Get it to a point where it works minimally on 1.13 Spigot.

worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/BukkitBlockRegistry.java

@@ -0,0 +1,68 @@
+/*
+ * 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.bukkit;
+
+import com.sk89q.worldedit.blocks.BlockMaterial;
+import com.sk89q.worldedit.world.block.BlockTypes;
+import com.sk89q.worldedit.world.registry.BundledBlockRegistry;
+import com.sk89q.worldedit.world.registry.PassthroughBlockMaterial;
+import org.bukkit.Material;
+
+import java.util.EnumMap;
+import java.util.Map;
+
+import javax.annotation.Nullable;
+
+public class BukkitBlockRegistry extends BundledBlockRegistry {
+
+    private Map<Material, BukkitBlockMaterial> materialMap = new EnumMap<>(Material.class);
+
+    @Nullable
+    @Override
+    public BlockMaterial getMaterial(String id) {
+        return materialMap.computeIfAbsent(BukkitUtil.toMaterial(BlockTypes.get(id)),
+                material -> new BukkitBlockMaterial(BukkitBlockRegistry.super.getMaterial(id), material));
+    }
+
+    public static class BukkitBlockMaterial extends PassthroughBlockMaterial {
+
+        private final Material material;
+
+        public BukkitBlockMaterial(@Nullable BlockMaterial material, Material bukkitMaterial) {
+            super(material);
+            this.material = bukkitMaterial;
+        }
+
+        @Override
+        public boolean isSolid() {
+            return material.isSolid();
+        }
+
+        @Override
+        public boolean isBurnable() {
+            return material.isBurnable();
+        }
+
+        @Override
+        public boolean isTranslucent() {
+            return material.isTransparent();
+        }
+    }
+}

worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/BukkitRegistries.java

@@ -20,6 +20,7 @@
 package com.sk89q.worldedit.bukkit;
 
 import com.sk89q.worldedit.world.registry.BiomeRegistry;
+import com.sk89q.worldedit.world.registry.BlockRegistry;
 import com.sk89q.worldedit.world.registry.BundledRegistries;
 
 /**
@@ -28,6 +29,7 @@ import com.sk89q.worldedit.world.registry.BundledRegistries;
 class BukkitRegistries extends BundledRegistries {
 
     private static final BukkitRegistries INSTANCE = new BukkitRegistries();
+    private final BlockRegistry blockRegistry = new BukkitBlockRegistry();
     private final BiomeRegistry biomeRegistry = new BukkitBiomeRegistry();
 
     /**
@@ -36,6 +38,11 @@ class BukkitRegistries extends BundledRegistries {
     BukkitRegistries() {
     }
 
+    @Override
+    public BlockRegistry getBlockRegistry() {
+        return blockRegistry;
+    }
+
     @Override
     public BiomeRegistry getBiomeRegistry() {
         return biomeRegistry;

worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/BukkitUtil.java

@@ -21,14 +21,18 @@ package com.sk89q.worldedit.bukkit;
 
 import com.sk89q.worldedit.BlockVector;
 import com.sk89q.worldedit.Vector;
+import com.sk89q.worldedit.WorldEdit;
 import com.sk89q.worldedit.WorldEditException;
 import com.sk89q.worldedit.blocks.BaseItemStack;
+import com.sk89q.worldedit.extension.input.InputParseException;
+import com.sk89q.worldedit.extension.input.ParserContext;
 import com.sk89q.worldedit.extent.Extent;
 import com.sk89q.worldedit.util.Location;
 import com.sk89q.worldedit.world.block.BlockState;
 import com.sk89q.worldedit.world.block.BlockStateHolder;
 import com.sk89q.worldedit.world.block.BlockType;
 import com.sk89q.worldedit.world.block.BlockTypes;
+import com.sk89q.worldedit.world.item.ItemType;
 import com.sk89q.worldedit.world.item.ItemTypes;
 import org.bukkit.Bukkit;
 import org.bukkit.Material;
@@ -48,6 +52,12 @@ public final class BukkitUtil {
     private BukkitUtil() {
     }
 
+    private static final ParserContext TO_BLOCK_CONTEXT = new ParserContext();
+
+    static {
+        TO_BLOCK_CONTEXT.setRestricted(false);
+    }
+
     public static com.sk89q.worldedit.world.World getWorld(World w) {
         return new BukkitWorld(w);
     }
@@ -130,12 +140,31 @@ public final class BukkitUtil {
         return ((BukkitWorld) world).getWorld();
     }
 
+    public static Material toMaterial(ItemType itemType) {
+        if (!itemType.getId().startsWith("minecraft:")) {
+            throw new IllegalArgumentException("Bukkit only supports Minecraft items");
+        }
+        return Material.getMaterial(itemType.getId().replace("minecraft:", "").toUpperCase());
+    }
+
+    public static Material toMaterial(BlockType blockType) {
+        if (!blockType.getId().startsWith("minecraft:")) {
+            throw new IllegalArgumentException("Bukkit only supports Minecraft blocks");
+        }
+        return Material.getMaterial(blockType.getId().replace("minecraft:", "").toUpperCase());
+    }
+
     public static BlockState toBlock(BlockData blockData) {
-        return null; // TODO BLOCKING
+        try {
+            return WorldEdit.getInstance().getBlockFactory().parseFromInput(blockData.getAsString(), TO_BLOCK_CONTEXT).toImmutableState();
+        } catch (InputParseException e) {
+            e.printStackTrace();
+        }
+        return null;
     }
 
