Configurable Allowance of Permanent Chunk Loaders

This disables the behavior that allows players to keep chunks permanently loaded
by default and allows server operators to enable it if they wish.

Spigot-Server-Patches/0290-Configurable-Allowance-of-Permanent-Chunk-Loaders.patch

@@ -0,0 +1,39 @@
+From 21f33d68a9d7e7836c15002ba8e08beef5dbad7a Mon Sep 17 00:00:00 2001
+From: Aikar <aikar@aikar.co>
+Date: Sat, 21 Apr 2018 11:21:48 -0400
+Subject: [PATCH] Configurable Allowance of Permanent Chunk Loaders
+
+This disables the behavior that allows players to keep chunks permanently loaded
+by default and allows server operators to enable it if they wish.
+
+diff --git a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
+index c903c89cf..e1ed267a2 100644
+--- a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
++++ b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
+@@ -500,4 +500,10 @@ public class PaperWorldConfig {
+     private void disableSprintInterruptionOnAttack() {
+         disableSprintInterruptionOnAttack = getBoolean("game-mechanics.disable-sprint-interruption-on-attack", false);
+     }
++
++    public boolean allowPermaChunkLoaders = false;
++    private void allowPermaChunkLoaders() {
++        allowPermaChunkLoaders = getBoolean("game-mechanics.allow-permanent-chunk-loaders", allowPermaChunkLoaders);
++        log("Allow Perma Chunk Loaders: " + (allowPermaChunkLoaders ? "enabled" : "disabled"));
++    }
+ }
+diff --git a/src/main/java/net/minecraft/server/ChunkProviderServer.java b/src/main/java/net/minecraft/server/ChunkProviderServer.java
+index 55dada668..0eba3df57 100644
+--- a/src/main/java/net/minecraft/server/ChunkProviderServer.java
++++ b/src/main/java/net/minecraft/server/ChunkProviderServer.java
+@@ -148,7 +148,7 @@ public class ChunkProviderServer implements IChunkProvider {
+     }
+ 
+     public Chunk getChunkAt(int i, int j, Runnable runnable, boolean generate) {
+-        Chunk chunk = getLoadedChunkAt(i, j);
++        Chunk chunk = world.paperConfig.allowPermaChunkLoaders ? getLoadedChunkAt(i, j) : getChunkIfLoaded(i, j); // Paper - Configurable perma chunk loaders
+         ChunkRegionLoader loader = null;
+ 
+         if (this.chunkLoader instanceof ChunkRegionLoader) {
+-- 
+2.17.0
+