Tru64 privsep patch testing

[David Potterveld]

Further news: the Tru64 privsep problem seems to be a clash between the
privileged and unprivileged processes, with both attempting to launch sia
sessions on the same (pseudo-)terminal. When I run the privileged process
in a debugger, with a breakpoint early in sia_setup, and then try to connect
with a client, the damn thing works. The privileged process stops at the
breakpoint, the unprivileged child forges ahead, and the client completes
the connection. I get a shell, and everything seems OK. X11 forwarding works
as well. Examining the data back in the parent, in the context of sia_setup,
I see it wants to launch a session on the same tty. The sia_ses_estab call
fails, and the parent exits, which brings down the working client session.

The next step for me is to try and figure out what the correct sequence of
sia calls from both priv and unpriv perspectives *should* be, and then how
to untangle them.

David Potterveld