Incorrect discount when combining item promotion that has total redemption limit

Description

Steps to reproduce:

1. Create a promotion: buy 2 men's shoes and get the cheapest for free (or any item promotion that has total redemption limit) and set total redemption limit = 1. This promotion has the highest priority.
2. Create another promotion "Buy Products for Discount from Other Selection": Get 20% off men shoes.
3. Add 4 pair of men's shoes to the cart.

Expected: One item of men's shoes is free, and the others get 20% off.

Actual: Only one item of men's shoes is free.