// When not yet set, use $handler or detect the preferred handler (string = string, otherwise serialize)
if (empty($this->content_handler) && empty($handler)) // (1)
{
if ( ! empty($handler)) // (2)
{
Due to (1), empty($handler) in (2) is always true, so cond is always false and never fire. I can't understand exactly what this code should do so i can't write fix commit, only issue