Create a directory with a file named "?.txt"
Try to encrypt the folder using GpgEX / Kleopatra.
This results in an error.
We need a way to pass gpgtar utf8 filenames (or wchar filenames but this would be uglyier) and then gpgtar needs to convert this internally to wchar or use estream functions that handle UTF8/wchar accordingly. Currently the 8bit stuff is only using native 8bit which usually is not utf8 and so does not handle unicode.