(dired-flag-backup-files): Under MS-DOS, search for

possible backup files by checking for filenames which end with a
`k' (the backup extension is `.bak').

1 files changed, 11 insertions, 12 deletions

diff --git a/lisp/dired.el b/lisp/dired.el
index 8d6b4058e34..5782e0ab012 100644
--- a/lisp/dired.el
+++ b/lisp/dired.el
@@ -2012,21 +2012,20 @@ A prefix argument says to unflag those files instead."
   "Flag all backup files (names ending with `~') for deletion.
 With prefix argument, unflag these files."
   (interactive "P")
-  (let ((dired-marker-char (if unflag-p ?\040 dired-del-marker)))
+  (let ((dired-marker-char (if unflag-p ?\  dired-del-marker))
+	(last-c (if (eq system-type 'ms-dos) ?k ?~)))
     (dired-mark-if
-     ;; It is less than general to check for ~ here,
+     ;; Don't call backup-file-name-p unless the last character looks like
+     ;; it might be the end of a backup file name.  This isn't very general,
      ;; but it's the only way this runs fast enough.
      (and (save-excursion (end-of-line)
-			  (or
-			   (eq (preceding-char) ?~)
-			   ;; Handle executables in case of -F option.
-			   ;; We need not worry about the other kinds
-			   ;; of markings that -F makes, since they won't
-			   ;; appear on real backup files.
-			   (if (eq (preceding-char) ?*)
-			       (progn
-				 (forward-char -1)
-				 (eq (preceding-char) ?~)))))
+			  ;; Handle executables in case of -F option.
+			  ;; We need not worry about the other kinds
+			  ;; of markings that -F makes, since they won't
+			  ;; appear on real backup files.
+			  (if (eq (preceding-char) ?*)
+			      (forward-char -1))
+			  (eq (preceding-char) last-c))
 	  (not (looking-at dired-re-dir))
 	  (let ((fn (dired-get-filename t t)))
 	    (if fn (backup-file-name-p fn))))