GNU logs - #44023, boring messages

Message sent to bug-gnu-emacs@HIDDEN:

Subject: bug#44023: dired-allow-duplicate-buffers
Resent-From: Boruch Baum <boruch_baum@HIDDEN>
Original-Sender: "Debbugs-submit" <debbugs-submit-bounces <at> debbugs.gnu.org>
Resent-CC: bug-gnu-emacs@HIDDEN
Resent-Date: Thu, 15 Oct 2020 19:23:02 +0000
Resent-Message-ID: <handler.44023.B.160278976726148 <at> debbugs.gnu.org>
Resent-Sender: help-debbugs@HIDDEN
To: 44023 <at> debbugs.gnu.org
Date: Thu, 15 Oct 2020 15:22:31 -0400
From: Boruch Baum <boruch_baum@HIDDEN>
Message-ID: <20201015192231.rezuhk7foiyq3uff@HIDDEN>
MIME-Version: 1.0
Content-Type: multipart/mixed; boundary="msxhrqipppmkva3s"
Content-Disposition: inline
User-Agent: NeoMutt/20180716
Received-SPF: pass client-ip=212.227.17.22; envelope-from=boruch_baum@HIDDEN;
 helo=mout.gmx.net
X-Spam_score_int: -25
X-Spam_score: -2.6
X-Spam_bar: --
X-Spam_report: (-2.6 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1,
 DKIM_VALID=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_LOW=-0.7,
 RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001,
 SPF_PASS=-0.001 autolearn=ham autolearn_force=no
X-Spam_action: no action
X-Spam-Score: 0.6 (/)
X-BeenThere: debbugs-submit <at> debbugs.gnu.org
X-Mailman-Version: 2.1.18
Precedence: list
List-Id: <debbugs-submit.debbugs.gnu.org>
List-Unsubscribe: <https://debbugs.gnu.org/cgi-bin/mailman/options/debbugs-submit>, 
 <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=unsubscribe>
List-Archive: <https://debbugs.gnu.org/cgi-bin/mailman/private/debbugs-submit/>
List-Post: <mailto:debbugs-submit <at> debbugs.gnu.org>
List-Help: <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=help>
List-Subscribe: <https://debbugs.gnu.org/cgi-bin/mailman/listinfo/debbugs-submit>, 
 <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=subscribe>
Errors-To: debbugs-submit-bounces <at> debbugs.gnu.org
Sender: "Debbugs-submit" <debbugs-submit-bounces <at> debbugs.gnu.org>
X-Spam-Score: -2.4 (--)


--msxhrqipppmkva3s
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

The attached patch adds a defcustom option to allow multiple buffers to
visit the same directory. This became desirable to me for an extension I
wrote (soon to be submitted) to store each chain of dired buffers'
'navigation history' and allow going back/forward to any point in the
history. As you all know, this has been a feature common to all file
*managers* since almost forever; technically dired is a directory
editor, not a file manager, but I expect many will find the feature
desirable, even expected, since all other similar programs have it.

In going through the existing dired code, it seems that some functions
presume that multiple buffers can be visiting the same directory. See:

  dired-find-buffer-nocreate
  dired-fun-in-all-buffers
  dired-clean-up-after-deletion

Also, implicit in the comment for `dired-find-buffer-nocreate' is that
more than one match may exist for a dired directory buffer.

So, maybe this once existed or was planned?

The first patch is for the option. The second patch is a change of
comments to docstrings.

=2D-
hkp://keys.gnupg.net
CA45 09B5 5351 7C11 A9D1  7286 0036 9E45 1595 8BC0

--msxhrqipppmkva3s
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment; filename="1.patch"
Content-Transfer-Encoding: quoted-printable

diff --git a/NEWS b/NEWS
index a76447d..ca7f31b 100644
=2D-- a/NEWS
+++ b/NEWS
@@ -284,6 +284,10 @@ time zones will use a form like "+0100" instead of "C=
ET".

 ** Dired

++++
+*** New user option: 'dired-allow-duplicate-buffers'
+If set, allows multiple dired buffers to visit the same directory.
+
 ---
 *** Broken and circular links are shown with the 'dired-broken-symlink' f=
ace.

diff --git a/dired.el b/dired.el
index 7839ace..36c2f17 100644
=2D-- a/dired.el
+++ b/dired.el
@@ -353,6 +353,12 @@ is anywhere on its Dired line, except the beginning o=
f the line."
   :group 'dired
   :version "28.1")

+(defcustom dired-allow-duplicate-buffers t
+  "Allow multiple `dired' buffers to visit the same directory."
+  :type 'boolean
+  :group 'dired
+  :version "28.1")
+
 ;; Internal variables

