For example If I jumped from 10 blocks and (for this lets say every 1 block is 1 heart of damage)

and logged out 5 blocks from the ground once I re logged I would fall 5 blocks and only take 5 blocks of damage, Instead of the full 10. I think you get it. I attached a clip, My friend and I discovered this bug together. (follow up If you want the video the size was to big)

thankyou! -uni