bug #22732 [Security] fix switch user _exit without having current to…

…ken (dmaicher)

This PR was merged into the 2.7 branch.

Discussion
----------

[Security] fix switch user _exit without having current token

| Q             | A
| ------------- | ---
| Branch?       | 2.7
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #22729
| License       | MIT
| Doc PR        | -

Attempting to `_exit` from a switched user caused an error when not having any token in the storage (for example happens when not logged in + disallowing anonymous users on that firewall):

`[1] Symfony\Component\Debug\Exception\FatalThrowableError: Type error: Argument 1 passed to Symfony\Component\Security\Http\Firewall\SwitchUserListener::getOriginalToken()
        must be an instance of Symfony\Component\Security\Core\Authentication\Token\TokenInterface, null given, called in
        symfony/symfony/src/Symfony/Component/Security/Http/Firewall/SwitchUserListener.php on line 164`

Commits
-------

16da686 [Security] fix switch user _exit without having current token

src/Symfony/Component/Security/Http/Firewall/SwitchUserListener.php

@@ -158,7 +158,7 @@ private function attemptSwitchUser(Request $request)
      */
     private function attemptExitUser(Request $request)
     {
-        if (false === $original = $this->getOriginalToken($this->tokenStorage->getToken())) {
+        if (null === ($currentToken = $this->tokenStorage->getToken()) || false === $original = $this->getOriginalToken($currentToken)) {
             throw new AuthenticationCredentialsNotFoundException('Could not find original Token object.');
         }
 

src/Symfony/Component/Security/Http/Tests/Firewall/SwitchUserListenerTest.php

@@ -65,6 +65,17 @@ public function testEventIsIgnoredIfUsernameIsNotPassedWithTheRequest()
         $this->assertNull($this->tokenStorage->getToken());
     }
 
+    /**
+     * @expectedException \Symfony\Component\Security\Core\Exception\AuthenticationCredentialsNotFoundException
+     */
+    public function testExitUserThrowsAuthenticationExceptionIfNoCurrentToken()
+    {
+        $this->tokenStorage->setToken(null);
+        $this->request->query->set('_switch_user', '_exit');
+        $listener = new SwitchUserListener($this->tokenStorage, $this->userProvider, $this->userChecker, 'provider123', $this->accessDecisionManager);
+        $listener->handle($this->event);
+    }
+
     /**
      * @expectedException \Symfony\Component\Security\Core\Exception\AuthenticationCredentialsNotFoundException
      */