getRootCausalityValueList : the causality may be something different from a delivery (e. g. item)

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@6096 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5/Document/Delivery.py

@@ -635,6 +635,9 @@ class Delivery(XMLObject, ImmobilisationDelivery):
         initial_list = [self]
       else:
         for causality in causality_value_list:
+          # The causality may be something which has not this method
+          # (e.g. item)
+          if hasattr(causality, 'getRootCausalityValueList'):
             tmp_causality_list = causality.getRootCausalityValueList()
             initial_list.extend([x for x in tmp_causality_list 
                                  if x not in initial_list])