PaperMC/todo.txt

Add Timings to LevelTicks and EntityTickList
Check if PlayerNaturallySpawnedEvent is called correctly
Improve Server Thread Pool and Thread Priorities: mojang added a max thread count property
Use Vanilla Minecart Speeds: is this needed?
0467-Optimize-WorldBorder-collision-checks-and-air check first hunk that has been removed

Not sure where this needs to go, if anywhere
diff --git a/src/main/java/net/minecraft/world/phys/shapes/Shapes.java b/src/main/java/net/minecraft/world/phys/shapes/Shapes.java
index 48812329969b7192acd948db974bb77bb546f979..5b1e0ea40dea6c7d787699ed25160c8b75ab3bf3 100644
--- a/src/main/java/net/minecraft/world/phys/shapes/Shapes.java
+++ b/src/main/java/net/minecraft/world/phys/shapes/Shapes.java
@@ -237,7 +237,8 @@ public final class Shapes {

                             if (s < 3) {
                                 mutableBlockPos.set(axisCycle, q, r, p);
-                                BlockState blockState = world.getBlockState(mutableBlockPos);
+                                BlockState blockState = world.getTypeIfLoaded(mutableBlockPos); // Paper
+                                if (blockState == null) return 0.0D; // Paper
                                 if ((s != 1 || blockState.hasLargeCollisionShape()) && (s != 2 || blockState.is(Blocks.MOVING_PISTON))) {
                                     initial = blockState.getCollisionShape(world, mutableBlockPos, context).collide(axis3, box.move((double)(-mutableBlockPos.getX()), (double)(-mutableBlockPos.getY()), (double)(-mutableBlockPos.getZ())), initial);
                                     if (Math.abs(initial) < 1.0E-7D) {



check ChunkHolder#updateFutures async catcher


leaf: check mid tick chunk task diff in ServerChunkCache
optimize nearby player lookups - look at patch and updateranges diff in chunkmap (why is it in this patch)
GENERAL_AREA_MAP_ACCEPTABLE_SEARCH_RANGE_SQUARED is unused?