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

[Jordan Lewis <jordan%cockroachlabs.com@localhost>]

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

From: Jordan Lewis <jordan%cockroachlabs.com@localhost>
To: "Raphael 'kena' Poss" <knz%thaumogen.net@localhost>
Cc: gnats-bugs%netbsd.org@localhost, Nikhil Benesch <nikhil.benesch%gmail.com@localhost>
Subject: Re: lib/54329: libedit: undefined terminal behavior in
 terminal_move_to_line (fix included)
Date: Sat, 29 Jun 2019 10:05:02 -0400

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 On Sat, Jun 29, 2019, 03:05 Raphael 'kena' Poss <knz%thaumogen.net@localhost> wrote:
 
 >
 > For reference I have tried this (recalling 2 lines of history at the
 > bottom of the terminal, with libedit) on the following terminals:
 >
 > - st
 > - lxterm
 > - xfce4-terminal
 > - xterm
 >
 > and I observe no issue whatsoever. also used `tput cud 5` on the last
 > line and observed no badness.
 
 
 It needs to be at least 3 lines of history. With 2 lines of history, the
 program uses newlines, not T_DO.
 
 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.
 
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 <div dir=3D"auto"><div><div class=3D"gmail_quote"><div dir=3D"ltr" class=3D=
 "gmail_attr">On Sat, Jun 29, 2019, 03:05 Raphael &#39;kena&#39; Poss &lt;<a=
  href=3D"mailto:knz%thaumogen.net@localhost";>knz%thaumogen.net@localhost</a>&gt; wrote:</div><b=
 lockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1px =
 #ccc solid;padding-left:1ex">
 <br>
 For reference I have tried this (recalling 2 lines of history at the<br>
 bottom of the terminal, with libedit) on the following terminals:<br>
 <br>
 - st<br>
 - lxterm<br>
 - xfce4-terminal<br>
 - xterm<br>
 <br>
 and I observe no issue whatsoever. also used `tput cud 5` on the last<br>
 line and observed no badness.</blockquote></div></div><div dir=3D"auto"><br=
 ></div><div dir=3D"auto">It needs to be at least 3 lines of history. With 2=
  lines of history, the program uses newlines, not T_DO.</div><div dir=3D"au=
 to"><br></div><div dir=3D"auto">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.</div>=
 <div dir=3D"auto"></div></div>
 
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