title: Ember this.render not working with controller param
body: <p>i have a website with an {{outlet sidebar}} to display the navigation menu.</p>
  
  <p>Because the navigation-menu have to be rendered independent of the current route, it starts to get complicated for me.</p>
  
  <p>As a first try, use this code:</p>
  
  <pre><code>Ember.Route.reopen({
      renderTemplate: function() {
          this.render();
          this.render('layout/sidebar', {
              into: 'application',
              outlet: 'sidebar'
           });
      }
  });
  </code></pre>
  
  <p>to overwrite the <code>renderTemplate</code> method of each route within my application.
  And it worked fine.</p>
  
  <p>But if I add the navigation-controller to be passed through, it does not work anymore. </p>
  
  <pre><code>Ember.Route.reopen({
      renderTemplate: function() {
          var navCont = this.controllerFor('navigation');
  
          this.render();
          this.render('layout/sidebar', {
              into: 'application',
              outlet: 'sidebar',
              controller: navCont
           });
      }
  });
  </code></pre>
  
  <p>I checked the var navCont and it holds the navigation-controller as expected.</p>
  
  <p>Does anyone know why it works without the controller?</p>