Subject: Re: bug#40967: 27.0.50; vc-diff in indirect buffers

From: Nathan Moreau <[email-masked]>
Date: Fri, 2 Oct 2020 02:27:40 +0200

Hi Lars,

Thanks for having a look. This looks good to me.

Best regards,
Nathan

On Thu, 1 Oct 2020 at 19:56, Lars Ingebrigtsen <[email-masked]> wrote:

> Nathan Moreau <[email-masked]> writes:
>
> > Gentle ping. This can be rebased on whichever branch you like if it
> > does not apply cleanly (currently it is based on d6f6353cfdbbea for
> > because it happened to be checked-out locally).
>
> The patch does not apply cleanly to Emacs 28, so I've respun it.  There
> were some conflicts; please check that it looks correct.
>
> diff --git a/lisp/vc/vc.el b/lisp/vc/vc.el
> index 3852a64550..46c44fa54b 100644
> --- a/lisp/vc/vc.el
> +++ b/lisp/vc/vc.el
> @@ -1038,7 +1038,9 @@ vc-deduce-fileset
>  list of marked files, or the current directory if no files are
>  marked.
>  Otherwise, if the current buffer is visiting a version-controlled
> -file, FILESET is a single-file list containing that file's name.
> +file or is an indirect buffer whose base buffer visits a
> +version-controlled file, FILESET is a single-file list containing
> +that file's name.
>  Otherwise, if ALLOW-UNREGISTERED is non-nil and the visited file
>  is unregistered, FILESET is a single-file list containing the
>  name of the visited file.
> @@ -1052,6 +1054,14 @@ vc-deduce-fileset
>  the returned list.
>
>  BEWARE: this function may change the current buffer."
> +  (with-current-buffer (or (buffer-base-buffer) (current-buffer))
> +    (vc-deduce-fileset-1 not-state-changing
> +                         allow-unregistered
> +                         state-model-only-files)))
> +
> +(defun vc-deduce-fileset-1 (not-state-changing
> +                            allow-unregistered
> +                            state-model-only-files)
>    (let (backend)
>      (cond
>       ((derived-mode-p 'vc-dir-mode)
> @@ -1073,7 +1083,7 @@ vc-deduce-fileset
>                                       (derived-mode-p 'dired-mode)))))
>        (progn                  ;FIXME: Why not `with-current-buffer'?
> --Stef.
>         (set-buffer vc-parent-buffer)
> -       (vc-deduce-fileset not-state-changing allow-unregistered
> state-model-only-files)))
> +       (vc-deduce-fileset-1 not-state-changing allow-unregistered
> state-model-only-files)))
>       ((and (not buffer-file-name)
>            (setq backend (vc-responsible-backend default-directory)))
>        (list backend nil))
> @@ -1883,6 +1893,10 @@ vc-root-version-diff
>         t (list backend (list rootdir)) rev1 rev2
>         (called-interactively-p 'interactive)))))
>
> +(defun vc-maybe-buffer-sync (not-urgent)
> +  (with-current-buffer (or (buffer-base-buffer) (current-buffer))
> +    (when buffer-file-name (vc-buffer-sync not-urgent))))
> +
>  ;;;###autoload
>  (defun vc-diff (&optional historic not-urgent)
>    "Display diffs between file revisions.
> @@ -1895,6 +1909,7 @@ vc-diff
>    (interactive (list current-prefix-arg t))
>    (if historic
>        (call-interactively 'vc-version-diff)
> +    (vc-maybe-buffer-sync not-urgent)
>      (let ((fileset (vc-deduce-fileset t)))
>        (vc-buffer-sync-fileset fileset not-urgent)
>        (vc-diff-internal t fileset nil nil
> @@ -1981,7 +1996,7 @@ vc-ediff
>    (interactive (list current-prefix-arg t))
>    (if historic
>        (call-interactively 'vc-version-ediff)
> -    (when buffer-file-name (vc-buffer-sync not-urgent))
> +    (vc-maybe-buffer-sync not-urgent)
>      (vc-version-ediff (cadr (vc-deduce-fileset t)) nil nil)))
>
>  ;;;###autoload
> @@ -1998,7 +2013,7 @@ vc-root-diff
>    (if historic
>        ;; We want the diff for the VC root dir.
>        (call-interactively 'vc-root-version-diff)
> -    (when buffer-file-name (vc-buffer-sync not-urgent))
> +    (vc-maybe-buffer-sync not-urgent)
>      (let ((backend (vc-deduce-backend))
>           (default-directory default-directory)
>           rootdir working-revision)
> @@ -2038,17 +2053,18 @@ vc-revision-other-window
>  If the current file is named `F', the revision is named `F.~REV~'.
>  If `F.~REV~' already exists, use it instead of checking it out again."
>    (interactive
> -   (save-current-buffer
> +   (with-current-buffer (or (buffer-base-buffer) (current-buffer))
>       (vc-ensure-vc-buffer)
>       (list
>        (vc-read-revision "Revision to visit (default is working revision):
> "
>                          (list buffer-file-name)))))
> -  (vc-ensure-vc-buffer)
> -  (let* ((file buffer-file-name)
> -        (revision (if (string-equal rev "")
> -                     (vc-working-revision file)
> -                   rev)))
> -    (switch-to-buffer-other-window (vc-find-revision file revision))))
> +  (with-current-buffer (or (buffer-base-buffer) (current-buffer))
> +    (vc-ensure-vc-buffer)
> +    (let* ((file buffer-file-name)
> +          (revision (if (string-equal rev "")
> +                        (vc-working-revision file)
> +                      rev)))
> +      (switch-to-buffer-other-window (vc-find-revision file revision)))))
>
>  (defun vc-find-revision (file revision &optional backend)
>    "Read REVISION of FILE into a buffer and return the buffer.
>
>
> --
> (domestic pets only, the antidote for overdose, milk.)
>    bloggy blog: http://lars.ingebrigtsen.no
>