check if variation_base_category_list is None

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@1383 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/Coramy/Document/OrderLine.py

@@ -133,4 +133,6 @@ Une ligne tarifaire."""
         """
         # Temp fix until upgrade of Variated XXX
         # XXX - may be incompatible with future versions of ERP5
+        if self.variation_base_category_list is None:
+          return []
         return list(self.variation_base_category_list)