     public static BlockData toBlock(BlockStateHolder block) {
-        return Bukkit.createBlockData(block.toString()); // TODO BLOCKING
+        return Bukkit.createBlockData(block.getAsString());
     }
 
     public static BlockState toBlock(ItemStack itemStack) throws WorldEditException {
@@ -151,7 +180,6 @@ public final class BukkitUtil {
     }
 
     public static ItemStack toItemStack(BaseItemStack item) {
-        BlockData blockData = Bukkit.createBlockData(item.getType().getId());
-        return new ItemStack(blockData.getMaterial(), item.getAmount());
+        return new ItemStack(toMaterial(item.getType()), item.getAmount());
     }
 }

worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/BukkitWorld.java

@@ -284,10 +284,8 @@ public class BukkitWorld extends AbstractWorld {
     public boolean generateTree(TreeGenerator.TreeType type, EditSession editSession, Vector pt) {
         World world = getWorld();
         TreeType bukkitType = toBukkitTreeType(type);
-        return type != null && world.generateTree(BukkitUtil.toLocation(world, pt), bukkitType);
-//        return type != null && world.generateTree(BukkitUtil.toLocation(world, pt), bukkitType,
-//                new EditSessionBlockChangeDelegate(editSession));
-        // TODO
+        return type != null && world.generateTree(BukkitUtil.toLocation(world, pt), bukkitType,
+                new EditSessionBlockChangeDelegate(editSession));
     }
 
     @Override
@@ -368,7 +366,7 @@ public class BukkitWorld extends AbstractWorld {
             return adapter.setBlock(BukkitAdapter.adapt(getWorld(), position), block, notifyAndLight);
         } else {
             Block bukkitBlock = getWorld().getBlockAt(position.getBlockX(), position.getBlockY(), position.getBlockZ());
-            bukkitBlock.setData(BukkitUtil.toBlock(block), notifyAndLight);
+            bukkitBlock.setBlockData(BukkitUtil.toBlock(block), notifyAndLight);
             return true;
         }
     }

worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/EditSessionBlockChangeDelegate.java

@@ -20,11 +20,16 @@
 package com.sk89q.worldedit.bukkit;
 
 import com.sk89q.worldedit.EditSession;
+import com.sk89q.worldedit.MaxChangedBlocksException;
+import com.sk89q.worldedit.Vector;
+import com.sk89q.worldedit.world.block.BlockTypes;
+import org.bukkit.BlockChangeDelegate;
+import org.bukkit.block.data.BlockData;
 
 /**
  * Proxy class to catch calls to set blocks.
  */
-public class EditSessionBlockChangeDelegate {//implements BlockChangeDelegate {
+public class EditSessionBlockChangeDelegate implements BlockChangeDelegate {
 
     private EditSession editSession;
 
@@ -32,50 +37,29 @@ public class EditSessionBlockChangeDelegate {//implements BlockChangeDelegate {
         this.editSession = editSession;
     }
 
-    // TODO This needs a fix in Spigot itself
+    @Override
+    public boolean setBlockData(int x, int y, int z, BlockData blockData) {
+        try {
+            editSession.setBlock(new Vector(x, y, z), BukkitUtil.toBlock(blockData));
+        } catch (MaxChangedBlocksException e) {
+            return false;
+        }
+        return true;
+    }
 
-//    @Override
-//    public boolean setRawTypeId(int x, int y, int z, int typeId) {
-//        try {
-//            return editSession.setBlock(new Vector(x, y, z), LegacyMapper.getInstance().getBlockFromLegacy(typeId));
-//        } catch (MaxChangedBlocksException ex) {
-//            return false;
-//        }
-//    }
-//
-//    @Override
-//    public boolean setRawTypeIdAndData(int x, int y, int z, int typeId, int data) {
-//        try {
-//            return editSession.setBlock(new Vector(x, y, z), LegacyMapper.getInstance().getBlockFromLegacy(typeId, data));
-//        } catch (MaxChangedBlocksException ex) {
-//            return false;
-//        }
-//    }
-//
-//    @Override
-//    public boolean setTypeId(int x, int y, int z, int typeId) {
-//        return setRawTypeId(x, y, z, typeId);
-//    }
-//
-//    @Override
-//    public boolean setTypeIdAndData(int x, int y, int z, int typeId, int data) {
-//        return setRawTypeIdAndData(x, y, z, typeId, data);
-//    }
-//
-//    @Override
-//    public int getTypeId(int x, int y, int z) {
-//        int[] datas = LegacyMapper.getInstance().getLegacyFromBlock(editSession.getBlock(new Vector(x, y, z)));
-//        return datas[0];
-//    }
-//
-//    @Override
-//    public int getHeight() {
-//        return editSession.getWorld().getMaxY() + 1;
-//    }
-//
-//    @Override
-//    public boolean isEmpty(int x, int y, int z) {
-//        return editSession.getBlock(new Vector(x, y, z)).getBlockType() == BlockTypes.AIR;
-//    }
+    @Override
+    public BlockData getBlockData(int x, int y, int z) {
+        return BukkitUtil.toBlock(editSession.getBlock(new Vector(x, y, z)));
+    }
+
+    @Override
+    public int getHeight() {
+        return editSession.getWorld().getMaxY() + 1;
+    }
+
+    @Override
+    public boolean isEmpty(int x, int y, int z) {
+        return editSession.getBlock(new Vector(x, y, z)).getBlockType() == BlockTypes.AIR;
+    }
 
 }