[issue40540] inconstent stdin buffering/seeking behaviour

Change by Eryk Sun : -- resolution: -> duplicate stage: -> resolved status: open -> closed superseder: -> seekable() returns True on pipe objects in Windows ___ Python tracker _

[issue40540] inconstent stdin buffering/seeking behaviour

New submission from Peter Law : `sys.stdin` (on Windows, tested Pythons 3.6-3.8) appears to have different seeking behaviour depending on the source of the incoming data. This seems arguably reasonable given that `stdin` isn't always seekable, however even in the failing case `sys.stdin.seeka