theme_username() does not truncate "external" usernames

Haven't got 6.x-dev checked out, so haven't provided a patch yet, but basically theme_username() in includes/theme.inc does this:

function theme_username($object) {

  if ($object->uid && $object->name) {
    // Shorten the name when it is too long or it will break many tables.
    if (drupal_strlen($object->name) > 20) {
      $name = drupal_substr($object->name, 0, 15) .'...';
    }
    else {
      $name = $object->name;
    }

    if (user_access('access user profiles')) {
      $output = l($name, 'user/'. $object->uid, array('attributes' => array('title' => t('View user profile.'))));
    }
    else {
      $output = check_plain($name);
    }
  }
  else if ($object->name) {
    // Sometimes modules display content composed by people who are
    // not registered members of the site (e.g. mailing list or news
    // aggregator modules). This clause enables modules to display
    // the true author of the content.
    if (!empty($object->homepage)) {
      $output = l($object->name, $object->homepage, array('attributes' => array('rel' => 'nofollow')));
    }
    else {
      $output = check_plain($object->name);
    }

    $output .= ' ('. t('not verified') .')';
  }
  else {
    $output = check_plain(variable_get('anonymous', t('Anonymous')));
  }

  return $output;
}

The whole chunk for non-registered member name display doesn't do the truncating of long usernames. I propose altering it like so:

function theme_username($object) {
  // Shorten the name when it is too long or it will break many tables.
  if (drupal_strlen($object->name) > 9) {
    $name = drupal_substr($object->name, 0, 6) .'...';
  }
  else {
    $name = $object->name;
  }

  if ($object->uid && $object->name) {
    if (user_access('access user profiles')) {
      $output = l($name, 'user/'. $object->uid, array('attributes' => array('title' => t('View user profile.'))));
    }
    else {
      $output = check_plain($name);
    }
  }
  else if ($object->name) {
    // Sometimes modules display content composed by people who are
    // not registered members of the site (e.g. mailing list or news
    // aggregator modules). This clause enables modules to display
    // the true author of the content.
    if (!empty($object->homepage)) {
      $output = l($name, $object->homepage, array('attributes' => array('rel' => 'nofollow')));
    }
    else {
      $output = check_plain($name);
    }

    $output .= ' ('. t('not verified') .')';
  }
  else {
    $output = check_plain(variable_get('anonymous', t('Anonymous')));
  }

  return $output;
}