From a15a76f76690fb3c9176c106419c62770b866ffc Mon Sep 17 00:00:00 2001
From: "Richard M. Stallman" <rms@gnu.org>
Date: Wed, 14 Jun 1995 11:46:56 +0000
Subject: [PATCH] (dired-change-marks): If OLD is a space, don't act on
 non-file lines.

---
 lisp/dired.el | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/lisp/dired.el b/lisp/dired.el
index d049ee706d8..4afb66871cf 100644
--- a/lisp/dired.el
+++ b/lisp/dired.el
@@ -2039,8 +2039,12 @@ OLD and NEW are both characters used to mark files."
       (save-excursion
 	(goto-char (point-min))
 	(while (search-forward string nil t)
-	  (subst-char-in-region (match-beginning 0)
-				(match-end 0) old new))))))
+	  (if (if (= old ?\ )
+		  (save-match-data
+		    (dired-get-filename 'no-dir t))
+		t)
+	      (subst-char-in-region (match-beginning 0)
+				    (match-end 0) old new)))))))
 
 (defun dired-unmark-all-files-no-query ()
   "Remove all marks from all files in the Dired buffer."