2 files changed, 11 insertions, 1 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 398b058a874..e799ead207b 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,5 +1,8 @@
 2012-10-18  Glenn Morris  <rgm@gnu.org>
 
+        * dired.el (dired-sort-toggle): Some ls implementations only allow
+        a single option string.  (Bug#12666)
+
         * minibuffer.el (completion-cycle-threshold): Doc fix.
 
 2012-10-17  Kenichi Handa  <handa@gnu.org>
diff --git a/lisp/dired.el b/lisp/dired.el
index a17e1805339..a4bc16caebf 100644
--- a/lisp/dired.el
+++ b/lisp/dired.el
@@ -3546,8 +3546,15 @@ With a prefix argument, edit the current listing switches instead."
         (setq dired-actual-switches
               (replace-match "" t t dired-actual-switches 3))))
     ;; Now, if we weren't sorting by date before, add the -t switch.
+    ;; Some simple-minded ls implementations (eg ftp servers) only
+    ;; allow a single option string, so try not to add " -t" if possible.
     (unless sorting-by-date
-      (setq dired-actual-switches (concat dired-actual-switches " -t"))))
+      (setq dired-actual-switches
+            (concat dired-actual-switches
+                    (if (string-match-p "\\`-[[:alnum:]]+\\'"
+                                        dired-actual-switches)
+                        "t"
+                      " -t")))))
   (dired-sort-set-mode-line)
   (revert-buffer))