bug symfony#59689 [HttpClient] Fix buffering AsyncResponse with no passthru (nicolas-grekas)

This PR was merged into the 6.4 branch.

Discussion
----------

[HttpClient] Fix buffering AsyncResponse with no passthru

| Q             | A
| ------------- | ---
| Branch?       | 6.4
| Bug fix?      | yes
| New feature?  | no
| Deprecations? | no
| Issues        | Fix symfony#59574
| License       | MIT

Commits
-------

19a50f7 [HttpClient] Fix buffering AsyncResponse with no passthru

Author: nicolas-grekas

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

@@ -12,7 +12,6 @@
 namespace Symfony\Component\HttpClient\Response;
 
 use Symfony\Component\HttpClient\Chunk\ErrorChunk;
-use Symfony\Component\HttpClient\Chunk\FirstChunk;
 use Symfony\Component\HttpClient\Chunk\LastChunk;
 use Symfony\Component\HttpClient\Exception\TransportException;
 use Symfony\Contracts\HttpClient\ChunkInterface;
@@ -245,7 +244,7 @@ public static function stream(iterable $responses, ?float $timeout = null, ?stri
                 $wrappedResponses[] = $r->response;
 
                 if ($r->stream) {
-                    yield from self::passthruStream($response = $r->response, $r, new FirstChunk(), $asyncMap);
+                    yield from self::passthruStream($response = $r->response, $r, $asyncMap, new LastChunk());
 
                     if (!isset($asyncMap[$response])) {
                         array_pop($wrappedResponses);
@@ -276,15 +275,9 @@ public static function stream(iterable $responses, ?float $timeout = null, ?stri
                 }
 
                 if (!$r->passthru) {
-                    if (null !== $chunk->getError() || $chunk->isLast()) {
-                        unset($asyncMap[$response]);
-                    } elseif (null !== $r->content && '' !== ($content = $chunk->getContent()) && \strlen($content) !== fwrite($r->content, $content)) {
-                        $chunk = new ErrorChunk($r->offset, new TransportException(sprintf('Failed writing %d bytes to the response buffer.', \strlen($content))));
-                        $r->info['error'] = $chunk->getError();
-                        $r->response->cancel();
-                    }
+                    $r->stream = (static fn () => yield $chunk)();
+                    yield from self::passthruStream($response, $r, $asyncMap);
 
-                    yield $r => $chunk;
                     continue;
                 }
 
@@ -347,13 +340,13 @@ private static function passthru(HttpClientInterface $client, self $r, ChunkInte
         }
         $r->stream = $stream;
 
-        yield from self::passthruStream($response, $r, null, $asyncMap);
+        yield from self::passthruStream($response, $r, $asyncMap);
     }
 
     /**
      * @param \SplObjectStorage<ResponseInterface, AsyncResponse>|null $asyncMap
      */
-    private static function passthruStream(ResponseInterface $response, self $r, ?ChunkInterface $chunk, ?\SplObjectStorage $asyncMap): \Generator
+    private static function passthruStream(ResponseInterface $response, self $r, ?\SplObjectStorage $asyncMap, ?ChunkInterface $chunk = null): \Generator
     {
         while (true) {
             try {

src/Symfony/Component/HttpClient/Tests/AsyncDecoratorTraitTest.php

@@ -232,6 +232,20 @@ public function testBufferPurePassthru()
 
         $this->assertStringContainsString('SERVER_PROTOCOL', $response->getContent());
         $this->assertStringContainsString('HTTP_HOST', $response->getContent());
+
+        $client = new class(parent::getHttpClient(__FUNCTION__)) implements HttpClientInterface {
+            use AsyncDecoratorTrait;
+
+            public function request(string $method, string $url, array $options = []): ResponseInterface
+            {
+                return new AsyncResponse($this->client, $method, $url, $options);
+            }
+        };
+
+        $response = $client->request('GET', 'http://localhost:8057/');
+
+        $this->assertStringContainsString('SERVER_PROTOCOL', $response->getContent());
+        $this->assertStringContainsString('HTTP_HOST', $response->getContent());
     }
 
     public function testRetryTimeout()