IDN support (e.g. köthe.de)

[Noël Köthe]

Hello,

mtr does not support internationalized domain name (IDN ) which is a standard since some years.

$ mtr köthe.de
Failed to resolve host: Name or service not known

With the help of libidn https://www.gnu.org/software/libidn/ or libidn2
https://www.gnu.org/software/libidn/#libidn2 this could be implemented.

You find some testdomains on https://wiki.debian.org/IDN

Thanks for your work.

Regards

Noel

[yvs (lrou2014)]

That code works for the examples I tried
https://github.com/yvs2014/mtr/commit/fdb56b27afd9cfa31a72b27e06178c0f6455c97b