[Bug libstdc++/95048] wstring-constructor of std::filesystem::path throws for non-ASCII characters

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95048

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2020-05-11

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
This happens because glibc won't convert the wide string to UTF-8:

#include <wchar.h>
#include <assert.h>

int main()
{
  const wchar_t wstr[] = L"ä";
  const wchar_t* from = wstr;
  char to[10];
  mbstate_t s;
  size_t res = wcsnrtombs(to, &from, 1, sizeof(to), &s);
  assert(res != (size_t)-1);
}

I'm not yet sure why glibc refuses to convert that.