TNT does not work properly when inside an anvil.

TNT does not work properly when an anvil falls into it

What I expected to happen was...:
The TNT would work as intended and blow up as well as damage the player

What actually happened was...:
The TNT gets primed, the anvil will fall down, the tnt will shoot above the anvil, not destroy blocks, and do minimal damage

Steps to Reproduce:
1. Place an anvil on top of a TNT
2. Light the TNT