bug#70994: [PATCH] Make cache regeneration work in group names with /

[Stefan Kangas <stefankangas@gmail.com>]

James Thomas via "Bug reports for GNU Emacs, the Swiss army knife of
text editors" <bug-gnu-emacs@gnu.org> writes:

> Reproduction steps for bug:
>
> - emacs -Q
> - (setq gnus-secondary-select-methods
>     '((nnatom "github.com/vedang/pdf-tools/commits.atom")))
>   (setq gnus-select-method '(nnnil ""))
> - M-x gnus
> - Open a message in the new group and press *
> - Add the cache virtual server (info "(gnus) Creating a Virtual Server")
> - ^ (server buffer) and: g on the cache
> - RET to open (fails)
>
> This is a possible fix that I've tested only on my (limited) setup, for
> now:

Eric, what do you think of the below patch?

> From 1252b4541b265f6da13c07d9a2ce16fdecd51731 Mon Sep 17 00:00:00 2001
> From: James Thomas <jimjoe@gmx.net>
> Date: Fri, 17 May 2024 10:18:14 +0530
> Subject: [PATCH] Make cache regeneration work in group names with /
>
> * lisp/gnus/nnheader.el (nnheader-file-to-group): Account for /
> in the last part of the group name.
> * lisp/gnus/nnmail.el (nnmail-group-pathname): Url-encode only
> the last part of the group name.
> ---
>  lisp/gnus/nnheader.el | 25 +++++++++++++++----------
>  lisp/gnus/nnmail.el   | 19 ++++++++++++++++---
>  2 files changed, 31 insertions(+), 13 deletions(-)
>
> diff --git a/lisp/gnus/nnheader.el b/lisp/gnus/nnheader.el
> index ea679759f3e..85a9f1bd8af 100644
> --- a/lisp/gnus/nnheader.el
> +++ b/lisp/gnus/nnheader.el
> @@ -827,16 +827,21 @@ nnheader-replace-duplicate-chars-in-string
>
>  (defun nnheader-file-to-group (file &optional top)
>    "Return a group name based on FILE and TOP."
> -  (nnheader-replace-chars-in-string
> -   (if (not top)
> -       file
> -     (condition-case ()
> -	 (substring (expand-file-name file)
> -		    (length
> -		     (expand-file-name
> -		      (file-name-as-directory top))))
> -       (error "")))
> -   nnheader-directory-separator-character ?.))
> +  (setq file
> +        (if (not top)
> +            file
> +          (condition-case ()
> +	      (substring (expand-file-name file)
> +		         (length
> +		          (expand-file-name
> +		           (file-name-as-directory top))))
> +            (error ""))))
> +  ;; The last part could have slashes.
> +  (concat
> +   (nnheader-replace-chars-in-string
> +    (file-name-directory file)
> +    nnheader-directory-separator-character ?.)
> +   (url-unhex-string (file-name-nondirectory file))))
>
>  (defun nnheader-message (level &rest args)
>    "Message if the Gnus backends are talkative."
> diff --git a/lisp/gnus/nnmail.el b/lisp/gnus/nnmail.el
> index a9f5b89c6fe..0e1bcf849ce 100644
> --- a/lisp/gnus/nnmail.el
> +++ b/lisp/gnus/nnmail.el
> @@ -627,9 +627,21 @@ nnmail-group-pathname
>    "Make file name for GROUP."
>    (concat
>     (let ((dir (file-name-as-directory (expand-file-name dir))))
> +     (setq group
> +           ;; The last part is allowed slashes. So url-encode.
> +           (let ((split-list (split-string group "\\.")))
> +             (string-join
> +              (append
> +               (butlast split-list)
> +               (list (browse-url-url-encode-chars
> +                      (car (last split-list))
> +                      (concat "[%"
> +                       (char-to-string
> +                        nnheader-directory-separator-character)
> +                       "]"))))
> +	      ".")))
>       (setq group (nnheader-replace-duplicate-chars-in-string
> -		  (browse-url-url-encode-chars group "[/%]")
> -		  ?. ?_))
> +		  group ?. ?_))
>       (setq group (nnheader-translate-file-chars group))
>       ;; If this directory exists, we use it directly.
>       (file-name-as-directory
> @@ -638,7 +650,8 @@ nnmail-group-pathname
>  	  (expand-file-name group dir)
>  	;; If not, we translate dots into slashes.
>  	(expand-file-name
> -	 (nnheader-replace-chars-in-string group ?. ?/)
> +	 (nnheader-replace-chars-in-string
> +          group ?. nnheader-directory-separator-character)
>  	 dir))))
>     (or file "")))
>
> --
> 2.40.1
>
>
> Regards,
> James