static int add_one_reference(struct string_list_item *item, void *cb_data)
{
	char *ref_git;
	const char *repo;
	struct strbuf alternate = STRBUF_INIT;

	/* Beware: read_gitfile(), real_path() and mkpath() return static buffer */
	ref_git = xstrdup(real_path(item->string));

	repo = read_gitfile(ref_git);
	if (!repo)
		repo = read_gitfile(mkpath("%s/.git", ref_git));
	if (repo) {
		free(ref_git);
		ref_git = xstrdup(repo);
	}

	if (!repo && is_directory(mkpath("%s/.git/objects", ref_git))) {
		char *ref_git_git = mkpathdup("%s/.git", ref_git);
		free(ref_git);
		ref_git = ref_git_git;
	} else if (!is_directory(mkpath("%s/objects", ref_git)))
		die(_("reference repository '%s' is not a local repository."),
		    item->string);

	strbuf_addf(&alternate, "%s/objects", ref_git);
	add_to_alternates_file(alternate.buf);
	strbuf_release(&alternate);
	free(ref_git);
	return 0;
}

void repo_set_gitdir(struct repository *repo,
		     const char *root,
		     const struct set_gitdir_args *o)
{
	const char *gitfile = read_gitfile(root);
	/*
	 * repo->gitdir is saved because the caller could pass "root"
	 * that also points to repo->gitdir. We want to keep it alive
	 * until after xstrdup(root). Then we can free it.
	 */
	char *old_gitdir = repo->gitdir;

	repo->gitdir = xstrdup(gitfile ? gitfile : root);
	free(old_gitdir);

	repo_set_commondir(repo, o->commondir);
	expand_base_dir(&repo->objects->objectdir, o->object_dir,
			repo->commondir, "objects");
	free(repo->objects->alternate_db);
	repo->objects->alternate_db = xstrdup_or_null(o->alternate_db);
	expand_base_dir(&repo->graft_file, o->graft_file,
			repo->commondir, "info/grafts");
	expand_base_dir(&repo->index_file, o->index_file,
			repo->gitdir, "index");
}

static void do_submodule_path(struct strbuf *buf, const char *path,
			      const char *fmt, va_list args)
{
	const char *git_dir;
	struct strbuf git_submodule_common_dir = STRBUF_INIT;
	struct strbuf git_submodule_dir = STRBUF_INIT;

	strbuf_addstr(buf, path);
	strbuf_complete(buf, '/');
	strbuf_addstr(buf, ".git");

	git_dir = read_gitfile(buf->buf);
	if (git_dir) {
		strbuf_reset(buf);
		strbuf_addstr(buf, git_dir);
	}
	strbuf_addch(buf, '/');
	strbuf_addstr(&git_submodule_dir, buf->buf);

	strbuf_vaddf(buf, fmt, args);

	if (get_common_dir_noenv(&git_submodule_common_dir, git_submodule_dir.buf))
		update_common_dir(buf, git_submodule_dir.len, git_submodule_common_dir.buf);

	strbuf_cleanup_path(buf);

	strbuf_release(&git_submodule_dir);
	strbuf_release(&git_submodule_common_dir);
}

int update_submodule(const char *path, const unsigned char sha1[20], int force)
{
	struct strbuf buf = STRBUF_INIT;
	struct child_process cp;
	const char *hex_sha1 = sha1_to_hex(sha1);
	const char *argv[] = {
		"checkout",
		force ? "-fq" : "-q",
		hex_sha1,
		NULL,
	};
	const char *git_dir;

	strbuf_addf(&buf, "%s/.git", path);
	git_dir = read_gitfile(buf.buf);
	if (!git_dir)
		git_dir = buf.buf;
	if (!is_directory(git_dir)) {
		strbuf_release(&buf);
		/* The submodule is not populated, so we can't check it out */
		return 0;
	}
	strbuf_release(&buf);

	memset(&cp, 0, sizeof(cp));
	cp.argv = argv;
	cp.env = local_repo_env;
	cp.git_cmd = 1;
	cp.no_stdin = 1;
	cp.dir = path;   /* GIT_WORK_TREE doesn't work for git checkout */
	if (run_command(&cp))
		return error("Could not checkout submodule %s", path);

	return 0;
}

int submodule_uses_gitfile(const char *path)
{
	struct child_process cp = CHILD_PROCESS_INIT;
	const char *argv[] = {
		"submodule",
		"foreach",
		"--quiet",
		"--recursive",
		"test -f .git",
		NULL,
	};
	struct strbuf buf = STRBUF_INIT;
	const char *git_dir;

	strbuf_addf(&buf, "%s/.git", path);
	git_dir = read_gitfile(buf.buf);
	if (!git_dir) {
		strbuf_release(&buf);
		return 0;
	}
	strbuf_release(&buf);

