Discount on negative quantity (credit note) should be deducted from subtotal amount

[Thomas]

When giving a discount on a negative quantity of lineitems (to create a credit note), the discount and subtotal are cumulated into a higher amount.

The discount should be deducted from a negative subtotal, not added.

[brieb]

I disagree. Discount function should not be dependent on the subtotals sign nor on individual line items sign.

If you discount is a percentage, then the resulting discount is a negative amount and subtracting a negative from a negative will then give you your desired affect.

If, however, you have a set discount amount, it is subtracting from the total sales order a set amount, regardless of what the subtotal is. If your want to decrease from a negative subtotal, you should put in a negative discount amount.

This way if you were to run a totals report adding up your total discounts, you get get a true monetary amount of how much money you have given out in discounts for let's say, a given time frame. If discount sign was dependent on subtotal sign, it would be much harder to compute. And, if discount sign was dependent on each line item's sign, it would make it near impossible.

[Thomas]

I though again about this after having created the ticket, and I wonder if the best way to achieve this wouldn't be to have a invoice type in the header...

[opthamologists]

I think one of your advertisements caused my internet browser to resize, you might want to put that on your blacklist.