refs: handle non-normal ref renames

Forbid cross-backend ref renames.  This would be pretty weird, but
since it will break, we should prevent it.

Also make the files backend deal with all non-normal ref renames.

Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 11 insertions, 1 deletions

diff --git a/refs.c b/refs.c
index 9ce92c116a..cef4c1b546 100644
--- a/refs.c
+++ b/refs.c
@@ -1415,5 +1415,15 @@ int delete_refs(struct string_list *refnames)
 
 int rename_ref(const char *oldref, const char *newref, const char *logmsg)
 {
-	return the_refs_backend->rename_ref(oldref, newref, logmsg);
+	if ((ref_type(oldref) == REF_TYPE_NORMAL) !=
+	    (ref_type(newref) == REF_TYPE_NORMAL)) {
+		return error(
+			_("Both ref arguments to rename_ref must be normal, "
+			  "or both must be per-worktree/pseudorefs"));
+	}
+	if (ref_type(oldref) == REF_TYPE_NORMAL)
+		/* The files backend always deals with non-normal refs */
+		return the_refs_backend->rename_ref(oldref, newref, logmsg);
+	else
+		return refs_be_files.rename_ref(oldref, newref, logmsg);
 }