	/* Now test that all nested submodules use a gitfile too */
	cp.argv = argv;
	cp.env = local_repo_env;
	cp.git_cmd = 1;
	cp.no_stdin = 1;
	cp.no_stderr = 1;
	cp.no_stdout = 1;
	cp.dir = path;
	if (run_command(&cp))
		return 0;

	return 1;
}

void repo_set_gitdir(struct repository *repo, const char *path)
{
	const char *gitfile = read_gitfile(path);
	char *old_gitdir = repo->gitdir;

	repo->gitdir = xstrdup(gitfile ? gitfile : path);
	repo_setup_env(repo);

	free(old_gitdir);
}

static int add_one_reference(struct string_list_item *item, void *cb_data)
{
	char *ref_git;
	const char *repo;
	struct strbuf alternate = STRBUF_INIT;

	/* Beware: read_gitfile(), real_path() and mkpath() return static buffer */
	ref_git = xstrdup(real_path(item->string));

	repo = read_gitfile(ref_git);
	if (!repo)
		repo = read_gitfile(mkpath("%s/.git", ref_git));
	if (repo) {
		free(ref_git);
		ref_git = xstrdup(repo);
	}

	if (!repo && is_directory(mkpath("%s/.git/objects", ref_git))) {
		char *ref_git_git = mkpathdup("%s/.git", ref_git);
		free(ref_git);
		ref_git = ref_git_git;
	} else if (!is_directory(mkpath("%s/objects", ref_git))) {
		struct strbuf sb = STRBUF_INIT;
		if (get_common_dir(&sb, ref_git))
			die(_("reference repository '%s' as a linked checkout is not supported yet."),
			    item->string);
		die(_("reference repository '%s' is not a local repository."),
		    item->string);
	}

	if (!access(mkpath("%s/shallow", ref_git), F_OK))
		die(_("reference repository '%s' is shallow"), item->string);

	if (!access(mkpath("%s/info/grafts", ref_git), F_OK))
		die(_("reference repository '%s' is grafted"), item->string);

	strbuf_addf(&alternate, "%s/objects", ref_git);
	add_to_alternates_file(alternate.buf);
	strbuf_release(&alternate);
	free(ref_git);
	return 0;
}

static void prepare_move_submodule(const char *src, int first,
				   const char **submodule_gitfile)
{
	struct strbuf submodule_dotgit = STRBUF_INIT;
	if (!S_ISGITLINK(active_cache[first]->ce_mode))
		die(_("Directory %s is in index and no submodule?"), src);
	if (!is_staging_gitmodules_ok())
		die(_("Please stage your changes to .gitmodules or stash them to proceed"));
	strbuf_addf(&submodule_dotgit, "%s/.git", src);
	*submodule_gitfile = read_gitfile(submodule_dotgit.buf);
	if (*submodule_gitfile)
		*submodule_gitfile = xstrdup(*submodule_gitfile);
	else
		*submodule_gitfile = SUBMODULE_WITH_GITDIR;
	strbuf_release(&submodule_dotgit);
}

static const char *get_repo_path_1(struct strbuf *path, int *is_bundle)
{
	static char *suffix[] = { "/.git", "", ".git/.git", ".git" };
	static char *bundle_suffix[] = { ".bundle", "" };
	size_t baselen = path->len;
	struct stat st;
	int i;

	for (i = 0; i < ARRAY_SIZE(suffix); i++) {
		strbuf_setlen(path, baselen);
		strbuf_addstr(path, suffix[i]);
		if (stat(path->buf, &st))
			continue;
		if (S_ISDIR(st.st_mode) && is_git_directory(path->buf)) {
			*is_bundle = 0;
			return path->buf;
		} else if (S_ISREG(st.st_mode) && st.st_size > 8) {
			/* Is it a "gitfile"? */
			char signature[8];
			const char *dst;
			int len, fd = open(path->buf, O_RDONLY);
			if (fd < 0)
				continue;
			len = read_in_full(fd, signature, 8);
			close(fd);
			if (len != 8 || strncmp(signature, "gitdir: ", 8))
				continue;
			dst = read_gitfile(path->buf);
			if (dst) {
				*is_bundle = 0;
				return dst;
			}
		}
	}

