[issue715] panic at shutdown using comconsole

[Nicolas Thery]

Um, there is a  comment in spec_close() that says that s_ttyvp may
have v_opencount==0 (if the tty was revoked).  But then vop_stdclose()
is called unconditionally at the end of spec_close().  It seems to me
that it should be called if and only if v_opencount > 0.

Thomas,

Could you check in the crash dump the value of p->p_session->s_ttyvp
in the innermost call to spec_close() please?

Cheers,
Nicolas