title: PrintWriter getting set with error flag on redirection
body: <p>I am developing a web application which uses DWR for push mechanism. I observed the <code>PrintWriter</code> class in <code>HttpServletResponse</code> is getting set with an error. 
  Logic: 
  dwr's custom flush method:</p>
  
  <pre>
  
      PrintWriter out = reponse.getWriter(); 
      public boolean flush() { 
          out.flush(); 
          if (out.checkError()) { 
              /* Error occurred while sending the response, so resend the response in the next push */ 
              return false; 
          } 
          /* response sent successfully */ 
          return true; 
      }
  
  </pre>
  
  <p>The strange thing is that even though PrintWriter with error successfully sends response to client side, since in the above code out.checkError() will return true, response will be resent to client.</p>
  
  <p>On further observation i found that the following statement getting logged everytime when this kind of misbehavior is there: 
     WARN:oejh.HttpGenerator:Ignoring extra content </p>
  
  <p>This is dependent on browser type and this is happening in chrome, firefox and not in opera, IE. </p>
  
  <ol>
  <li>Is this (HttpGenerator: Ignoring extra content) going update anything to PrintWriter ? </li>
  <li>When PrintWriter sets error flag ? </li>
  <li>How browsers response to this kind of response (HttpGenerator: Ignoring extra content) ? </li>
  </ol>
  
  <p>Server: jetty-7.6.3
  DWR: dwr-3.0.0-RC3-dev-425</p>