don't call catalogObjectList with an empty stock_object_list

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@42335 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5/Document/BalanceTransaction.py

@@ -477,6 +477,7 @@ class BalanceTransaction(AccountingTransaction, Inventory):
     self.portal_catalog.catalogObjectList([self])
     
     # Catalog differences calculated from lines
+    if stock_object_list:
       self.portal_catalog.catalogObjectList(stock_object_list[::],
            method_id_list=('z_catalog_stock_list',),
            disable_cache=1, check_uid=0,