update

pkg/checkout/checkout-grain.go

@@ -100,7 +100,7 @@ type CheckoutGrain struct {
 }
 
 func NewCheckoutGrain(id uint64, cartId cart.CartId, cartVersion uint64, ts time.Time, cartState *cart.CartGrain) *CheckoutGrain {
-	return &CheckoutGrain{
+	r := &CheckoutGrain{
 		lastDeliveryId: 0,
 		lastGiftcardId: 0,
 		lastAccess:     ts,
@@ -110,9 +110,12 @@ func NewCheckoutGrain(id uint64, cartId cart.CartId, cartVersion uint64, ts time
 		CartVersion:    cartVersion,
 		Deliveries:     []*CheckoutDelivery{},
 		Payments:       []*Payment{},
-		CartState:      cartState,
-		CartTotalPrice: cartState.TotalPrice,
 	}
+	if cartState != nil {
+		r.CartState = cartState
+		r.CartTotalPrice = cartState.TotalPrice
+	}
+	return r
 }
 
 func (c *CheckoutGrain) GetId() uint64 {