bug #45452 [Security] Fix UserNotFoundException is not thrown (damienfa)

This PR was merged into the 6.1 branch.

Discussion
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[Security] Fix UserNotFoundException is not thrown

| Q             | A
| ------------- | ---
| Branch?       |  5.4
| Bug fix?      | yes
| New feature?  | no
| Deprecations? | no
| Tickets       | Fix #45070
| License       | MIT
| Doc PR        |  N/A

Commits
-------

7e0ed85d9a Fix issue 45070 :  UserNotFoundException is not thrown

Author: fabpot

Authenticator/Passport/Badge/UserBadge.php

@@ -13,6 +13,7 @@
 
 use Symfony\Component\Security\Core\Exception\AuthenticationException;
 use Symfony\Component\Security\Core\Exception\AuthenticationServiceException;
+use Symfony\Component\Security\Core\Exception\UserNotFoundException;
 use Symfony\Component\Security\Core\User\UserInterface;
 use Symfony\Component\Security\Http\EventListener\UserProviderListener;
 
@@ -66,6 +67,15 @@ public function getUser(): UserInterface
             }
 
             $user = ($this->userLoader)($this->userIdentifier);
+
+            // No user has been found via the $this->userLoader callback
+            if (null === $user) {
+                $exception = new UserNotFoundException();
+                $exception->setUserIdentifier($this->userIdentifier);
+
+                throw $exception;
+            }
+
             if (!$user instanceof UserInterface) {
                 throw new AuthenticationServiceException(sprintf('The user provider must return a UserInterface object, "%s" given.', get_debug_type($this->user)));
             }