GNU bug report logs - #59491
29.0.50; [PATCH] Mode-line elements too wide in some VC buffers

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

From: Gabriel <gabriel376 <at> hotmail.com>
To: bug-gnu-emacs <at> gnu.org
Subject: 29.0.50; [PATCH] Mode-line elements too wide in some VC buffers
Date: Tue, 22 Nov 2022 17:58:25 -0300

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

Severity: wishlist

Description:

Some mode-line elements are too wide in some VC buffers, which affects
the information visibility.

Steps:

1) emacs -Q

2) Open some file controlled by Git VC, e.g.: C-x f ~/git/emacs/README

The buffer named "README" will be shown, the buffer name is displayed on
the left side of the mode-line.

(length (buffer-name)) => 6

3) Annotate the buffer: C-x v g

The VC-Annotate buffer named "*Annotate README (rev 1f39da3098a2a4cec9985e6db934ed14b7b522b7)*"
will be shown, the buffer name is displayed on the left side of the
mode-line.  The revision number might differ.

(length (buffer-name)) => 64

4) Show log revision at line: l

The Git-Log-View buffer will be shown.  The value of
`vc-parent-buffername' is " from *Annotate README (rev 1f39da3098a2a4cec9985e6db934ed14b7b522b7)*",
displayed on the right side of the mode-line.  The revision number might
differ.

(length vc-parent-buffer-name) => 70

Analysis:

A short named buffer "README" with length of 6 had information displayed
in the mode-line with lengths of 64 (with `vc-annotate') and 70 (with
`vc-annotate-show-log-revision-at-line').  This excessive length affects
the visibility of information in mode-line, which was supposed to ease
the access of information to the user.  A long buffer name can also
affect the display and usability in other interfaces, e.g.:
`list-buffers', `ibuffer' etc.

The problem, in this case, is the long revision string used by Git.  I
am not sure how other VCs behaves in this matter (bzr, cvs, dav, hg,
rcs, sccs, src, svc etc).

Solutions:

For Git, a better option would be to use a "short revision" (by default
the first 7 characters of the "long revision"), which would reduce, for
the example above, the length from 64 to 39 (and `vc-parent-buffer-name'
from 70 to 45):

diff --git a/lisp/vc/vc-annotate.el b/lisp/vc/vc-annotate.el
index a15cf417de..63485af52e 100644
--- a/lisp/vc/vc-annotate.el
+++ b/lisp/vc/vc-annotate.el
@@ -409,7 +409,9 @@ vc-annotate
 				  nil nil "20")))))))
   (vc-ensure-vc-buffer)
   (setq vc-annotate-display-mode display-mode) ;Not sure why.  --Stef
-  (let* ((temp-buffer-name (format "*Annotate %s (rev %s)*" (buffer-name) rev))
+  (let* ((temp-buffer-name (format "*Annotate %s (rev %s)*"
+                                   (buffer-name)
+                                   (string-limit rev 7)))
          (temp-buffer-show-function 'vc-annotate-display-select)
          ;; If BUF is specified, we presume the caller maintains current line,
          ;; so we don't need to do it here.  This implementation may give

Another option would be to display additional information in the
header-line.

Another option would be to allow the user to format how the VC-Annotate
buffer name is displayed (and optionally also the
`vc-parent-buffer-name').  See attached patches.

[0001-New-option-vc-annotate-buffer-name-function.patch (text/x-diff, attachment)]

[0001-New-option-vc-parent-buffer-name-format-function.patch (text/x-diff, attachment)]

[Message part 4 (text/plain, inline)]

Please share your suggestions.

