Potion of Harming Arrows Don't Heal Undead Mobs

Potion of Harming Arrows Don't Heal Undead Mobs

What I expected to happen was if Wither Skeletons, Zombies, Zombie Pigman, and Skeletons were shot by Potion of Harming Arrows, they would be healed.

What actually happened was Wither Skeletons, Zombies, Zombie Pigman, and Skeletons took damage from Potion of Harming Arrows

Steps to Reproduce:
1. Get a bow
2. Get Potion of Harming Arrows
3. Shoot Wither Skeletons, Zombies, Zombie Pigman, or Skeletons