Thumbnail formatter does not set image width and height

I would love to write a patch for this but since this issue was closed as won't fix, we use a preprocess_field that does this:

    foreach ($variables['items'] as $i => $item) {
      if (isset($item['content']['#theme']) && $item['content']['#theme'] == 'image_style') {
        $image = \Drupal::service('image.factory')
          ->get($item['content']['#uri']);
        $variables['items'][$i]['content']['#width'] = $image->getWidth();
        $variables['items'][$i]['content']['#height'] = $image->getHeight();
      }
    }