fix bug

shopping-cart-application-service/src/main/java/cn/freemud/service/impl/mcoffee/calculation/CalculationServiceImpl.java

@@ -181,8 +181,12 @@ public class CalculationServiceImpl {
         shoppingCartGoodsDto.setTotalDiscountAmount(shoppingCartGoodsResponseVo.getTotalDiscountAmount());
         //随单购 月卡价格
         shoppingCartGoodsDto.setPayCardFee(shoppingCartGoodsResponseVo.getPayCardFee());
-        long buyThreeGiveOneCouponFee = calculationDiscountResult == null ? 0l : calculationDiscountResult.getDiscounts().stream().filter(t -> t.getExtendType() == 7).mapToLong(apportionGoods -> apportionGoods.getCardAmount()).sum();
-        shoppingCartGoodsDto.setBuyThreeGiveOneCouponFee(buyThreeGiveOneCouponFee);
+        if (calculationDiscountResult != null ) {
+            if (CollectionUtils.isNotEmpty(calculationDiscountResult.getDiscounts())) {
+                long buyThreeGiveOneCouponFee = calculationDiscountResult.getDiscounts().stream().filter(t -> t.getExtendType() == 7).mapToLong(apportionGoods -> apportionGoods.getCardAmount()).sum();
+                shoppingCartGoodsDto.setBuyThreeGiveOneCouponFee(buyThreeGiveOneCouponFee);
+            }
+        }
         shoppingCartGoodsDto.setDeliveryAmount(shoppingCartGoodsResponseVo.getDeliveryAmount());
         shoppingCartGoodsDto.setDiscountDeliveryAmount(shoppingCartGoodsResponseVo.getDiscountDeliveryAmount());
         shoppingCartGoodsDto.setThresholdAmount(shoppingCartGoodsResponseVo.getThresholdAmount());