Ticket #11923: django-ticket-11923.patch

django/db/models/sql/query.py

@@ -1397 +1397 @@
                     lhs_col = int_opts.parents[int_model].column
                     dedupe = lhs_col in opts.duplicate_targets
                     if dedupe:
-                        avoid.update(self.dupe_avoidance.get(id(opts), lhs_col),
-                                ())
+                        avoid.update(self.dupe_avoidance.get((id(opts), lhs_col),
+                                ()))
                         dupe_set.add((opts, lhs_col))
                     int_opts = int_model._meta
                     alias = self.join((alias, int_opts.db_table, lhs_col,