Handling of upgrade promo for addon with existing promo

[dansgalaxy]

I noticed an issue with a client who used an upgrade coupon to add an IP

 

The situation was a hosting product which had an existing 25% discount applied (with coupon associated).

 

The user applies a coupon for 50% off the IP configoption.

 

It was expected that the 50% would be applied to the IP price and then add this to the normal hosting fee.

 

So £5 - 25% = £3.75

 

and then £2 - 50% = £1

 

Total: £4.75.

 

Instead however it appears to have applied a 25% discount to the IP, and then the 50% discount, and THEN changed the coupon on the product to the 50% one.

 

So the total came out at £4.50 (£5 - 25%) + ((£2 - 25%)-50%)

 

This also caused the product pricing on the next invoice to be shown as the product price as £9 and the discount being 50% off (to £4.50).