Merge branch '4.4' into 5.0

* 4.4: (26 commits)
  [HttpClient] NativeHttpClient should not send >1.1 protocol version
  [HttpClient] fix support for non-blocking resource streams
  [Mailer] Make sure you can pass custom headers to Mailgun
  [Mailer] Remove line breaks in email attachment content
  Update links to documentation
  [Validator] Add the missing translations for the Arabic (ar) locale
  ensure to expect no validation for the right reasons
  [Security-Guard] fixed 35203 missing name tag in param docblock
  [HttpClient] fix casting responses to PHP streams
  [PhpUnitBridge] Add test case for @expectedDeprecation annotation
  [PhpUnitBridge][SymfonyTestsListenerTrait] Remove $testsWithWarnings stack
  [Mailer] Fix addresses management in Sendgrid API payload
  [Mailer][MailchimpBridge] Fix missing attachments when sending via Mandrill API
  [Mailer][MailchimpBridge] Fix incorrect sender address when sender has name
  [HttpClient] fix capturing SSL certificates with NativeHttpClient
  Update year in license files
  [TwigBridge][Form] Added missing help messages in form themes
  Update year in license files
  Update year in license files
  fix version when "anonymous: lazy" was introduced
  ...

LICENSE

@@ -1,4 +1,4 @@
-Copyright (c) 2019 Fabien Potencier
+Copyright (c) 2019-2020 Fabien Potencier
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

Tests/Transport/PostmarkApiTransportTest.php

@@ -13,6 +13,9 @@
 
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\Mailer\Bridge\Postmark\Transport\PostmarkApiTransport;
+use Symfony\Component\Mailer\Envelope;
+use Symfony\Component\Mime\Address;
+use Symfony\Component\Mime\Email;
 
 class PostmarkApiTransportTest extends TestCase
 {
@@ -41,4 +44,21 @@ public function getTransportData()
             ],
         ];
     }
+
+    public function testCustomHeader()
+    {
+        $email = new Email();
+        $email->getHeaders()->addTextHeader('foo', 'bar');
+        $envelope = new Envelope(new Address('alice@system.com'), [new Address('bob@system.com')]);
+
+        $transport = new PostmarkApiTransport('ACCESS_KEY');
+        $method = new \ReflectionMethod(PostmarkApiTransport::class, 'getPayload');
+        $method->setAccessible(true);
+        $payload = $method->invoke($transport, $email, $envelope);
+
+        $this->assertArrayHasKey('Headers', $payload);
+        $this->assertCount(1, $payload['Headers']);
+
+        $this->assertEquals(['Name' => 'foo', 'Value' => 'bar'], $payload['Headers'][0]);
+    }
 }

Transport/PostmarkApiTransport.php

@@ -84,7 +84,7 @@ private function getPayload(Email $email, Envelope $envelope): array
 
             $payload['Headers'][] = [
                 'Name' => $name,
-                'Value' => $header->toString(),
+                'Value' => $header->getBodyAsString(),
             ];
         }