Allow the file descriptor received from the client to be -1 - it can be on Cygwin when stdin is not a terminal. Reported by A Young, SF bug 52.
Allow the file descriptor received from the client to be -1 - it can be on
Cygwin when stdin is not a terminal. Reported by A Young, SF bug 52.

klaxalk/tmux,klaxalk/tmux,klaxalk/tmux,klaxalk/tmux,klaxalk/tmux