Developer forum

Hello.

While trying to reproduce an error, I came across this behaviour:

- I add a product to the cart, PROD1

- I add another product to the cart, PROD2, and increase the quantity to trigger a (custom) discount that offers PROD1 with quantity 1

This all works fine, except that if I then change the quantity for the PROD2 line, while maintaining it in a value that triggers the discount, it increments the amount in the non discount line. So the lines will go from, for example, PROD1:1, PROD2:9, PROD1 (discount):1 to PROD1:2, PROD2:10, PROD1 (discount):1, if I increment from 9 to 10. And it will keep incrementing if I change the amount for PROD2 again.

The discount will always add only one line, the discount one. Here is the code that creates the discount line:

private OrderLine CreateProductOrderLine(Order order, Products.Product product, double quantity = 1.0) {
    OrderLine line = new OrderLine();
 
    line.OrderID = order.ID;
    line.Order = order;
    line.Modified = DateTime.Now;
    line.Quantity = quantity;
    line.ProductID = product.ID;
    line.ProductVariantID = product.VariantID;
    line.ProductName = product.Name;
    line.ProductNumber = product.Number;
    line.Reference = String.Format("Default.aspx?ID={0}&ProductID={1}&VariantID={2}", PageId, product.ID, product.VariantID);
    line.Type = Base.ChkString(Base.ChkNumber(OrderLine.OrderLineType.ProductDiscount));
    line.PageID = PageId;
    line.Product = product;
    line.DiscountID = DiscountID;
 
    return line;
}

This is in version 8.5.1.25. Can you spot anything missing in the created line that coud trigger the behaviour? I have tried setting the tryMerge parameter to false when adding the line to the order, but the behaviour stays the same.

Thanks.