1 files changed, 52 insertions, 0 deletions
diff --git a/patches/server/0309-Guard-against-serializing-mismatching-chunk-coordina.patch b/patches/server/0309-Guard-against-serializing-mismatching-chunk-coordina.patch
new file mode 100644
index 0000000000..6752b44617
--- /dev/null
+++ b/patches/server/0309-Guard-against-serializing-mismatching-chunk-coordina.patch
@@ -0,0 +1,52 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Spottedleaf <[email protected]>
+Date: Fri, 27 Dec 2019 09:42:26 -0800
+Subject: [PATCH] Guard against serializing mismatching chunk coordinate
+
+Should help if something dumb happens
+
+diff --git a/src/main/java/net/minecraft/world/level/chunk/storage/ChunkSerializer.java b/src/main/java/net/minecraft/world/level/chunk/storage/ChunkSerializer.java
+index 47f5f3d58bb3bf85cf35f9baae77df7fab5c844f..0dd6f1bce4913cb84ba21a20df5573bab3a64645 100644
+--- a/src/main/java/net/minecraft/world/level/chunk/storage/ChunkSerializer.java
++++ b/src/main/java/net/minecraft/world/level/chunk/storage/ChunkSerializer.java
+@@ -88,8 +88,21 @@ public class ChunkSerializer {
+ 
+     public ChunkSerializer() {}
+ 
++    // Paper start - guard against serializing mismatching coordinates
++    // TODO Note: This needs to be re-checked each update
++    public static ChunkPos getChunkCoordinate(final CompoundTag chunkData) {
++        final int dataVersion = ChunkStorage.getVersion(chunkData);
++        if (dataVersion < 2842) { // Level tag is removed after this version
++            final CompoundTag levelData = chunkData.getCompound("Level");
++            return new ChunkPos(levelData.getInt("xPos"), levelData.getInt("zPos"));
++        } else {
++            return new ChunkPos(chunkData.getInt("xPos"), chunkData.getInt("zPos"));
++        }
++    }
++    // Paper end - guard against serializing mismatching coordinates
++
+     public static ProtoChunk read(ServerLevel world, PoiManager poiStorage, RegionStorageInfo key, ChunkPos chunkPos, CompoundTag nbt) {
+-        ChunkPos chunkcoordintpair1 = new ChunkPos(nbt.getInt("xPos"), nbt.getInt("zPos"));
++        ChunkPos chunkcoordintpair1 = new ChunkPos(nbt.getInt("xPos"), nbt.getInt("zPos")); // Paper - guard against serializing mismatching coordinates; diff on change, see ChunkSerializer#getChunkCoordinate
+ 
+         if (!Objects.equals(chunkPos, chunkcoordintpair1)) {
+             ChunkSerializer.LOGGER.error("Chunk file at {} is in the wrong location; relocating. (Expected {}, got {})", new Object[]{chunkPos, chunkPos, chunkcoordintpair1});
+diff --git a/src/main/java/net/minecraft/world/level/chunk/storage/ChunkStorage.java b/src/main/java/net/minecraft/world/level/chunk/storage/ChunkStorage.java
+index 3e194944e50f8395074d68d4abe4c084c3fadcc1..9aa9ab894080a5819fc45698771afd034906d36a 100644
+--- a/src/main/java/net/minecraft/world/level/chunk/storage/ChunkStorage.java
++++ b/src/main/java/net/minecraft/world/level/chunk/storage/ChunkStorage.java
+@@ -172,6 +172,13 @@ public class ChunkStorage implements AutoCloseable {
+     }
+ 
+     public CompletableFuture<Void> write(ChunkPos chunkPos, CompoundTag nbt) {
++        // Paper start - guard against serializing mismatching coordinates
++        if (nbt != null && !chunkPos.equals(ChunkSerializer.getChunkCoordinate(nbt))) {
++            final String world = (this instanceof net.minecraft.server.level.ChunkMap) ? ((net.minecraft.server.level.ChunkMap) this).level.getWorld().getName() : null;
++            throw new IllegalArgumentException("Chunk coordinate and serialized data do not have matching coordinates, trying to serialize coordinate " + chunkPos
++                + " but compound says coordinate is " + ChunkSerializer.getChunkCoordinate(nbt) + (world == null ? " for an unknown world" : (" for world: " + world)));
++        }
++        // Paper end - guard against serializing mismatching coordinates
+         this.handleLegacyStructureIndex(chunkPos);
+         return this.worker.store(chunkPos, nbt);
+     }