Merge branch 'ps/submodule-ref-format'

Support to specify ref backend for submodules has been enhanced.

* ps/submodule-ref-format:
  object: fix leaking packfiles when closing object store
  submodule: fix leaking seen submodule names
  submodule: fix leaking fetch tasks
  builtin/submodule: allow "add" to use different ref storage format
  refs: fix ref storage format for submodule ref stores
  builtin/clone: propagate ref storage format to submodules
  builtin/submodule: allow cloning with different ref storage format
  git-submodule.sh: break overly long command lines

Documentation/git-submodule.txt

@@ -34,7 +34,7 @@ COMMANDS
 With no arguments, shows the status of existing submodules.  Several
 subcommands are available to perform operations on the submodules.
 
-add [-b <branch>] [-f|--force] [--name <name>] [--reference <repository>] [--depth <depth>] [--] <repository> [<path>]::
+add [-b <branch>] [-f|--force] [--name <name>] [--reference <repository>] [--ref-format <format>] [--depth <depth>] [--] <repository> [<path>]::
 	Add the given repository as a submodule at the given path
 	to the changeset to be committed next to the current
 	project: the current project is termed the "superproject".
@@ -71,6 +71,9 @@ submodule repositories will be kept together in the same relative
 location, and only the superproject's URL needs to be provided.
 git-submodule will correctly locate the submodule using the relative
 URL in `.gitmodules`.
++
+If `--ref-format <format>`  is specified, the ref storage format of newly
+cloned submodules will be set accordingly.
 
 status [--cached] [--recursive] [--] [<path>...]::
 	Show the status of the submodules. This will print the SHA-1 of the
@@ -136,7 +139,7 @@ If you really want to remove a submodule from the repository and commit
 that use linkgit:git-rm[1] instead. See linkgit:gitsubmodules[7] for removal
 options.
 
-update [--init] [--remote] [-N|--no-fetch] [--[no-]recommend-shallow] [-f|--force] [--checkout|--rebase|--merge] [--reference <repository>] [--depth <depth>] [--recursive] [--jobs <n>] [--[no-]single-branch] [--filter <filter-spec>] [--] [<path>...]::
+update [--init] [--remote] [-N|--no-fetch] [--[no-]recommend-shallow] [-f|--force] [--checkout|--rebase|--merge] [--reference <repository>] [--ref-format <format>] [--depth <depth>] [--recursive] [--jobs <n>] [--[no-]single-branch] [--filter <filter-spec>] [--] [<path>...]::
 +
 --
 Update the registered submodules to match what the superproject
@@ -185,6 +188,9 @@ submodule with the `--init` option.
 If `--recursive` is specified, this command will recurse into the
 registered submodules, and update any nested submodules within.
 
+If `--ref-format <format>`  is specified, the ref storage format of newly
+cloned submodules will be set accordingly.
+
 If `--filter <filter-spec>` is specified, the given partial clone filter will be
 applied to the submodule. See linkgit:git-rev-list[1] for details on filter
 specifications.

builtin/clone.c

@@ -729,7 +729,8 @@ static int git_sparse_checkout_init(const char *repo)
 	return result;
 }
 
-static int checkout(int submodule_progress, int filter_submodules)
+static int checkout(int submodule_progress, int filter_submodules,
+		    enum ref_storage_format ref_storage_format)
 {
 	struct object_id oid;
 	char *head;
@@ -813,6 +814,10 @@ static int checkout(int submodule_progress, int filter_submodules)
 			strvec_push(&cmd.args, "--no-fetch");
 		}
 
+		if (ref_storage_format != REF_STORAGE_FORMAT_UNKNOWN)
+			strvec_pushf(&cmd.args, "--ref-format=%s",
+				     ref_storage_format_to_name(ref_storage_format));
+
 		if (filter_submodules && filter_options.choice)
 			strvec_pushf(&cmd.args, "--filter=%s",
 				     expand_list_objects_filter_spec(&filter_options));
@@ -1536,7 +1541,8 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 		return 1;
 
 	junk_mode = JUNK_LEAVE_REPO;
-	err = checkout(submodule_progress, filter_submodules);
+	err = checkout(submodule_progress, filter_submodules,
+		       ref_storage_format);
 
 	free(remote_name);
 	strbuf_release(&reflog_msg);

