ms-files.php generates bad content-types for REQUEST_URI's with query string

[chrisbliss18]

File requests of the type /subsite/files/style.css?ver=1 produce a bad content-type output. The request has to be for a multisite subsite as the request has to pass through wp-includes/ms-files.php.

The problem is caused by a call to wp_check_filetype that is passed an argument of $_SERVER['REQUEST_URI'] rather than $file. Since this variable contains the querystring of the request, it causes a failure of the regular expressions that are used in wp_check_filetype function.

This problem isn't present for all files as a fallback to mime_content_type is present, and that function is called with the correct argument.

Files with extensions of CSS are good examples of the problem as the mime_content_type function returns a type of text/plain in these cases. However, I have seen some servers that will return content-types such as "text/css?ver=1".

Attached is a patch that fixes this improper argument issue. It is built off of [15473].

Updated to replace other $_SERVERREQUEST_URI? instances with $file

I just updated the patch to replace two other instances of $_SERVER['REQUEST_URI'] with $file as these uses would also fail in the event that the request has a query string.

I didn't test, but that looks ok to me.

Looks sane.
Would like to soak this in trunk before backporting to 3.0.x moving into 3.0.2 for that purpose.

(In [15749]) Ensure we don't generate incorrect content types when files are requested with query strings. Fixes #14450 props chrisbliss18.

Re-opening to allow it to soak in trunk before potential backport.

Security Note: w/o patch header injection, reported in #14594

+1 for backport beacuse of that.

Also, I closed #14594 even though it's not, technically, fully fixed yet... But since it was ignored for two months, I figured security is no longer a priority...

@Denis: There is absolutely no need for that tone. Security is always a priority.

(In [16632]) Ensure we don't generate incorrect content types when files are requested with query strings. props chrisbliss18. fixes #14450 for the 3.0 branch.