Change the block type check to be implementation-dependent. The Bukkit plugin now checks Bukkit's Material.

src/main/java/com/sk89q/worldedit/EditSession.java

@@ -164,7 +164,7 @@ public class EditSession {
         }
         
         // No invalid blocks
-        if ((type > 32 && type < 35) || type == 36 || type == 29 || type > 96) {
+        if (!world.isValidBlockType(type)) {
             return false;
         }
         

src/main/java/com/sk89q/worldedit/LocalWorld.java

@@ -305,6 +305,16 @@ public abstract class LocalWorld {
      */
     public abstract int removeEntities(EntityType type, Vector origin, int radius);
     
+    /**
+     * Returns whether a block has a valid ID.
+     * 
+     * @param type
+     * @return
+     */
+    public boolean isValidBlockType(int type) {
+        return !((type > 32 && type < 35) || type == 36 || type == 29 || type > 96);
+    }
+
     /**
      * Compare if the other world is equal.
      * 

src/main/java/com/sk89q/worldedit/ServerInterface.java

@@ -40,6 +40,16 @@ public abstract class ServerInterface {
      */
     public abstract boolean isValidMobType(String type);
     
+    /**
+     * Returns whether a block has a valid ID.
+     * 
+     * @param type
+     * @return
+     */
+    public boolean isValidBlockType(int type) {
+        return !((type > 32 && type < 35) || type == 36 || type == 29 || type > 96);
+    }
+    
     /**
      * Reload WorldEdit configuration.
      */

src/main/java/com/sk89q/worldedit/WorldEdit.java

@@ -202,13 +202,15 @@ public class WorldEdit {
         String[] args0 = arg.split("\\|");
         String[] args1 = args0[0].split(":", 2);
         String testID = args1[0];
+        int blockId = -1;
         
         int data = -1;
 
         // Attempt to parse the item ID or otherwise resolve an item/block
         // name to its numeric ID
         try {
-            blockType = BlockType.fromID(Integer.parseInt(testID));
+            blockId = Integer.parseInt(testID);
+            blockType = BlockType.fromID(blockId);
         } catch (NumberFormatException e) {
             blockType = BlockType.lookup(testID);
             if (blockType == null) {
@@ -219,7 +221,7 @@ public class WorldEdit {
             }
         }
 
-        if (blockType == null) {
+        if (blockId == -1 && blockType == null) {
             // Maybe it's a cloth
             ClothColor col = ClothColor.lookup(testID);
             
@@ -231,6 +233,15 @@ public class WorldEdit {
             }
         }
         
+        // Read block ID
+        if (blockId == -1) {
+            blockId = blockType.getID();
+        }
+        
+        if (!server.isValidBlockType(blockId)) {
+            throw new UnknownItemException(arg);
+        }
+        
         if (data == -1) { // Block data not yet detected
             // Parse the block data (optional)
             try {
@@ -274,7 +285,7 @@ public class WorldEdit {
 
         // Check if the item is allowed
         if (allAllowed || player.hasPermission("worldedit.anyblock")
-                || !config.disallowedBlocks.contains(blockType.getID())) {
+                || !config.disallowedBlocks.contains(blockId)) {
             
             // Allow special sign text syntax
             if (blockType == BlockType.SIGN_POST
@@ -317,7 +328,7 @@ public class WorldEdit {
                 }
             }
 
-            return new BaseBlock(blockType.getID(), data);
+            return new BaseBlock(blockId, data);
         }
 
         throw new DisallowedItemException(arg);

src/main/java/com/sk89q/worldedit/bukkit/BukkitServerInterface.java

@@ -43,6 +43,11 @@ public class BukkitServerInterface extends ServerInterface {
         return CreatureType.fromName(type) != null;
     }
     
+    @Override
+    public boolean isValidBlockType(int type) {
+        return Material.getMaterial(type) != null;
+    }
+
     @Override
     public void reload() {
         plugin.loadConfiguration();

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

@@ -39,6 +39,7 @@ import org.bukkit.entity.Wolf;
 import org.bukkit.inventory.Inventory;
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.Location;
+import org.bukkit.Material;
 import org.bukkit.TreeType;
 import org.bukkit.World;
 import com.sk89q.worldedit.EditSession;
@@ -628,6 +629,17 @@ public class BukkitWorld extends LocalWorld {
         return true;
     }
     
+    /**
+     * Returns whether a block has a valid ID.
+     * 
+     * @param type
+     * @return
+     */
+    @Override
+    public boolean isValidBlockType(int type) {
+        return Material.getMaterial(type) != null;
+    }
+
     @Override
     public boolean equals(Object other) {
         if (!(other instanceof BukkitWorld)) {