int i, max;
 
                max = get_max_object_index();
-               for (i = 0; i < max; i++)
-                       show_name(get_indexed_object(i), NULL,
+               for (i = 0; i < max; i++) {
+                       struct object *obj = get_indexed_object(i);
+                       if (!obj)
+                               continue;
+                       show_name(obj, NULL,
                                  always, allow_undefined, data.name_only);
+               }
        } else {
                int i;
                for (i = 0; i < revs.nr; i++)