The bug
When trading with villagers and using Shift
to trade as many items as possible, the trade only succeeds once, even if you never used that trade before.
Note: This doesn't seem to happen with the first trade the villager offers.
To reproduce
Spawn or find a villager
Interact with that villager
Select a trade of that villager that you haven't used yet after the villager refreshed its trades the last time
Press
Shift
while clicking onto the output item❌ The trade will only succeed once
❌ The villager instantly locks up
Confirmed for 19w14a