rightclick on skeleton with helmet crashes game

What I expected to happen was...:
The skeleton being hit by the diamond helmet, or wearing the helmet, after I hit it with it

What actually happened was...:
The game crashed and stopped working.

Steps to Reproduce:
1 Open existing world in creative mode (previous version of snapshots)
2. Hold diamond helmet in right hand still in creative mode
3. Rightclick on skeleton with diamond helmet