builtin/submodule--helper.c

@@ -1532,6 +1532,7 @@ struct module_clone_data {
 	const char *url;
 	int depth;
 	struct list_objects_filter_options *filter_options;
+	enum ref_storage_format ref_storage_format;
 	unsigned int quiet: 1;
 	unsigned int progress: 1;
 	unsigned int dissociate: 1;
@@ -1540,6 +1541,7 @@ struct module_clone_data {
 };
 #define MODULE_CLONE_DATA_INIT { \
 	.single_branch = -1, \
+	.ref_storage_format = REF_STORAGE_FORMAT_UNKNOWN, \
 }
 
 struct submodule_alternate_setup {
@@ -1738,6 +1740,9 @@ static int clone_submodule(const struct module_clone_data *clone_data,
 				strvec_pushl(&cp.args, "--reference",
 					     item->string, NULL);
 		}
+		if (clone_data->ref_storage_format != REF_STORAGE_FORMAT_UNKNOWN)
+			strvec_pushf(&cp.args, "--ref-format=%s",
+				     ref_storage_format_to_name(clone_data->ref_storage_format));
 		if (clone_data->dissociate)
 			strvec_push(&cp.args, "--dissociate");
 		if (sm_gitdir && *sm_gitdir)
@@ -1832,6 +1837,7 @@ static int module_clone(int argc, const char **argv, const char *prefix)
 	struct string_list reference = STRING_LIST_INIT_NODUP;
 	struct list_objects_filter_options filter_options =
 		LIST_OBJECTS_FILTER_INIT;
+	const char *ref_storage_format = NULL;
 
 	struct option module_clone_options[] = {
 		OPT_STRING(0, "prefix", &clone_data.prefix,
@@ -1849,6 +1855,8 @@ static int module_clone(int argc, const char **argv, const char *prefix)
 		OPT_STRING_LIST(0, "reference", &reference,
 			   N_("repo"),
 			   N_("reference repository")),
+		OPT_STRING(0, "ref-format", &ref_storage_format, N_("format"),
+			   N_("specify the reference format to use")),
 		OPT_BOOL(0, "dissociate", &dissociate,
 			   N_("use --reference only while cloning")),
 		OPT_INTEGER(0, "depth", &clone_data.depth,
@@ -1874,6 +1882,11 @@ static int module_clone(int argc, const char **argv, const char *prefix)
 	argc = parse_options(argc, argv, prefix, module_clone_options,
 			     git_submodule_helper_usage, 0);
 
