Make sure that _v_activity_buffer is present in deferredDeleteMessage.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@3282 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/CMFActivity/ActivityTool.py

@@ -306,6 +306,7 @@ class ActivityTool (Folder, UniqueObject):
       self._v_activity_buffer.deferredQueueMessage(self, activity, message)
 
     def deferredDeleteMessage(self, activity, message):
+      if not hasattr(self, '_v_activity_buffer'): self._v_activity_buffer = ActivityBuffer()
       self._v_activity_buffer.deferredDeleteMessage(self, activity, message)
 
     def getRegisteredMessageList(self, activity):