[Plugin: WordPress MU Domain Mapping] undefined GETs

in redirect_login_to_orig it requests directly the $_GET[‘action’] this will work but is not desired:

a) it will trigger a php notics “Notice: Undefined index: action in /opt/htdocs/html/wp-content/mu-plugins/domain_mapping.php on line 647” for users who have php turned on to show notices
b) it is no longer preferred to query $_GET directly but use filter_input(INPUT_GET, ‘action’, FILTER_SANITIZE_STRING); instead (see http://php.net/manual/en/function.filter-input.php)

e.g. replacing it with:

$action = filter_input(INPUT_GET,  'action', FILTER_SANITIZE_STRING);
	if ( !get_site_option( 'dm_remote_login' ) || $action == 'logout' || isset( $_GET[ 'loggedout' ] ) ) {
		return false;
	}

removes the php notice

You could also use

$action = filter_input(INPUT_GET, 'action', FILTER_CALLBACK, $options);

to callback to the list of available actions

now for the “loggedout” you could use FILTER_NULL_ON_FAILURE instead

http://ww.wp.xz.cn/extend/plugins/wordpress-mu-domain-mapping/