Index: thunar/thunar-list-model.c
===================================================================
--- thunar/thunar-list-model.c	(revision 22285)
+++ thunar/thunar-list-model.c	(working copy)
@@ -943,7 +943,7 @@
     *sort_column_id = THUNAR_COLUMN_GROUP;
   else
     g_assert_not_reached ();
-
+  if (!order) return TRUE;
   if (store->sort_sign > 0)
     *order = GTK_SORT_ASCENDING;
   else