, const char *reference, int quiet)
+{
+	struct child_process cp;
+	child_process_init(&cp);
+
+	argv_array_push(&cp.args, "clone");
+	argv_array_push(&cp.args, "--no-checkout");
+	if (quiet)
+		argv_array_push(&cp.args, "--quiet");
+	if (depth && *depth)
+		argv_array_pushl(&cp.args, "--depth", depth, NULL);
+	if (reference && *reference)
+		argv_array_pushl(&cp.args, "--reference", reference, NULL);
+	if (gitdir && *gitdir)
+		argv_array_pushl(&cp.args, "--separate-git-dir", gitdir, NULL);
+
+	argv_array_push(&cp.args, url);
+	argv_array_push(&cp.args, path);
+
+	cp.git_cmd = 1;
+	cp.env = local_repo_env;
+
+	cp.no_stdin = 1;
+	cp.no_stdout = 1;
+	cp.no_stderr = 1;
+
+	return run_command(&cp);
+}
+
+static int module_clone(int argc, const char **argv, const char *prefix)
+{
+	const char *path = NULL, *name = NULL, *url = NULL;
+	const char *reference = NULL, *depth = NULL;
+	const char *alternative_path = NULL, *p;
+	int quiet = 0;
+	FILE *submodule_dot_git;
+	char *sm_gitdir;
+	struct strbuf rel_path = STRBUF_INIT;
+	struct strbuf sb = STRBUF_INIT;
+
+	struct option module_clone_options[] = {
+		OPT_STRING(0, "prefix", &alternative_path,
+			   N_("path"),
+			   N_("alternative anchor for relative paths")),
+		OPT_STRING(0, "path", &path,
+			   N_("path"),
+			   N_("where the new submodule will be cloned to")),
+		OPT_STRING(0, "name", &name,
+			   N_("string"),
+			   N_("name of the new submodule")),
+		OPT_STRING(0, "url", &url,
+			   N_("string"),
+			   N_("url where to clone the submodule from")),
+		OPT_STRING(0, "reference", &reference,
+			   N_("string"),
+			   N_("reference repository")),
+		OPT_STRING(0, "depth", &depth,
+			   N_("string"),
+			   N_("depth for shallow clones")),
+		OPT__QUIET(&quiet, "Suppress output for cloning a submodule"),
+		OPT_END()
+	};
+
+	const char * const git_submodule_helper_usage[] = {
+		N_("git submodule--helper clone [--prefix=<path>] [--quiet] "
+		   "[--reference <repository>] [--name <name>] [--url <url>]"
+		   "[--depth <depth>] [--] [<path>...]"),
+		NULL
+	};
+
+	argc = parse_options(argc, argv, prefix, module_clone_options,
+			     git_submodule_helper_usage, 0);
+
+	strbuf_addf(&sb, "%s/modules/%s", get_git_dir(), name);
+	sm_gitdir = strbuf_detach(&sb, NULL);
+
+	if (!file_exists(sm_gitdir)) {
+		if (safe_create_leading_directories_const(sm_gitdir) < 0)
+			die(_("could not create directory '%s'"), sm_gitdir);
+		if (clone_submodule(path, sm_gitdir, url, depth, reference, quiet))
+			die(N_("clone of '%s' into submodule path '%s' failed"),
+			    url, path);
+	} else {
+		if (safe_create_leading_directories_const(path) < 0)
+			die(_("could not create directory '%s'"), path);
+		if (unlink(sm_gitdir) < 0)
+			die_errno(_("failed to delete '%s'"), sm_gitdir);
+	}
+
+	/* Write a .git file in the submodule to redirect to the superproject. */
+	if (alternative_path && *alternative_path)) {
+		p = relative_path(path, alternative_path, &sb);
+		strbuf_reset(&sb);
+	} else
+		p = path;
+
+	if (safe_create_leading_directories_const(p) < 0)
+		die(_("could not create directory '%s'"), p);
+
+	strbuf_addf(&sb, "%s/.git", p);
+
+	if (safe_create_leading_directories_const(sb.buf) < 0)
+		die(_("could not create leading directories of '%s'"), sb.buf);
+	submodule_dot_git = fopen(sb.buf, "w");
+	if (!submodule_dot_git)
+		die (_("cannot open file '%s': %s"), sb.buf, strerror(errno));
+
+	fprintf(submodule_dot_git, "gitdir: %s\n",
+		relative_path(sm_gitdir, path, &rel_path));
+	if (fclose(submodule_dot_git))
+		die(_("could not close file %s"), sb.buf);
+	strbuf_reset(&sb);
+
+	/* Redirect the worktree of the submodule in the superproject's config */
+	if (strbuf_getcwd(&sb))
+		die_errno(_("unable to get current working directory"));
+
+	if (!is_absolute_path(sm_gitdir)) {
+		if (strbuf_getcwd(&sb))
+			die_errno(_("unable to get current working directory"));
+		strbuf_addf(&sb, "/%s", sm_gitdir);
+		free(sm_gitdir);
+		sm_gitdir = strbuf_detach(&sb, NULL);
+	}
+
+
+	strbuf_addf(&sb, "/%s", path);
+
+	p = git_pathdup_submodule(path, "config");
+	if (!p)
+		die(_("could not get submodule directory for '%s'"), path);
+	git_config_set_in_file(p, "core.worktree",
+			       relative_path(sb.buf, sm_gitdir, &rel_path));
+	strbuf_release(&sb);
+	free(sm_gitdir);
+	return 0;
+}
 
