we do not want the same tag multiple times in the xml generated

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@42994 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5Type/XMLExportImport.py

@@ -87,7 +87,7 @@ def Base_asXML(object, root=None):
                       portal_type=self.getPortalType()))
 
   # We have to find every property
-  for prop_id in self.propertyIds():
+  for prop_id in set(self.propertyIds()):
     # In most case, we should not synchronize acquired properties
     if prop_id not in ('uid', 'workflow_history', 'id', 'portal_type',):
       value = self.getProperty(prop_id)