Thanks, allowing for multiple group cookies in a hierarchy is a nice improvement.
> + if (tgi != tg) {
> + if (tgi->core_cookie || (tgi->core_parent &&
> tgi->core_parent != tg))
> + continue;
> +
> + tgi->core_parent = parent;
> + tgi->core_cookie = 0;
core_cookie must already be 0, given the check above.
