Player-caused damage while trading allows villager trades to be completed without payment

Short description of the issue

If a player damages a villager while that player has the trading screen open, the villager’s price can increase without clearing the existing trade result. The player can then take the result without consuming the payment or increasing the trade’s use count.

Steps to reproduce the issue

1. Find a villager with a trade affected by negative reputation, such as an enchanted-book trade.

2. Carry exactly enough emeralds for the currently displayed price.

3. Throw an egg upward or along a delayed path toward the villager.

4. Before the egg hits, open the trading screen.

5. Select the affected trade and place the required emeralds so that the result appears.

6. Allow the egg thrown by the trading player to hit the villager.

7. Take or shift-click the trade result.

Expected result

When the price changes, the trade inputs and result should be recalculated. If the existing payment is insufficient, the result should be cleared or taking it should be rejected.

Actual result

The result is added to the player’s inventory, but the emeralds remain in the payment slot and the trade’s use count does not increase. Repeating this after further price increases allows multiple items to be obtained without payment.