WordPress Version: 6.4
/**
* Filters post thumbnail lookup to set the post thumbnail.
*
* @since 4.6.0
* @access private
*
* @param null|array|string $value The value to return - a single metadata value, or an array of values.
* @param int $post_id Post ID.
* @param string $meta_key Meta key.
* @return null|array The default return value or the post thumbnail meta array.
*/
function _wp_preview_post_thumbnail_filter($value, $post_id, $meta_key)
{
$post = get_post();
if (!$post) {
return $value;
}
if (empty($_REQUEST['_thumbnail_id']) || empty($_REQUEST['preview_id']) || $post->ID !== $post_id || $post_id !== (int) $_REQUEST['preview_id'] || '_thumbnail_id' !== $meta_key || 'revision' === $post->post_type) {
return $value;
}
$thumbnail_id = (int) $_REQUEST['_thumbnail_id'];
if ($thumbnail_id <= 0) {
return '';
}
return (string) $thumbnail_id;
}