 struct cmd_struct {
 	const char *cmd;

@@ -132,6 +271,7 @@ struct cmd_struct {
 static struct cmd_struct commands[] = {
 	{"list", module_list},
 	{"name", module_name},
+	{"clone", module_clone},
 };
 
 int cmd_submodule__helper(int argc, const char **argv, const char *prefix)

@@ -178,80 +178,6 @@ get_submodule_config () {
 	printf '%s' "${value:-$default}"
 }
 
-#
-# Clone a submodule
-#
-# $1 = submodule path
-# $2 = submodule name
-# $3 = URL to clone
-# $4 = reference repository to reuse (empty for independent)
-# $5 = depth argument for shallow clones (empty for deep)
-#
-# Prior to calling, cmd_update checks that a possibly existing
-# path is not a git repository.
-# Likewise, cmd_add checks that path does not exist at all,
-# since it is the location of a new submodule.
-#
-module_clone()
-{
-	sm_path=$1
-	name=$2
-	url=$3
-	reference="$4"
-	depth="$5"
-	quiet=
-	if test -n "$GIT_QUIET"
-	then
-		quiet=-q
-	fi
-
-	gitdir=
-	gitdir_base=
-	base_name=$(dirname "$name")
-
-	gitdir=$(git rev-parse --git-dir)
-	gitdir_base="$gitdir/modules/$base_name"
-	gitdir="$gitdir/modules/$name"
-
-	if test -d "$gitdir"
-	then
-		mkdir -p "$sm_path"
-		rm -f "$gitdir/index"
-	else
-		mkdir -p "$gitdir_base"
-		(
-			clear_local_git_env
-			git clone $quiet ${depth:+"$depth"} -n ${reference:+"$reference"} \
-				--separate-git-dir "$gitdir" "$url" "$sm_path"
-		) ||
-		die "$(eval_gettext "Clone of '\$url' into submodule path '\$sm_path' failed")"
-	fi
-
-	# We already are at the root of the work tree but cd_to_toplevel will
-	# resolve any symlinks that might be present in $PWD
-	a=$(cd_to_toplevel && cd "$gitdir" && pwd)/
-	b=$(cd_to_toplevel && cd "$sm_path" && pwd)/
-	# Remove all common leading directories after a sanity check
-	if test "${a#$b}" != "$a" || test "${b#$a}" != "$b"; then
-		die "$(eval_gettext "Gitdir '\$a' is part of the submodule path '\$b' or vice versa")"
-	fi
-	while test "${a%%/*}" = "${b%%/*}"
-	do
-		a=${a#*/}
-		b=${b#*/}
-	done
-	# Now chop off the trailing '/'s that were added in the beginning
-	a=${a%/}
-	b=${b%/}
-
-	# Turn each leading "*/" component into "../"
-	rel=$(printf '%s\n' "$b" | sed -e 's|[^/][^/]*|..|g')
-	printf '%s\n' "gitdir: $rel/$a" >"$sm_path/.git"
-
-	rel=$(printf '%s\n' "$a" | sed -e 's|[^/][^/]*|..|g')
-	(clear_local_git_env; cd "$sm_path" && GIT_WORK_TREE=. git config core.worktree "$rel/$b")
-}
-
 isnumber()
 {
 	n=$(($1 + 0)) 2>/dev/null && test "$n" = "$1"

