check if we have a mapped value or not

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@3080 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5/Document/Resource.py

@@ -516,6 +516,7 @@ class Resource(XMLMatrix, CoreResource, Variated):
       domain_tool = getToolByName(self,'portal_domains')
       portal_type_list = self.getPortalSupplyTypeList()
       mapped_value = domain_tool.generateMappedValue(tmp_context,portal_type=portal_type_list,**kw)
+      if mapped_value is not None:
         base_price = mapped_value.getBasePrice()
 
       unit_base_price = None