	for (i = 0; i < ARRAY_SIZE(bundle_suffix); i++) {
		strbuf_setlen(path, baselen);
		strbuf_addstr(path, bundle_suffix[i]);
		if (!stat(path->buf, &st) && S_ISREG(st.st_mode)) {
			*is_bundle = 1;
			return path->buf;
		}
	}

	return NULL;
}

static char *get_repo_path(const char *repo, int *is_bundle)
{
	static char *suffix[] = { "/.git", "", ".git/.git", ".git" };
	static char *bundle_suffix[] = { ".bundle", "" };
	struct stat st;
	int i;

	for (i = 0; i < ARRAY_SIZE(suffix); i++) {
		const char *path;
		path = mkpath("%s%s", repo, suffix[i]);
		if (stat(path, &st))
			continue;
		if (S_ISDIR(st.st_mode) && is_git_directory(path)) {
			*is_bundle = 0;
			return xstrdup(absolute_path(path));
		} else if (S_ISREG(st.st_mode) && st.st_size > 8) {
			/* Is it a "gitfile"? */
			char signature[8];
			int len, fd = open(path, O_RDONLY);
			if (fd < 0)
				continue;
			len = read_in_full(fd, signature, 8);
			close(fd);
			if (len != 8 || strncmp(signature, "gitdir: ", 8))
				continue;
			path = read_gitfile(path);
			if (path) {
				*is_bundle = 0;
				return xstrdup(absolute_path(path));
			}
		}
	}

	for (i = 0; i < ARRAY_SIZE(bundle_suffix); i++) {
		const char *path;
		path = mkpath("%s%s", repo, bundle_suffix[i]);
		if (!stat(path, &st) && S_ISREG(st.st_mode)) {
			*is_bundle = 1;
			return xstrdup(absolute_path(path));
		}
	}

	return NULL;
}

static void separate_git_dir(const char *git_dir, const char *git_link)
{
	struct stat st;

	if (!stat(git_link, &st)) {
		const char *src;

		if (S_ISREG(st.st_mode))
			src = read_gitfile(git_link);
		else if (S_ISDIR(st.st_mode))
			src = git_link;
		else
			die(_("unable to handle file type %d"), (int)st.st_mode);

		if (rename(src, git_dir))
			die_errno(_("unable to move %s to %s"), src, git_dir);
	}

	write_file(git_link, "gitdir: %s", git_dir);
}

static int add_submodule_odb(const char *path)
{
	struct strbuf objects_directory = STRBUF_INIT;
	struct alternate_object_database *alt_odb;
	int ret = 0;
	const char *git_dir;

	strbuf_addf(&objects_directory, "%s/.git", path);
	git_dir = read_gitfile(objects_directory.buf);
	if (git_dir) {
		strbuf_reset(&objects_directory);
		strbuf_addstr(&objects_directory, git_dir);
	}
	strbuf_addstr(&objects_directory, "/objects/");
	if (!is_directory(objects_directory.buf)) {
		ret = -1;
		goto done;
	}
	/* avoid adding it twice */
	for (alt_odb = alt_odb_list; alt_odb; alt_odb = alt_odb->next)
		if (alt_odb->name - alt_odb->base == objects_directory.len &&
				!strncmp(alt_odb->base, objects_directory.buf,
					objects_directory.len))
			goto done;

	alt_odb = xmalloc(objects_directory.len + 42 + sizeof(*alt_odb));
	alt_odb->next = alt_odb_list;
	strcpy(alt_odb->base, objects_directory.buf);
	alt_odb->name = alt_odb->base + objects_directory.len;
	alt_odb->name[2] = '/';
	alt_odb->name[40] = '\0';
	alt_odb->name[41] = '\0';
	alt_odb_list = alt_odb;

