Bug premium sale

modules/purchase_trade/tests/test_module.py

@@ -2164,6 +2164,22 @@ class PurchaseTradeTestCase(ModuleTestCase):
 
         self.assertEqual(line.get_premium('premium'), Decimal('10.2500'))
 
+    def test_sale_line_premium_price_falls_back_to_decomposition(self):
+        'sale line premium price works when the function field is not loaded'
+        class LineWithoutPremium:
+            premium_decomposition = [
+                Mock(base_amount=Decimal('7.25')),
+                Mock(base_amount=Decimal('-1.00')),
+            ]
+
+            get_premium = sale_module.SaleLine.get_premium
+
+        line = LineWithoutPremium()
+
+        self.assertEqual(
+            sale_module.SaleLine._get_premium_price(line),
+            Decimal('6.2500'))
+
     def test_purchase_and_sale_line_premium_fields_are_readonly_totals(self):
         'line premium fields are readonly totals from premium decomposition'
         PurchaseLine = Pool().get('purchase.line')