Using TNT deletes lava

Affected version 0.11.1
Excepted:
While Using a TNT Block with flint steel nearest lava
Happened:
It deletes a lava while the TNT has exploded!
Reproduce:
1. Go to cave to where it's lava.
2. Place a TNT with nearest lava.
3. Use TNT with flint and steel.
4. It deletes lava while tnt has exploding