@@ -301,7 +227,7 @@ cmd_add()
 			shift
 			;;
 		--depth=*)
-			depth=$1
+			depth="$1"
 			;;
 		--)
 			shift

@@ -412,7 +338,7 @@ Use -f if you really want to add it." >&2
 				echo "$(eval_gettext "Reactivating local git directory for submodule '\$sm_name'.")"
 			fi
 		fi
-		module_clone "$sm_path" "$sm_name" "$realrepo" "$reference" "$depth" || exit
+		git submodule--helper clone ${GIT_QUIET:+--quiet} --prefix "$wt_prefix" --path "$sm_path" --name "$sm_name" --url "$realrepo" "$reference" "$depth" || exit
 		(
 			clear_local_git_env
 			cd "$sm_path" &&

@@ -774,7 +700,7 @@ Maybe you want to use 'update --init'?")"
 
 		if ! test -d "$sm_path"/.git && ! test -f "$sm_path"/.git
 		then
-			module_clone "$sm_path" "$name" "$url" "$reference" "$depth" || exit
+			git submodule--helper clone ${GIT_QUIET:+--quiet} --prefix "$prefix" --path "$sm_path" --name "$name" --url "$url" "$reference" "$depth" || exit
 			cloned_modules="$cloned_modules;$name"
 			subsha1=
 		else

@@ -5,6 +5,9 @@
 #include "pathspec.h"
 #include "dir.h"
 #include "utf8.h"
+#include "submodule.h"
+#include "submodule-config.h"
+#include "string-list.h"
 
 static const struct cache_entry **ce_entries;
 static int ce_alloc, ce_used;

@@ -102,6 +105,24 @@ static int module_list(int argc, const char **argv, const char *prefix)
 	return 0;
 }
 
+static int module_name(int argc, const char **argv, const char *prefix)
+{
+	const struct submodule *sub;
+
+	if (argc != 2)
+		usage("git submodule--helper module_name <path>\n");
+
+	gitmodules_config();
+	sub = submodule_from_path(null_sha1, argv[1]);
+
+	if (!sub)
+		die(N_("No submodule mapping found in .gitmodules for path '%s'"),
+		    argv[1]);
+
+	printf("%s\n", sub->name);
+
+	return 0;
+}
 
 struct cmd_struct {
 	const char *cmd;

@@ -110,6 +131,7 @@ struct cmd_struct {
 
 static struct cmd_struct commands[] = {
 	{"list", module_list},
+	{"name", module_name},
 };
 
 int cmd_submodule__helper(int argc, const char **argv, const char *prefix)

@@ -178,24 +178,6 @@ get_submodule_config () {
 	printf '%s' "${value:-$default}"
 }
 
-
-#
-# Map submodule path to submodule name
-#
-# $1 = path
-#
-module_name()
-{
-	# Do we have "submodule.<something>.path = $1" defined in .gitmodules file?
-	sm_path="$1"
-	re=$(printf '%s\n' "$1" | sed -e 's/[].[^$\\*]/\\&/g')
-	name=$( git config -f .gitmodules --get-regexp '^submodule\..*\.path$' |
-		sed -n -e 's|^submodule\.\(.*\)\.path '"$re"'$|\1|p' )
-	test -z "$name" &&
-	die "$(eval_gettext "No submodule mapping found in .gitmodules for path '\$sm_path'")"
-	printf '%s\n' "$name"
-}
-
 #
 # Clone a submodule
 #

@@ -498,7 +480,7 @@ cmd_foreach()
 		then
 			displaypath=$(relative_path "$sm_path")
 			say "$(eval_gettext "Entering '\$prefix\$displaypath'")"
-			name=$(module_name "$sm_path")
+			name=$(git submodule--helper name "$sm_path")
 			(
 				prefix="$prefix$sm_path/"
 				clear_local_git_env

@@ -554,7 +536,7 @@ cmd_init()
 	while read mode sha1 stage sm_path
 	do
 		die_if_unmatched "$mode"
-		name=$(module_name "$sm_path") || exit
+		name=$(git submodule--helper name "$sm_path") || exit
 
 		displaypath=$(relative_path "$sm_path")
 

@@ -636,7 +618,7 @@ cmd_deinit()
 	while read mode sha1 stage sm_path
 	do
 		die_if_unmatched "$mode"
-		name=$(module_name "$sm_path") || exit
+		name=$(git submodule--helper name "$sm_path") || exit
 
 		displaypath=$(relative_path "$sm_path")
 

