bug#53012: closed (28.0.90; completion--nth-completion: Throw a meaningful error)

[GNU bug Tracking System]

Your message dated Sun, 9 Jan 2022 09:31:36 -0600
with message-id 
<CADwFkm=8K3HgQno0sa6Az2NDK2eR-mn7N-oapQkXVqmsc6_x1A@mail.gmail.com>
and subject line Re: bug#53012: 28.0.90; completion--nth-completion: Throw a 
meaningful error
has caused the debbugs.gnu.org bug report #53012,
regarding 28.0.90; completion--nth-completion: Throw a meaningful error
to be marked as done.

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53012: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=53012
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> --- Begin Message ---
>
>
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> Subject: 
>
> 28.0.90; completion--nth-completion: Throw a meaningful error
>
>
>
>
> Date: 
>
> Tue, 4 Jan 2022 21:12:47 +0100
>
>
>
>
> In the context of the GNU ELPA Vertico/Mct/Orderless/Embark ecosystem we
> teach users to adjust the completion style. Unfortunately
> completion--nth-completion is not very robust against misconfiguration.
> I propose to throw a more meaningful error instead of the nil error.
> Patch follows.
>
> ---
>
> >From da92169572e375facabb28b6d3c14cb2158ab1c9 Mon Sep 17 00:00:00 2001
> From: Daniel Mendler <mail@daniel-mendler.de>
> Date: Tue, 4 Jan 2022 21:08:04 +0100
> Subject: [PATCH] completion--nth-completion: Throw meaningful error
>
> If a configured completion style does not exist, throw a meaningful
> error. Also make completion-styles-alist a defvar, since completion
> styles like orderless extend it.
> ---
>  lisp/minibuffer.el | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/lisp/minibuffer.el b/lisp/minibuffer.el
> index 1d596694e4..ab760a42d1 100644
> --- a/lisp/minibuffer.el
> +++ b/lisp/minibuffer.el
> @@ -900,7 +900,7 @@ completion-auto-help
>  the second failed attempt to complete."
>    :type '(choice (const nil) (const t) (const lazy)))
>
> -(defconst completion-styles-alist
> +(defvar completion-styles-alist
>    '((emacs21
>       completion-emacs21-try-completion completion-emacs21-all-completions
>       "Simple prefix-based completion.
> @@ -1076,9 +1076,10 @@ completion--nth-completion
>           (result-and-style
>            (completion--some
>             (lambda (style)
> -             (let ((probe (funcall (nth n (assq style
> -                                                completion-styles-alist))
> -                                   string table pred point)))
> +             (let ((probe (funcall
> +                           (or (nth n (assq style completion-styles-alist))
> +                               (error "Invalid completion style %s" style))
> +                           string table pred point)))
>                 (and probe (cons probe style))))
>             (completion--styles md)))
>           (adjust-fn (get (cdr result-and-style)
> 'completion--adjust-metadata)))
> -- 
> 2.20.1
>
>
>
>
> --- End Message ---
> --- Begin Message ---
>
>
>
> Subject: 
>
> Re: bug#53012: 28.0.90; completion--nth-completion: Throw a meaningful error
>
>
>
>
> Date: 
>
> Sun, 9 Jan 2022 09:31:36 -0600
>
>
>
>
> User-agent: 
>
> Gnus/5.13 (Gnus v5.13) Emacs/29.0.50 (gnu/linux)
>
>
>
>
> Daniel Mendler <mail@daniel-mendler.de> writes:
>
> > On 1/5/22 1:19 AM, Stefan Monnier wrote:
> >> Daniel Mendler [2022-01-04 21:12:47] wrote:
> >>> In the context of the GNU ELPA Vertico/Mct/Orderless/Embark ecosystem we
> >>> teach users to adjust the completion style. Unfortunately
> >>> completion--nth-completion is not very robust against misconfiguration.
> >>> I propose to throw a more meaningful error instead of the nil error.
> >>
> >> Thanks, looks good.
> >> Pushed to `master`.
> >
> > Thanks!
>
> I'm therefore closing this bug report.
>
>
> --- End Message ---