Subject: bug#30582: closed (Re: bug#30582: Line number shifts left when horizontal scrolling with a tab.)

From: [email-masked] (GNU bug Tracking System)
Date: Wed, 07 Mar 2018 18:45:02 +0000

Your bug report

#30582: Line number shifts left when horizontal scrolling with a tab.

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].

-- 
30582: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=30582
GNU Bug Tracking System
Contact [email-masked] with problems

Subject: Re: bug#30582: Line number shifts left when horizontal scrolling with a tab.
From: Eli Zaretskii <[email-masked]>
To: Keith David Bershatsky <[email-masked]>
Cc: [email-masked]
Date: Wed, 07 Mar 2018 20:44:29 +0200
List-Id: <debbugs-submit.debbugs.gnu.org>

> Date: Thu, 22 Feb 2018 12:51:29 -0800
> From: Keith David Bershatsky <[email-masked]>
> 
> Step 1:  Launch Emacs 26
> 
> Step 2:  Switch to the *scratch* buffer.  We should be on line 4, with the default scratch message on the first 2 lines above.
> 
> Step 3:  M-x display-line-numbers-mode
> 
> Step 4:  Type:  C-q TAB Hello-world.
> 
> Step 5:  Evaluate:  (scroll-left 5)
> 
> Observe that the line number of the current line shifts to the left such that it is no longer aligned with the other line numbers.  The same will hold true under a variety of similar circumstances; e.g., line numbers exist below the current line; more than 10 lines exist, etc.

Thanks, should be fixed on the master branch now.

Subject: Line number shifts left when horizontal scrolling with a tab.
From: Keith David Bershatsky <[email-masked]>
To: Emacs Bug Reports <[email-masked]>
Date: Thu, 22 Feb 2018 12:51:29 -0800
List-Id: <debbugs-submit.debbugs.gnu.org>

Step 1:  Launch Emacs 26

Step 2:  Switch to the *scratch* buffer.  We should be on line 4, with the default scratch message on the first 2 lines above.

Step 3:  M-x display-line-numbers-mode

Step 4:  Type:  C-q TAB Hello-world.

Step 5:  Evaluate:  (scroll-left 5)

Observe that the line number of the current line shifts to the left such that it is no longer aligned with the other line numbers.  The same will hold true under a variety of similar circumstances; e.g., line numbers exist below the current line; more than 10 lines exist, etc.

Related issue:  I am still working on debugging a few semi-related issues involving move_it_in_display_line_to in conjunction with bug #30226, and I see the need to either fix the problem described above; or, create a programmatic workaround when calculating X and HPOS along on the current line whenever line numbers shift to the left.  If the problem described above is fixed, then no programmatic workaround would be needed.

Thanks,

Keith