https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70609
--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
The problem is due to my lazy approach to copying the file:
__gnu_cxx::stdio_filebuf<char> sbin(in.fd, std::ios::in);
__gnu_cxx::stdio_filebuf<char> sbout(out.fd, std::ios::out);
if ( !(std::ostream(&sbout) << &sbin) )
{
ec = std::make_error_code(std::errc::io_error);
return false;
}
The condition is false when no bytes are copied. We just want to make that code
conditional with:
if (from_st->st_size)
That function should also check the result of ::close(fd), on at least the
target file.
