specific exception when no login info found in session

Lib/Exception/AuthenticationException.php

@@ -12,4 +12,5 @@ class AuthenticationException extends WebException {
     const USER_NOT_FOUND = 200;
     const BAD_LOGIN = 201;
     const AUTHENTICATION_FAILED = 202;
+    const LOGIN_EMPTY = 203;
 }

NetBiblio.php

@@ -13,7 +13,7 @@ use BSR\Lib\WebService;
 class NetBiblio extends WebService
 {
     /** @var string $version version number */
-    public static $version = '1.1.0';
+    public static $version = '1.1.1';
 
     private $login = '';
     private $client = 'website';
@@ -28,7 +28,7 @@ class NetBiblio extends WebService
      */
     private function CheckSession()
     {
-        if (! isset ($_SESSION["user"]["login"])) {
+        if (! isset ($_SESSION["user"]["login"]) || empty($_SESSION["user"]["login"])) {
             return;
         }
 
@@ -53,6 +53,10 @@ class NetBiblio extends WebService
 
         $this->checkSession();
 
+        if(strlen($this->login) == 0) {
+            throw new AuthenticationException("LoginEmpty", "No login information found in session.", AuthenticationException::LOGIN_EMPTY);
+        }
+
         $user = User::find($this->login);
 
         if (!$user) {