(dired-diff): Use dired-dwim-target-directory

instead of the file at the mark as default if the file at the mark
is the same as the file at point or if dired-dwim-target-directory
is not the same as the current directory and the mark is not active.

2 files changed, 14 insertions, 3 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 63378f163f6..5c286c57b8f 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,5 +1,10 @@
 2006-01-17  Juri Linkov  <juri@jurta.org>
 
+        * dired-aux.el (dired-diff): Use dired-dwim-target-directory
+        instead of the file at the mark as default if the file at the mark
+        is the same as the file at point or if dired-dwim-target-directory
+        is not the same as the current directory and the mark is not active.
+
         * log-view.el (log-view-minor-wrap): Use the same logic to get
         revisions as `log-view-diff'.
 
diff --git a/lisp/dired-aux.el b/lisp/dired-aux.el
index f946199bbd6..7a34c39bed5 100644
--- a/lisp/dired-aux.el
+++ b/lisp/dired-aux.el
@@ -53,14 +53,20 @@ FILE defaults to the file at the mark.  (That's the mark set by
 \\[set-mark-command], not by Dired's \\[dired-mark] command.)
 The prompted-for file is the first file given to `diff'.
 With prefix arg, prompt for second argument SWITCHES,
- which is options for `diff'."
+which is options for `diff'."
   (interactive
-   (let ((default (if (mark t)
+   (let ((current (dired-get-filename t))
+         (default (if (mark t)
                       (save-excursion (goto-char (mark t))
                                       (dired-get-filename t t)))))
+     (if (or (equal default current)
+             (and (not (equal (dired-dwim-target-directory)
+                              (dired-current-directory)))
+                  (not mark-active)))
+         (setq default nil))
      (require 'diff)
      (list (read-file-name (format "Diff %s with%s: "
-                                   (dired-get-filename t)
+                                   current
                                    (if default
                                        (concat " (default " default ")")
                                      ""))