sunyu::fix bug about combo-product calculate price

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

@@ -72,7 +72,8 @@ public class SetMealCalculation {
             productGroupTotalAmount += productGroupAmount * cartGoods.getQty();
 
             // 固定商品现总价
-            long productComboAmount = cartGoods.getProductComboList().stream().mapToLong(t -> t.getFinalPrice() * t.getQty()).sum();
+            long productComboAmount = cartGoods.getProductComboList().stream().mapToLong(t -> (null != t.getFinalPrice() ?
+                    t.getFinalPrice():0) * (null != t.getQty() ? t.getQty():0)).sum();
             long productComboTotalAmount = productComboAmount * cartGoods.getQty();
 
             long materialPrice = 0l;