Support legacy HTTP servers that use only LF instead of CRLF

src/Request.php

@@ -134,7 +134,8 @@ public function handleData($data)
     {
         $this->buffer .= $data;
 
-        if (false !== strpos($this->buffer, "\r\n\r\n")) {
+        // buffer until double CRLF (or double LF for compatibility with legacy servers)
+        if (false !== strpos($this->buffer, "\r\n\r\n") || false !== strpos($this->buffer, "\n\n")) {
             try {
                 list($response, $bodyChunk) = $this->parseResponse($this->buffer);
             } catch (\InvalidArgumentException $exception) {

tests/FunctionalIntegrationTest.php

@@ -29,6 +29,29 @@ public function testRequestToLocalhostEmitsSingleRemoteConnection()
         $loop->run();
     }
 
+    public function testRequestLegacyHttpServerWithOnlyLineFeedReturnsSuccessfulResponse()
+    {
+        $loop = Factory::create();
+
+        $server = new Server(0, $loop);
+        $server->on('connection', function (ConnectionInterface $conn) use ($server) {
+            $conn->end("HTTP/1.0 200 OK\n\nbody");
+            $server->close();
+        });
+
+        $client = new Client($loop);
+        $request = $client->request('GET', str_replace('tcp:', 'http:', $server->getAddress()));
+
+        $once = $this->expectCallableOnceWith('body');
+        $request->on('response', function (Response $response) use ($once) {
+            $response->on('data', $once);
+        });
+
+        $request->end();
+
+        $loop->run();
+    }
+
     /** @group internet */
     public function testSuccessfulResponseEmitsEnd()
     {

tests/TestCase.php

@@ -26,6 +26,17 @@ protected function expectCallableOnce()
         return $mock;
     }
 
+    protected function expectCallableOnceWith($value)
+    {
+        $mock = $this->createCallableMock();
+        $mock
+            ->expects($this->once())
+            ->method('__invoke')
+            ->with($value);
+
+        return $mock;
+    }
+
     protected function expectCallableNever()
     {
         $mock = $this->createCallableMock();