make "filter" case insensitive

[Fourhundred Thecat]

 > On 2022-02-23 17:59, Frank Dietrich via mc wrote:
> Hi,
>
> the filter uses shell globbing pattern. For example
>
> *.[Pp][Dd][Ff]
>
> would filter files *.PDF, *.pdf (and all other permutations of the
> characters).

thank you, but that is extremly laborious.

If there is no configuration option to make the matching
case-nonsensitive, would it be possible to change this in the source
code easily?