From 5bd8ffda82f98b275325f1ad5953da7d78ad2d28 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Thu, 31 Mar 2016 19:17:58 -0400
Subject: [PATCH] Do not load chunks for light checks

Should only happen for blocks on the edge that uses neighbors light level
(certain blocks). In that case, there will be 3-4 other neighbors to get a light level from.

diff --git a/src/main/java/net/minecraft/server/World.java b/src/main/java/net/minecraft/server/World.java
index c8a859d7ba..6f9c35cd18 100644
--- a/src/main/java/net/minecraft/server/World.java
+++ b/src/main/java/net/minecraft/server/World.java
@@ -592,6 +592,7 @@ public abstract class World implements IIBlockAccess, GeneratorAccess, AutoClose
                 if (blockposition.getY() >= 256) {
                     blockposition = new BlockPosition(blockposition.getX(), 255, blockposition.getZ());
                 }
+                if (!this.isLoaded(blockposition)) return 0; // Paper
 
                 return this.getChunkAtWorldCoords(blockposition).a(blockposition, i);
             }
-- 
2.21.0