From: Lars Ingebrigtsen <larsi@gnus.org>
Date: Tue, 13 Jul 2021 17:49:50 +0000 (+0200)
Subject: Add new user option to avoid piling on Dired buffers
X-Git-Tag: emacs-28.0.90~1888^2
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=5afe27624f7168713611dc9c24043091f8f820b6;p=emacs.git

Add new user option to avoid piling on Dired buffers

* doc/emacs/dired.texi (Dired Visiting): Document it.

* lisp/dired.el (dired-kill-when-opening-new-dired-buffer): New
user option (bug#20598).
(dired-up-directory, dired-find-file): Use it.
(dired--find-possibly-alternative-file): New convenience command
to respect the user option.
---

diff --git a/doc/emacs/dired.texi b/doc/emacs/dired.texi
index 36257030c88..3fbaf8bab7a 100644
--- a/doc/emacs/dired.texi
+++ b/doc/emacs/dired.texi
@@ -457,6 +457,15 @@ Visit the parent directory of the current directory
 for @file{..} and typing @kbd{f} there.
 @end table
 
+@defopt dired-kill-when-opening-new-dired-buffer
+  When visiting a new sub-directory in Dired, Emacs will (by default)
+open a new buffer to display this new directory, and leave the old
+Dired buffer as is.  If this user option is non-@code{nil}, the old
+Dired buffer will be killed after selecting the new directory.  This
+means that if you're traversing a directory structure in Dired, you
+won't end up with more than a single Dired buffer.
+@end defopt
+
 @node Marks vs Flags
 @section Dired Marks vs.@: Flags
 
diff --git a/etc/NEWS b/etc/NEWS
index 923cfcc4722..75be112fd31 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -778,6 +778,11 @@ time zones will use a form like "+0100" instead of "CET".
 
 ** Dired
 
++++
+*** New user option 'dired-kill-when-opening-new-dired-buffer'.
+If non-nil, Dired will kill the current buffer when selecting a new
+directory to display.
+
 ---
 *** Behavior change on 'dired-clean-confirm-killing-deleted-buffers'.
 Previously, if 'dired-clean-up-buffers-too' was non-nil, and
diff --git a/lisp/dired.el b/lisp/dired.el
index fb353a92e45..da803feaa18 100644
--- a/lisp/dired.el
+++ b/lisp/dired.el
@@ -356,6 +356,11 @@ is anywhere on its Dired line, except the beginning of the line."
   :group 'dired
   :version "28.1")
 
+(defcustom dired-kill-when-opening-new-dired-buffer nil
+  "If non-nil, kill the current buffer when selecting a new directory."
+  :type 'boolean
+  :version "28.1")
+
 
 ;;; Internal variables
 
@@ -2379,7 +2384,7 @@ directory in another window."
 	(progn
 	  (if other-window
 	      (dired-other-window up)
-	    (dired up))
+	    (dired--find-possibly-alternative-file up))
 	  (dired-goto-file dir)))))
 
 (defun dired-get-file-for-visit ()
@@ -2403,7 +2408,16 @@ directory in another window."
 (defun dired-find-file ()
   "In Dired, visit the file or directory named on this line."
   (interactive)
-  (dired--find-file #'find-file (dired-get-file-for-visit)))
+  (dired--find-possibly-alternative-file (dired-get-file-for-visit)))
+
+(defun dired--find-possibly-alternative-file (file)
+  "Find FILE, but respect `dired-kill-when-opening-new-dired-buffer'."
+  (if (and dired-kill-when-opening-new-dired-buffer
+           (file-directory-p file))
+      (progn
+        (set-buffer-modified-p nil)
+        (dired--find-file #'find-alternate-file file))
+    (dired--find-file #'find-file file)))
 
 (defun dired--find-file (find-file-function file)
   "Call FIND-FILE-FUNCTION on FILE, but bind some relevant variables."