Renaming and combining in anvil causes it to dissapear.

I noticed that this has already been uploaded.

I was combining 2 swords with enchantments and was renaming them.

What I expected to happen was...:
I thought I would get a sword with both enchantments and with the new name and spend some xp on it.

What actually happened was...:
I spend the levels and picked it up, but the second after that it vanished.

Steps to Reproduce:
1. Enchant and use 2 diamond swords, so that they have a durability of about 1/2 and barely used.
2. Combine and rename the swords in an anvil.
3. Take out the sword. Notice that it vanishes.