Ticket #15146: patch.diff

django/db/models/fields/related.py

@@ -419 +419 @@
 
         class RelatedManager(superclass):
             def get_query_set(self):
-                db = self._db or router.db_for_read(rel_model, instance=instance)
-                return superclass.get_query_set(self).using(db).filter(**(self.core_filters))
+                if instance.pk is None:
+                    query = superclass.get_empty_query_set(self)
+                else:
+                    db = self._db or router.db_for_read(rel_model, instance=instance)
+                    query = superclass.get_query_set(self).using(db).filter(**(self.core_filters))
+                return query
 
             def add(self, *objs):
                 for obj in objs: