[ci skip] update changelog

changelogs/4.0-snapshot.md

@@ -70,6 +70,11 @@ This major version features substantial changes throughout the core, including s
 - New PHP extensions are required by this version:
   - [chunkutils2](https://github.com/pmmp/ext-chunkutils2)
   - [morton](https://github.com/pmmp/ext-morton)
+- Many bugs in player respawning have been fixed, including:
+  - Spawning underneath bedrock when spawn position referred to ungenerated terrain
+  - Spawning underneath bedrock on first server join on very slow machines (or when the machine was under very high load)
+  - Spawning inside blocks (or above the ground) when respawning with a custom spawn position set
+  - Player spawn positions sticking to the old location when world spawn position changed - this was because the world spawn at time of player creation was used as the player's custom spawn, so the bug will persist for older player data, but will work as expected for new players.
 
 ### World handling
 #### Interface
@@ -679,6 +684,7 @@ This version features substantial changes to the network system, improving coher
   - `Player::SPECTATOR` - use `GameMode::SPECTATOR()`
   - `Player::VIEW` - use `GameMode::SPECTATOR()`
 - (almost) all packet handlers have been removed from `Player`. They are now encapsulated within the network layer.
+- `Player->getSpawn()` no longer returns the world's safe spawn if the player's spawn position isn't set. Returning the safe spawn at the time of call made no sense, because it might not have been safe when actually used. You should pass the result of this function to `World->getSafeSpawn()` to get a safe spawn position instead.
 - The following API methods have been added:
   - `Player->attackBlock()`: attack (left click) the target block, e.g. to start destroying it (survival)
   - `Player->attackEntity()`: melee-attack (left click) the target entity (if within range)