Bring back hopper optimization patch

patches/server/0089-Don-t-load-Chunks-from-Hoppers-and-other-things.patch

@@ -0,0 +1,39 @@
+From 97b54501b4a9c1796bd79f714ff88a949c1dc4dd 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
+---
+ src/main/java/net/minecraft/server/DoubleBlockFinder.java | 8 ++++++--
+ 1 file changed, 6 insertions(+), 2 deletions(-)
+
+diff --git a/src/main/java/net/minecraft/server/DoubleBlockFinder.java b/src/main/java/net/minecraft/server/DoubleBlockFinder.java
+index 3cb6e6089..7a16a3e0e 100644
+--- a/src/main/java/net/minecraft/server/DoubleBlockFinder.java
++++ b/src/main/java/net/minecraft/server/DoubleBlockFinder.java
+@@ -21,8 +21,12 @@ public class DoubleBlockFinder {
+                 return new DoubleBlockFinder.Result.Single<>(s0);
+             } else {
+                 BlockPosition blockposition1 = blockposition.shift((EnumDirection) function1.apply(iblockdata));
+-                IBlockData iblockdata1 = generatoraccess.getType(blockposition1);
+-
++                // Paper start - don't load chunks if the other side of the chest is in unloaded chunk
++                IBlockData iblockdata1 = generatoraccess.getTypeIfLoaded(blockposition1);
++                if (iblockdata1 == null) {
++                    return new DoubleBlockFinder.Result.Single<>(s0);
++                }
++                // Paper end
+                 if (iblockdata1.getBlock() == iblockdata.getBlock()) {
+                     DoubleBlockFinder.BlockType doubleblockfinder_blocktype1 = (DoubleBlockFinder.BlockType) function.apply(iblockdata1);
+ 
+-- 
+2.24.0.rc1
+