* Fix wrong setting of sessionVar.

module/misc/config.php

@@ -2,3 +2,5 @@
 $config->misc->api     = 'https://api.zentao.net';
 $config->misc->enApi   = 'https://api.zentao.pm';
 $config->misc->qucheng = 'https://www.qucheng.com';
+
+$config->misc->disabledSessionVar = array('user', 'tutorialmode');

module/misc/control.php

@@ -179,7 +179,7 @@ class misc extends control
     /**
      * Show version changelog
      * @access public
-     * @return viod
+     * @return void
      */
     public function changeLog($version = '')
     {
@@ -224,13 +224,13 @@ class misc extends control
      * Show captcha and save to session.
      *
      * @param  string $sessionVar
-     * @param  string $uuid
      * @access public
      * @return void
      */
-    public function captcha($sessionVar = 'captcha', $uuid = '')
+    public function captcha($sessionVar = 'captcha')
     {
-        if($sessionVar == 'user') die('The string user is not allowed to be defined as a session field.');
+        if(in_array(strtolower($sessionVar), $this->config->misc->disabledSessionVar)) die("The string {$sessionVar} is not allowed to be defined as a session field.");
+
         $obLevel = ob_get_level();
         for($i = 0; $i < $obLevel; $i++) ob_end_clean();