bug #36417 Force ping after transport exception (oesteve)

This PR was merged into the 4.4 branch.

Discussion
----------

Force ping after transport exception

| Q             | A
| ------------- | ---
| Branch?       | 4.4
| Bug fix?      | yes
| New feature?  | no
| Deprecations? | no
| Tickets       | Fix #36301
| License       | MIT
| Doc PR        |

SMTP transport fails for long running processes after tranport exception, if stream is closed all messages will throw a transport exception until $lastMessageTime exceds $pingThreshold.

With this PR, after transport expception the transport will ping the server to check if the connection is still alive.

Commits
-------

7ccbef6 Force ping after transport Exception

src/Symfony/Component/Mailer/Tests/Transport/Smtp/SmtpTransportTest.php

@@ -13,6 +13,7 @@
 
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\Mailer\Envelope;
+use Symfony\Component\Mailer\Exception\TransportException;
 use Symfony\Component\Mailer\Transport\Smtp\SmtpTransport;
 use Symfony\Component\Mailer\Transport\Smtp\Stream\AbstractStream;
 use Symfony\Component\Mailer\Transport\Smtp\Stream\SocketStream;
@@ -43,6 +44,29 @@ public function testSendDoesNotPingBelowThreshold(): void
         $this->assertNotContains("NOOP\r\n", $stream->getCommands());
     }
 
+    public function testSendPingAfterTransportException(): void
+    {
+        $stream = new DummyStream();
+        $envelope = new Envelope(new Address('sender@example.org'), [new Address('recipient@example.org')]);
+
+        $transport = new SmtpTransport($stream);
+        $transport->send(new RawMessage('Message 1'), $envelope);
+        $stream->close();
+        $catch = false;
+
+        try {
+            $transport->send(new RawMessage('Message 2'), $envelope);
+        } catch (TransportException $exception) {
+            $catch = true;
+        }
+        $this->assertTrue($catch);
+        $this->assertTrue($stream->isClosed());
+
+        $transport->send(new RawMessage('Message 3'), $envelope);
+
+        $this->assertFalse($stream->isClosed());
+    }
+
     public function testSendDoesPingAboveThreshold(): void
     {
         $stream = new DummyStream();
@@ -76,13 +100,23 @@ class DummyStream extends AbstractStream
      */
     private $commands;
 
+    /**
+     * @var bool
+     */
+    private $closed = true;
+
     public function initialize(): void
     {
+        $this->closed = false;
         $this->nextResponse = '220 localhost';
     }
 
     public function write(string $bytes, $debug = true): void
     {
+        if ($this->closed) {
+            throw new TransportException('Unable to write bytes on the wire.');
+        }
+
         $this->commands[] = $bytes;
 
         if (0 === strpos($bytes, 'DATA')) {
@@ -120,4 +154,14 @@ protected function getReadConnectionDescription(): string
     {
         return 'null';
     }
+
+    public function close(): void
+    {
+        $this->closed = true;
+    }
+
+    public function isClosed(): bool
+    {
+        return $this->closed;
+    }
 }

src/Symfony/Component/Mailer/Transport/Smtp/SmtpTransport.php

@@ -206,12 +206,11 @@ protected function doSend(SentMessage $message): void
             $this->stream->flush();
             $this->executeCommand("\r\n.\r\n", [250]);
             $message->appendDebug($this->stream->getDebug());
+            $this->lastMessageTime = microtime(true);
         } catch (TransportExceptionInterface $e) {
             $e->appendDebug($this->stream->getDebug());
-
+            $this->lastMessageTime = 0;
             throw $e;
-        } finally {
-            $this->lastMessageTime = microtime(true);
         }
     }