---
Gabriel

Message #8 received at 59491 <at> debbugs.gnu.org (full text, mbox):

From: Eli Zaretskii <eliz <at> gnu.org>
To: Gabriel <gabriel376 <at> hotmail.com>
Cc: 59491 <at> debbugs.gnu.org
Subject: Re: bug#59491: 29.0.50;
 [PATCH] Mode-line elements too wide in some VC buffers
Date: Wed, 23 Nov 2022 14:14:25 +0200

> From: Gabriel <gabriel376 <at> hotmail.com>
> Date: Tue, 22 Nov 2022 17:58:25 -0300
> 
> For Git, a better option would be to use a "short revision" (by default
> the first 7 characters of the "long revision")

AFAIR, just taking the first 7 characters is not safe; you need to ask Git.
But maybe for this purpose taking 7 would be enough?

> Another option would be to allow the user to format how the VC-Annotate
> buffer name is displayed (and optionally also the
> `vc-parent-buffer-name').  See attached patches.

That sounds like overkill to me.

Let's see what Dmitry thinks about this.

Thanks.

Message #11 received at 59491 <at> debbugs.gnu.org (full text, mbox):

From: Jim Porter <jporterbugs <at> gmail.com>
To: Eli Zaretskii <eliz <at> gnu.org>, Gabriel <gabriel376 <at> hotmail.com>
Cc: 59491 <at> debbugs.gnu.org
Subject: Re: bug#59491: 29.0.50; [PATCH] Mode-line elements too wide in some
 VC buffers
Date: Wed, 23 Nov 2022 10:43:29 -0800

On 11/23/2022 4:14 AM, Eli Zaretskii wrote:
>> From: Gabriel <gabriel376 <at> hotmail.com>
>> Date: Tue, 22 Nov 2022 17:58:25 -0300
>>
>> For Git, a better option would be to use a "short revision" (by default
>> the first 7 characters of the "long revision")
> 
> AFAIR, just taking the first 7 characters is not safe; you need to ask Git.
> But maybe for this purpose taking 7 would be enough?

It'd be nice to pass this through `git rev-parse --short` or maybe even 
`git describe --always --all`. vc-git.el could also use something like 
this when it gets the ref for the modeline (see 
'vc-git-mode-line-string' and 'vc-git--symbolic-ref').

In fact, maybe there should be a generic VC function for getting a 
"friendly" string describing a commit. Then code could use that function 
in some/most cases instead of showing the full commit ID.

Message #18 received at 59491-done <at> debbugs.gnu.org (full text, mbox):

From: Stefan Kangas <stefankangas <at> gmail.com>
To: Gabriel <gabriel376 <at> hotmail.com>
Cc: 59491-done <at> debbugs.gnu.org
Subject: Re: bug#59491: 29.0.50; [PATCH] Mode-line elements too wide in some
 VC buffers
Date: Wed, 12 Feb 2025 07:56:31 -0800

Gabriel <gabriel376 <at> hotmail.com> writes:

> Severity: wishlist
>
> Description:
>
> Some mode-line elements are too wide in some VC buffers, which affects
> the information visibility.
>
> Steps:
>
> 1) emacs -Q
>
> 2) Open some file controlled by Git VC, e.g.: C-x f ~/git/emacs/README
>
> The buffer named "README" will be shown, the buffer name is displayed on
> the left side of the mode-line.
>
> (length (buffer-name)) => 6
>
> 3) Annotate the buffer: C-x v g
>
> The VC-Annotate buffer named "*Annotate README (rev 1f39da3098a2a4cec9985e6db934ed14b7b522b7)*"
> will be shown, the buffer name is displayed on the left side of the
> mode-line.  The revision number might differ.
>
> (length (buffer-name)) => 64
>
> 4) Show log revision at line: l
>
> The Git-Log-View buffer will be shown.  The value of
> `vc-parent-buffername' is " from *Annotate README (rev 1f39da3098a2a4cec9985e6db934ed14b7b522b7)*",
> displayed on the right side of the mode-line.  The revision number might
> differ.
>
> (length vc-parent-buffer-name) => 70

This seems to have been fixed in recent versions of Emacs, so I'm
closing this bug now.

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