(mark-sexp): Preserve direction when repeating.

1 files changed, 5 insertions, 3 deletions

diff --git a/lisp/emacs-lisp/lisp.el b/lisp/emacs-lisp/lisp.el
index 63d9f759ceb..87b3fcff96c 100644
--- a/lisp/emacs-lisp/lisp.el
+++ b/lisp/emacs-lisp/lisp.el
@@ -75,17 +75,19 @@ The place mark goes is the same place \\[forward-sexp] would
 move to with the same argument.
 If this command is repeated, it marks the next ARG sexps after the ones
 already marked."
-  (interactive "p")
+  (interactive "P")
   (cond ((and (eq last-command this-command) (mark t))
+         (setq arg (if arg (prefix-numeric-value arg)
+                     (if (> (mark) (point)) 1 -1)))
          (set-mark
           (save-excursion
            (goto-char (mark))
-           (forward-sexp (or arg 1))
+           (forward-sexp arg)
            (point))))
         (t
          (push-mark
           (save-excursion
-            (forward-sexp (or arg 1))
+            (forward-sexp (prefix-numeric-value arg))
             (point))
           nil t))))