+	if (ref_storage_format) {
+		clone_data.ref_storage_format = ref_storage_format_by_name(ref_storage_format);
+		if (clone_data.ref_storage_format == REF_STORAGE_FORMAT_UNKNOWN)
+			die(_("unknown ref storage format '%s'"), ref_storage_format);
+	}
 	clone_data.dissociate = !!dissociate;
 	clone_data.quiet = !!quiet;
 	clone_data.progress = !!progress;
@@ -1973,6 +1986,7 @@ struct update_data {
 	struct submodule_update_strategy update_strategy;
 	struct list_objects_filter_options *filter_options;
 	struct module_list list;
+	enum ref_storage_format ref_storage_format;
 	int depth;
 	int max_jobs;
 	int single_branch;
@@ -1996,6 +2010,7 @@ struct update_data {
 #define UPDATE_DATA_INIT { \
 	.update_strategy = SUBMODULE_UPDATE_STRATEGY_INIT, \
 	.list = MODULE_LIST_INIT, \
+	.ref_storage_format = REF_STORAGE_FORMAT_UNKNOWN, \
 	.recommend_shallow = -1, \
 	.references = STRING_LIST_INIT_DUP, \
 	.single_branch = -1, \
@@ -2131,6 +2146,9 @@ static int prepare_to_clone_next_submodule(const struct cache_entry *ce,
 			     expand_list_objects_filter_spec(suc->update_data->filter_options));
 	if (suc->update_data->require_init)
 		strvec_push(&child->args, "--require-init");
+	if (suc->update_data->ref_storage_format != REF_STORAGE_FORMAT_UNKNOWN)
+		strvec_pushf(&child->args, "--ref-format=%s",
+			     ref_storage_format_to_name(suc->update_data->ref_storage_format));
 	strvec_pushl(&child->args, "--path", sub->path, NULL);
 	strvec_pushl(&child->args, "--name", sub->name, NULL);
 	strvec_pushl(&child->args, "--url", url, NULL);
@@ -2565,6 +2583,9 @@ static void update_data_to_args(const struct update_data *update_data,
 		for_each_string_list_item(item, &update_data->references)
 			strvec_pushl(args, "--reference", item->string, NULL);
 	}
+	if (update_data->ref_storage_format != REF_STORAGE_FORMAT_UNKNOWN)
+		strvec_pushf(args, "--ref-format=%s",
+			     ref_storage_format_to_name(update_data->ref_storage_format));
 	if (update_data->filter_options && update_data->filter_options->choice)
 		strvec_pushf(args, "--filter=%s",
 				expand_list_objects_filter_spec(
@@ -2740,6 +2761,7 @@ static int module_update(int argc, const char **argv, const char *prefix)
 	struct update_data opt = UPDATE_DATA_INIT;
 	struct list_objects_filter_options filter_options =
 		LIST_OBJECTS_FILTER_INIT;
+	const char *ref_storage_format = NULL;
 	int ret;
 	struct option module_update_options[] = {
 		OPT__SUPER_PREFIX(&opt.super_prefix),
@@ -2763,6 +2785,8 @@ static int module_update(int argc, const char **argv, const char *prefix)
 			SM_UPDATE_REBASE),
 		OPT_STRING_LIST(0, "reference", &opt.references, N_("repo"),
 			   N_("reference repository")),
+		OPT_STRING(0, "ref-format", &ref_storage_format, N_("format"),
+			   N_("specify the reference format to use")),
 		OPT_BOOL(0, "dissociate", &opt.dissociate,
 			   N_("use --reference only while cloning")),
 		OPT_INTEGER(0, "depth", &opt.depth,
@@ -2806,6 +2830,12 @@ static int module_update(int argc, const char **argv, const char *prefix)
 				   module_update_options);
 	}
 
+	if (ref_storage_format) {
+		opt.ref_storage_format = ref_storage_format_by_name(ref_storage_format);
+		if (opt.ref_storage_format == REF_STORAGE_FORMAT_UNKNOWN)
+			die(_("unknown ref storage format '%s'"), ref_storage_format);
+	}
+
 	opt.filter_options = &filter_options;
 	opt.prefix = prefix;
 
@@ -3101,13 +3131,17 @@ struct add_data {
 	const char *sm_name;
 	const char *repo;
 	const char *realrepo;
+	enum ref_storage_format ref_storage_format;
 	int depth;
 	unsigned int force: 1;
 	unsigned int quiet: 1;
 	unsigned int progress: 1;
 	unsigned int dissociate: 1;
 };
-#define ADD_DATA_INIT { .depth = -1 }
+#define ADD_DATA_INIT { \
+	.depth = -1, \
+	.ref_storage_format = REF_STORAGE_FORMAT_UNKNOWN, \
+}
 
 static void append_fetch_remotes(struct strbuf *msg, const char *git_dir_path)
 {
@@ -3201,6 +3235,7 @@ static int add_submodule(const struct add_data *add_data)
 
 			string_list_append(&reference, p)->util = p;
 		}
+		clone_data.ref_storage_format = add_data->ref_storage_format;
 		clone_data.dissociate = add_data->dissociate;
 		if (add_data->depth >= 0)
 			clone_data.depth = add_data->depth;
@@ -3366,6 +3401,7 @@ static int module_add(int argc, const char **argv, const char *prefix)
 {
 	int force = 0, quiet = 0, progress = 0, dissociate = 0;
 	struct add_data add_data = ADD_DATA_INIT;
+	const char *ref_storage_format = NULL;
 	char *to_free = NULL;
 	struct option options[] = {
 		OPT_STRING('b', "branch", &add_data.branch, N_("branch"),
@@ -3376,6 +3412,8 @@ static int module_add(int argc, const char **argv, const char *prefix)
 		OPT_BOOL(0, "progress", &progress, N_("force cloning progress")),
 		OPT_STRING(0, "reference", &add_data.reference_path, N_("repository"),
 			   N_("reference repository")),
+		OPT_STRING(0, "ref-format", &ref_storage_format, N_("format"),
+			   N_("specify the reference format to use")),
 		OPT_BOOL(0, "dissociate", &dissociate, N_("borrow the objects from reference repositories")),
 		OPT_STRING(0, "name", &add_data.sm_name, N_("name"),
 			   N_("sets the submodule's name to the given string "
@@ -3402,6 +3440,12 @@ static int module_add(int argc, const char **argv, const char *prefix)
 	if (argc == 0 || argc > 2)
 		usage_with_options(usage, options);
 
