Reference on Trade Model Line is always necessary. It must not be empty.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@30881 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5/Document/TradeCondition.py

@@ -237,6 +237,8 @@ class TradeCondition(Path, Transformation, XMLMatrix):
       aggregated_amount_list = AggregatedAmountList()
       for movement in movement_list:
         movement_reference = movement.getReference()
+        if movement_reference is None:
+            raise ValueError, 'Reference on Trade Model Line is None. Reference must be set.'
         for model_line in trade_model_line_composed_list:
           if model_line.getReference() == movement_reference and\
               model_line.isCreateLine():