Paper/patches/server/0254-Prevent-various-interactions-from-causing-chunk-load.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Mon, 10 Sep 2018 23:56:36 -0400
Subject: [PATCH] Prevent various interactions from causing chunk loads

Co-authored-by: Shane Freeder <theboyetronic@gmail.com>

diff --git a/src/main/java/net/minecraft/world/entity/ai/goal/RemoveBlockGoal.java b/src/main/java/net/minecraft/world/entity/ai/goal/RemoveBlockGoal.java
index e3d070d46729c023d594699619a4b3f8658edbce..5580a396a56c6e0f364a5368985ee99b9e2be0a8 100644
--- a/src/main/java/net/minecraft/world/entity/ai/goal/RemoveBlockGoal.java
+++ b/src/main/java/net/minecraft/world/entity/ai/goal/RemoveBlockGoal.java
@@ -126,7 +126,9 @@ public class RemoveBlockGoal extends MoveToBlockGoal {
 
     @Nullable
     private BlockPos getPosWithBlock(BlockPos pos, BlockGetter world) {
-        if (world.getBlockState(pos).is(this.blockToRemove)) {
+        net.minecraft.world.level.block.state.BlockState block = world.getBlockStateIfLoaded(pos); // Paper - Prevent AI rules from loading chunks
+        if (block == null) return null; // Paper - Prevent AI rules from loading chunks
+        if (block.is(this.blockToRemove)) { // Paper - Prevent AI rules from loading chunks
             return pos;
         } else {
             BlockPos[] ablockposition = new BlockPos[]{pos.below(), pos.west(), pos.east(), pos.north(), pos.south(), pos.below().below()};
@@ -136,7 +138,8 @@ public class RemoveBlockGoal extends MoveToBlockGoal {
             for (int j = 0; j < i; ++j) {
                 BlockPos blockposition1 = ablockposition1[j];
 
-                if (world.getBlockState(blockposition1).is(this.blockToRemove)) {
+                net.minecraft.world.level.block.state.BlockState block2 = world.getBlockStateIfLoaded(blockposition1); // Paper - Prevent AI rules from loading chunks
+                if (block2 != null && block2.is(this.blockToRemove)) { // Paper - Prevent AI rules from loading chunks
                     return blockposition1;
                 }
             }
@@ -147,7 +150,7 @@ public class RemoveBlockGoal extends MoveToBlockGoal {
 
     @Override
     protected boolean isValidTarget(LevelReader world, BlockPos pos) {
-        ChunkAccess ichunkaccess = world.getChunk(SectionPos.blockToSectionCoord(pos.getX()), SectionPos.blockToSectionCoord(pos.getZ()), ChunkStatus.FULL, false);
+        ChunkAccess ichunkaccess = world.getChunkIfLoadedImmediately(pos.getX() >> 4, pos.getZ() >> 4); // Paper - Prevent AI rules from loading chunks
 