+	if (ref_storage_format) {
+		add_data.ref_storage_format = ref_storage_format_by_name(ref_storage_format);
+		if (add_data.ref_storage_format == REF_STORAGE_FORMAT_UNKNOWN)
+			die(_("unknown ref storage format '%s'"), ref_storage_format);
+	}
+
 	add_data.repo = argv[0];
 	if (argc == 1)
 		add_data.sm_path = git_url_basename(add_data.repo, 0, 0);

git-submodule.sh

@@ -94,6 +94,14 @@ cmd_add()
 		--reference=*)
 			reference_path="${1#--reference=}"
 			;;
+		--ref-format)
+			case "$2" in '') usage ;; esac
+			ref_format="--ref-format=$2"
+			shift
+			;;
+		--ref-format=*)
+			ref_format="$1"
+			;;
 		--dissociate)
 			dissociate=1
 			;;
@@ -129,7 +137,18 @@ cmd_add()
 		usage
 	fi
 
-	git ${wt_prefix:+-C "$wt_prefix"} submodule--helper add ${quiet:+--quiet} ${force:+--force} ${progress:+"--progress"} ${branch:+--branch "$branch"} ${reference_path:+--reference "$reference_path"} ${dissociate:+--dissociate} ${custom_name:+--name "$custom_name"} ${depth:+"$depth"} -- "$@"
+	git ${wt_prefix:+-C "$wt_prefix"} submodule--helper add \
+		${quiet:+--quiet} \
+		${force:+--force} \
+		${progress:+"--progress"} \
+		${branch:+--branch "$branch"} \
+		${reference_path:+--reference "$reference_path"} \
+		${ref_format:+"$ref_format"} \
+		${dissociate:+--dissociate} \
+		${custom_name:+--name "$custom_name"} \
+		${depth:+"$depth"} \
+		-- \
+		"$@"
 }
 
 #
@@ -160,7 +179,11 @@ cmd_foreach()
 		shift
 	done
 
-	git ${wt_prefix:+-C "$wt_prefix"} submodule--helper foreach ${quiet:+--quiet} ${recursive:+--recursive} -- "$@"
+	git ${wt_prefix:+-C "$wt_prefix"} submodule--helper foreach \
+		${quiet:+--quiet} \
+		${recursive:+--recursive} \
+		-- \
+		"$@"
 }
 
 #
@@ -191,7 +214,10 @@ cmd_init()
 		shift
 	done
 
-	git ${wt_prefix:+-C "$wt_prefix"} submodule--helper init ${quiet:+--quiet} -- "$@"
+	git ${wt_prefix:+-C "$wt_prefix"} submodule--helper init \
+		${quiet:+--quiet} \
+		-- \
+		"$@"
 }
 
 #
@@ -227,7 +253,12 @@ cmd_deinit()
 		shift
 	done
 
-	git ${wt_prefix:+-C "$wt_prefix"} submodule--helper deinit ${quiet:+--quiet} ${force:+--force} ${deinit_all:+--all} -- "$@"
+	git ${wt_prefix:+-C "$wt_prefix"} submodule--helper deinit \
+		${quiet:+--quiet} \
+		${force:+--force} \
+		${deinit_all:+--all} \
+		-- \
+		"$@"
 }
 
 #
@@ -268,6 +299,14 @@ cmd_update()
 		-r|--rebase)
 			rebase=1
 			;;
+		--ref-format)
+			case "$2" in '') usage ;; esac
+			ref_format="--ref-format=$2"
+			shift
+			;;
+		--ref-format=*)
+			ref_format="$1"
+			;;
 		--reference)
 			case "$2" in '') usage ;; esac
 			reference="--reference=$2"
@@ -349,6 +388,7 @@ cmd_update()
 		${rebase:+--rebase} \
 		${merge:+--merge} \
 		${checkout:+--checkout} \
+		${ref_format:+"$ref_format"} \
 		${reference:+"$reference"} \
 		${dissociate:+"--dissociate"} \
 		${depth:+"$depth"} \
@@ -399,7 +439,12 @@ cmd_set_branch() {
 		shift
 	done
 
