[HttpFoundation] Mimetype invalid guesser, Suggest adding magic file?

So, I had an odd issue which has been discussed various times and already has a number of issues for it already. Not much has been really said in the ways of a good work around. Would like to see what the thoughts are on having a default magic file maintained. According to http://www.php.net/manual/en/function.finfo-open.php you are able to pass in your own. Which should clear up some of the "application/zip" for docx files and others.