Sorting Posts by Expiration Date (patch included)

Whenever someone clicked the Expiration Date column to sort it, WordPress returned an empty set. I got sorting working properly by adding the following code to the plugin:

function expirationdate_column_orderby($vars){
	if(isset($vars['orderby']) && 'expirationdate' == $vars['orderby'] ) {
		$vars = array_merge($vars, array(
			'meta_key' => '_expiration-date',
			'orderby' => 'meta_value_num'
		));
	}

	return $vars;
}
add_filter('request','expirationdate_column_orderby');

If you’re on GitHub I can submit a pull request.

http://ww.wp.xz.cn/plugins/post-expirator/