bug#71823: 31.0.50; project-mode-line and eglot duplicate project-name in mode-line

[Eli Zaretskii <eliz@gnu.org>]

> From: Spencer Baugh <sbaugh@janestreet.com>
> Date: Fri, 28 Jun 2024 10:15:45 -0400
> 
> >From 928101e122725866ee95172730ebff03f4d54d5a Mon Sep 17 00:00:00 2001
> From: Spencer Baugh <sbaugh@janestreet.com>
> Date: Fri, 28 Jun 2024 10:00:10 -0400
> Subject: [PATCH] Skip eglot project-name when project-mode-line=t
> 
> Both the eglot mode line entry and project-mode-line add
> project-name to the modeline.  When both of them are enabled,
> this is unnecessary duplication.
> 
> To fix, add the customization eglot-mode-line-project-name to
> allow disabling the project-name in eglot's mode-line entry.
> 
> Furthermore, by default, set this customization so that eglot
> will check project-mode-line and omit the project-name if
> project-mode-line is non-nil.  This allows a user to just set
> project-mode-line without having to separately customize eglot.
> 
> * lisp/progmodes/eglot.el (eglot-mode-line-project-name): Add.
> (eglot--mode-line-format): Check
> eglot-mode-line-project-name. (bug#71823)
> ---
>  lisp/progmodes/eglot.el | 23 +++++++++++++++++++++--
>  1 file changed, 21 insertions(+), 2 deletions(-)
> 
> diff --git a/lisp/progmodes/eglot.el b/lisp/progmodes/eglot.el
> index df4cbe50dc0..60e68b323f6 100644
> --- a/lisp/progmodes/eglot.el
> +++ b/lisp/progmodes/eglot.el
> @@ -2237,10 +2237,29 @@ eglot--mode-line-props
>                                           keymap ,map help-echo ,(concat prepend blurb)
>                                           mouse-face mode-line-highlight))))
>  
> +(defcustom eglot-mode-line-project-name
> +  (if (version< "30" emacs-version)
> +      ;; The project mode-line entry was added to `mode-line-format' in
> +      ;; Emacs 30; before that, `project-mode-line' has no effect.
> +      'unless-project-mode-line
> +    nil)
> +  "If non-nil, the eglot mode-line entry may contain `project-name'.
> +
> +If t, the eglot mode-line entry always contains `project-name'; if nil,
> +it never contains `project-name'.
> +
> +If the symbol `unless-project-mode-line', the eglot mode-line entry only
> +contains `project-name' if `project-mode-line' is nil.  (This avoids
> +showing `project-name' in the modeline twice.)")
> +
>  (defun eglot--mode-line-format ()
>    "Compose Eglot's mode-line."
>    (let* ((server (eglot-current-server))
>           (nick (and server (eglot-project-nickname server)))
> +         (use-nick (cl-case eglot-mode-line-project-name
> +                 (nil nil)
> +                 (unless-project-mode-line (not (bound-and-true-p project-mode-line)))
> +                 (t t)))
>           (pending (and server (jsonrpc-continuation-count server)))
>           (last-error (and server (jsonrpc-last-error server))))
>      (append
> @@ -2253,9 +2272,9 @@ eglot--mode-line-format
>                     (define-key map [mode-line down-mouse-1] eglot-menu)
>                     map)))
>       (when nick
> -       `(":"
> +       `(,(if use-nick ":" "")
>           ,(propertize
> -           nick
> +           (if use-nick nick ":")
>             'face 'eglot-mode-line
>             'mouse-face 'mode-line-highlight
>             'help-echo (format "Project '%s'\nmouse-1: LSP server control menu" nick)
> -- 
> 2.39.3

João, any comments?