 (defvar dired-marker-char ?*		; the answer is 42
@@ -1152,9 +1158,11 @@ The return value is the target column for the file =
names."
   ;; see there.
   (let* ((old-buf (current-buffer))
 	 (dirname (if (consp dir-or-list) (car dir-or-list) dir-or-list))
-         ;; Look for an existing buffer.
-         (buffer (dired-find-buffer-nocreate dirname mode))
-	 ;; Note that buffer already is in dired-mode, if found.
+         (buffer (when (not (bound-and-true-p dired-allow-duplicate-buffe=
rs))
+                   ;; Look for an existing buffer.
+                   (dired-find-buffer-nocreate dirname mode)
+                   ;; Note that buffer already is in dired-mode, if found=
.
+                   ))
 	 (new-buffer-p (null buffer)))
     (or buffer
         (setq buffer (create-file-buffer (directory-file-name dirname))))

--msxhrqipppmkva3s
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment; filename="2.patch"

diff --git a/dired.el b/dired.el
index 36c2f17..2ecd6bd 100644
--- a/dired.el
+++ b/dired.el
@@ -1143,19 +1143,21 @@ The return value is the target column for the file names."
             (forward-line)))))))

 (defun dired-internal-noselect (dir-or-list &optional switches mode)
-  ;; If DIR-OR-LIST is a string and there is an existing dired buffer
-  ;; for it, just leave buffer as it is (don't even call dired-revert).
-  ;; This saves time especially for deep trees or with ange-ftp.
-  ;; The user can type `g' easily, and it is more consistent with find-file.
-  ;; But if SWITCHES are given they are probably different from the
-  ;; buffer's old value, so call dired-sort-other, which does
-  ;; revert the buffer.
-  ;; Revert the buffer if DIR-OR-LIST is a cons or `dired-directory'
-  ;; is a cons and DIR-OR-LIST is a string.
-  ;; A pity we can't possibly do "Directory has changed - refresh? "
-  ;; like find-file does.
-  ;; Optional argument MODE is passed to dired-find-buffer-nocreate,
-  ;; see there.
+  "Internal function for `dired-noselect'.
+
+If DIR-OR-LIST is a string and there is an existing dired buffer
+for it, just leave buffer as it is (don't even call `dired-revert').
+This saves time especially for deep trees or with `ange-ftp'.
+The user can type `g' easily, and it is more consistent with `find-file'.
+But if SWITCHES are given they are probably different from the
+buffer's old value, so call `dired-sort-other', which does
+revert the buffer.
+Revert the buffer if DIR-OR-LIST is a cons or `dired-directory'
+is a cons and DIR-OR-LIST is a string.
+A pity we can't possibly do \"Directory has changed - refresh?\"
+like `find-file' does.
+Optional argument MODE is passed to `dired-find-buffer-nocreate',
+see there."
   (let* ((old-buf (current-buffer))
 	 (dirname (if (consp dir-or-list) (car dir-or-list) dir-or-list))
          (buffer (when (not (bound-and-true-p dired-allow-duplicate-buffers))
@@ -1219,20 +1221,24 @@ The return value is the target column for the file names."
     buffer))

 (defvar dired-buffers nil
-  ;; Enlarged by dired-advertise
-  ;; Queried by function dired-buffers-for-dir. When this detects a
-  ;; killed buffer, it is removed from this list.
-  "Alist of expanded directories and their associated Dired buffers.")
+  "Alist of expanded directories and their associated Dired buffers.
+The list is enlarged by `dired-advertise'. Function
+`dired-buffers-for-dir' queries this list and removes killed
+buffers from it, when detected.")

 (defvar dired-find-subdir)
+;; `dired-find-subdir' is defined in `dired-x.el'

 ;; FIXME add a doc-string, and document dired-x extensions.
 (defun dired-find-buffer-nocreate (dirname &optional mode)
-  ;; This differs from dired-buffers-for-dir in that it does not consider
-  ;; subdirs of default-directory and searches for the first match only.
-  ;; Also, the major mode must be MODE.
-  (if (and (featurep 'dired-x)
-           dired-find-subdir
+  "Internal function for `dired-internal-noselect'.
+Searches among buffers of major-mode MODE (default `dired-mode')
+for one visiting DIRNAME, and returns the first one found. This
+differs from `dired-buffers-for-dir' in that it does not consider
+subdirs of `default-directory', it searches only for the first
+match, and it can restrict its search to buffers of
+major-mode MODE."
+  (if (and (featurep 'dired-x) dired-find-subdir
            ;; Don't try to find a wildcard as a subdirectory.
 	   (string-equal dirname (file-name-directory dirname)))
       (let* ((cur-buf (current-buffer))

--msxhrqipppmkva3s--

Message sent:

Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-Mailer: MIME-tools 5.505 (Entity 5.505)
Content-Type: text/plain; charset=utf-8
X-Loop: help-debbugs@HIDDEN
From: help-debbugs@HIDDEN (GNU bug Tracking System)
To: Boruch Baum <boruch_baum@HIDDEN>
Subject: bug#44023: Acknowledgement (dired-allow-duplicate-buffers)
Message-ID: <handler.44023.B.160278976726148.ack <at> debbugs.gnu.org>
References: <20201015192231.rezuhk7foiyq3uff@HIDDEN>
X-Gnu-PR-Message: ack 44023
X-Gnu-PR-Package: emacs
Reply-To: 44023 <at> debbugs.gnu.org
Date: Thu, 15 Oct 2020 19:23:02 +0000

Thank you for filing a new bug report with debbugs.gnu.org.