	/* add possible alternates from the submodule */
	read_info_alternates(objects_directory.buf, 0);
	prepare_alt_odb();
done:
	strbuf_release(&objects_directory);
	return ret;
}

unsigned is_submodule_checkout_safe(const char *path, const unsigned char sha1[20])
{
	struct strbuf buf = STRBUF_INIT;
	struct child_process cp;
	const char *hex_sha1 = sha1_to_hex(sha1);
	const char *argv[] = {
		"read-tree",
		"-n",
		"-m",
		"HEAD",
		hex_sha1,
		NULL,
	};
	const char *git_dir;

	strbuf_addf(&buf, "%s/.git", path);
	git_dir = read_gitfile(buf.buf);
	if (!git_dir)
		git_dir = buf.buf;
	if (!is_directory(git_dir)) {
		strbuf_release(&buf);
		/* The submodule is not populated, it's safe to check it out */
		/*
		 * TODO: When git learns to re-populate submodules, a check must be
		 * added here to assert that no local files will be overwritten.
		 */
		return 1;
	}
	strbuf_release(&buf);

	memset(&cp, 0, sizeof(cp));
	cp.argv = argv;
	cp.env = local_repo_env;
	cp.git_cmd = 1;
	cp.no_stdin = 1;
	cp.dir = path;
	return run_command(&cp) == 0;
}

char *git_path_submodule(const char *path, const char *fmt, ...)
{
	char *pathname = get_pathname();
	struct strbuf buf = STRBUF_INIT;
	const char *git_dir;
	va_list args;
	unsigned len;

	len = strlen(path);
	if (len > PATH_MAX-100)
		return bad_path;

	strbuf_addstr(&buf, path);
	if (len && path[len-1] != '/')
		strbuf_addch(&buf, '/');
	strbuf_addstr(&buf, ".git");

	git_dir = read_gitfile(buf.buf);
	if (git_dir) {
		strbuf_reset(&buf);
		strbuf_addstr(&buf, git_dir);
	}
	strbuf_addch(&buf, '/');

	if (buf.len >= PATH_MAX)
		return bad_path;
	memcpy(pathname, buf.buf, buf.len + 1);

	strbuf_release(&buf);
	len = strlen(pathname);

	va_start(args, fmt);
	len += vsnprintf(pathname + len, PATH_MAX - len, fmt, args);
	va_end(args);
	if (len >= PATH_MAX)
		return bad_path;
	return cleanup_path(pathname);
}

const char *git_path_submodule(const char *path, const char *fmt, ...)
{
	struct strbuf *buf = get_pathname();
	const char *git_dir;
	va_list args;

	strbuf_addstr(buf, path);
	if (buf->len && buf->buf[buf->len - 1] != '/')
		strbuf_addch(buf, '/');
	strbuf_addstr(buf, ".git");

	git_dir = read_gitfile(buf->buf);
	if (git_dir) {
		strbuf_reset(buf);
		strbuf_addstr(buf, git_dir);
	}
	strbuf_addch(buf, '/');

	va_start(args, fmt);
	strbuf_vaddf(buf, fmt, args);
	va_end(args);
	strbuf_cleanup_path(buf);
	return buf->buf;
}

/*
 * 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.
 */
static const char *setup_git_directory_gently_1(int *nongit_ok)
{
	const char *env_ceiling_dirs = getenv(CEILING_DIRECTORIES_ENVIRONMENT);
	struct string_list ceiling_dirs = STRING_LIST_INIT_DUP;
	static struct strbuf cwd = STRBUF_INIT;
	const char *gitdirenv, *ret;
	char *gitfile;
	int offset, offset_parent, ceil_offset = -1;
	dev_t current_device = 0;
	int one_filesystem = 1;

	/*
	 * We may have read an incomplete configuration before
	 * setting-up the git directory. If so, clear the cache so
	 * that the next queries to the configuration reload complete
	 * configuration (including the per-repo config file that we
	 * ignored previously).
	 */
	git_config_clear();

	/*
	 * Let's assume that we are in a git repository.
	 * If it turns out later that we are somewhere else, the value will be
	 * updated accordingly.
	 */
	if (nongit_ok)
		*nongit_ok = 0;

	if (strbuf_getcwd(&cwd))
		die_errno("Unable to read current working directory");
	offset = cwd.len;

	/*
	 * If GIT_DIR is set explicitly, we're not going
	 * to do any discovery, but we still do repository
	 * validation.
	 */
	gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
	if (gitdirenv)
		return setup_explicit_git_dir(gitdirenv, &cwd, nongit_ok);

	if (env_ceiling_dirs) {
		int empty_entry_found = 0;

		string_list_split(&ceiling_dirs, env_ceiling_dirs, PATH_SEP, -1);
		filter_string_list(&ceiling_dirs, 0,
				   canonicalize_ceiling_entry, &empty_entry_found);
		ceil_offset = longest_ancestor_length(cwd.buf, &ceiling_dirs);
		string_list_clear(&ceiling_dirs, 0);
	}

	if (ceil_offset < 0 && has_dos_drive_prefix(cwd.buf))
		ceil_offset = 1;

