From 0b59bda9e5d84d262d223225d2f651a71c5509b5 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Thu, 3 Nov 2016 20:28:12 -0400
Subject: [PATCH] Don't load Chunks from Hoppers and other things

Hoppers call this to I guess "get the primary side" of a double sided chest.

If the double sided chest crosses chunk lines, it causes the chunk to load.
This will end up causing sync chunk loads, which will unload with Chunk GC,
only to be reloaded again the next tick.

This of course is undesirable, so just return the loaded side as "primary"
and treat it as a single chest if the other sides are unloaded

diff --git a/src/main/java/net/minecraft/server/BlockChest.java b/src/main/java/net/minecraft/server/BlockChest.java
index 9c4d1c938..dd1c1a39b 100644
--- a/src/main/java/net/minecraft/server/BlockChest.java
+++ b/src/main/java/net/minecraft/server/BlockChest.java
@@ -339,7 +339,13 @@ public class BlockChest extends BlockTileEntity {
                 while (iterator.hasNext()) {
                     EnumDirection enumdirection = (EnumDirection) iterator.next();
                     BlockPosition blockposition1 = blockposition.shift(enumdirection);
-                    Block block = world.getType(blockposition1).getBlock();
+                    // Paper start - don't load chunks if the other side of the chest is in unloaded chunk
+                    final IBlockData type = world.getTypeIfLoaded(blockposition1); // Paper
+                    if (type ==  null) {
+                        continue;
+                    }
+                    Block block = type.getBlock();
+                    // Paper end
 
                     if (block == this) {
                         if (this.e(world, blockposition1)) {
-- 
2.12.2