WordPress redirect single search result

gistfile1.aw

<?php

add_action( 'template_redirect', 'kkf_single_search_redirect' );
/**
 * If only one search result match, automatically redirect to that result.
 * 
 * @author Michael Bishop
 * @link   https://gist.github.com/2437076
 *
 * @global WP_Query $wp_query Query object.
 * 
 * @return null Returns early if not a search query.
 */
function kkf_single_search_redirect() {
	if ( ! is_search() )
		return;
	
	global $wp_query;
	if ( 1 == $wp_query->post_count ) {
		wp_redirect( get_permalink( $wp_query->posts['0']->ID ) );
		exit;
	}
}