Re: UTF-8 directory listings broken
I know that this is more a question of design, but I would still consider it more appropriate to just issue a warning and mask the illegal character with underscore or whatever. This way users will be able to download the file, albeit with crippled filename, even if they forced UTF-8.
Unfortunately WinSCP does not work internally in Unicode, so it cannot keep the original filename. Thus implementing your suggestion would imply major change. But it would be possible to simply skip the files with non-UTF8 names.
Edit 2021: WinSCP is a Unicode application for a long time now,so the above is not an issue.
https://winscp.net/tracker/586
For other similar problems, see:
https://winscp.net/eng/docs/faq_utf8