improved 4.2BSD signal(2) library routine

[William L. Sebok]

> .......  There are many times
> when I DO NOT WANT terminal i/o restarted after a signal, especially
> after a keyboard-generated signal.  This is difficult to arrange when
> terminal i/o gets automatically restarted by the system!

There are several problems of this sort in vnews under 4.1 BSD.  The problem
in signal 2 (SIGINT) I fixed with a kluge in the version of visual.c I posted
a couple of months ago.  The problem with Signal 1 (SIGHUP) is still
outstanding.  When vnews receives a hangup signal instead of exiting it goes
into an endless loop, eating up cpu time.  Maybe that is fixed in 4.2. The
SIGHUP signal is handled in code shared with readnews.  Under 4.1 readnews did
not have to worry about this issue because it used the old signal mechanism.
If the 4.2 readnews has not been changed it will now also have this bug.  I
will know in a few days when I try to bring up 4.2 here.
-- 
Bill Sebok			Princeton University, Astrophysics
{allegra,akgua,burl,cbosgd,decvax,ihnp4,kpno,princeton,vax135}!astrovax!wls