[Box Backup] Non-ASCII file and folder names crash Boxi at restore but not at backup

[Achim]

Hello list:

I am more than a bit surprised that nobody else is using the fantastic
Boxi in a non-English (non-ASCII) environment, or did really nobody else
encounter the filename issues that I tried to outline in my message from
8 April?

Any hints on where to start debugging (gdb) or looking for how Boxi
(which is broken for these filenames) uses Box Backup (which works just
fine) would be very welcome.

If more details are required, I am happy to test away and try to make
more specific use cases and/or bug reports.

Thank you in advance, Achim