From 2d53913c288c1fa5b130d89ebd836ff56060a699 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Wed, 21 Sep 2016 22:54:28 -0400
Subject: [PATCH] Chunk registration fixes

World checks and the Chunk Add logic are inconsistent on how Y > 256, < 0, is treated

Keep them consistent

diff --git a/src/main/java/net/minecraft/server/World.java b/src/main/java/net/minecraft/server/World.java
index 3051a3e4..5cd7b22f 100644
--- a/src/main/java/net/minecraft/server/World.java
+++ b/src/main/java/net/minecraft/server/World.java
@@ -1770,7 +1770,7 @@ public abstract class World implements IBlockAccess {
         }
 
         i = MathHelper.floor(entity.locX / 16.0D);
-        j = MathHelper.floor(entity.locY / 16.0D);
+        j = Math.min(15, Math.max(0, MathHelper.floor(entity.locY / 16.0D))); // Paper - stay consistent with chunk add/remove behavior
         int k = MathHelper.floor(entity.locZ / 16.0D);
 
         if (!entity.aa || entity.ab != i || entity.ac != j || entity.ad != k) {
-- 
2.17.0