
   The following patch fixes a problem I've been having with sz under
System V Release 2.   Seems that since SVR2 doesn't have FIONREAD,
sz tells the receiver to use ^C interruption on error.  Unfortunately,
if you are the originator, the tty is probably not the controlling
terminal, thus the signal has nowhere to go, and sz never notices
there is a transmission problem until it finishes sending the file.

   The solution is a hack that uses SVR2 non-blocking I/O to check
the reverse channel, and saves the character it finds waiting,
if any.  I've wrung this out, and it seems to work quite well.  This
is an unauthorized patch; I've mailed it to Chuck, and it awaits
his judgement on whether it will become official.

   Use `patch' to install these changes, then compile sz with
-DSVR2.  No changes are necessary to rz.

