diff options
Diffstat (limited to 'lisp/dired-aux.el')
| -rw-r--r-- | lisp/dired-aux.el | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/lisp/dired-aux.el b/lisp/dired-aux.el index 13443419bd7..f6ff32b0b01 100644 --- a/lisp/dired-aux.el +++ b/lisp/dired-aux.el @@ -55,7 +55,8 @@ into this list; they also should call `dired-log' to log the errors.") (defun dired-diff (file &optional switches) "Compare file at point with file FILE using `diff'. If called interactively, prompt for FILE. If the file at point -has a backup file, use that as the default. If the mark is active +has a backup file, use that as the default. If the file at point +is a backup file, use its original. If the mark is active in Transient Mark mode, use the file at the mark as the default. \(That's the mark set by \\[set-mark-command], not by Dired's \\[dired-mark] command.) @@ -67,8 +68,10 @@ With prefix arg, prompt for second argument SWITCHES, which is the string of command switches for the third argument of `diff'." (interactive (let* ((current (dired-get-filename t)) - ;; Get the latest existing backup file. - (oldf (diff-latest-backup-file current)) + ;; Get the latest existing backup file or its original. + (oldf (if (backup-file-name-p current) + (file-name-sans-versions current) + (diff-latest-backup-file current))) ;; Get the file at the mark. (file-at-mark (if (and transient-mark-mode mark-active) (save-excursion (goto-char (mark t)) @@ -107,7 +110,10 @@ the string of command switches for the third argument of `diff'." (equal (expand-file-name current file) (expand-file-name current)))) (error "Attempt to compare the file to itself")) - (diff file current switches))) + (if (and (backup-file-name-p current) + (equal file (file-name-sans-versions current))) + (diff current file switches) + (diff file current switches)))) ;;;###autoload (defun dired-backup-diff (&optional switches) |