Affects all very short effects (those that only last a single tick) - this most likely also includes saturation, see MC-19648.

How to reproduce

1. Prevent you from regenerating automatically, for example by using the following command:

   /gamerule naturalRegeneration false
   

2. Use the following command twice

   /summon Arrow ~ ~5 ~ {damage:0.5d,player:1b,Potion:"strong_healing"}
   

You will see that you only take 0.5 damage but don't get any health back

mojang nerfed all the time of all the arrows. Im ok with that... but I find out that the instant health/damage got nerfed as well. and healing 2 hearts turned to be 0 hearts :|

well... sorry if I sound rude but... 0 heart? lol its nothing! Im shooting my self with instant health arrows and get damaged more then healed. :|

mojang... I think you should nerf the instant arrows but not that much!!! :|

I guess its just a bug...

Code analysis by marcono1234 can be found in this comment.