Paper/patches/server/0393-Do-not-let-the-server-load-chunks-from-newer-version.patch
Spottedleaf 8c5b837e05 Rework async chunk api implementation
Firstly, the old methods all routed to the CompletableFuture method.
However, the CF method could not guarantee that if the caller
was off-main that the future would be "completed" on-main. Since
the callback methods used the CF one, this meant that the callback
methods did not guarantee that the callbacks were to be called on
the main thread.

Now, all methods route to getChunkAtAsync(x, z, gen, urgent, cb)
so that the methods with the callback are guaranteed to invoke
the callback on the main thread. The CF behavior remains unchanged;
it may still appear to complete on main if invoked off-main.

Secondly, remove the scheduleOnMain invocation in the async
chunk completion. This unnecessarily delays the callback
by 1 tick.

Thirdly, add getChunksAtAsync(minX, minZ, maxX, maxZ, ...) which
will load chunks within an area. This method is provided as a helper
as keeping all chunks loaded within an area can be complicated to
implement for plugins (due to the lacking ticket API), and is
already implemented internally anyways.

Fourthly, remove the ticket addition that occured with getChunkAt
and getChunkAtAsync. The ticket addition may delay the unloading
of the chunk unnecessarily. It also fixes a very rare timing bug
where the future/callback would be completed after the chunk
unloads.
2024-11-18 23:00:59 -08:00

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Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Zach Brown <zach@zachbr.io>
Date: Tue, 23 Jul 2019 20:44:47 -0500
Subject: [PATCH] Do not let the server load chunks from newer versions
If the server attempts to load a chunk generated by a newer version of
the game, immediately stop the server to prevent data corruption.
You can override this functionality at your own peril.
diff --git a/src/main/java/net/minecraft/world/level/chunk/storage/SerializableChunkData.java b/src/main/java/net/minecraft/world/level/chunk/storage/SerializableChunkData.java
index 92ad7704a77c024afe090488764eaf59a4f7505f..d7a204216332ccbd6bece23bd507be0366ea4d61 100644
--- a/src/main/java/net/minecraft/world/level/chunk/storage/SerializableChunkData.java
+++ b/src/main/java/net/minecraft/world/level/chunk/storage/SerializableChunkData.java
@@ -104,11 +104,25 @@ public record SerializableChunkData(Registry<Biome> biomeRegistry, ChunkPos chun
}
// Paper end - guard against serializing mismatching coordinates
+ // Paper start - Do not let the server load chunks from newer versions
+ private static final int CURRENT_DATA_VERSION = net.minecraft.SharedConstants.getCurrentVersion().getDataVersion().getVersion();
+ private static final boolean JUST_CORRUPT_IT = Boolean.getBoolean("Paper.ignoreWorldDataVersion");
+ // Paper end - Do not let the server load chunks from newer versions
+
@Nullable
public static SerializableChunkData parse(LevelHeightAccessor world, RegistryAccess registryManager, CompoundTag nbt) {
if (!nbt.contains("Status", 8)) {
return null;
} else {
+ // Paper start - Do not let the server load chunks from newer versions
+ if (nbt.contains("DataVersion", net.minecraft.nbt.Tag.TAG_ANY_NUMERIC)) {
+ final int dataVersion = nbt.getInt("DataVersion");
+ if (!JUST_CORRUPT_IT && dataVersion > CURRENT_DATA_VERSION) {
+ new RuntimeException("Server attempted to load chunk saved with newer version of minecraft! " + dataVersion + " > " + CURRENT_DATA_VERSION).printStackTrace();
+ System.exit(1);
+ }
+ }
+ // Paper end - Do not let the server load chunks from newer versions
ChunkPos chunkcoordintpair = new ChunkPos(nbt.getInt("xPos"), nbt.getInt("zPos")); // Paper - guard against serializing mismatching coordinates; diff on change, see ChunkSerializer#getChunkCoordinate
long i = nbt.getLong("LastUpdate");
long j = nbt.getLong("InhabitedTime");