-	git ${wt_prefix:+-C "$wt_prefix"} submodule--helper set-branch ${quiet:+--quiet} ${branch:+--branch "$branch"} ${default:+--default} -- "$@"
+	git ${wt_prefix:+-C "$wt_prefix"} submodule--helper set-branch \
+		${quiet:+--quiet} \
+		${branch:+--branch "$branch"} \
+		${default:+--default} \
+		-- \
+		"$@"
 }
 
 #
@@ -428,7 +473,10 @@ cmd_set_url() {
 		shift
 	done
 
-	git ${wt_prefix:+-C "$wt_prefix"} submodule--helper set-url ${quiet:+--quiet} -- "$@"
+	git ${wt_prefix:+-C "$wt_prefix"} submodule--helper set-url \
+		${quiet:+--quiet} \
+		-- \
+		"$@"
 }
 
 #
@@ -480,7 +528,13 @@ cmd_summary() {
 		shift
 	done
 
-	git ${wt_prefix:+-C "$wt_prefix"} submodule--helper summary ${files:+--files} ${cached:+--cached} ${for_status:+--for-status} ${summary_limit:+-n $summary_limit} -- "$@"
+	git ${wt_prefix:+-C "$wt_prefix"} submodule--helper summary \
+		${files:+--files} \
+		${cached:+--cached} \
+		${for_status:+--for-status} \
+		${summary_limit:+-n $summary_limit} \
+		-- \
+		"$@"
 }
 #
 # List all submodules, prefixed with:
@@ -521,8 +575,14 @@ cmd_status()
 		shift
 	done
 
-	git ${wt_prefix:+-C "$wt_prefix"} submodule--helper status ${quiet:+--quiet} ${cached:+--cached} ${recursive:+--recursive} -- "$@"
+	git ${wt_prefix:+-C "$wt_prefix"} submodule--helper status \
+		${quiet:+--quiet} \
+		${cached:+--cached} \
+		${recursive:+--recursive} \
+		-- \
+		"$@"
 }
+
 #
 # Sync remote urls for submodules
 # This makes the value for remote.$remote.url match the value
@@ -554,7 +614,11 @@ cmd_sync()
 		esac
 	done
 
-	git ${wt_prefix:+-C "$wt_prefix"} submodule--helper sync ${quiet:+--quiet} ${recursive:+--recursive} -- "$@"
+	git ${wt_prefix:+-C "$wt_prefix"} submodule--helper sync \
+		${quiet:+--quiet} \
+		${recursive:+--recursive} \
+		-- \
+		"$@"
 }
 
 cmd_absorbgitdirs()

object.c

@@ -614,6 +614,15 @@ void raw_object_store_clear(struct raw_object_store *o)
 
 	INIT_LIST_HEAD(&o->packed_git_mru);
 	close_object_store(o);
+
+	/*
+	 * `close_object_store()` only closes the packfiles, but doesn't free
+	 * them. We thus have to do this manually.
+	 */
+	for (struct packed_git *p = o->packed_git, *next; p; p = next) {
+		next = p->next;
+		free(p);
+	}
 	o->packed_git = NULL;
 
 	hashmap_clear(&o->pack_map);

refs.c

@@ -2009,7 +2009,7 @@ struct ref_store *repo_get_submodule_ref_store(struct repository *repo,
 		free(subrepo);
 		goto done;
 	}
-	refs = ref_store_init(subrepo, repo->ref_storage_format,
+	refs = ref_store_init(subrepo, subrepo->ref_storage_format,
 			      submodule_sb.buf,
 			      REF_STORE_READ | REF_STORE_ODB);
 	register_ref_store_map(&repo->submodule_ref_stores, "submodule",

submodule.c

@@ -1496,7 +1496,7 @@ static const struct submodule *get_non_gitmodules_submodule(const char *path)
 	return (const struct submodule *) ret;
 }
 
