Add DFUs. Currently used by //restore.

worldedit-core/src/main/java/com/sk89q/worldedit/extension/platform/AbstractPlatform.java

@@ -19,6 +19,7 @@
 
 package com.sk89q.worldedit.extension.platform;
 
+import com.sk89q.worldedit.world.DataFixer;
 import com.sk89q.worldedit.world.World;
 
 import java.util.Collections;
@@ -39,4 +40,8 @@ public abstract class AbstractPlatform implements Platform {
         return Collections.emptyList();
     }
 
+    @Override
+    public DataFixer getDataFixer() {
+        return null;
+    }
 }

worldedit-core/src/main/java/com/sk89q/worldedit/extension/platform/Platform.java

@@ -21,6 +21,7 @@ package com.sk89q.worldedit.extension.platform;
 
 import com.sk89q.worldedit.LocalConfiguration;
 import com.sk89q.worldedit.entity.Player;
+import com.sk89q.worldedit.world.DataFixer;
 import com.sk89q.worldedit.world.World;
 import com.sk89q.worldedit.world.registry.Registries;
 import org.enginehub.piston.CommandManager;
@@ -51,6 +52,13 @@ public interface Platform {
      */
     int getDataVersion();
 
+    /**
+     * Get a DataFixer capable of upgrading old data.
+     *
+     * @return a data fixer, or null if not supported by this platform
+     */
+    DataFixer getDataFixer();
+
     /**
      * Checks if a mob type is valid.
      *

worldedit-core/src/main/java/com/sk89q/worldedit/world/DataFixer.java

@@ -0,0 +1,34 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.world;
+
+import com.google.common.annotations.Beta;
+import com.sk89q.jnbt.CompoundTag;
+
+@Beta
+public interface DataFixer {
+
+    /**
+     * API SUBJECT TO CHANGE. DON'T USE THIS.
+     */
+    @Beta
+    CompoundTag fixChunk(CompoundTag originalChunk);
+
+}

worldedit-core/src/main/java/com/sk89q/worldedit/world/chunk/AnvilChunk13.java

@@ -35,12 +35,11 @@ import com.sk89q.worldedit.world.block.BlockType;
 import com.sk89q.worldedit.world.block.BlockTypes;
 import com.sk89q.worldedit.world.storage.InvalidFormatException;
 
+import javax.annotation.Nullable;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
-import javax.annotation.Nullable;
-
 /**
  * The chunk format for Minecraft 1.13 and newer
  */
@@ -160,11 +159,13 @@ public class AnvilChunk13 implements Chunk {
      * @throws DataException
      */
     private void populateTileEntities() throws DataException {
+        tileEntities = new HashMap<>();
+        if (!rootTag.getValue().containsKey("TileEntities")) {
+            return;
+        }
         List<Tag> tags = NBTUtils.getChildTag(rootTag.getValue(),
                 "TileEntities", ListTag.class).getValue();
 
-        tileEntities = new HashMap<>();
-
         for (Tag tag : tags) {
             if (!(tag instanceof CompoundTag)) {
                 throw new InvalidFormatException("CompoundTag expected in TileEntities");

worldedit-core/src/main/java/com/sk89q/worldedit/world/storage/ChunkStore.java

@@ -21,9 +21,13 @@ package com.sk89q.worldedit.world.storage;
 
 import com.sk89q.jnbt.CompoundTag;
 import com.sk89q.jnbt.Tag;
+import com.sk89q.worldedit.WorldEdit;
+import com.sk89q.worldedit.extension.platform.Capability;
+import com.sk89q.worldedit.extension.platform.Platform;
 import com.sk89q.worldedit.math.BlockVector2;
 import com.sk89q.worldedit.math.BlockVector3;
 import com.sk89q.worldedit.world.DataException;
+import com.sk89q.worldedit.world.DataFixer;
 import com.sk89q.worldedit.world.World;
 import com.sk89q.worldedit.world.chunk.AnvilChunk;
 import com.sk89q.worldedit.world.chunk.AnvilChunk13;
@@ -42,7 +46,7 @@ public abstract class ChunkStore implements Closeable {
     /**
      * The DataVersion for Minecraft 1.13
      */
-    public static final int DATA_VERSION_MC_1_13 = 1519;
+    private static final int DATA_VERSION_MC_1_13 = 1519;
 
     /**
      * {@code >>} - to chunk
@@ -102,6 +106,14 @@ public abstract class ChunkStore implements Closeable {
         }
 
         int dataVersion = rootTag.getInt("DataVersion");
+        final Platform platform = WorldEdit.getInstance().getPlatformManager().queryCapability(Capability.WORLD_EDITING);
+        final int currentDataVersion = platform.getDataVersion();
+        if (dataVersion < currentDataVersion) {
+            final DataFixer dataFixer = platform.getDataFixer();
+            if (dataFixer != null) {
+                return new AnvilChunk13((CompoundTag) dataFixer.fixChunk(rootTag).getValue().get("Level"));
+            }
+        }
         if (dataVersion >= DATA_VERSION_MC_1_13) {
             return new AnvilChunk13(tag);
         }
@@ -114,6 +126,7 @@ public abstract class ChunkStore implements Closeable {
         return new OldChunk(world, tag);
     }
 
+    @Override
     public void close() throws IOException {
     }