From 6d8ae6ccc27d04cfc36e663794f51d8b56830b6d 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 9d4c15f..9470dd6 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)) {
-- 
2.10.2