Ticket #13203: 13203_r12773_2.diff

django/django/contrib/contenttypes/generic.py

@@ -123 +123 @@
         return smart_unicode([instance._get_pk_val() for instance in qs])
 
     def m2m_db_table(self):
-        return self.rel.to._meta.db_table
+        # check current model with all its parents for generic relation fields
+        main_model = self.rel.to
+        object_id_field = main_model._meta.get_field(self.object_id_field_name)
+        content_type_field = main_model._meta.get_field(self.content_type_field_name)
 
+        object_id_model = content_type_model = None
+
+        for field, model in main_model._meta.get_fields_with_model():
+            model = model or main_model
+            if field == object_id_field:
+                object_id_model = model
+            elif field == content_type_field:
+                content_type_model = model
+
+        if object_id_model and object_id_model == content_type_model:
+            return object_id_model._meta.db_table
+        else:
+            raise Exception("Fields '%s' and '%s' are located in different models"
+            % (self.object_id_field_name, self.content_type_field_name))
+
     def m2m_column_name(self):
         return self.object_id_field_name