if calculated date is None, do not use it.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@32584 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5/Document/PaymentRule.py

@@ -71,8 +71,12 @@ class PaymentRule(Rule):
       # Since we need to consider business_path only for bank movement,
       # not for payable movement, we pass None as business_path here.
       kw = self._getExpandablePropertyDict(applied_rule, input_movement, None)
-      kw['start_date'] = business_path.getExpectedStartDate(input_movement)
-      kw['stop_date'] = business_path.getExpectedStopDate(input_movement)
+      start_date = business_path.getExpectedStartDate(input_movement)
+      if start_date is not None:
+        kw['start_date'] = start_date
+      stop_date = business_path.getExpectedStopDate(input_movement)
+      if stop_date is not None:
+        kw['stop_date'] = stop_date
       quantity = business_path.getExpectedQuantity(input_movement)
 
       # one for payable