fix: check if # rule matches with coupon code

[nikolas-beckel]

Summary

There are two coupon codes, each with distinct # rules:

1. Karneval2024: Discounts a specific item (20%, Item Code 003).
2. Winter2024: Discounts items from a specific item group (50%, Item Group "Accessoire").

In a sales order, two items are added. The first item belongs to the item group eligible for a discount from Winter2024, while the second item is the specific item eligible for a discount through Karneval2024.

When I apply Karneval2024 in the sales order to discount only the specific item, Winter2024 # rule is also incorrectly applied, as it matches the second item (because it is in the item group).

Changes

Update the check in get_#_rule_for_item and check whether the current # rule matches the specified voucher code.

Backports

version-14
version-15

Issue

closes #40013

Images

Winter2024 Coupon Code and # Rule:

Karneval2024 Coupon Code and # Rule:

Added Karneval2024 Coupon Code to Sales Order, both Items discounted: