Vouchers total not correct in Order

[zen]

I just discovered a new bug on our TB platform, I think it is there since looooong time, let me explain it :

- Need to setup 2 vouchers, on my test they donot have any code so it is added automatically to the cart when conditons are there, my vouchers give one free Product when 5 bought, the second give one more when 10 boughts in total.

- create an order on front office with these 2 vouchers, so add 10 products of the selected categorie, the cart is good and you can pay the correct amount.

- go to back office Orders tab and look into the order, there are the 2 coupons in cart Rule details but the payment say that customer didn't payed enough, and the Order detail just show one of the 2 coupons in the reduction line, so only one is taken into account for Total amount of the order.. that's where the bug is.

Please confirm or not that this bug is real and if you have any idea on how to fix it, I'll dig it when I'll got time enough for that.