@@ -758,7 +740,7 @@ cmd_update()
 			echo >&2 "Skipping unmerged submodule $prefix$sm_path"
 			continue
 		fi
-		name=$(module_name "$sm_path") || exit
+		name=$(git submodule--helper name "$sm_path") || exit
 		url=$(git config submodule."$name".url)
 		branch=$(get_submodule_config "$name" branch master)
 		if ! test -z "$update"

@@ -1022,7 +1004,7 @@ cmd_summary() {
 			# Respect the ignore setting for --for-status.
 			if test -n "$for_status"
 			then
-				name=$(module_name "$sm_path")
+				name=$(git submodule--helper name "$sm_path")
 				ignore_config=$(get_submodule_config "$name" ignore none)
 				test $status != A && test $ignore_config = all && continue
 			fi

@@ -1184,7 +1166,7 @@ cmd_status()
 	while read mode sha1 stage sm_path
 	do
 		die_if_unmatched "$mode"
-		name=$(module_name "$sm_path") || exit
+		name=$(git submodule--helper name "$sm_path") || exit
 		url=$(git config submodule."$name".url)
 		displaypath=$(relative_path "$prefix$sm_path")
 		if test "$stage" = U

@@ -1261,7 +1243,7 @@ cmd_sync()
 	while read mode sha1 stage sm_path
 	do
 		die_if_unmatched "$mode"
-		name=$(module_name "$sm_path")
+		name=$(git submodule--helper name "$sm_path")
 		url=$(git config -f .gitmodules --get submodule."$name".url)
 
 		# Possibly a url relative to parent

@@ -155,6 +155,7 @@
 /git-status
 /git-stripspace
 /git-submodule
+/git-submodule--helper
 /git-svn
 /git-symbolic-ref
 /git-tag

@@ -901,6 +901,7 @@ BUILTIN_OBJS += builtin/shortlog.o
 BUILTIN_OBJS += builtin/show-branch.o
 BUILTIN_OBJS += builtin/show-ref.o
 BUILTIN_OBJS += builtin/stripspace.o
+BUILTIN_OBJS += builtin/submodule--helper.o
 BUILTIN_OBJS += builtin/symbolic-ref.o
 BUILTIN_OBJS += builtin/tag.o
 BUILTIN_OBJS += builtin/unpack-file.o

@@ -119,6 +119,7 @@ extern int cmd_show(int argc, const char **argv, const char *prefix);
 extern int cmd_show_branch(int argc, const char **argv, const char *prefix);
 extern int cmd_status(int argc, const char **argv, const char *prefix);
 extern int cmd_stripspace(int argc, const char **argv, const char *prefix);
+extern int cmd_submodule__helper(int argc, const char **argv, const char *prefix);
 extern int cmd_symbolic_ref(int argc, const char **argv, const char *prefix);
 extern int cmd_tag(int argc, const char **argv, const char *prefix);
 extern int cmd_tar_tree(int argc, const char **argv, const char *prefix);

