[net.bugs.v7] more on flushtty vs XON/XOFF

henry (04/01/83)

A little while ago, I observed that there was an apparent bug in the
V7 tty driver:  the flushtty() routine turns off the "stopped" bit
used for stop/start handshaking.  This is really fun if your terminal
does expect the cpu to honor this protocol all the time.  At the time,
I asked if anybody could think of any reason why this behavior was
useful (except at final close, when the bit gets taken care of by
other code anyway!).  No replies.  I think it is safe to call this
line of code an out-and-out mistake, and call for its removal.  The
offending line is about line 339 in tty.c, in the flushtty() routine,
and reads:

	tp->t_state &= ~TTSTOP;

The fix is, remove it.  I haven't actually had a chance to try this
yet;  I will post the results when I do.

					Henry Spencer
					U of Toronto