bug#59311: closed (29.0.50; tab-bar global-mode-string affected by global-display-line-numbers)

[GNU bug Tracking System]

Your message dated Sun, 20 Nov 2022 20:02:51 +0200
with message-id <86k03pv704.fsf@mail.linkov.net>
and subject line Re: bug#59311: 29.0.50; tab-bar global-mode-string affected by 
global-display-line-numbers
has caused the debbugs.gnu.org bug report #59311,
regarding 29.0.50; tab-bar global-mode-string affected by 
global-display-line-numbers
to be marked as done.

(If you believe you have received this mail in error, please contact
help-debbugs@gnu.org.)


-- 
59311: https://debbugs.gnu.org/cgi/bugreport.cgi?bug=59311
GNU Bug Tracking System
Contact help-debbugs@gnu.org with problems

--- Begin Message --- Subject: 29.0.50; tab-bar global-mode-string affected by global-display-line-numbers Date: Wed, 16 Nov 2022 13:10:07 -0300

Description:

The global-mode-string is incorrectly right-aligned in the tab-bar when
global-display-line-numbers-mode is enabled.  The issue actually depends
on the order of execution of global-display-line-numbers-mode.  I could
not find an offending commit, so I am not sure for how long this issue
exists.  I am currently debugging the Emacs internals to find the root
cause.

Steps:

1) emacs -Q (master 690f7ac86ad9a9d714b1107d05c5e856a43bb18d)

2) Eval the following to enable global-display-line-numbers-mode:

(progn
  (global-display-line-numbers-mode 1))

3) Eval the following to enable display-time-mode, which at this moment
will be displayed in the mode-line:

(progn
  (setopt display-time-interval 1
          display-time-string-forms '((format-time-string "%d/%m/%Y %H:%M:%S" 
now)))
  (display-time-mode 1))

4) Eval the following to add global-mode-line to tab-bar, right-aligned:

(progn
  (setopt tab-bar-format '(tab-bar-format-tabs-groups
                           tab-bar-separator
                           tab-bar-format-align-right
                           tab-bar-format-global))
  (tab-bar-mode 1))

Result: the global-mode-line is displayed in the tab-bar, right-aligned,
as expected.

5) Run step 2) again

Result: the global-mode-line is displayed in the tab-bar, right-aligned,
with an incorrect padding on the right. See attached video.

bug.mp4
Description: video/mp4

---
Gabriel

--- End Message ---

> --- Begin Message ---
>
>
>
> Subject: 
>
> Re: bug#59311: 29.0.50; tab-bar global-mode-string affected by global-display-line-numbers
>
>
>
>
> Date: 
>
> Sun, 20 Nov 2022 20:02:51 +0200
>
>
>
>
> User-agent: 
>
> Gnus/5.13 (Gnus v5.13) Emacs/29.0.50 (x86_64-pc-linux-gnu)
>
>
>
>
> >> I still don't understand why string-pixel-width should handle line-numbers
> >> that also degrades its performance.
> >
> > Because string-pixel-width uses a temporary buffer as its internal
> > implementation detail.  (And why do you think this degrades performance? any
> > measurements?)
>
> Any additional code makes it slower.  How much slower is a separate question.
>
> >> I think it should be sufficient only
> >> to disable line-numbers in internal buffers.
> >
> > I think it's too late for that, since display-line-numbers-mode is with us
> > for the last 2 major releases.
>
> Leaving it as is means waiting for more trouble in other places.
>
> >> @@ -324,7 +324,8 @@ string-pixel-width
> >>      (with-current-buffer (get-buffer-create " *string-pixel-width*")
> >>        (delete-region (point-min) (point-max))
> >>        (insert string)
> >> -      (car (buffer-text-pixel-size nil nil t)))))
> >> +      (- (car (buffer-text-pixel-size nil nil t))
> >> +         (line-number-display-width t)))))
> >
> > This is fine by me.  (Or you could turn off display-line-numbers-mode
> > instead, right after with-current-buffer.)
>
> Ok, fixed with the latter, and closed.
>
>
> --- End Message ---