tag: add repository argument to deref_tag

Add a repository argument to allow the callers of deref_tag
to be more specific about which repository to act on. This is a small
mechanical change; it doesn't change the implementation to handle
repositories other than the_repository yet.

As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/remote.c b/remote.c
index 8c75c45..26b1fbd 100644
--- a/remote.c
+++ b/remote.c
@@ -1802,12 +1802,14 @@ int ref_newer(const struct object_id *new_oid, const struct object_id *old_oid)
 	 * Both new_commit and old_commit must be commit-ish and new_commit is descendant of
 	 * old_commit.  Otherwise we require --force.
 	 */
-	o = deref_tag(parse_object(the_repository, old_oid), NULL, 0);
+	o = deref_tag(the_repository, parse_object(the_repository, old_oid),
+		      NULL, 0);
 	if (!o || o->type != OBJ_COMMIT)
 		return 0;
 	old_commit = (struct commit *) o;
 
-	o = deref_tag(parse_object(the_repository, new_oid), NULL, 0);
+	o = deref_tag(the_repository, parse_object(the_repository, new_oid),
+		      NULL, 0);
 	if (!o || o->type != OBJ_COMMIT)
 		return 0;
 	new_commit = (struct commit *) o;