Fixes issue 3515: Twitter parser NPEs in the ctor if you dont give it a user

Change-Id: I754c511f161c0ba4ef1b1cba36e0c8a6d9e9e717
Reviewed-on: http://gerrit.dmdirc.com/743
Automatic-Compile: DMDirc Local Commits <dmdirc@googlemail.com>
Reviewed-by: Chris Smith <chris@dmdirc.com>

src/com/dmdirc/addons/parser_twitter/Twitter.java

      * @param myPlugin Plugin that created this parser
      */
     protected Twitter(final MyInfo myInfo, final URI address, final TwitterPlugin myPlugin) {
-        final String[] bits = address.getUserInfo().split(":");
-        this.myUsername = bits[0];
+        final String[] bits;
+        if (address.getUserInfo() == null) {
+            bits = new String[]{};
+        } else {
+            bits = address.getUserInfo().split(":");
+        }
+        this.myUsername = bits.length == 0 ? "" : bits[0];
         this.myPassword = (bits.length > 1) ? bits[1] : "";
 
         this.myPlugin = myPlugin;
     public void run() {
         resetState();
 
+        if (myUsername.isEmpty()) {
+            sendPrivateNotice("Unable to connect to "+myServerName+" without a username. Disconnecting.");
+            getCallbackManager().getCallbackType(SocketCloseListener.class).call();
+            return;
+        }
+
         // Get the consumerKey and consumerSecret for this server if known
         // else default to our twitter key and secret
         final String consumerKey;