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If the server attempts to load a chunk generated by a newer version of
the game, immediately stop the server to prevent data corruption.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.

1 files changed, 40 insertions, 0 deletions

diff --git a/Spigot-Server-Patches/0366-Do-not-let-the-server-load-chunks-from-newer-version.patch b/Spigot-Server-Patches/0366-Do-not-let-the-server-load-chunks-from-newer-version.patch
new file mode 100644
index 0000000000..c11afbeaff
--- /dev/null
+++ b/Spigot-Server-Patches/0366-Do-not-let-the-server-load-chunks-from-newer-version.patch
@@ -0,0 +1,40 @@
+From 652ddff89bc697d79803e1fc33b767bc5af0c1a8 Mon Sep 17 00:00:00 2001
+From: Zach Brown <[email protected]>
+Date: Tue, 23 Oct 2018 22:03:37 -0400
+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/server/ChunkRegionLoader.java b/src/main/java/net/minecraft/server/ChunkRegionLoader.java
+index bad287fca..e6906effb 100644
+--- a/src/main/java/net/minecraft/server/ChunkRegionLoader.java
++++ b/src/main/java/net/minecraft/server/ChunkRegionLoader.java
+@@ -90,8 +90,22 @@ public class ChunkRegionLoader implements IChunkLoader, IAsyncChunkSaver {
+         return nbttagcompound != null ? true : RegionFileCache.chunkExists(this.d, i, j);
+     }
+ 
++    // Paper start
++    private static final int CURRENT_DATA_VERSION = 1343; // Paper
++    private static final boolean JUST_CORRUPT_IT = Boolean.valueOf("Paper.ignoreWorldDataVersion");
++    // Paper end
++
+     @Nullable
+     protected Object[] a(World world, int i, int j, NBTTagCompound nbttagcompound) { // CraftBukkit - return Chunk -> Object[]
++        // Paper start - Do NOT attempt to load chunks saved with newer versions
++        if (nbttagcompound.hasKeyOfType("DataVersion", 3)) {
++            int dataVersion = nbttagcompound.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
+         if (!nbttagcompound.hasKeyOfType("Level", 10)) {
+             ChunkRegionLoader.a.error("Chunk file at {},{} is missing level data, skipping", Integer.valueOf(i), Integer.valueOf(j));
+             return null;
+-- 
+2.19.1
+