GNU bug report logs - #60781
28.2; column-number-mode counts differently based on character encoding

Previous Next

To add a comment to this bug, you must first unarchive it, by sending
a message to control AT debbugs.gnu.org, with unarchive 60781 in the body.
You can then email your comments to 60781 AT debbugs.gnu.org in the normal way.

Toggle the display of automated, internal messages from the tracker.

Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Van Ly <van.ly <at> sdf.org>
To: bug-gnu-emacs <at> gnu.org
Subject: 28.2;
 column-number-mode counts differently based on character encoding
Date: Fri, 13 Jan 2023 13:31:29 GMT

[Message part 1 (text/plain, inline)]

Hello,

// one right arrow key move of the cursor from the left most position
// numbers differently in column-number-mode based on character encoding

These steps reproduce the observed unexpected behavior:

* emacs -Q /tmp/example.text
* move cursor to line two at left most position, then right arrow key once
* M-x column-number-mode
* the modeline indicator shows (2,2)
* move cursor to line nine at left most position, then right arrow key once
* the modeline indicator shows (9,1)

// for cjk the column number is two
// for ascii the column number is one

* expected modeline indicator to show (2,1) and (9,1)

See attached: bug-report.text, example.text

[bug-report.text (application/octet-stream, attachment)]

[example.text (application/octet-stream, attachment)]

Message #8 received at 60781 <at> debbugs.gnu.org (full text, mbox):

From: Eli Zaretskii <eliz <at> gnu.org>
To: Van Ly <van.ly <at> sdf.org>
Cc: 60781 <at> debbugs.gnu.org
Subject: Re: bug#60781: 28.2;
 column-number-mode counts differently based on character encoding
Date: Fri, 13 Jan 2023 20:32:57 +0200

tags 60781 notabug
thanks

> Date: Fri, 13 Jan 2023 13:31:29 GMT
> From: Van Ly <van.ly <at> sdf.org>
> 
> // one right arrow key move of the cursor from the left most position
> // numbers differently in column-number-mode based on character encoding
> 
> These steps reproduce the observed unexpected behavior:
> 
> * emacs -Q /tmp/example.text
> * move cursor to line two at left most position, then right arrow key once
> * M-x column-number-mode
> * the modeline indicator shows (2,2)
> * move cursor to line nine at left most position, then right arrow key once
> * the modeline indicator shows (9,1)
> 
> // for cjk the column number is two
> // for ascii the column number is one
> 
> * expected modeline indicator to show (2,1) and (9,1)

Your expectations are incorrect.  Some characters, including the ones
in line 2 of your example file, are double-width characters, they take
up more than one column on display.  Which characters take two columns
is defined by the Unicode standard, and most fonts follow that
standard, in that the character glyphs they provide are indeed wider
than ASCII or Latin characters.  And column-number-mode counts columns
on display, it doesn't count characters.

This is not a bug, but the expected and correct behavior.

Message #13 received at 60781 <at> debbugs.gnu.org (full text, mbox):

From: Van Ly <van.ly <at> sdf.org>
To: Eli Zaretskii <eliz <at> gnu.org>
Cc: 60781 <at> debbugs.gnu.org
Subject: Re: bug#60781: 28.2;
 column-number-mode counts differently based on character encoding
Date: Sat, 14 Jan 2023 03:10:50 GMT

Thanks.

I will file it a bug in my idea of human centered design principle. \smiley

Message #18 received at 60781-done <at> debbugs.gnu.org (full text, mbox):

From: Eli Zaretskii <eliz <at> gnu.org>
To: Van Ly <van.ly <at> sdf.org>
Cc: 60781-done <at> debbugs.gnu.org
Subject: Re: bug#60781: 28.2;
 column-number-mode counts differently based on character encoding
Date: Sat, 14 Jan 2023 09:26:41 +0200

> Date: Sat, 14 Jan 2023 03:10:50 GMT
> From: Van Ly <van.ly <at> sdf.org>
> Cc: 60781 <at> debbugs.gnu.org
> 
> 
> Thanks.
> 
> I will file it a bug in my idea of human centered design principle. \smiley

I'm therefore closing the bug.

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.