	/*
	 * Test in the following order (relative to the cwd):
	 * - .git (file containing "gitdir: <path>")
	 * - .git/
	 * - ./ (bare)
	 * - ../.git
	 * - ../.git/
	 * - ../ (bare)
	 * - ../../.git/
	 *   etc.
	 */
	one_filesystem = !git_env_bool("GIT_DISCOVERY_ACROSS_FILESYSTEM", 0);
	if (one_filesystem)
		current_device = get_device_or_die(".", NULL, 0);
	for (;;) {
		gitfile = (char*)read_gitfile(DEFAULT_GIT_DIR_ENVIRONMENT);
		if (gitfile)
			gitdirenv = gitfile = xstrdup(gitfile);
		else {
			if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT))
				gitdirenv = DEFAULT_GIT_DIR_ENVIRONMENT;
		}

		if (gitdirenv) {
			ret = setup_discovered_git_dir(gitdirenv,
						       &cwd, offset,
						       nongit_ok);
			free(gitfile);
			return ret;
		}
		free(gitfile);

		if (is_git_directory("."))
			return setup_bare_git_dir(&cwd, offset, nongit_ok);

		offset_parent = offset;
		while (--offset_parent > ceil_offset && cwd.buf[offset_parent] != '/');
		if (offset_parent <= ceil_offset)
			return setup_nongit(cwd.buf, nongit_ok);
		if (one_filesystem) {
			dev_t parent_device = get_device_or_die("..", cwd.buf,
								offset);
//.........这里部分代码省略.........

const char *resolve_gitdir(const char *suspect)
{
	if (is_git_directory(suspect))
		return suspect;
	return read_gitfile(suspect);
}

unsigned is_submodule_modified(const char *path, int ignore_untracked)
{
	ssize_t len;
	struct child_process cp;
	const char *argv[] = {
		"status",
		"--porcelain",
		NULL,
		NULL,
	};
	struct strbuf buf = STRBUF_INIT;
	unsigned dirty_submodule = 0;
	const char *line, *next_line;
	const char *git_dir;

	strbuf_addf(&buf, "%s/.git", path);
	git_dir = read_gitfile(buf.buf);
	if (!git_dir)
		git_dir = buf.buf;
	if (!is_directory(git_dir)) {
		strbuf_release(&buf);
		/* The submodule is not checked out, so it is not modified */
		return 0;

	}
	strbuf_reset(&buf);

	if (ignore_untracked)
		argv[2] = "-uno";

	memset(&cp, 0, sizeof(cp));
	cp.argv = argv;
	cp.env = local_repo_env;
	cp.git_cmd = 1;
	cp.no_stdin = 1;
	cp.out = -1;
	cp.dir = path;
	if (start_command(&cp))
		die("Could not run git status --porcelain");

	len = strbuf_read(&buf, cp.out, 1024);
	line = buf.buf;
	while (len > 2) {
		if ((line[0] == '?') && (line[1] == '?')) {
			dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
			if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
				break;
		} else {
			dirty_submodule |= DIRTY_SUBMODULE_MODIFIED;
			if (ignore_untracked ||
			    (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED))
				break;
		}
		next_line = strchr(line, '\n');
		if (!next_line)
			break;
		next_line++;
		len -= (next_line - line);
		line = next_line;
	}
	close(cp.out);

	if (finish_command(&cp))
		die("git status --porcelain failed");

	strbuf_release(&buf);
	return dirty_submodule;
}

int fetch_populated_submodules(int num_options, const char **options,
			       const char *prefix, int command_line_option,
			       int quiet)
{
	int i, result = 0, argc = 0, default_argc;
	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)
		goto out;

	if (!the_index.initialized)
		if (read_cache() < 0)
			die("index file corrupt");

	/* 6: "fetch" (options) --recurse-submodules-default default "--submodule-prefix" prefix NULL */
	argv = xcalloc(num_options + 6, sizeof(const char *));
	argv[argc++] = "fetch";
	for (i = 0; i < num_options; i++)
		argv[argc++] = options[i];
	argv[argc++] = "--recurse-submodules-default";
	default_argc = argc++;
	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;

	calculate_changed_submodule_paths();

