Trading with villagers sometimes causes crashes.

What I expected to happen was...:
The trade would be complete, I could retrieve my items, and then wait for the villager to offer me a new trade.

What actually happened was...:
After the trade, everything was still for a moment and the game crashed.

Steps to Reproduce:
1. Find a villager and unlock all of his trades by trading with him. (I was trading with a farmer, having 19 wheat for 1 emerald as the first trade)
2. Trade with the villager so he locks his first trade.
3. Unlock the first trade again by using the last trade.
4. Repeatedly and quickly use the first trade again so when you normally exit the trading screen he will cancel that trade. (It will exit automatically)
5. You should automatically exit the screen, have everything freeze for a second, and then crash the game.