Symfony version(s) affected

>=2.0.15

Description

When uploading a file that contains a backslash, UploadedFile calls the File::getName() method to set the $originalName property. This method chops off everything before the backslash to "sanitize" it. There is currently no way to get the full original filename other than searching through $_FILES manually. This was added way back in symfony/http-foundation@a3f936e!

How to reproduce

In http-foundation/Tests/File/UploadedFileTest.php:

    public function testGetClientOriginalNameWithBackslash()
    {
        $file = new UploadedFile(
            __DIR__.'/Fixtures/test.gif',
            'prefix\original.gif',
            'image/gif'
        );

        $this->assertEquals('prefix\original.gif', $file->getClientOriginalName());
    }

Possible Solution

Since other sanitization methods were rejected (e.g. #49283), I would propose that this isn't needed at all. However, if it is kept, then my suggestion is to simply replace the backslashes with a hyphen on Windows only, seeing as they are perfectly fine on other systems. I would be happy to provide a PR either way.

Additional Context

No response