How to produce this issue: Turn on Auto Pickup, and hit a skull with custom textures, or mob heads (Zombie, Creeper, Skeleton, Dragon, Steve head etc.). Skull will enter inventory as a piece of stone. Player Skulls are not afflicted by this issue.

What Should Happen: Skulls should enter inventory in their original form, and not as stone.

Reproduced on 3.8 and 5.0.3

tested and working corectly on the latest version