Merge branch 'nd/files-backend-git-dir'

The "submodule" specific field in the ref_store structure is
replaced with a more generic "gitdir" that can later be used also
when dealing with ref_store that represents the set of refs visible
from the other worktrees.

* nd/files-backend-git-dir: (28 commits)
  refs.h: add a note about sorting order of for_each_ref_*
  t1406: new tests for submodule ref store
  t1405: some basic tests on main ref store
  t/helper: add test-ref-store to test ref-store functions
  refs: delete pack_refs() in favor of refs_pack_refs()
  files-backend: avoid ref api targeting main ref store
  refs: new transaction related ref-store api
  refs: add new ref-store api
  refs: rename get_ref_store() to get_submodule_ref_store() and make it public
  files-backend: replace submodule_allowed check in files_downcast()
  refs: move submodule code out of files-backend.c
  path.c: move some code out of strbuf_git_path_submodule()
  refs.c: make get_main_ref_store() public and use it
  refs.c: kill register_ref_store(), add register_submodule_ref_store()
  refs.c: flatten get_ref_store() a bit
  refs: rename lookup_ref_store() to lookup_submodule_ref_store()
  refs.c: introduce get_main_ref_store()
  files-backend: remove the use of git_path()
  files-backend: add and use files_ref_path()
  files-backend: add and use files_reflog_path()
  ...

1 files changed, 31 insertions, 0 deletions

diff --git a/submodule.c b/submodule.c
index 620504d..5615d73 100644
--- a/submodule.c
+++ b/submodule.c
@@ -1866,3 +1866,34 @@ const char *get_superproject_working_tree(void)
 
 	return ret;
 }
+
+int submodule_to_gitdir(struct strbuf *buf, const char *submodule)
+{
+	const struct submodule *sub;
+	const char *git_dir;
+	int ret = 0;
+
+	strbuf_reset(buf);
+	strbuf_addstr(buf, submodule);
+	strbuf_complete(buf, '/');
+	strbuf_addstr(buf, ".git");
+
+	git_dir = read_gitfile(buf->buf);
+	if (git_dir) {
+		strbuf_reset(buf);
+		strbuf_addstr(buf, git_dir);
+	}
+	if (!is_git_directory(buf->buf)) {
+		gitmodules_config();
+		sub = submodule_from_path(null_sha1, submodule);
+		if (!sub) {
+			ret = -1;
+			goto cleanup;
+		}
+		strbuf_reset(buf);
+		strbuf_git_path(buf, "%s/%s", "modules", sub->name);
+	}
+
+cleanup:
+	return ret;
+}