Implement node flags

user.php

@@ -61,13 +61,14 @@ switch ($submit = form_get_action()) {
         $role_manage = sanitize($_POST['role_manage']);
         $role_admin = sanitize($_POST['role_admin']);
 
-        // construct menu set
+        // construct role set
         $role = array();
         if ($role_add) $role[] = 'add';
         if ($role_edit) $role[] = 'edit';
         if ($role_delete) $role[] = 'delete';
         if ($role_manage) $role[] = 'manage';
         if ($role_admin) $role[] = 'admin';
+        $role = empty($role) ? NULL : implode(',', $role);
 
         $sql = "UPDATE user SET
                     user_name=?, user_displayname=?, user_realm=?,
@@ -75,7 +76,7 @@ switch ($submit = form_get_action()) {
                 WHERE user_id=?";
         $sth = $dbh->prepare($sql);
         $sth->execute([$user_name ,$user_displayname, $user_realm,
-                       implode(',', $role), $id]);
+                       $role, $id]);
         $action = ACT_VIEW;
         break;