From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Jason Penilla <11360596+jpenilla@users.noreply.github.com>
Date: Thu, 9 Dec 2021 00:08:11 -0800
Subject: [PATCH] Fix ChunkSnapshot#isSectionEmpty(int)


diff --git a/src/main/java/org/bukkit/craftbukkit/CraftChunk.java b/src/main/java/org/bukkit/craftbukkit/CraftChunk.java
index db344e5b9f96f317a232304587e6b1673fc6067d..ca9282a0e608541837573d155bf9b95a105ba87d 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftChunk.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftChunk.java
@@ -53,6 +53,7 @@ public class CraftChunk implements Chunk {
     private final int x;
     private final int z;
     private static final PalettedContainer<net.minecraft.world.level.block.state.BlockState> emptyBlockIDs = new PalettedContainer<>(net.minecraft.world.level.block.Block.BLOCK_STATE_REGISTRY, Blocks.AIR.defaultBlockState(), PalettedContainer.Strategy.SECTION_STATES, null); // Paper - Anti-Xray - Add preset block states
+    private static final PalettedContainer<net.minecraft.world.level.biome.Biome> EMPTY_BIOMES = new PalettedContainer<>(net.minecraft.server.MinecraftServer.getServer().registryAccess().registryOrThrow(Registry.BIOME_REGISTRY), net.minecraft.server.MinecraftServer.getServer().registryAccess().registryOrThrow(Registry.BIOME_REGISTRY).getOrThrow(Biomes.PLAINS), PalettedContainer.Strategy.SECTION_BIOMES, null); // Paper
     private static final byte[] emptyLight = new byte[2048];
 
     public CraftChunk(net.minecraft.world.level.chunk.LevelChunk chunk) {
@@ -284,6 +285,20 @@ public class CraftChunk implements Chunk {
         Codec<PalettedContainer<Biome>> biomeCodec = PalettedContainer.codec(iregistry, iregistry.byNameCodec(), PalettedContainer.Strategy.SECTION_BIOMES, iregistry.getOrThrow(Biomes.PLAINS), null); // Paper - Anti-Xray - Add preset biomes
 
         for (int i = 0; i < cs.length; i++) {
+            // Paper start
+            if (cs[i].hasOnlyAir()) {
+                sectionEmpty[i] = true;
+                sectionBlockIDs[i] = emptyBlockIDs;
+                sectionSkyLights[i] = emptyLight;
+                sectionEmitLights[i] = emptyLight;
+                if (biome != null) {
+                    biome[i] = EMPTY_BIOMES;
+                }
+                continue;
+            } else {
+                sectionEmpty[i] = false;
+            }
+            // Paper end
             CompoundTag data = new CompoundTag();
 
             data.put("block_states", ChunkSerializer.BLOCK_STATE_CODEC.encodeStart(NbtOps.INSTANCE, cs[i].getStates()).get().left().get());