amount_generator: collect all categories when merging cells

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@33968 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5/mixin/amount_generator.py

@@ -217,9 +217,10 @@ class AmountGeneratorMixin:
             for key in amount_generator_cell.getMappedValuePropertyList():
               # XXX-JPS Make sure handling of list properties can be handled
               property_dict[key] = amount_generator_cell.getProperty(key)
-            property_dict['category_list'] = \
-              amount_generator_cell.getCategoryMembershipList(
-                amount_generator_cell.getMappedValueBaseCategoryList(), base=1)
+            category_list = amount_generator_cell.getCategoryMembershipList(
+              amount_generator_cell.getMappedValueBaseCategoryList(), base=1)
+            if category_list:
+              property_dict.setdefault('category_list', []) += category_list
             property_dict['resource'] = resource
             # For final amounts, base_application and id MUST be defined
             property_dict['base_application'] = getBaseApplication() # Required