Burning mobs do not catch player on fire

For several updates now, burning mobs have been unable to catch the player on fire by attacking them. 

Observed Results: 

Mob simply melees the player, doesn't catch them on fire.

Expected results:

Mob should catch the player on fire.

Steps to Reproduce:

1. Start a creative world.
2. Spawn a zombie in daylight.
3. Switch to survival mode.
4. Let the zombie attack you. Notice you don't catch on fire.