PHP: Prevent Theme from Updating

theme_update.php

<?php

add_filter( 'http_request_args', 'gs_prevent_theme_update', 5, 2 );
/**
 * Don't update theme from .org repo.
 *
 * If there is a theme in the repo with the same name,
 * this prevents WP from prompting an update. Future proofs themes.
 *
 * @since 1.1.0
 *
 * @author Mark Jaquith
 * @author Travis Smith
 * @link   http://markjaquith.wordpress.com/2009/12/14/excluding-your-plugin-or-theme-from-update-checks/
 */
function gs_prevent_theme_update( $r, $url ) {
	if ( 0 !== strpos( $url, 'http://api.wordpress.org/themes/update-check' ) ) {
		// Not a theme update request. Bail immediately.
		return $r;
	}
	$themes = unserialize( preg_replace( '!s:(\d+):"(.*?)";!e', "'s:'.strlen('$2').':\"$2\";'", $r['body']['themes'] ) );
	unset( $themes[ get_option( 'template' ) ] );
	unset( $themes[ get_option( 'stylesheet' ) ] );
	$r['body']['themes'] = serialize( $themes );
	return $r;
}