Subject: bug#23570: closed (Re: bug#23570: 25.1.50; Cursor motion error with visual-line-mode)

From: [email-masked] (GNU bug Tracking System)
Date: Mon, 23 May 2016 02:38:01 +0000

Your bug report

#23570: 25.1.50; Cursor motion error with visual-line-mode

which was filed against the emacs package, has been closed.

The explanation is attached below, along with your original report.
If you require more details, please reply to [email-masked].

-- 
23570: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=23570
GNU Bug Tracking System
Contact [email-masked] with problems

Subject: Re: bug#23570: 25.1.50; Cursor motion error with visual-line-mode
From: Eli Zaretskii <[email-masked]>
To: Chong Yidong <[email-masked]>, John Wiegley <[email-masked]>
Cc: [email-masked]
Date: Mon, 23 May 2016 05:36:55 +0300
List-Id: <debbugs-submit.debbugs.gnu.org>

> From: Chong Yidong <[email-masked]>
> Cc: [email-masked]
> Date: Mon, 23 May 2016 10:09:39 +0800
> 
> > Thanks, I've pushed a fix to the master branch (commit 99848b3).
> > Please test.
> >
> > (I think this change is too low-level to be safe for the emacs-25
> > branch at this late stage of pretest.)
> 
> Thanks, verified that the bug seems to be fixed now.

Thanks, closing.

> FWIW, I think the fix ought to be considered for the emacs-25 branch,
> since (i) it is a regression relative to Emacs 24.4, and (ii) it is
> quite simple to trigger on natural-language text with long lines, which
> should be considered a common use-case.

I considered that, but since the release is imminent, I was uneasy to
put such low-level changes in basic functionality in the release.

John, would you please provide a second opinion here?

Thanks.

Subject: 25.1.50; Cursor motion error with visual-line-mode
From: Chong Yidong <[email-masked]>
To: [email-masked]
Date: Wed, 18 May 2016 19:20:28 +0800
List-Id: <debbugs-submit.debbugs.gnu.org>

When visual-line mode is enabled, there is a bug causing the cursor to
fail to find the right start/end of a screen line.  I see the bug with
Emacs 24.5, as well as the latest git version.  No bug in Emacs 24.4.

1. emacs -Q

2. Insert the following (at the start of a new line):

123456789 123456789 123456789 123456789 123456789 123456789 123456789 12 ABCDEFGHIJK  MOPQ

3. M-x visual-line-mode RET

4. Adjust the window width until it is just large enough for
   "ABCDEFGHIJK" to be on the first line.

5. Decrease the window width by 1 character.  Now, "ABCDEFGHIJK" should
   be wrapped to the second line.

5. Move point to the beginning of the line starting with "1234...".
   Now, typing C-e moves to the second screen line.  Expected result: it
   should move to the end of the first screen line.

   Various other screen oddities are observable in the vicinity of this
   wrapped line.  For instance, when point is on "Q", C-a moves to the
   space before "M", rather than the start of the line.

In GNU Emacs 25.1.50.1 (x86_64-unknown-linux-gnu, GTK+ Version 3.20.3)
 of 2016-05-17 built on tsparkle
Repository revision: 631ca55c6decccca2dc0961dc28962819eacc35b
Windowing system distributor 'The X.Org Foundation', version 11.0.11801000
System Description:	Arch Linux