repository: support unabsorbed in repo_submodule_init

In preparation for a subsequent commit that migrates code using
add_submodule_odb() to repo_submodule_init(), teach
repo_submodule_init() to support submodules with unabsorbed gitdirs.
(See the documentation for "git submodule absorbgitdirs" for more
information about absorbed and unabsorbed gitdirs.)

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/grep.c

@@ -433,17 +433,14 @@ static int grep_submodule(struct grep_opt *opt,
 {
 	struct repository *subrepo;
 	struct repository *superproject = opt->repo;
-	const struct submodule *sub;
 	struct grep_opt subopt;
 	int hit = 0;
 
-	sub = submodule_from_path(superproject, null_oid(), path);
-
 	if (!is_submodule_active(superproject, path))
 		return 0;
 
 	subrepo = xmalloc(sizeof(*subrepo));
-	if (repo_submodule_init(subrepo, superproject, sub)) {
+	if (repo_submodule_init(subrepo, superproject, path, null_oid())) {
 		free(subrepo);
 		return 0;
 	}

builtin/ls-files.c

@@ -209,10 +209,8 @@ static void show_submodule(struct repository *superproject,
 			   struct dir_struct *dir, const char *path)
 {
 	struct repository subrepo;
-	const struct submodule *sub = submodule_from_path(superproject,
-							  null_oid(), path);
 
-	if (repo_submodule_init(&subrepo, superproject, sub))
+	if (repo_submodule_init(&subrepo, superproject, path, null_oid()))
 		return;
 
 	if (repo_read_index(&subrepo) < 0)

builtin/submodule--helper.c

@@ -2540,7 +2540,6 @@ static int push_check(int argc, const char **argv, const char *prefix)
 
 static int ensure_core_worktree(int argc, const char **argv, const char *prefix)
 {
-	const struct submodule *sub;
 	const char *path;
 	const char *cw;
 	struct repository subrepo;
@@ -2550,11 +2549,7 @@ static int ensure_core_worktree(int argc, const char **argv, const char *prefix)
 
 	path = argv[1];
 
-	sub = submodule_from_path(the_repository, null_oid(), path);
+	if (repo_submodule_init(&subrepo, the_repository, path, null_oid()))
-	if (!sub)
-		BUG("We could get the submodule handle before?");
-
-	if (repo_submodule_init(&subrepo, the_repository, sub))
 		die(_("could not get a repository handle for submodule '%s'"), path);
 
 	if (!repo_config_get_string_tmp(&subrepo, "core.worktree", &cw)) {

repository.c

@@ -190,19 +190,15 @@ error:
 
 int repo_submodule_init(struct repository *subrepo,
 			struct repository *superproject,
-			const struct submodule *sub)
+			const char *path,
+			const struct object_id *treeish_name)
 {
 	struct strbuf gitdir = STRBUF_INIT;
 	struct strbuf worktree = STRBUF_INIT;
 	int ret = 0;
 
-	if (!sub) {
+	strbuf_repo_worktree_path(&gitdir, superproject, "%s/.git", path);
-		ret = -1;
+	strbuf_repo_worktree_path(&worktree, superproject, "%s", path);
-		goto out;
-	}
-
-	strbuf_repo_worktree_path(&gitdir, superproject, "%s/.git", sub->path);
-	strbuf_repo_worktree_path(&worktree, superproject, "%s", sub->path);
 
 	if (repo_init(subrepo, gitdir.buf, worktree.buf)) {
 		/*
@@ -212,6 +208,13 @@ int repo_submodule_init(struct repository *subrepo,
 		 * in the superproject's 'modules' directory.  In this case the
 		 * submodule would not have a worktree.
 		 */
+		const struct submodule *sub =
+			submodule_from_path(superproject, treeish_name, path);
+		if (!sub) {
+			ret = -1;
+			goto out;
+		}
+
 		strbuf_reset(&gitdir);
 		strbuf_repo_git_path(&gitdir, superproject,
 				     "modules/%s", sub->name);
@@ -225,7 +228,7 @@ int repo_submodule_init(struct repository *subrepo,
 	subrepo->submodule_prefix = xstrfmt("%s%s/",
 					    superproject->submodule_prefix ?
 					    superproject->submodule_prefix :
-					    "", sub->path);
+					    "", path);
 
 out:
 	strbuf_release(&gitdir);

repository.h

@@ -172,15 +172,18 @@ void initialize_the_repository(void);
 int repo_init(struct repository *r, const char *gitdir, const char *worktree);
 
 /*
- * Initialize the repository 'subrepo' as the submodule given by the
+ * Initialize the repository 'subrepo' as the submodule at the given path. If
- * struct submodule 'sub' in parent repository 'superproject'.
+ * the submodule's gitdir cannot be found at <path>/.git, this function calls
- * Return 0 upon success and a non-zero value upon failure, which may happen
+ * submodule_from_path() to try to find it. treeish_name is only used if
- * if the submodule is not found, or 'sub' is NULL.
+ * submodule_from_path() needs to be called; see its documentation for more
+ * information.
+ * Return 0 upon success and a non-zero value upon failure.
  */
-struct submodule;
+struct object_id;
 int repo_submodule_init(struct repository *subrepo,
 			struct repository *superproject,
-			const struct submodule *sub);
+			const char *path,
+			const struct object_id *treeish_name);
 void repo_clear(struct repository *repo);
 
 /*

submodule.c

@@ -520,9 +520,6 @@ static void prepare_submodule_repo_env_in_gitdir(struct strvec *out)
 /*
  * Initialize a repository struct for a submodule based on the provided 'path'.
  *
- * Unlike repo_submodule_init, this tolerates submodules not present
- * in .gitmodules. This function exists only to preserve historical behavior,
- *
  * Returns the repository struct on success,
  * NULL when the submodule is not present.
  */
@@ -1404,11 +1401,11 @@ static void fetch_task_release(struct fetch_task *p)
 }
 
 static struct repository *get_submodule_repo_for(struct repository *r,
-						 const struct submodule *sub)
+						 const char *path)
 {
 	struct repository *ret = xmalloc(sizeof(*ret));
 
-	if (repo_submodule_init(ret, r, sub)) {
+	if (repo_submodule_init(ret, r, path, null_oid())) {
 		free(ret);
 		return NULL;
 	}
@@ -1452,7 +1449,7 @@ static int get_next_submodule(struct child_process *cp,
 			continue;
 		}
 
-		task->repo = get_submodule_repo_for(spf->r, task->sub);
+		task->repo = get_submodule_repo_for(spf->r, task->sub->path);
 		if (task->repo) {
 			struct strbuf submodule_prefix = STRBUF_INIT;
 			child_process_init(cp);

t/helper/test-submodule-nested-repo-config.c

@@ -11,15 +11,13 @@ static void die_usage(const char **argv, const char *msg)
 int cmd__submodule_nested_repo_config(int argc, const char **argv)
 {
 	struct repository subrepo;
-	const struct submodule *sub;
 
 	if (argc < 3)
 		die_usage(argv, "Wrong number of arguments.");
 
 	setup_git_directory();
 
-	sub = submodule_from_path(the_repository, null_oid(), argv[1]);
+	if (repo_submodule_init(&subrepo, the_repository, argv[1], null_oid())) {
-	if (repo_submodule_init(&subrepo, the_repository, sub)) {
 		die_usage(argv, "Submodule not found.");
 	}