iis7_save_url_rewrite_rules(): bool|null

302function iis7_save_url_rewrite_rules() {303	global $wp_rewrite;304 305	if ( is_multisite() ) {306		return null;307	}308 309	// Ensure get_home_path() is declared.310	require_once ABSPATH . 'wp-admin/includes/file.php';311 312	$home_path       = get_home_path();313	$web_config_file = $home_path . 'web.config';314 315	// Using win_is_writable() instead of is_writable() because of a bug in Windows PHP.316	if ( iis7_supports_permalinks()317		&& ( ! file_exists( $web_config_file ) && win_is_writable( $home_path ) && $wp_rewrite->using_mod_rewrite_permalinks()318			|| win_is_writable( $web_config_file ) )319	) {320		$rule = $wp_rewrite->iis7_url_rewrite_rules( false );321 322		if ( ! empty( $rule ) ) {323			return iis7_add_rewrite_rule( $web_config_file, $rule );324		} else {325			return iis7_delete_rewrite_rule( $web_config_file );326		}327	}328 329	return false;330}