From 54931f1f95c1d6da58766dbdf10592932a73e3df Mon Sep 17 00:00:00 2001
From: Valery Ivashchanka <likemusicdev@gmail.com>
Date: Mon, 20 Jul 2026 02:28:33 +0300
Subject: [PATCH] fix: do not corrupt streamed response bodies

Streamed responses (`StreamedResponse`, `BinaryFileResponse`) are captured
via an output buffer, because `getContent()` returns `false` for them. The
captured buffer was passed through `mb_trim()`, which is UTF-8 aware and
therefore unsafe for arbitrary bytes.

When the body starts or ends with a whitespace byte, `mb_trim()` decodes the
whole buffer as UTF-8 and replaces every invalid byte with `?` (0x3F), so a
binary body is silently destroyed. Trimming also changes the body length
while the original `Content-Length` header is forwarded untouched, leaving
the response inconsistent.

The buffer is now forwarded verbatim, which also matches the non-streamed
branch above, where `getContent()` is never trimmed.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
---
 src/Drivers/LaravelHttpServer.php      |  5 +-
 tests/Browser/StreamedResponseTest.php | 66 ++++++++++++++++++++++++++
 2 files changed, 69 insertions(+), 2 deletions(-)
 create mode 100644 tests/Browser/StreamedResponseTest.php

diff --git a/src/Drivers/LaravelHttpServer.php b/src/Drivers/LaravelHttpServer.php
index 97ae5fdb..b8cfa4fb 100644
--- a/src/Drivers/LaravelHttpServer.php
+++ b/src/Drivers/LaravelHttpServer.php
@@ -300,9 +300,10 @@ private function handleRequest(AmpRequest $request): Response
                 ob_start();
                 $response->sendContent();
             } finally {
-                // @phpstan-ignore-next-line
-                $content = mb_trim(ob_get_clean());
+                $buffer = ob_get_clean();
             }
+
+            $content = $buffer === false ? '' : $buffer;
         }
 
         return new Response(
diff --git a/tests/Browser/StreamedResponseTest.php b/tests/Browser/StreamedResponseTest.php
new file mode 100644
index 00000000..d681ae5a
--- /dev/null
+++ b/tests/Browser/StreamedResponseTest.php
@@ -0,0 +1,66 @@
+<?php
+
+declare(strict_types=1);
+
+use Illuminate\Support\Facades\Route;
+use Symfony\Component\HttpFoundation\StreamedResponse;
+
+it('may serve a binary streamed response without corrupting its bytes', function (): void {
+    $bytes = "\x20\x0A\xFF\xD8\xFF\xE0PAYLOAD-1234567890\xFF\x00\x0A\x20";
+
+    Route::get('/', fn (): string => '<div>Home</div>');
+    Route::get('/binary', fn (): StreamedResponse => response()->stream(
+        function () use ($bytes): void {
+            echo $bytes;
+        },
+        200,
+        ['Content-Type' => 'image/jpeg'],
+    ));
+
+    $page = visit('/');
+
+    $page->assertScript(
+        "async () => {
+            const response = await fetch('/binary');
+            const bytes = new Uint8Array(await response.arrayBuffer());
+
+            return Array.from(bytes).join(',');
+        }",
+        implode(',', unpack('C*', $bytes)),
+    );
+});
+
+it('may serve a binary streamed image that the browser is able to decode', function (): void {
+    $image = file_get_contents(__DIR__.'/../Fixtures/v4.jpg');
+
+    Route::get('/', fn (): string => '<img id="image" src="/image" alt="Streamed Image">');
+    Route::get('/image', fn (): StreamedResponse => response()->stream(
+        function () use ($image): void {
+            echo $image;
+        },
+        200,
+        ['Content-Type' => 'image/jpeg'],
+    ));
+
+    $page = visit('/');
+
+    $page->assertScript("document.getElementById('image').complete && document.getElementById('image').naturalWidth > 0");
+});
+
+it('may serve a textual streamed response without altering its whitespace', function (): void {
+    Route::get('/', fn (): string => '<div>Home</div>');
+    Route::get('/text', fn (): StreamedResponse => response()->stream(
+        function (): void {
+            echo "\n  Hello World  \n";
+        },
+        200,
+        ['Content-Type' => 'text/plain'],
+    ));
+
+    $page = visit('/');
+
+    $page->assertScript(
+        "async () => JSON.stringify(await (await fetch('/text')).text())",
+        json_encode("\n  Hello World  \n"),
+    );
+});