bug symfony#38518 [HttpClient] fix decorating timeout errors (nicolas-grekas)

This PR was merged into the 5.x branch.

Discussion
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[HttpClient] fix decorating timeout errors

| Q             | A
| ------------- | ---
| Branch?       | 5.x
| Bug fix?      | yes
| New feature?  | no
| Deprecations? | no
| Tickets       | Replaces symfony#38501
| License       | MIT
| Doc PR        | -

/cc @jderusse

Commits
-------

84cda3f [HttpClient] fix decorating timeout errors

Author: nicolas-grekas

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

@@ -45,7 +45,25 @@ public function __construct(HttpClientInterface $client, string $method, string
         $this->response = $client->request($method, $url, ['buffer' => false] + $options);
         $this->passthru = $passthru;
         $this->initializer = static function (self $response) {
-            return null !== $response->shouldBuffer;
+            if (null === $response->shouldBuffer) {
+                return false;
+            }
+
+            foreach (self::stream([$response]) as $chunk) {
+                if ($chunk->isTimeout() && $response->passthru) {
+                    foreach (self::passthru($response->client, $response, new ErrorChunk($response->offset, new TransportException($chunk->getError()))) as $chunk) {
+                        return !$chunk->isFirst();
+                    }
+
+                    return true;
+                }
+
+                if ($chunk->isFirst()) {
+                    break;
+                }
+            }
+
+            return false;
         };
         if (\array_key_exists('user_data', $options)) {
             $this->info['user_data'] = $options['user_data'];

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

@@ -212,4 +212,22 @@ public function testBufferPurePassthru()
         $this->assertStringContainsString('SERVER_PROTOCOL', $response->getContent());
         $this->assertStringContainsString('HTTP_HOST', $response->getContent());
     }
+
+    public function testRetryTimeout()
+    {
+        $client = $this->getHttpClient(__FUNCTION__, function (ChunkInterface $chunk, AsyncContext $context) {
+            try {
+                $this->assertTrue($chunk->isTimeout());
+                yield $chunk;
+            } catch (TransportExceptionInterface $e) {
+                $context->passthru();
+                $context->getResponse()->cancel();
+                $context->replaceRequest('GET', 'http://localhost:8057/timeout-header', ['timeout' => 1]);
+            }
+        });
+
+        $response = $client->request('GET', 'http://localhost:8057/timeout-header', ['timeout' => 0.1]);
+
+        $this->assertSame(200, $response->getStatusCode());
+    }
 }