TNT doesn't kill you in Survival mode when dispensed from a dispenser.

Put the summary of the bug you're having here

What I expected to happen was...:
I expected the dispensed TNT to kill me.

What actually happened was...:
The dispensed TNT destroyed blocks around me but did not kill me.

Steps to Reproduce:
1. Put a selected amount of TNT in a dispenser.
2. Trigger the dispenser.
3. Stand where the TNT is dispensed and watch what happens.