Ticket #7778: fix_delete.diff

django/db/models/query.py

@@ -822 +822 @@
         update_query = sql.UpdateQuery(cls, connection)
         for field, model in cls._meta.get_fields_with_model():
             if (field.rel and field.null and field.rel.to in seen_objs and
-                    filter(lambda f: f.column == field.column,
+                    filter(lambda f: f.column == field.rel.get_related_field().name,
                     field.rel.to._meta.fields)):
                 if model:
                     sql.UpdateQuery(model, connection).clear_related(field,