skip budget variations returning [[]] as a cell range

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@25362 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5/Document/BudgetModel.py

@@ -69,7 +69,9 @@ class BudgetModel(Predicate):
         continue
       variation_cell_range = budget_variation.getCellRangeForBudgetLine(
                                budget_line, matrixbox=matrixbox)
-      if variation_cell_range and variation_cell_range not in cell_range:
+      if variation_cell_range \
+          and variation_cell_range != [[]] \
+          and variation_cell_range not in cell_range:
         cell_range.extend(variation_cell_range)
     return cell_range