Copying a custom player head with NBT data does not display custom skin.

What I expected to happen was when the NBT data was copied by CTRL middle mouse clicking a custom head, the item placed in my inventory should be the custom player skull.

What actually happened was the item in my inventory was the default Steve head that had NBT data copied, but the custom skin on the head I tried to copy was not there.

Steps to Reproduce:
1. Spawn in a skull with a custom player skin on it
2. Place that skull down
3. Clear inventory
4. CTRL middle mouse click on the head to copy it and its NBT data
5. The copied head is the default steve skin