stephenmcd/cartridge — pull request #149 by molokov (2013-12-08 03:51:03+00:00)
Title: Allow Discount Code to reduce item amount to 0

Basically replacing < with <= so that a discount code that is the same amount as an item can reduce that item's price to 0. Handy if the code is essentially a 'voucher' for a free item of that product.