Add a warning about ambiguous code (loop must only be executed once for code to work).

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@22984 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ZSQLCatalog/SQLCatalog.py

@@ -1833,6 +1833,7 @@ class Catalog(Folder,
           if hasattr(current_query, 'order_by'): query_group_by_list = current_query.order_by
         else:
           if isinstance(value, dict):
+            # XXX: If dictionary has more that one key, subsequent Query() will raise.
             for value_key in value.keys():
               if value_key == 'query':
                 new_query_dict[key] = value['query']