refs: plumb repo into ref stores

In preparation for the next 2 patches that adds (partial) support for
arbitrary repositories to ref iterators, plumb a repository into all ref
stores. There are no changes to program logic.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/refs/files-backend.c b/refs/files-backend.c
index 1148c0c..6a481e9 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -79,13 +79,15 @@ static void clear_loose_ref_cache(struct files_ref_store *refs)
  * Create a new submodule ref cache and add it to the internal
  * set of caches.
  */
-static struct ref_store *files_ref_store_create(const char *gitdir,
+static struct ref_store *files_ref_store_create(struct repository *repo,
+						const char *gitdir,
 						unsigned int flags)
 {
 	struct files_ref_store *refs = xcalloc(1, sizeof(*refs));
 	struct ref_store *ref_store = (struct ref_store *)refs;
 	struct strbuf sb = STRBUF_INIT;
 
+	ref_store->repo = repo;
 	ref_store->gitdir = xstrdup(gitdir);
 	base_ref_store_init(ref_store, &refs_be_files);
 	refs->store_flags = flags;
@@ -93,7 +95,7 @@ static struct ref_store *files_ref_store_create(const char *gitdir,
 	get_common_dir_noenv(&sb, gitdir);
 	refs->gitcommondir = strbuf_detach(&sb, NULL);
 	strbuf_addf(&sb, "%s/packed-refs", refs->gitcommondir);
-	refs->packed_ref_store = packed_ref_store_create(sb.buf, flags);
+	refs->packed_ref_store = packed_ref_store_create(repo, sb.buf, flags);
 	strbuf_release(&sb);
 
 	chdir_notify_reparent("files-backend $GIT_DIR", &refs->base.gitdir);