The Bug:

Fall momentum is not saved when a world is closed and reopened, which can be exploited by survival mode players to avoid damage from a fall of any height by quitting immediately before impact. With the newly added pause button, this becomes even easier.

Steps to Reproduce:

1. Find or create a high place whose fall damage would be lethal
2. In survival mode, stand on top of it
3. Jump off the edge and be prepared to quit the world before you die (easier with the pause added in 1.21.60.21 Preview)
4. Save & quit just before hitting the ground
5. Load into the world once again and as you do this, watch your health closely.

Observed Behavior:

The game only takes the distance from your loaded position into account when calculating the damage, allowing you to survive any fall.

Expected Behavior:

You take the damage that corresponds to the total distance you've fallen from.