-static void fetch_task_release(struct fetch_task *p)
+static void fetch_task_free(struct fetch_task *p)
 {
 	if (p->free_sub)
 		free((void*)p->sub);
@@ -1508,6 +1508,7 @@ static void fetch_task_release(struct fetch_task *p)
 	FREE_AND_NULL(p->repo);
 
 	strvec_clear(&p->git_args);
+	free(p);
 }
 
 static struct repository *get_submodule_repo_for(struct repository *r,
@@ -1576,8 +1577,7 @@ static struct fetch_task *fetch_task_create(struct submodule_parallel_fetch *spf
 	return task;
 
  cleanup:
-	fetch_task_release(task);
+	fetch_task_free(task);
-	free(task);
 	return NULL;
 }
 
@@ -1607,8 +1607,7 @@ get_fetch_task_from_index(struct submodule_parallel_fetch *spf,
 		} else {
 			struct strbuf empty_submodule_path = STRBUF_INIT;
 
-			fetch_task_release(task);
+			fetch_task_free(task);
-			free(task);
 
 			/*
 			 * An empty directory is normal,
@@ -1654,8 +1653,7 @@ get_fetch_task_from_changed(struct submodule_parallel_fetch *spf,
 				    cs_data->path,
 				    repo_find_unique_abbrev(the_repository, cs_data->super_oid, DEFAULT_ABBREV));
 
-			fetch_task_release(task);
+			fetch_task_free(task);
-			free(task);
 			continue;
 		}
 
@@ -1763,7 +1761,7 @@ static int fetch_start_failure(struct strbuf *err UNUSED,
 
 	spf->result = 1;
 
-	fetch_task_release(task);
+	fetch_task_free(task);
 	return 0;
 }
 
@@ -1828,8 +1826,7 @@ static int fetch_finish(int retvalue, struct strbuf *err UNUSED,
 	}
 
 out:
-	fetch_task_release(task);
+	fetch_task_free(task);
-
 	return 0;
 }
 
@@ -1883,6 +1880,7 @@ int fetch_submodules(struct repository *r,
 	strvec_clear(&spf.args);
 out:
 	free_submodules_data(&spf.changed_submodule_names);
+	string_list_clear(&spf.seen_submodule_names, 0);
 	return spf.result;
 }
 

t/t5572-pull-submodule.sh

@@ -5,6 +5,7 @@ test_description='pull can handle submodules'
 GIT_TEST_FATAL_REGISTER_SUBMODULE_ODB=1
 export GIT_TEST_FATAL_REGISTER_SUBMODULE_ODB
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 . "$TEST_DIRECTORY"/lib-submodule-update.sh
 

t/t7418-submodule-sparse-gitmodules.sh

@@ -15,6 +15,7 @@ also by committing .gitmodules and then just removing it from the filesystem.
 GIT_TEST_FATAL_REGISTER_SUBMODULE_ODB=1
 export GIT_TEST_FATAL_REGISTER_SUBMODULE_ODB
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success 'setup' '

