bug#25983: 25.2; set dired-directory in vc-dir mode

bug#25983: 25.2; set dired-directory in vc-dir mode

[Tom Tromey]

I'd find it handy if vc-dir buffers had dired-directory set.
This can serve as an indication that the buffer is associated with some
directory, even though it's not visiting a file.

I've appended the patch I would like to apply.
Let me know what you think.

Tom


diff --git a/lisp/vc/vc-dir.el b/lisp/vc/vc-dir.el
index 0363aab..2281333 100644
--- a/lisp/vc/vc-dir.el
+++ b/lisp/vc/vc-dir.el
@@ -1016,6 +1016,7 @@ vc-dir-mode
     (set (make-local-variable 'vc-ewoc) (ewoc-create #'vc-dir-printer))
     (set (make-local-variable 'revert-buffer-function)
 	 'vc-dir-revert-buffer-function)
+    (setq dired-directory default-directory)
     (setq list-buffers-directory (expand-file-name "*vc-dir*" default-directory))
     (add-to-list 'vc-dir-buffers (current-buffer))
     ;; Make sure that if the directory buffer is killed, the update





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bug#25983: 25.2; set dired-directory in vc-dir mode

[Glenn Morris]

Tom Tromey wrote:

> I'd find it handy if vc-dir buffers had dired-directory set.
> This can serve as an indication that the buffer is associated with some
> directory, even though it's not visiting a file.

Is dired-directory not basically an internal dired variable that should
only be set in Dired mode, and modes derived from it, which vc-dir is not?

    Documentation:
    The directory name or wildcard spec that this Dired directory lists.
    Local to each Dired buffer.

bug#25983: 25.2; set dired-directory in vc-dir mode

[Tom Tromey]

>>>>> "GM" == Glenn Morris <rgm@gnu.org> writes:

GM> Is dired-directory not basically an internal dired variable that should
GM> only be set in Dired mode, and modes derived from it, which vc-dir is not?

Various bits of code (and some other code I have seen, not part of
Emacs) seem to examine it.  And vc-dir seems dired-like.

The basic problem is that I don't think there's a good way to indicate:
"this buffer is associated with this directory, but isn't visiting a
file".  dired-directory is the only one I know of.

default-directory seems almost right but it's a bit random for some
buffers; like *shell* or *compilation*.

There's list-buffer-directory but it is just a random string, not
actually a directory name.

The backstory for this bug is that I have this handy bit of code I got
from someone on #emacs:

    ;; From fledermaus
    (defun kill-buffers-under (under)
      (interactive "DKill buffers under: ")
      (setq under (concat "^" (expand-file-name under)))
      (mapc
       (lambda (buf)
         (let ((path
                (or (buffer-file-name buf)
                    (progn
                      (set-buffer buf)
                      (and dired-directory
                           (expand-file-name dired-directory)) )) ))
           ;;(message "checking %S: %S vs |%s|" buf path under)
           (and path (string-match under path)
                (progn
                  (message "Killing buffer %s" (buffer-name buf))
                  (kill-buffer buf))) ))
       (buffer-list)))

... and I'd rather not add a special hack just for vc-dir, and then for
whatever other modes crop up.

I guess I'm being a bit lazy trying to avoid introducing a new variable.
But maybe I should?

Tom

bug#25983: 25.2; set dired-directory in vc-dir mode

[Lars Ingebrigtsen]

Tom Tromey <tom@tromey.com> writes:

>>>>>> "GM" == Glenn Morris <rgm@gnu.org> writes:
>
> GM> Is dired-directory not basically an internal dired variable that should
> GM> only be set in Dired mode, and modes derived from it, which vc-dir is not?
>
> Various bits of code (and some other code I have seen, not part of
> Emacs) seem to examine it.  And vc-dir seems dired-like.

Hm...  Well, there's a bunch of buffers that are kinda-sorta dired-like
(like `M-x grep'), so adding this just to vc-dir seems a bit odd to me.

> The backstory for this bug is that I have this handy bit of code I got
> from someone on #emacs:
>
>     ;; From fledermaus
>     (defun kill-buffers-under (under)

[...]

>                       (and dired-directory
>                            (expand-file-name dired-directory)) )) ))

[...]

> ... and I'd rather not add a special hack just for vc-dir, and then for
> whatever other modes crop up.
>
> I guess I'm being a bit lazy trying to avoid introducing a new variable.
> But maybe I should?

All buffers have a default-directory, but you want to make a function
that kills are buffers that are "like" dired (in that they display a
buffer pointing to a directory, and there are things you can do there)?

I don't think you'll be able to find a definition of what's "like" dired
enough that this would make sense...  especially when the use case
doesn't seem that ... comprehensible?  That is, I think only the user
that writes a function like this knows what buffer types they want to
consider killing.  Finding a general solution here doesn't seem very
likely, so I'm closing this bug report.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no