> We can also switch to calling _get_osfhandle always instead of caching the handle, it will break when the fd is redirected to a non-console. But so does _WindowsConsoleIO in general since it will try to continue writing to the console despite the redirection, meaning that Python code doing redirection has to handle sys.std* anyhow.

This might be the best approach, ultimately. I bet there's an optimization here, though it's not obvious.

Probably the main issue here is readline not properly handling sys.std*. If that was fixed, I think many of these problems (at least at the interactive prompt) would simply go away.