drush_shutdown() prints non-bootstrap error when bootstrap has occurred in d7

drush_shutdown() contains the following test:

  if (!function_exists('drupal_set_content')) {
    $message = "E: Drush was not able to start (bootstrap) Drupal.\n";
    $message .= "Hint: This error often occurs when Drush is trying to bootstrap a site\n";
    $message .= "that has not been installed or does not have a configured \$db_url.\n";
    $message .= "Drush was looking in the site '$conf_path'. You can select another site\n";
    $message .= "with a working database setup by specifying the URI to use with the --uri\n";
    $message .= "parameter on the command line or \$options['uri'] in your drushrc.php file.\n";
    die($message);
  }

drupal_set_content() does not exist in the current source tree for Drupal 7. In the interests of helpfulness, I've attached a patch which sets the function to be tested to drupal_set_message(), but it could be any function that exists in all supported versions of Drupal.

Cheers

Stuart