How can I set a draft page as parent without publishing?

Anyone know a way round this?

http://wordpress.org/support/topic/set-draft-page-as-parent

I can’t risk publishing as a public-facing system updates periodically from the same install.

This works for me:

add_filter('page_attributes_dropdown_pages_args', 'my_attributes_dropdown_pages_args', 1, 1);

function my_attributes_dropdown_pages_args($dropdown_args) {

    $dropdown_args['post_status'] = array('publish','draft');

    return $dropdown_args;
}