Paper/patches/server/0827-Fix-WorldGenRegion-leak-when-converting-pre-1.18-chu.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Jason Penilla <11360596+jpenilla@users.noreply.github.com>
Date: Sun, 12 Dec 2021 04:43:30 -0800
Subject: [PATCH] Fix WorldGenRegion leak when converting pre-1.18 chunks

The Blender passed in here holds a WorldGenRegion which contains a list of surrounding chunks

diff --git a/src/main/java/net/minecraft/world/level/chunk/ChunkAccess.java b/src/main/java/net/minecraft/world/level/chunk/ChunkAccess.java
index 96cb3e8cad9e7a5edd2a448ea88f2447104fbb5a..5aeaaae6f15050a2da271fe196d0a234ecafc8a1 100644
--- a/src/main/java/net/minecraft/world/level/chunk/ChunkAccess.java
+++ b/src/main/java/net/minecraft/world/level/chunk/ChunkAccess.java
@@ -410,6 +410,11 @@ public abstract class ChunkAccess implements BlockGetter, BiomeManager.NoiseBiom
     }
 
     public NoiseChunk getOrCreateNoiseChunk(NoiseSampler noiseColumnSampler, Supplier<NoiseChunk.NoiseFiller> columnSampler, NoiseGeneratorSettings chunkGeneratorSettings, Aquifer.FluidPicker fluidLevelSampler, Blender blender) {
+        // Paper start - create a new one each time to avoid leaking
+        if (blender != Blender.empty()) {
+            return NoiseChunk.forChunk(this, noiseColumnSampler, columnSampler, chunkGeneratorSettings, fluidLevelSampler, blender);
+        }
+        // Paper end
         if (this.noiseChunk == null) {
             this.noiseChunk = NoiseChunk.forChunk(this, noiseColumnSampler, columnSampler, chunkGeneratorSettings, fluidLevelSampler, blender);
         }