2 files changed, 28 insertions, 9 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 26ff5d4c7ce..cd139b72456 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,12 @@
+2009-12-16  Juri Linkov  <juri@jurta.org>
+
+        Revert to old 23.1 logic of using the file at the mark as default.
+        * dired-aux.el (dired-diff): Use the file at the mark as default
+        if it's not the same as the current file, and the target dir is
+        the current dir or the mark is active.  Add the current file
+        as the arg of `dired-dwim-target-defaults'.  Use the default file
+        in the prompt.  (Bug#5225)
+
 2009-12-15  Michael Albinus  <michael.albinus@gmx.de>
 
         * net/tramp.el (tramp-echo-mark-marker-length): New defconst.
diff --git a/lisp/dired-aux.el b/lisp/dired-aux.el
index 4976d2cd683..d3f5de72c7f 100644
--- a/lisp/dired-aux.el
+++ b/lisp/dired-aux.el
@@ -60,21 +60,31 @@ With prefix arg, prompt for second argument SWITCHES,
 which is options for `diff'."
   (interactive
    (let* ((current (dired-get-filename t))
-          (target-dir (dired-dwim-target-directory))
-          (marked (and (mark t) (save-excursion
-                                  (goto-char (mark t))
-                                  (dired-get-filename nil t))))
-          (defaults
-            (append (dired-dwim-target-defaults nil target-dir)
-                    ;; Additional file with the mark.
-                    (and marked (list marked)))))
+          ;; Get the file at the mark.
+          (file-at-mark (if (mark t)
+                            (save-excursion (goto-char (mark t))
+                                            (dired-get-filename t t))))
+          ;; Use it as default if it's not the same as the current file,
+          ;; and the target dir is the current dir or the mark is active.
+          (default (if (and (not (equal file-at-mark current))
+                            (or (equal (dired-dwim-target-directory)
+                                       (dired-current-directory))
+                                mark-active))
+                       file-at-mark))
+          (target-dir (if default
+                          (dired-current-directory)
+                        (dired-dwim-target-directory)))
+          (defaults (dired-dwim-target-defaults (list current) target-dir)))
      (require 'diff)
      (list
       (minibuffer-with-setup-hook
           (lambda ()
             (set (make-local-variable 'minibuffer-default-add-function) nil)
             (setq minibuffer-default defaults))
-        (read-file-name (format "Diff %s with: " current) target-dir nil t))
+        (read-file-name
+         (format "Diff %s with%s: " current
+                 (if default (format " (default %s)" default) ""))
+         target-dir default t))
       (if current-prefix-arg
           (read-string "Options for diff: "
                        (if (stringp diff-switches)