Re: lib/53682

[Nikhil Benesch <nikhil.benesch%gmail.com@localhost>]

The following reply was made to PR lib/53682; it has been noted by GNATS.

From: Nikhil Benesch <nikhil.benesch%gmail.com@localhost>
To: christos%zoulas.com@localhost
Cc: gnats-bugs%netbsd.org@localhost, jordan%cockroachlabs.com@localhost
Subject: Re: lib/53682
Date: Wed, 21 Nov 2018 13:43:08 -0500

 > | The code I removed *unconditionally* issues
 > |
 > |     <move-to-right-margin><space><backspace>
 >
 > I thought it does it only for terminals that have automatic margins. There
 > is also the magic margins complication... This code is from 25 years ago,
 > see the Fixes file for the magic margins changes.
 
 Sorry, yes. I meant that, once you have an automargin terminal, the
 code unconditionally uses the <space><backspace> trick, regardless of
 where your cursor is located.
 
 > No, I have not tried your patch but I am guessing that it will break the
 > single line in two. I will try to test, but I am really busy this week.
 > The easiest way to test is to make the change on a NetBSD box and use
 > the NetBSD /bin/sh with the editor on using an xterm (which has automatic
 > margins and magic margins in the default setup).
 
 No problem. I appreciate you taking the time to respond. I'll set myself
 up a NetBSD VM in the meantime.
 
 The reason I suspect that things work fine with the patch is that if
 re_update_line draws a line that reaches the right margin,
 terminal_overwrite will properly mark the cursor as having advanced to
 the next line if the terminal has automatic margins. The next call to
 terminal_move_to_line will thus be a no-op and no newline will be
 emitted.