This is an automatically generated reply to let you know your message
has been received.

Your message is being forwarded to the package maintainers and other
interested parties for their attention; they will reply in due course.

Your message has been sent to the package maintainer(s):
 bug-gnu-emacs@HIDDEN

If you wish to submit further information on this problem, please
send it to 44023 <at> debbugs.gnu.org.

Please do not send mail to help-debbugs@HIDDEN unless you wish
to report a problem with the Bug-tracking system.

--=20
44023: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=3D44023
GNU Bug Tracking System
Contact help-debbugs@HIDDEN with problems

Message sent to bug-gnu-emacs@HIDDEN:

Subject: bug#44023: dired-allow-duplicate-buffers
Resent-From: Lars Ingebrigtsen <larsi@HIDDEN>
Original-Sender: "Debbugs-submit" <debbugs-submit-bounces <at> debbugs.gnu.org>
Resent-CC: bug-gnu-emacs@HIDDEN
Resent-Date: Fri, 16 Oct 2020 05:33:02 +0000
Resent-Message-ID: <handler.44023.B44023.16028263613506 <at> debbugs.gnu.org>
Resent-Sender: help-debbugs@HIDDEN
To: Boruch Baum <boruch_baum@HIDDEN>
Cc: 44023 <at> debbugs.gnu.org
From: Lars Ingebrigtsen <larsi@HIDDEN>
References: <20201015192231.rezuhk7foiyq3uff@HIDDEN>
Date: Fri, 16 Oct 2020 07:32:29 +0200
In-Reply-To: <20201015192231.rezuhk7foiyq3uff@HIDDEN> (Boruch
 Baum's message of "Thu, 15 Oct 2020 15:22:31 -0400")
Message-ID: <87wnzqrb0y.fsf@HIDDEN>
User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux)
MIME-Version: 1.0
Content-Type: text/plain
Precedence: list
Errors-To: debbugs-submit-bounces <at> debbugs.gnu.org
Sender: "Debbugs-submit" <debbugs-submit-bounces <at> debbugs.gnu.org>

Boruch Baum <boruch_baum@HIDDEN> writes:

> Also, implicit in the comment for `dired-find-buffer-nocreate' is that
> more than one match may exist for a dired directory buffer.
>
> So, maybe this once existed or was planned?

Dired has always supported having several buffers visiting the same
directory, so I'm not quite sure what the proposed patch is trying to
fix.  You just rename the buffer to something else, like with any
command that defaults to a single buffer name (like, say, `M-x grep').

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

Message sent to bug-gnu-emacs@HIDDEN:

Subject: bug#44023: dired-allow-duplicate-buffers
Resent-From: Boruch Baum <boruch_baum@HIDDEN>
Original-Sender: "Debbugs-submit" <debbugs-submit-bounces <at> debbugs.gnu.org>
Resent-CC: bug-gnu-emacs@HIDDEN
Resent-Date: Fri, 16 Oct 2020 06:47:02 +0000
Resent-Message-ID: <handler.44023.B44023.160283081618862 <at> debbugs.gnu.org>
Resent-Sender: help-debbugs@HIDDEN
To: Lars Ingebrigtsen <larsi@HIDDEN>
Cc: 44023 <at> debbugs.gnu.org
Date: Fri, 16 Oct 2020 02:46:44 -0400
From: Boruch Baum <boruch_baum@HIDDEN>
Message-ID: <20201016064644.poo6ljwpgdhbsksy@HIDDEN>
References: <20201015192231.rezuhk7foiyq3uff@HIDDEN>
 <87wnzqrb0y.fsf@HIDDEN>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <87wnzqrb0y.fsf@HIDDEN>
User-Agent: NeoMutt/20180716
Content-Transfer-Encoding: quoted-printable
Precedence: list
Errors-To: debbugs-submit-bounces <at> debbugs.gnu.org
Sender: "Debbugs-submit" <debbugs-submit-bounces <at> debbugs.gnu.org>

On 2020-10-16 07:32, Lars Ingebrigtsen wrote:
> Boruch Baum <boruch_baum@HIDDEN> writes:
>
> > Also, implicit in the comment for `dired-find-buffer-nocreate' is that
> > more than one match may exist for a dired directory buffer.
> >
> > So, maybe this once existed or was planned?
>
> Dired has always supported having several buffers visiting the same
> directory, so I'm not quite sure what the proposed patch is trying to
> fix.  You just rename the buffer to something else, like with any
> command that defaults to a single buffer name (like, say, `M-x grep').

That's not "dired support" in any shape or form! That's an emacs kludge
external to dired that exploits how dired handles buffer names (likewise
for grep). Dired internally (in the very line being modified by my
patch) actively subverts having several buffers visiting the same
directory, and my experience in testing is that no harm is done when
using the patch.

=2D-
hkp://keys.gnupg.net
CA45 09B5 5351 7C11 A9D1  7286 0036 9E45 1595 8BC0

Last modified: Fri, 16 Oct 2020 07:00:02 UTC

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997 nCipher Corporation Ltd, 1994-97 Ian Jackson.