Merge branch '5.3' into 5.4

* 5.3:
  fix tests (ter)
  Fix tests (bis)
  [travis] fix travis hopefuly
  [PasswordHasher] Prevent PHP fatal error when using auto algorithm
  [Security] Fix SerializableUser fixture
  [FrameworkBundle][WebProfilerBundle] Don't pass null to string parameters

Author: nicolas-grekas

Hasher/PasswordHasherFactory.php

@@ -116,9 +116,13 @@ private function getHasherConfigFromAlgorithm(array $config): array
         if ('auto' === $config['algorithm']) {
             // "plaintext" is not listed as any leaked hashes could then be used to authenticate directly
             if (SodiumPasswordHasher::isSupported()) {
-                $algorithms = ['native', 'sodium', 'pbkdf2', $config['hash_algorithm']];
+                $algorithms = ['native', 'sodium', 'pbkdf2'];
             } else {
-                $algorithms = ['native', 'pbkdf2', $config['hash_algorithm']];
+                $algorithms = ['native', 'pbkdf2'];
+            }
+
+            if ($config['hash_algorithm'] ?? '') {
+                $algorithms[] = $config['hash_algorithm'];
             }
 
             $hasherChain = [];

Tests/Hasher/PasswordHasherFactoryTest.php

@@ -18,6 +18,7 @@
 use Symfony\Component\PasswordHasher\Hasher\PasswordHasherAwareInterface;
 use Symfony\Component\PasswordHasher\Hasher\PasswordHasherFactory;
 use Symfony\Component\PasswordHasher\Hasher\SodiumPasswordHasher;
+use Symfony\Component\PasswordHasher\PasswordHasherInterface;
 use Symfony\Component\Security\Core\Encoder\PlaintextPasswordEncoder;
 use Symfony\Component\Security\Core\User\InMemoryUser;
 use Symfony\Component\Security\Core\User\UserInterface;
@@ -85,6 +86,16 @@ public function testGetHasherConfiguredForConcreteClassWithClassName()
         $this->assertEquals($expectedHasher->hash('foo', ''), $hasher->hash('foo', ''));
     }
 
+    public function testGetHasherConfiguredWithAuto()
+    {
+        $factory = new PasswordHasherFactory([
+            'auto' => ['algorithm' => 'auto'],
+        ]);
+
+        $hasher = $factory->getPasswordHasher('auto');
+        $this->assertInstanceOf(PasswordHasherInterface::class, $hasher);
+    }
+
     public function testGetNamedHasherForHasherAware()
     {
         $factory = new PasswordHasherFactory([