upload-pack: strip refs before calling ref_is_hidden()

Make hideRefs handling in upload-pack consistent with the behavior
described in the documentation by stripping refs before comparing them
with prefixes in hideRefs.

Signed-off-by: Lukas Fleischer <lfleischer@lfos.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/upload-pack.c b/upload-pack.c
index d0bc3ca..4ca960e 100644
--- a/upload-pack.c
+++ b/upload-pack.c
@@ -692,7 +692,7 @@
 {
 	struct object *o = lookup_unknown_object(oid->hash);
 
-	if (ref_is_hidden(refname)) {
+	if (refname && ref_is_hidden(refname)) {
 		o->flags |= HIDDEN_REF;
 		return 1;
 	}
@@ -703,7 +703,7 @@
 static int check_ref(const char *refname, const struct object_id *oid,
 		     int flag, void *cb_data)
 {
-	mark_our_ref(refname, oid);
+	mark_our_ref(strip_namespace(refname), oid);
 	return 0;
 }
 
@@ -726,7 +726,7 @@
 	const char *refname_nons = strip_namespace(refname);
 	struct object_id peeled;
 
-	if (mark_our_ref(refname, oid))
+	if (mark_our_ref(refname_nons, oid))
 		return 0;
 
 	if (capabilities) {