PaperMC/patches/server/0300-Don-t-load-Chunks-from-Hoppers-and-other-things.patch

From 0000000000000000000000000000000000000000 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/world/level/block/DoubleBlockCombiner.java b/src/main/java/net/minecraft/world/level/block/DoubleBlockCombiner.java
index cccdaa29ea97ec1d9e79f5a4811884d54e641677..b5025914678484cc615dc1982762d5d7f55a4557 100644
--- a/src/main/java/net/minecraft/world/level/block/DoubleBlockCombiner.java
+++ b/src/main/java/net/minecraft/world/level/block/DoubleBlockCombiner.java
@@ -34,7 +34,12 @@ public class DoubleBlockCombiner {
                 return new DoubleBlockCombiner.NeighborCombineResult.Single<>(blockEntity);
             } else {
                 BlockPos blockPos = pos.relative(directionMapper.apply(state));
-                BlockState blockState = world.getBlockState(blockPos);
+                // Paper start - Don't load Chunks from Hoppers and other things
+                BlockState blockState = world.getBlockStateIfLoaded(blockPos);
+                if (blockState == null) {
+                    return new DoubleBlockCombiner.NeighborCombineResult.Single<>(blockEntity);
+                }
+                // Paper end - Don't load Chunks from Hoppers and other things
                 if (blockState.is(state.getBlock())) {
                     DoubleBlockCombiner.BlockType blockType2 = typeMapper.apply(blockState);
                     if (blockType2 != DoubleBlockCombiner.BlockType.SINGLE