From 76dd4b39097e8ea2c9c1de56ae047c199aa66326 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Mon, 10 Sep 2018 23:56:36 -0400
Subject: [PATCH] Prevent Mob AI Rules from Loading Chunks


diff --git a/src/main/java/net/minecraft/server/PathfinderGoalRemoveBlock.java b/src/main/java/net/minecraft/server/PathfinderGoalRemoveBlock.java
index bf8ca9b32a..7ccb3d5c06 100644
--- a/src/main/java/net/minecraft/server/PathfinderGoalRemoveBlock.java
+++ b/src/main/java/net/minecraft/server/PathfinderGoalRemoveBlock.java
@@ -12,11 +12,13 @@ public class PathfinderGoalRemoveBlock extends PathfinderGoalGotoTarget {
     private final Block g;
     private final EntityInsentient entity;
     private int i;
+    private World world; // Paper
 
     public PathfinderGoalRemoveBlock(Block block, EntityCreature entitycreature, double d0, int i) {
         super(entitycreature, d0, 24, i);
         this.g = block;
         this.entity = entitycreature;
+        this.world = entitycreature.world; // Paper
     }
 
     @Override
@@ -114,7 +116,9 @@ public class PathfinderGoalRemoveBlock extends PathfinderGoalGotoTarget {
 
     @Nullable
     private BlockPosition a(BlockPosition blockposition, IBlockAccess iblockaccess) {
-        if (iblockaccess.getType(blockposition).getBlock() == this.g) {
+        Block block = world.getBlockIfLoaded(blockposition); // Paper
+        if (block == null) return null; // Paper
+        if (block == this.g) { // Paper
             return blockposition;
         } else {
             BlockPosition[] ablockposition = new BlockPosition[]{blockposition.down(), blockposition.west(), blockposition.east(), blockposition.north(), blockposition.south(), blockposition.down().down()};
@@ -124,7 +128,7 @@ public class PathfinderGoalRemoveBlock extends PathfinderGoalGotoTarget {
             for (int j = 0; j < i; ++j) {
                 BlockPosition blockposition1 = ablockposition1[j];
 
-                if (iblockaccess.getType(blockposition1).getBlock() == this.g) {
+                if (world.getBlockIfLoaded(blockposition1) == this.g) { // Paper
                     return blockposition1;
                 }
             }
@@ -135,7 +139,7 @@ public class PathfinderGoalRemoveBlock extends PathfinderGoalGotoTarget {
 
     @Override
     protected boolean a(IWorldReader iworldreader, BlockPosition blockposition) {
-        IChunkAccess ichunkaccess = iworldreader.getChunkAt(blockposition.getX() >> 4, blockposition.getZ() >> 4, ChunkStatus.FULL, false);
+        IChunkAccess ichunkaccess = iworldreader.getChunkIfLoadedImmediately(blockposition.getX() >> 4, blockposition.getZ() >> 4); // Paper
 
         return ichunkaccess == null ? false : ichunkaccess.getType(blockposition).getBlock() == this.g && ichunkaccess.getType(blockposition.up()).isAir() && ichunkaccess.getType(blockposition.up(2)).isAir();
     }
diff --git a/src/main/java/net/minecraft/server/RandomPositionGenerator.java b/src/main/java/net/minecraft/server/RandomPositionGenerator.java
index d4cd50918b..d6a3b99339 100644
--- a/src/main/java/net/minecraft/server/RandomPositionGenerator.java
+++ b/src/main/java/net/minecraft/server/RandomPositionGenerator.java
@@ -109,6 +109,7 @@ public class RandomPositionGenerator {
                 }
 
                 blockposition2 = new BlockPosition((double) k1 + entitycreature.locX(), (double) l1 + entitycreature.locY(), (double) i2 + entitycreature.locZ());
+                if (!entitycreature.world.isLoaded(blockposition2)) continue; // Paper
                 if (blockposition2.getY() >= 0 && blockposition2.getY() <= entitycreature.world.getBuildHeight() && (!flag3 || entitycreature.a(blockposition2)) && (!flag2 || navigationabstract.a(blockposition2))) {
                     if (flag1) {
                         blockposition2 = a(blockposition2, random.nextInt(l + 1) + i1, entitycreature.world.getBuildHeight(), (blockposition3) -> {
@@ -116,7 +117,8 @@ public class RandomPositionGenerator {
                         });
                     }
 
-                    if (flag || !entitycreature.world.getFluid(blockposition2).a(TagsFluid.WATER)) {
+                    Fluid fluid = entitycreature.world.getFluidIfLoaded(blockposition2); // Paper
+                    if (flag || (fluid != null && !fluid.a(TagsFluid.WATER))) { // Paper
                         PathType pathtype = PathfinderNormal.b(entitycreature.world, blockposition2.getX(), blockposition2.getY(), blockposition2.getZ());
 
                         if (entitycreature.a(pathtype) == 0.0F) {
-- 
2.26.2