1 files changed, 57 insertions, 0 deletions
diff --git a/patches/server/0339-Guard-against-serializing-mismatching-chunk-coordina.patch b/patches/server/0339-Guard-against-serializing-mismatching-chunk-coordina.patch
new file mode 100644
index 0000000000..7018c6fabf
--- /dev/null
+++ b/patches/server/0339-Guard-against-serializing-mismatching-chunk-coordina.patch
@@ -0,0 +1,57 @@
+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 e59910540458ca912efea64d9f7cd212d63d110a..f4bf0ecde863f1795d764d8cc8d6525af02356ea 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
+@@ -92,6 +92,18 @@ 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(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
+     // Paper start
+     public static final class InProgressChunkHolder {
+ 
+@@ -117,7 +129,7 @@ public class ChunkSerializer {
+     public static InProgressChunkHolder loadChunk(ServerLevel world, PoiManager poiStorage, ChunkPos chunkPos, CompoundTag nbt, boolean distinguish) {
+         java.util.ArrayDeque<Runnable> tasksToExecuteOnMain = new java.util.ArrayDeque<>();
+         // Paper end
+-        ChunkPos chunkcoordintpair1 = new ChunkPos(nbt.getInt("xPos"), nbt.getInt("zPos"));
++        ChunkPos chunkcoordintpair1 = new ChunkPos(nbt.getInt("xPos"), nbt.getInt("zPos")); // Paper - 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 f2539f2aab4086bc6772db9985ca9f75ff6a7c71..aa915195d4aab3e931a92bf844f6dc18a0a59b9e 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
+@@ -178,6 +178,13 @@ public class ChunkStorage implements AutoCloseable {
+ 
+     // Paper start - async chunk io
+     public void write(ChunkPos chunkPos, CompoundTag nbt) throws IOException {
++        // Paper start
++        if (!chunkPos.equals(ChunkSerializer.getChunkCoordinate(nbt))) {
++            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.toString()
++                + " but compound says coordinate is " + ChunkSerializer.getChunkCoordinate(nbt).toString() + (world == null ? " for an unknown world" : (" for world: " + world)));
++        }
++        // Paper end
+         this.regionFileCache.write(chunkPos, nbt);
+         // Paper end - Async chunk loading
+         if (this.legacyStructureHandler != null) {