Undefined property: views_plugin_display_page::$output in view->render()

At line 957 in the current 7.x-dev the display handler output is used before it is set.

      // Let the theme play too, because pre render is a very themey thing.
      $function = $GLOBALS['theme'] . '_views_pre_render';
      if (function_exists($function)) {
        $function($this, $this->display_handler->output, $cache); <--USED HERE
      }

      // Give field handlers the opportunity to perform additional queries
      // using the entire resultset prior to rendering.
      if ($this->style_plugin->uses_fields()) {
        foreach ($this->field as $id => $handler) {
          if (!empty($this->field[$id])) {
            $this->field[$id]->pre_render($this->result);
          }
        }
      }
      $this->display_handler->output = $this->display_handler->render(); <--SET HERE

When a theme_views_pre_render() function is used the following error is generated:

Notice: Undefined property: views_plugin_display_page::$output in view->render() (line 861 of /var/www/html/sites/all/modules/contrib/views/includes/view.inc).

Potential fix is to not attempt to pass the unrendered output. Patch below fixes issue.