Merge branch '6.0' into 6.1

* 6.0:
  [Console] Fixes "Incorrectly nested style tag found" error when using multi-line header content
  Fix LDAP connection options
  fix probably undefined variable $expireAt
  Fix aliases handling in command name completion
  Fix division by zero
  Allow ErrorHandler ^5.0 to be used in HttpKernel
  [Security/Http] Ignore invalid URLs found in failure/success paths
  Fix typo

CsrfTokenManager.php

@@ -136,6 +136,9 @@ private function derandomize(string $value): string
             return $value;
         }
         $key = base64_decode(strtr($parts[1], '-_', '+/'));
+        if ('' === $key || false === $key) {
+            return $value;
+        }
         $value = base64_decode(strtr($parts[2], '-_', '+/'));
 
         return $this->xor($value, $key);

Tests/CsrfTokenManagerTest.php

@@ -193,6 +193,26 @@ public function testNonExistingTokenIsNotValid($namespace, $manager, $storage)
         $this->assertFalse($manager->isTokenValid(new CsrfToken('token_id', 'FOOBAR')));
     }
 
+    public function testTokenShouldNotTriggerDivisionByZero()
+    {
+        [$generator, $storage] = $this->getGeneratorAndStorage();
+        $manager = new CsrfTokenManager($generator, $storage);
+
+        // Scenario: the token that was returned is abc.def.ghi, and gets modified in the browser to abc..ghi
+
+        $storage->expects($this->once())
+            ->method('hasToken')
+            ->with('https-token_id')
+            ->willReturn(true);
+
+        $storage->expects($this->once())
+            ->method('getToken')
+            ->with('https-token_id')
+            ->willReturn('def');
+
+        $this->assertFalse($manager->isTokenValid(new CsrfToken('token_id', 'abc..ghi')));
+    }
+
     /**
      * @dataProvider getManagerGeneratorAndStorage
      */