Sulfur cubes with blocks are immune to redstone-activated TNT

The bug

Sulfur cubes that have blocks take no damage from TNT that was activated with redstone or a dispenser. According to MC-307441, this is incorrect.

How to reproduce

1. Spawn a sulfur cube

2. Feed it a block

3. Place TNT

4. Place a redstone block

Expected behavior

The sulfur cube should die

Observed behavior

It goes flying