t/t7424-submodule-mixed-ref-formats.sh

@@ -0,0 +1,144 @@
+#!/bin/sh
+
+test_description='submodules handle mixed ref storage formats'
+
+TEST_PASSES_SANITIZE_LEAK=true
+. ./test-lib.sh
+
+test_ref_format () {
+	echo "$2" >expect &&
+	git -C "$1" rev-parse --show-ref-format >actual &&
+	test_cmp expect actual
+}
+
+for OTHER_FORMAT in files reftable
+do
+	if test "$OTHER_FORMAT" = "$GIT_DEFAULT_REF_FORMAT"
+	then
+		continue
+	fi
+
+test_expect_success 'setup' '
+	git config set --global protocol.file.allow always &&
+	# Some tests migrate the ref storage format, which does not work with
+	# reflogs at the time of writing these tests.
+	git config set --global core.logAllRefUpdates false
+'
+
+test_expect_success 'add existing repository with different ref storage format' '
+	test_when_finished "rm -rf parent" &&
+
+	git init parent &&
+	(
+		cd parent &&
+		test_commit parent &&
+		git init --ref-format=$OTHER_FORMAT submodule &&
+		test_commit -C submodule submodule &&
+		git submodule add ./submodule
+	)
+'
+
+test_expect_success 'add submodules with different ref storage format' '
+	test_when_finished "rm -rf submodule upstream" &&
+
+	git init submodule &&
+	test_commit -C submodule submodule-initial &&
+	git init upstream &&
+	test_ref_format upstream "$GIT_DEFAULT_REF_FORMAT" &&
+	git -C upstream submodule add --ref-format="$OTHER_FORMAT" "file://$(pwd)/submodule" &&
+	test_ref_format upstream/submodule "$OTHER_FORMAT"
+'
+
+test_expect_success 'recursive clone propagates ref storage format' '
+	test_when_finished "rm -rf submodule upstream downstream" &&
+
+	git init submodule &&
+	test_commit -C submodule submodule-initial &&
+	git init upstream &&
+	git -C upstream submodule add "file://$(pwd)/submodule" &&
+	git -C upstream commit -am "add submodule" &&
+
+	# The upstream repository and its submodule should be using the default
+	# ref format.
+	test_ref_format upstream "$GIT_DEFAULT_REF_FORMAT" &&
+	test_ref_format upstream/submodule "$GIT_DEFAULT_REF_FORMAT" &&
+
+	# The cloned repositories should use the other ref format that we have
+	# specified via `--ref-format`. The option should propagate to cloned
+	# submodules.
+	git clone --ref-format=$OTHER_FORMAT --recurse-submodules \
+		upstream downstream &&
+	test_ref_format downstream "$OTHER_FORMAT" &&
+	test_ref_format downstream/submodule "$OTHER_FORMAT"
+'
+
+test_expect_success 'clone submodules with different ref storage format' '
+	test_when_finished "rm -rf submodule upstream downstream" &&
+
+	git init submodule &&
+	test_commit -C submodule submodule-initial &&
+	git init upstream &&
+	git -C upstream submodule add "file://$(pwd)/submodule" &&
+	git -C upstream commit -m "upstream submodule" &&
+
+	git clone --no-recurse-submodules "file://$(pwd)/upstream" downstream &&
+	test_ref_format downstream "$GIT_DEFAULT_REF_FORMAT" &&
+	git -C downstream submodule update --init --ref-format=$OTHER_FORMAT &&
+	test_ref_format downstream/submodule "$OTHER_FORMAT"
+'
+
+test_expect_success 'status with mixed submodule ref storages' '
+	test_when_finished "rm -rf submodule main" &&
+
+	git init submodule &&
+	test_commit -C submodule submodule-initial &&
+	git init main &&
+	git -C main submodule add "file://$(pwd)/submodule" &&
+	git -C main commit -m "add submodule" &&
+	git -C main/submodule refs migrate --ref-format=$OTHER_FORMAT &&
+
+	# The main repository should use the default ref format now, whereas
+	# the submodule should use the other format.
+	test_ref_format main "$GIT_DEFAULT_REF_FORMAT" &&
+	test_ref_format main/submodule "$OTHER_FORMAT" &&
+
+	cat >expect <<-EOF &&
+	 $(git -C main/submodule rev-parse HEAD) submodule (submodule-initial)
+	EOF
+	git -C main submodule status >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'recursive pull with mixed formats' '
+	test_when_finished "rm -rf submodule upstream downstream" &&
+
+	# Set up the initial structure with an upstream repository that has a
+	# submodule, as well as a downstream clone of the upstream repository.
+	git init submodule &&
+	test_commit -C submodule submodule-initial &&
+	git init upstream &&
+	git -C upstream submodule add "file://$(pwd)/submodule" &&
+	git -C upstream commit -m "upstream submodule" &&
+
+	# Clone the upstream repository such that the main repo and its
+	# submodules have different formats.
+	git clone --no-recurse-submodules "file://$(pwd)/upstream" downstream &&
+	git -C downstream submodule update --init --ref-format=$OTHER_FORMAT &&
+	test_ref_format downstream "$GIT_DEFAULT_REF_FORMAT" &&
+	test_ref_format downstream/submodule "$OTHER_FORMAT" &&
+
+	# Update the upstream submodule as well as the owning repository such
+	# that we can do a recursive pull.
+	test_commit -C submodule submodule-update &&
+	git -C upstream/submodule pull &&
+	git -C upstream commit -am "update the submodule" &&
+
+	git -C downstream pull --recurse-submodules &&
+	git -C upstream/submodule rev-parse HEAD >expect &&
+	git -C downstream/submodule rev-parse HEAD >actual &&
+	test_cmp expect actual
+'
+
+done
+
+test_done