4.2BSD DH hangup problems

[Mark Horton]

Lately we've been having some weird problems with our Able DH's
and 4.2BSD.  There are two classes of problem:

(1) Whenever someone hangs up, their process isn't sent a SIGHUP.
    Instead, the process goes into a loop trying to read from the
    tty.  This pounds pretty badly on the CPU.
(2) When we dial out with cu, if the connection fails for some
    reason, the line doesn't drop carrier, so the next person gets
    a woken up Penril dialer or dataswitch.  UUCP doesn't have this
    problem, perhaps it does stty 0 on the port when done.

The second problem might just be that one of the cu's doesn't close
the port or some such thing - it's a locally hacked cu, unrelated
to tip.  Our UUCP is Honey DanBer so it isn't stock either.

However, the first problem seems to involve vanilla software.  Yes,
I checked that the DM is working - autoconfigure notices that it's
there when booting, and explicit stty 0's seem to reset the port.

Has anyone else had this problem, and hopefully a fix?

	Mark