Merge branch '4.4'

* 4.4:
  [Cache] Fixed undefined variable in ArrayTrait
  [HttpClient] revert bad logic around JSON_THROW_ON_ERROR
  [HttpKernel] Fix handling non-catchable fatal errors
  Fix json-encoding when JSON_THROW_ON_ERROR is used
  [HttpFoundation] work around PHP 7.3 bug related to json_encode()
  [HttpClient] add $response->cancel()
  [Security] added support for updated \"distinguished name\" format in x509 authentication

HttpClient/Test/HttpClientTestCase.php

@@ -495,6 +495,16 @@ public function testPostCallback()
         $this->assertSame(['foo' => '0123456789', 'REQUEST_METHOD' => 'POST'], $response->toArray());
     }
 
+    public function testCancel()
+    {
+        $client = $this->getHttpClient(__FUNCTION__);
+        $response = $client->request('GET', 'http://localhost:8057/timeout-header');
+
+        $response->cancel();
+        $this->expectException(TransportExceptionInterface::class);
+        $response->getHeaders();
+    }
+
     public function testOnProgressCancel()
     {
         $client = $this->getHttpClient(__FUNCTION__);