Villagers cannot support the buyB NBT tag and crash

All Gamemodes.

I have a villager with a lot of trades (80 tardes)
This villager trades 2 items (diamond and sword) for 1 enchanted one.
For all his trades. I just discovered that in all 1.7 snapshots the bug is present.
If you click on any (buyB, buy, and sell) items you will crash.

To test the error, crate any villager with buyB tag, and see.

I really hope this bug will fastly be fixed in 13w39b! Bye