Doors aren't the same if you break them.

What I expected to happen was that a birch door would still be a birch door if you broke it
Door type should stay the same after breaking them.

What actually happened was I broke a birch door and got a plain wooden door back.
Describe what happened here

Steps to Reproduce:
1. I made birch doors
2. I placed them on the ground
3. I broke them and got back normal wooden doors back