From 25496ec74347f65858d1b02bf856dc89c3e44a65 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Wed, 12 Sep 2018 21:12:57 -0400
Subject: [PATCH] Prevent mob spawning from loading/generating chunks

also prevents if out of world border bounds

diff --git a/src/main/java/net/minecraft/server/SpawnerCreature.java b/src/main/java/net/minecraft/server/SpawnerCreature.java
index d125fae03b..297c53d15c 100644
--- a/src/main/java/net/minecraft/server/SpawnerCreature.java
+++ b/src/main/java/net/minecraft/server/SpawnerCreature.java
@@ -129,9 +129,9 @@ public final class SpawnerCreature {
                             int i2 = blockposition1.getX();
                             int j2 = blockposition1.getY();
                             int k2 = blockposition1.getZ();
-                            IBlockData iblockdata = worldserver.getType(blockposition1);
+                            IBlockData iblockdata = worldserver.getTypeIfLoadedAndInBounds(blockposition1);  // Paper - don't load chunks for mob spawn
 
-                            if (!iblockdata.isOccluding()) {
+                            if (iblockdata != null && !iblockdata.isOccluding()) { // Paper - don't load chunks for mob spawn
                                 int l2 = 0;
                                 int i3 = 0;
 
@@ -158,7 +158,7 @@ public final class SpawnerCreature {
                                                 float f1 = (float) l3 + 0.5F;
                                                 EntityHuman entityhuman1 = worldserver.a((double) f, (double) f1, -1.0D);
 
-                                                if (entityhuman1 != null) {
+                                                if (entityhuman1 != null && worldserver.isLoadedAndInBounds(blockposition_mutableblockposition)) { // Paper - don't load chunks for mob spawn
                                                     double d0 = entityhuman1.d((double) f, (double) k3, (double) f1);
 
                                                     if (d0 > 576.0D && blockposition.distanceSquared((double) f, (double) k3, (double) f1) >= 576.0D) {
-- 
2.21.0