Null out message buffer before calling onMessage handler

src/Messaging/MessageBuffer.php

@@ -98,13 +98,15 @@ class MessageBuffer {
 
         if ($this->messageBuffer->isCoalesced()) {
             $msgCheck = $this->checkMessage($this->messageBuffer);
+
+            $msgBuffer = $this->messageBuffer;
+            $this->messageBuffer = null;
+
             if (true !== $msgCheck) {
                 $onControl($this->newCloseFrame($msgCheck, 'Ratchet detected an invalid UTF-8 payload'));
             } else {
-                $onMessage($this->messageBuffer);
+                $onMessage($msgBuffer);
             }
-
-            $this->messageBuffer = null;
         }
 
         return $overflow;

tests/unit/Messaging/MessageBufferTest.php

@@ -6,6 +6,7 @@ use Ratchet\RFC6455\Messaging\CloseFrameChecker;
 use Ratchet\RFC6455\Messaging\Frame;
 use Ratchet\RFC6455\Messaging\Message;
 use Ratchet\RFC6455\Messaging\MessageBuffer;
+use React\EventLoop\Factory;
 
 class MessageBufferTest extends \PHPUnit_Framework_TestCase
 {
@@ -36,4 +37,36 @@ class MessageBufferTest extends \PHPUnit_Framework_TestCase
 
         $this->assertEquals(1000, $messageCount);
     }
+
+    public function testProcessingMessagesAsynchronouslyWhileBlockingInMessageHandler() {
+        $loop = Factory::create();
+
+        $frameA = new Frame('a', true, Frame::OP_TEXT);
+        $frameB = new Frame('b', true, Frame::OP_TEXT);
+
+        $bReceived = false;
+
+        $messageBuffer = new MessageBuffer(
+            new CloseFrameChecker(),
+            function (Message $message) use (&$messageCount, &$bReceived, $loop) {
+                $payload = $message->getPayload();
+                $bReceived = $payload === 'b';
+
+                if (!$bReceived) {
+                    $loop->run();
+                }
+            },
+            null,
+            false
+        );
+
+        $loop->addPeriodicTimer(0.1, function () use ($messageBuffer, $frameB, $loop) {
+            $loop->stop();
+            $messageBuffer->onData($frameB->getContents());
+        });
+
+        $messageBuffer->onData($frameA->getContents());
+
+        $this->assertTrue($bReceived);
+    }
 }