External command fixes

CommandArguments.getWordsAsString now sanity checks its arguments
External /mode command now uses correct offset
All external commands are now passed the correct arguments
Fixes issue 3125

Change-Id: Ib546c03443ac51a1bb6b5d3d4b6a2204e04a8be1
Reviewed-on: http://gerrit.dmdirc.com/58
Reviewed-by: Gregory Holmes <greboid@dmdirc.com>
Tested-by: Gregory Holmes <greboid@dmdirc.com>

src/com/dmdirc/commandparser/CommandArguments.java

@@ -22,6 +22,9 @@
 
 package com.dmdirc.commandparser;
 
+import com.dmdirc.Precondition;
+import com.dmdirc.logger.Logger;
+
 import java.util.Arrays;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
@@ -144,7 +147,10 @@ public class CommandArguments {
      * @param end The index of the last word to include
      * @return A String representation of the requested words
      */
+    @Precondition("Start index is less than or equal to end index")
     public String getWordsAsString(final int start, final int end) {
+        Logger.assertTrue(start <= end);
+
         final Pattern pattern = Pattern.compile("(\\S+\\s*){" + (start) + "}"
                 + "((\\S+\\s*){" + (end - start) + "}).*?");
         final Matcher matcher = pattern.matcher(line);

src/com/dmdirc/commandparser/commands/channel/Mode.java

@@ -69,10 +69,10 @@ public final class Mode extends ChannelCommand implements IntelligentCommand,
     @Override
     public void execute(final InputWindow origin, final Server server,
             final String channel, final boolean isSilent, final CommandArguments args) {
-        if (args.getArguments().length == 1) {
+        if (args.getArguments().length == 0) {
             server.getParser().sendRawMessage("MODE " + channel);
         } else {
-            server.getParser().sendRawMessage("MODE " + channel + " " + args.getArgumentsAsString(1));
+            server.getParser().sendRawMessage("MODE " + channel + " " + args.getArgumentsAsString());
         }
     }
 

src/com/dmdirc/commandparser/parsers/CommandParser.java

@@ -147,7 +147,8 @@ public abstract class CommandParser implements Serializable {
                     if (actCommand != null && actCommand.getValue() instanceof ExternalCommand) {
                         ((ExternalCommand) actCommand.getValue()).execute(
                                 origin, server, cargs[0], silent,
-                                new CommandArguments(args.getWordsAsString(2)));
+                                new CommandArguments(args.getCommandName()
+                                + " " + args.getWordsAsString(2)));
                         return;
                     }
                 }