title: Symfony HttpFoundation/File guessing incorrect mime type
body: <p>I have raw png file content and after storing it with <code>file_put_contents($path, $content)</code> I'm creating <code>$file = new File($path);</code> and when I'm trying to get mine type <code>$file-&gt;getMimeType()</code> I'm getting <strong>application/octet-stream</strong> instead of <strong>image/png</strong>. Any idea how I can get correct mime type?</p>