@@ -0,0 +1,137 @@
+#include "builtin.h"
+#include "cache.h"
+#include "parse-options.h"
+#include "quote.h"
+#include "pathspec.h"
+#include "dir.h"
+#include "utf8.h"
+
+static const struct cache_entry **ce_entries;
+static int ce_alloc, ce_used;
+
+static int module_list_compute(int argc, const char **argv,
+				const char *prefix,
+				struct pathspec *pathspec)
+{
+	int i, result = 0;
+	char *max_prefix, *ps_matched = NULL;
+	int max_prefix_len;
+	parse_pathspec(pathspec, 0,
+		       PATHSPEC_PREFER_FULL |
+		       PATHSPEC_STRIP_SUBMODULE_SLASH_CHEAP,
+		       prefix, argv);
+
+	/* Find common prefix for all pathspec's */
+	max_prefix = common_prefix(pathspec);
+	max_prefix_len = max_prefix ? strlen(max_prefix) : 0;
+
+	if (pathspec->nr)
+		ps_matched = xcalloc(pathspec->nr, 1);
+
+	if (read_cache() < 0)
+		die(_("index file corrupt"));
+
+	for (i = 0; i < active_nr; i++) {
+		const struct cache_entry *ce = active_cache[i];
+
+		if (!match_pathspec(pathspec, ce->name, ce_namelen(ce),
+				    max_prefix_len, ps_matched,
+				    S_ISGITLINK(ce->ce_mode) | S_ISDIR(ce->ce_mode)))
+			continue;
+
+		if (S_ISGITLINK(ce->ce_mode)) {
+			ALLOC_GROW(ce_entries, ce_used + 1, ce_alloc);
+			ce_entries[ce_used++] = ce;
+		}
+
+		while (i + 1 < active_nr && !strcmp(ce->name, active_cache[i + 1]->name))
+			/*
+			 * Skip entries with the same name in different stages
+			 * to make sure an entry is returned only once.
+			 */
+			i++;
+	}
+	free(max_prefix);
+
+	if (ps_matched && report_path_error(ps_matched, pathspec, prefix))
+		result = -1;
+
+	free(ps_matched);
+
+	return result;
+}
+
+static int module_list(int argc, const char **argv, const char *prefix)
+{
+	int i;
+	struct pathspec pathspec;
+	const char *alternative_path;
+
+	struct option module_list_options[] = {
+		OPT_STRING(0, "prefix", &alternative_path,
+			   N_("path"),
+			   N_("alternative anchor for relative paths")),
+		OPT_END()
+	};
+
+	const char *const git_submodule_helper_usage[] = {
+		N_("git submodule--helper list [--prefix=<path>] [<path>...]"),
+		NULL
+	};
+
+	argc = parse_options(argc, argv, prefix, module_list_options,
+			     git_submodule_helper_usage, 0);
+
+	if (module_list_compute(argc, argv, alternative_path
+					    ? alternative_path
+					    : prefix, &pathspec) < 0) {
+		printf("#unmatched\n");
+		return 1;
+	}
+
+	for (i = 0; i < ce_used; i++) {
+		const struct cache_entry *ce = ce_entries[i];
+
+		if (ce_stage(ce))
+			printf("%06o %s U\t", ce->ce_mode, sha1_to_hex(null_sha1));
+		else
+			printf("%06o %s %d\t", ce->ce_mode, sha1_to_hex(ce->sha1), ce_stage(ce));
+
+		utf8_fprintf(stdout, "%s\n", ce->name);
+	}
+	return 0;
+}
+
+
+struct cmd_struct {
+	const char *cmd;
+	int (*fct)(int, const char **, const char *);
+};
+
+static struct cmd_struct commands[] = {
+	{"list", module_list},
+};
+
+int cmd_submodule__helper(int argc, const char **argv, const char *prefix)
+{
+	int i;
+	if (argc < 2)
+		goto out;
+
+	for (i = 0; i < ARRAY_SIZE(commands); i++)
+		if (!strcmp(argv[1], commands[i].cmd))
+			return commands[i].fct(argc - 1, argv + 1, prefix);
+
+out:
+	if (argc > 1)
+		fprintf(stderr, _("fatal: '%s' is not a valid submodule--helper "
+				  "subcommand, which are:\n"), argv[1]);
+	else
+		fprintf(stderr, _("fatal: submodule--helper subcommand must be "
+				  "called with a subcommand, which are:\n"));
+
+	for (i = 0; i < ARRAY_SIZE(commands); i++)
+		fprintf(stderr, "\t%s\n", commands[i].cmd);
+
+	exit(129);
+}

@@ -145,48 +145,6 @@ relative_path ()
 	echo "$result$target"
 }
 
-#
-# Get submodule info for registered submodules
-# $@ = path to limit submodule list
-#
-module_list()
-{
-	eval "set $(git rev-parse --sq --prefix "$wt_prefix" -- "$@")"
-	(
-		git ls-files -z --error-unmatch --stage -- "$@" ||
-		echo "unmatched pathspec exists"
-	) |
-	@@PERL@@ -e '
-	my %unmerged = ();
-	my ($null_sha1) = ("0" x 40);
-	my @out = ();
-	my $unmatched = 0;
-	$/ = "\0";
-	while (<STDIN>) {
-		if (/^unmatched pathspec/) {
-			$unmatched = 1;
-			next;
-		}
-		chomp;
-		my ($mode, $sha1, $stage, $path) =
-			/^([0-7]+) ([0-9a-f]{40}) ([0-3])\t(.*)$/;
-		next unless $mode eq "160000";
-		if ($stage ne "0") {
-			if (!$unmerged{$path}++) {
-				push @out, "$mode $null_sha1 U\t$path\n";
-			}
-			next;
-		}
-		push @out, "$_\n";
-	}
-	if ($unmatched) {
-		print "#unmatched\n";
-	} else {
-		print for (@out);
-	}
-	'
-}
-
 die_if_unmatched ()
 {
 	if test "$1" = "#unmatched"