Call apply tax rule with empty tax

Handle list return for apply

invoice.py

@@ -1585,17 +1585,23 @@ class InvoiceLine(ModelSQL, ModelView):
             except:
                 pass
             res['taxes'] = []
+            pattern = self._get_tax_rule_pattern(cursor, user, party, vals,
+                    context=context)
             for tax in product.supplier_taxes_used:
                 if party and party.supplier_tax_rule:
-                    pattern = self._get_tax_rule_pattern(cursor, user, party,
-                            vals, context=context)
-                    tax_id = tax_rule_obj.apply(cursor, user,
+                    tax_ids = tax_rule_obj.apply(cursor, user,
                             party.supplier_tax_rule, tax, pattern,
                             context=context)
-                    if tax_id:
-                        res['taxes'].append(tax_id)
+                    if tax_ids:
+                        res['taxes'].extend(tax_ids)
                     continue
                 res['taxes'].append(tax.id)
+            if party and party.supplier_tax_rule:
+                tax_ids = tax_rule_obj.apply(cursor, user,
+                        party.supplier_tax_rule, False, pattern,
+                        context=context)
+                if tax_ids:
+                    res['taxes'].extend(tax_ids)
         else:
             if company and currency:
                 res['unit_price'] = currency_obj.compute(cursor, user,
@@ -1609,17 +1615,23 @@ class InvoiceLine(ModelSQL, ModelView):
             except:
                 pass
             res['taxes'] = []
+            pattern = self._get_tax_rule_pattern(cursor, user, party, vals,
+                    context=context)
             for tax in product.customer_taxes_used:
                 if party and party.customer_tax_rule:
-                    pattern = self._get_tax_rule_pattern(cursor, user, party,
-                            vals, context=context)
-                    tax_id = tax_rule_obj.apply(cursor, user,
+                    tax_ids = tax_rule_obj.apply(cursor, user,
                             party.customer_tax_rule, tax, pattern,
                             context=context)
-                    if tax_id:
-                        res['taxes'].append(tax_id)
+                    if tax_ids:
+                        res['taxes'].extend(tax_ids)
                     continue
                 res['taxes'].append(tax.id)
+            if party and party.customer_tax_rule:
+                tax_ids = tax_rule_obj.apply(cursor, user,
+                        party.customer_tax_rule, False, pattern,
+                        context=context)
+                if tax_ids:
+                    res['taxes'].extend(tax_ids)
 
         if not vals.get('description'):
             res['description'] = product_obj.browse(cursor, user, product.id,