adapt conflict resolution code for zope 2.8

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@17598 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5Form/SelectionTool.py

@@ -1422,11 +1422,11 @@ class SelectionPersistentMapping(PersistentMapping):
     # update keys that only savedState has
     oldState = newState
     # dict returned by PersistentMapping.__getstate__ contains the data
-    # under _container key, so only compare this key (this is coupled with
-    # PersistentMapping implementation, but this implementation is lot likely
-    # to change, because it would break existing pickles).
-    oldState['_container'].update(savedState['_container'])
-
+    # under '_container' key in zope 2.7 and 'data' in zope 2.8
+    if 'data' in state:
+      oldState['data'].update(savedState['data'])
+    else:
+      oldState['_container'].update(savedState['_container'])
     return oldState