Re: lib/54329: libedit: undefined terminal behavior in terminal_move_to_line (fix included)

[Valery Ushakov <uwe%stderr.spb.ru@localhost>]

The following reply was made to PR lib/54329; it has been noted by GNATS.

From: Valery Ushakov <uwe%stderr.spb.ru@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: Christos Zoulas <christos%zoulas.com@localhost>
Subject: Re: lib/54329: libedit: undefined terminal behavior in
 terminal_move_to_line (fix included)
Date: Sun, 30 Jun 2019 14:34:50 +0300

 On Sat, Jun 29, 2019 at 14:10:01 +0000, Jordan Lewis wrote:
 
 >  Regardless of whether some terminals handle this ok, the old behavior works
 >  only by accident. The manual is very clear that T_DO at the bottom of the
 >  screen results in undefined behavior.
 
 But the code just above is also very clearly checking for that, isn't
 it?  It may be getting confused about the window size and end up using
 DO when it shouldn't, but then it's the size tracking that should be
 fixed (as it likely has other bad consequences), not the innocent
 bystander.
 
 Also, as far as I can tell you still haven't provided complete
 reproduction scenario.  The emulator you use, window size, the value
 of TERM, etc.
 
 Christos, were you able to reproduce this?  Yyou said you didn't and
 then suddenly applied the diff.  This is confusing.
 
 -uwe