When using BinaryStreamResponse for file downloading, it generates a fatal error for files with non-ASCII characters. Here is an excerpt from logs:

[2017-09-25 14:30:59] request.CRITICAL: Uncaught PHP Exception InvalidArgumentException: "The filename fallback must only contain ASCII characters." at xxx\ezpublish\vendor\symfony\symfony\src\Symfony\Component\HttpFoundation\ResponseHeaderBag.php line 251 {"exception":"[object] (InvalidArgumentException(code: 0): The filename fallback must only contain ASCII characters. at xxx\\ezpublish\\vendor\\symfony\\symfony\\src\\Symfony\\Component\\HttpFoundation\\ResponseHeaderBag.php:251)"} []

This issue was already solved for version 1.6.0 and later (see EZP-26554), but it should be backported to 5.4 since it can also be reproduced there.

Steps to reproduce

1. Create new eZ Publish 5.4 installation.
2. Create and register a custom bundle (AppBundle).
3. In the AppBundle, create a new Controller file named DownloadController.php with the following contents:

   <?php
   
   namespace AppBundle\Controller;
   
   use eZ\Bundle\EzPublishCoreBundle\Controller;
   use eZ\Bundle\EzPublishIOBundle\BinaryStreamResponse;
   use Symfony\Component\HttpFoundation\Request;
   use Symfony\Component\HttpFoundation\ResponseHeaderBag;
   use Symfony\Component\Routing\Annotation\Route;
   
   class DownloadController extends Controller
   {
       /**
        * @Route("/content/download/{contentId}/{attributeId}/{fieldIdentifier}/{filename}", name = "custom_content_download")
        */
       public function downloadBinaryFileAction($contentId, $attributeId, $fieldIdentifier, $filename, Request $request)
       {
           $contentService = $this->getRepository()->getContentService();
           $translationHelper = $this->get('ezpublish.translation_helper');
           $ioService = $this->get('ezpublish.fieldType.ezbinaryfile.io_service');
   
           $content = $contentService->loadContent($contentId);
   
           $field = $translationHelper->getTranslatedField(
               $content,
               $fieldIdentifier,
               $request->query->has('language') ? $request->query->get('language') : null
           );
   
           $response = new BinaryStreamResponse($ioService->loadBinaryFile($field->value->id), $ioService);
           $response->setContentDisposition(ResponseHeaderBag::DISPOSITION_ATTACHMENT, $filename);
   
           return $response;
       }
   }
   

4. Add the following to the ezpublish/config/routing.yml file:

   custom_download:
       resource: "@AppBundle/Controller/DownloadController.php"
       type:     annotation
   

5. Choose any file and rename it to wontÆØÅwork.ext.
6. Open the admin interface, create a new file and upload wontÆØÅwork.ext.
7. Embed this file inside a Folder Content Object.
8. Open that Content Object with the wontÆØÅwork.ext in the frontend, and try to download the file.