Passed a string of parent commands rather than just the current command.

src/main/java/com/sk89q/worldedit/extension/platform/CommandManager.java

@@ -216,7 +216,7 @@ public final class CommandManager {
         long start = System.currentTimeMillis();
 
         try {
-            dispatcher.call(null, Joiner.on(" ").join(split), locals);
+            dispatcher.call(Joiner.on(" ").join(split), locals, new String[0]);
         } catch (CommandPermissionsException e) {
             actor.printError("You don't have permission to do this.");
         } catch (InvalidUsageException e) {

src/main/java/com/sk89q/worldedit/util/command/CommandCallable.java

@@ -22,7 +22,6 @@ package com.sk89q.worldedit.util.command;
 import com.sk89q.minecraft.util.commands.CommandException;
 import com.sk89q.minecraft.util.commands.CommandLocals;
 
-import javax.annotation.Nullable;
 import java.util.List;
 import java.util.Set;
 
@@ -43,14 +42,13 @@ public interface CommandCallable {
      * </p>
      * The implementing class must perform the necessary permission checks.
      *
-     * @param alias the alias that was used to invoke this command,
-     *              which may be null if this is a "root" command
      * @param arguments the arguments
      * @param locals the locals
+     * @param parentCommands a list of parent commands, with the first most entry being the top-level command
      * @return the called command, or null if there was no command found
      * @throws CommandException thrown on a command error
      */
-    boolean call(@Nullable String alias, String arguments, CommandLocals locals) throws CommandException;
+    boolean call(String arguments, CommandLocals locals, String[] parentCommands) throws CommandException;
 
     /**
      * Get a list of suggestions based on input.

src/main/java/com/sk89q/worldedit/util/command/SimpleDispatcher.java

@@ -22,7 +22,6 @@ package com.sk89q.worldedit.util.command;
 import com.google.common.base.Joiner;
 import com.sk89q.minecraft.util.commands.*;
 
-import javax.annotation.Nullable;
 import java.util.*;
 
 /**
@@ -87,7 +86,7 @@ public class SimpleDispatcher implements Dispatcher {
     }
 
     @Override
-    public boolean call(@Nullable String alias, String arguments, CommandLocals locals) throws CommandException {
+    public boolean call(String arguments, CommandLocals locals, String[] parentCommands) throws CommandException {
         // We have permission for this command if we have permissions for subcommands
         if (!testPermission(locals)) {
             throw new CommandPermissionsException();
@@ -101,11 +100,13 @@ public class SimpleDispatcher implements Dispatcher {
         } else if (split.length > 0) {
             String subCommand = split[0];
             String subArguments = Joiner.on(" ").join(Arrays.copyOfRange(split, 1, split.length));
+            String[] subParents = Arrays.copyOf(parentCommands, parentCommands.length + 1);
+            subParents[parentCommands.length] = subCommand;
             CommandMapping mapping = get(subCommand);
 
             if (mapping != null) {
                 try {
-                    mapping.getCallable().call(subCommand, subArguments, locals);
+                    mapping.getCallable().call(subArguments, locals, subParents);
                 } catch (CommandException e) {
                     e.prependStack(subCommand);
                     throw e;

src/main/java/com/sk89q/worldedit/util/command/parametric/ParametricCallable.java

@@ -23,7 +23,6 @@ import com.sk89q.minecraft.util.commands.*;
 import com.sk89q.worldedit.util.command.*;
 import com.sk89q.worldedit.util.command.binding.Switch;
 
-import javax.annotation.Nullable;
 import java.lang.annotation.Annotation;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
@@ -160,13 +159,14 @@ class ParametricCallable implements CommandCallable {
     }
 
     @Override
-    public boolean call(@Nullable String alias, String stringArguments, CommandLocals locals) throws CommandException {
+    public boolean call(String stringArguments, CommandLocals locals, String[] parentCommands) throws CommandException {
         // Test permission
         if (!testPermission(locals)) {
             throw new CommandPermissionsException();
         }
 
-        String[] split = CommandContext.split(alias + " " + stringArguments);
+        String calledCommand = parentCommands.length > 0 ? parentCommands[parentCommands.length - 1] : "_";
+        String[] split = CommandContext.split(calledCommand + " " + stringArguments);
         CommandContext context = new CommandContext(split, getValueFlags(), false, locals);
 
         Object[] args = new Object[parameters.length];