From b5567e738aa372e0f3408c40e96bd4bd445bf3a1 Mon Sep 17 00:00:00 2001
From: Alexandre Daubois <alex.daubois@gmail.com>
Date: Mon, 16 Dec 2024 17:04:34 +0100
Subject: [PATCH] [HttpFoundation] Avoid mime type guess with temp files in
 `BinaryFileResponse`

---
 BinaryFileResponse.php           |  7 ++++++-
 Tests/BinaryFileResponseTest.php | 11 +++++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/BinaryFileResponse.php b/BinaryFileResponse.php
index a2b160f8a..0f5b3fca5 100644
--- a/BinaryFileResponse.php
+++ b/BinaryFileResponse.php
@@ -189,7 +189,12 @@ public function prepare(Request $request): static
         }
 
         if (!$this->headers->has('Content-Type')) {
-            $this->headers->set('Content-Type', $this->file->getMimeType() ?: 'application/octet-stream');
+            $mimeType = null;
+            if (!$this->tempFileObject) {
+                $mimeType = $this->file->getMimeType();
+            }
+
+            $this->headers->set('Content-Type', $mimeType ?: 'application/octet-stream');
         }
 
         parent::prepare($request);
diff --git a/Tests/BinaryFileResponseTest.php b/Tests/BinaryFileResponseTest.php
index 77bc32e8c..d4d84b305 100644
--- a/Tests/BinaryFileResponseTest.php
+++ b/Tests/BinaryFileResponseTest.php
@@ -458,4 +458,15 @@ public function testCreateFromTemporaryFile()
         $string = ob_get_clean();
         $this->assertSame('foo,bar', $string);
     }
+
+    public function testCreateFromTemporaryFileWithoutMimeType()
+    {
+        $file = new \SplTempFileObject();
+        $file->fwrite('foo,bar');
+
+        $response = new BinaryFileResponse($file);
+        $response->prepare(new Request());
+
+        $this->assertSame('application/octet-stream', $response->headers->get('Content-Type'));
+    }
 }