bug #32141 [HttpClient] fix dealing with 1xx informational responses (nicolas-grekas)

This PR was merged into the 4.3 branch.

Discussion
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[HttpClient] fix dealing with 1xx informational responses

| Q             | A
| ------------- | ---
| Branch?       | 4.3
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | -
| License       | MIT
| Doc PR        | -

I never had a look at 1xx status codes until today.
This PR fixes reading them when using curl.

If one wonders:
- `NativeHttpClient` uses `fopen()`, which skips informational parts as allowed by the HTTP spec and doesn't give any way to access their response headers.
- `CurlHttpClient` allows reading informational responses using the progress callback or via the getInfo() method. That's the way if you need to implement e.g. HTTP 103 early hints.

Commits
-------

412411d795 [HttpClient] fix dealing with 1xx informational responses

src/Symfony/Component/HttpClient/Response/CurlResponse.php

@@ -287,7 +287,19 @@ final class CurlResponse implements ResponseInterface
             // Regular header line: add it to the list
             self::addResponseHeaders([substr($data, 0, -2)], $info, $headers);
 
-            if (0 === strpos($data, 'HTTP') && 300 <= $info['http_code'] && $info['http_code'] < 400) {
+            if (0 !== strpos($data, 'HTTP/')) {
+                if (0 === stripos($data, 'Location:')) {
+                    $location = trim(substr($data, 9, -2));
+                }
+
+                return \strlen($data);
+            }
+
+            if (\function_exists('openssl_x509_read') && $certinfo = curl_getinfo($ch, CURLINFO_CERTINFO)) {
+                $info['peer_certificate_chain'] = array_map('openssl_x509_read', array_column($certinfo, 'Cert'));
+            }
+
+            if (300 <= $info['http_code'] && $info['http_code'] < 400) {
                 if (curl_getinfo($ch, CURLINFO_REDIRECT_COUNT) === $options['max_redirects']) {
                     curl_setopt($ch, CURLOPT_FOLLOWLOCATION, false);
                 } elseif (303 === $info['http_code'] || ('POST' === $info['http_method'] && \in_array($info['http_code'], [301, 302], true))) {
@@ -296,15 +308,14 @@ final class CurlResponse implements ResponseInterface
                 }
             }
 
-            if (0 === stripos($data, 'Location:')) {
-                $location = trim(substr($data, 9, -2));
-            }
-
             return \strlen($data);
         }
 
         // End of headers: handle redirects and add to the activity list
-        $statusCode = curl_getinfo($ch, CURLINFO_RESPONSE_CODE);
+        if (200 > $statusCode = curl_getinfo($ch, CURLINFO_RESPONSE_CODE)) {
+            return \strlen($data);
+        }
+
         $info['redirect_url'] = null;
 
         if (300 <= $statusCode && $statusCode < 400 && null !== $location) {
@@ -334,10 +345,6 @@ final class CurlResponse implements ResponseInterface
                 return 0;
             }
 
-            if (\function_exists('openssl_x509_read') && $certinfo = curl_getinfo($ch, CURLINFO_CERTINFO)) {
-                $info['peer_certificate_chain'] = array_map('openssl_x509_read', array_column($certinfo, 'Cert'));
-            }
-
             curl_setopt($ch, CURLOPT_PRIVATE, 'content');
         } elseif (null !== $info['redirect_url'] && $logger) {
             $logger->info(sprintf('Redirecting: "%s %s"', $info['http_code'], $info['redirect_url']));

src/Symfony/Contracts/HttpClient/Test/Fixtures/web/index.php

@@ -41,6 +41,17 @@ switch ($vars['REQUEST_URI']) {
         ob_start('ob_gzhandler');
         break;
 
+    case '/103':
+        header('HTTP/1.1 103 Early Hints');
+        header('Link: </style.css>; rel=preload; as=style', false);
+        header('Link: </script.js>; rel=preload; as=script', false);
+        echo "HTTP/1.1 200 OK\r\n";
+        echo "Date: Fri, 26 May 2017 10:02:11 GMT\r\n";
+        echo "Content-Length: 13\r\n";
+        echo "\r\n";
+        echo 'Here the body';
+        exit;
+
     case '/404':
         header('Content-Type: application/json', true, 404);
         break;

src/Symfony/Contracts/HttpClient/Test/HttpClientTestCase.php

@@ -721,6 +721,15 @@ abstract class HttpClientTestCase extends TestCase
         $this->assertSame('/?a=a&b=b', $body['REQUEST_URI']);
     }
 
+    public function testInformationalResponse()
+    {
+        $client = $this->getHttpClient(__FUNCTION__);
+        $response = $client->request('GET', 'http://localhost:8057/103');
+
+        $this->assertSame('Here the body', $response->getContent());
+        $this->assertSame(200, $response->getStatusCode());
+    }
+
     /**
      * @requires extension zlib
      */