Issue #3055474 by Gribnif, Berdir: template_preprocess_file_link will not work...

 *

 * @param array $variables

 *   An associative array containing:

 *   - file: A file object to which the link will be created.

 *   - file: A File entity to which the link will be created.

 *   - icon_directory: (optional) A path to a directory of icons to be used for

 *     files. Defaults to the value of the "icon.directory" variable.

 *   - description: A description to be displayed instead of the filename.

  $file = $variables['file'];

  $options = [];

  $file_entity = ($file instanceof File) ? $file : File::load($file->fid);

  // @todo Wrap in file_url_transform_relative(). This is currently

  // impossible. As a work-around, we currently add the 'url.site' cache context

  // to ensure different file URLs are generated for different sites in a

  // multisite setup, including HTTP and HTTPS versions of the same site.

  // Fix in https://www.drupal.org/node/2646744.

  $url = $file_entity->createFileUrl(FALSE);

  $url = $file->createFileUrl(FALSE);

  $variables['#cache']['contexts'][] = 'url.site';

  $mime_type = $file->getMimeType();

  // Use the description as the link text if available.

  if (empty($variables['description'])) {

    $link_text = $file_entity->getFilename();

    $link_text = $file->getFilename();

  }

  else {

    $link_text = $variables['description'];

    $options['attributes']['title'] = $file_entity->getFilename();

    $options['attributes']['title'] = $file->getFilename();

  }

  // Classes to add to the file field for icons.