Class active-trail not added to li element when linking to front page

The following workaround code was adapted from #64. It corrects the problem of flagging all routes of the same name by also comparing the route parameters.

/**
 * Prepares variables for block__system_menu_block templates.
 *
 * Work around an issue where front page menu links are not set in the
 * active trail.
 *
 * Default template: block.html.twig.
 *
 * @see https://www.drupal.org/project/drupal/issues/1578832
 */
function my_theme_preprocess_block__system_menu_block(&$variables) {
  if (!\Drupal::service('path.matcher')->isFrontPage()) {
    return;
  }

  $homepage_path = \Drupal::config('system.site')->get('page.front');
  $homepage_url = \Drupal::service('path.validator')->getUrlIfValid($homepage_path);
  if (!$homepage_url instanceof Url) {
    return;
  }

  foreach ($variables['content']['#items'] as $key => $item) {
    /** @var \Drupal\Core\Url $url */
    $url = $item['url'];
    if (!($url instanceof Url) || !$url->isRouted()) {
      continue;
    }

    $is_front = $url->getRouteName() == '<front>';
    $is_configured_route = $url->getRouteName() == $homepage_url->getRouteName() &&
      $url->getRouteParameters() == $homepage_url->getRouteParameters();
    if ($is_front || $is_configured_route) {
      $variables['content']['#items'][$key]['in_active_trail'] = TRUE;
    }
  }
}