         return ichunkaccess == null ? false : ichunkaccess.getBlockState(pos).is(this.blockToRemove) && ichunkaccess.getBlockState(pos.above()).isAir() && ichunkaccess.getBlockState(pos.above(2)).isAir();
     }
diff --git a/src/main/java/net/minecraft/world/entity/monster/EnderMan.java b/src/main/java/net/minecraft/world/entity/monster/EnderMan.java
index 5c620989acaff4fdb842944ea2d8ae331699a2b4..a859f02074c698c68713568ed99089e33f38ccca 100644
--- a/src/main/java/net/minecraft/world/entity/monster/EnderMan.java
+++ b/src/main/java/net/minecraft/world/entity/monster/EnderMan.java
@@ -517,7 +517,8 @@ public class EnderMan extends Monster implements NeutralMob {
             int j = Mth.floor(this.enderman.getY() + randomsource.nextDouble() * 2.0D);
             int k = Mth.floor(this.enderman.getZ() - 1.0D + randomsource.nextDouble() * 2.0D);
             BlockPos blockposition = new BlockPos(i, j, k);
-            BlockState iblockdata = world.getBlockState(blockposition);
+            BlockState iblockdata = world.getBlockStateIfLoaded(blockposition); // Paper - Prevent endermen from loading chunks
+            if (iblockdata == null) return; // Paper - Prevent endermen from loading chunks
             BlockPos blockposition1 = blockposition.below();
             BlockState iblockdata1 = world.getBlockState(blockposition1);
             BlockState iblockdata2 = this.enderman.getCarriedBlock();
@@ -561,7 +562,8 @@ public class EnderMan extends Monster implements NeutralMob {
             int j = Mth.floor(this.enderman.getY() + randomsource.nextDouble() * 3.0D);
             int k = Mth.floor(this.enderman.getZ() - 2.0D + randomsource.nextDouble() * 4.0D);
             BlockPos blockposition = new BlockPos(i, j, k);
-            BlockState iblockdata = world.getBlockState(blockposition);
+            BlockState iblockdata = world.getBlockStateIfLoaded(blockposition); // Paper - Prevent endermen from loading chunks
+            if (iblockdata == null) return; // Paper - Prevent endermen from loading chunks
             Vec3 vec3d = new Vec3((double) this.enderman.getBlockX() + 0.5D, (double) j + 0.5D, (double) this.enderman.getBlockZ() + 0.5D);
             Vec3 vec3d1 = new Vec3((double) i + 0.5D, (double) j + 0.5D, (double) k + 0.5D);
             BlockHitResult movingobjectpositionblock = world.clip(new ClipContext(vec3d, vec3d1, ClipContext.Block.OUTLINE, ClipContext.Fluid.NONE, this.enderman));
diff --git a/src/main/java/net/minecraft/world/item/CompassItem.java b/src/main/java/net/minecraft/world/item/CompassItem.java
index 5d3047a420efe59063e90bfc7b42392127e0ad7d..b3c67c954acf7e518d89d6af65a55d6f22dac059 100644
--- a/src/main/java/net/minecraft/world/item/CompassItem.java
+++ b/src/main/java/net/minecraft/world/item/CompassItem.java
@@ -77,7 +77,7 @@ public class CompassItem extends Item implements Vanishable {
                 Optional<ResourceKey<Level>> optional = getLodestoneDimension(compoundTag);
                 if (optional.isPresent() && optional.get() == world.dimension() && compoundTag.contains("LodestonePos")) {
                     BlockPos blockPos = NbtUtils.readBlockPos(compoundTag.getCompound("LodestonePos"));
-                    if (!world.isInWorldBounds(blockPos) || !((ServerLevel)world).getPoiManager().existsAtPosition(PoiTypes.LODESTONE, blockPos)) {
+                    if (!world.isInWorldBounds(blockPos) || (world.hasChunkAt(blockPos) && !((ServerLevel)world).getPoiManager().existsAtPosition(PoiTypes.LODESTONE, blockPos))) { // Paper - Prevent compass from loading chunks
                         compoundTag.remove("LodestonePos");
                     }
                 }
diff --git a/src/main/java/net/minecraft/world/level/BlockGetter.java b/src/main/java/net/minecraft/world/level/BlockGetter.java
index 3b31a1927aaed7fffc1b4f4bcefc12120d66af3d..618d6a94d695a3bf114307f85f0f151ee24f1879 100644
--- a/src/main/java/net/minecraft/world/level/BlockGetter.java
+++ b/src/main/java/net/minecraft/world/level/BlockGetter.java
@@ -83,7 +83,15 @@ public interface BlockGetter extends LevelHeightAccessor {
 
     // CraftBukkit start - moved block handling into separate method for use by Block#rayTrace
     default BlockHitResult clip(ClipContext raytrace1, BlockPos blockposition) {
-            BlockState iblockdata = this.getBlockState(blockposition);
+            // Paper start - Prevent raytrace from loading chunks
+            BlockState iblockdata = this.getBlockStateIfLoaded(blockposition);
+            if (iblockdata == null) {
+                // copied the last function parameter (listed below)
+                Vec3 vec3d = raytrace1.getFrom().subtract(raytrace1.getTo());
+
+                return BlockHitResult.miss(raytrace1.getTo(), Direction.getNearest(vec3d.x, vec3d.y, vec3d.z), BlockPos.containing(raytrace1.getTo()));
+            }
+            // Paper end - Prevent raytrace from loading chunks
             FluidState fluid = this.getFluidState(blockposition);
             Vec3 vec3d = raytrace1.getFrom();
             Vec3 vec3d1 = raytrace1.getTo();