Correct a potential concurent access bug with hasattr.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@6903 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5/Tool/IdTool.py

@@ -74,7 +74,8 @@ class IdTool(UniqueObject, Folder):
     """
       Generate a new Id
     """
-    if not hasattr(self,'dict_ids'):
+    
+    if getattr(self, 'dict_ids', None) is None:
       self.dict_ids = PersistentMapping()
 
     new_id = None