	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, *default_argv;

		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;

		default_argv = "yes";
		if (command_line_option == RECURSE_SUBMODULES_DEFAULT) {
			struct string_list_item *fetch_recurse_submodules_option;
			fetch_recurse_submodules_option = unsorted_string_list_lookup(&config_fetch_recurse_submodules_for_name, name);
			if (fetch_recurse_submodules_option) {
				if ((intptr_t)fetch_recurse_submodules_option->util == RECURSE_SUBMODULES_OFF)
					continue;
				if ((intptr_t)fetch_recurse_submodules_option->util == RECURSE_SUBMODULES_ON_DEMAND) {
					if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
						continue;
					default_argv = "on-demand";
				}
			} else {
				if ((config_fetch_recurse_submodules == RECURSE_SUBMODULES_OFF) ||
				    gitmodules_is_unmerged)
					continue;
				if (config_fetch_recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND) {
					if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
						continue;
					default_argv = "on-demand";
				}
			}
		} else if (command_line_option == RECURSE_SUBMODULES_ON_DEMAND) {
			if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
				continue;
			default_argv = "on-demand";
		}

		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(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[default_argc] = default_argv;
			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);
out:
	string_list_clear(&changed_submodule_paths, 1);
	return result;
}

static int get_next_submodule(struct child_process *cp,
			      struct strbuf *err, void *data, void **task_cb)
{
	int ret = 0;
	struct submodule_parallel_fetch *spf = data;

	for (; spf->count < active_nr; spf->count++) {
		struct strbuf submodule_path = STRBUF_INIT;
		struct strbuf submodule_git_dir = STRBUF_INIT;
		struct strbuf submodule_prefix = STRBUF_INIT;
		const struct cache_entry *ce = active_cache[spf->count];
		const char *git_dir, *default_argv;
		const struct submodule *submodule;

		if (!S_ISGITLINK(ce->ce_mode))
			continue;

		submodule = submodule_from_path(null_sha1, ce->name);
		if (!submodule)
			submodule = submodule_from_name(null_sha1, ce->name);

		default_argv = "yes";
		if (spf->command_line_option == RECURSE_SUBMODULES_DEFAULT) {
			if (submodule &&
			    submodule->fetch_recurse !=
						RECURSE_SUBMODULES_NONE) {
				if (submodule->fetch_recurse ==
						RECURSE_SUBMODULES_OFF)
					continue;
				if (submodule->fetch_recurse ==
						RECURSE_SUBMODULES_ON_DEMAND) {
					if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
						continue;
					default_argv = "on-demand";
				}
			} else {
				if ((config_fetch_recurse_submodules == RECURSE_SUBMODULES_OFF) ||
				    gitmodules_is_unmerged)
					continue;
				if (config_fetch_recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND) {
					if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
						continue;
					default_argv = "on-demand";
				}
			}
		} else if (spf->command_line_option == RECURSE_SUBMODULES_ON_DEMAND) {
			if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
				continue;
			default_argv = "on-demand";
		}

		strbuf_addf(&submodule_path, "%s/%s", spf->work_tree, ce->name);
		strbuf_addf(&submodule_git_dir, "%s/.git", submodule_path.buf);
		strbuf_addf(&submodule_prefix, "%s%s/", spf->prefix, ce->name);
		git_dir = read_gitfile(submodule_git_dir.buf);
		if (!git_dir)
			git_dir = submodule_git_dir.buf;
		if (is_directory(git_dir)) {
			child_process_init(cp);
			cp->dir = strbuf_detach(&submodule_path, NULL);
			cp->env = local_repo_env;
			cp->git_cmd = 1;
			if (!spf->quiet)
				strbuf_addf(err, "Fetching submodule %s%s\n",
					    spf->prefix, ce->name);
			argv_array_init(&cp->args);
			argv_array_pushv(&cp->args, spf->args.argv);
			argv_array_push(&cp->args, default_argv);
			argv_array_push(&cp->args, "--submodule-prefix");
			argv_array_push(&cp->args, submodule_prefix.buf);
			ret = 1;
		}
		strbuf_release(&submodule_path);
		strbuf_release(&submodule_git_dir);
		strbuf_release(&submodule_prefix);
		if (ret) {
			spf->count++;
			return 1;
		}
	}
	return 0;
}