2 files changed, 8 insertions, 9 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 12768f3578b..7fb63964b6e 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,7 @@
+2011-01-07  Chong Yidong  <cyd@stupidchicken.com>
+
+        * fns.c (Fyes_or_no_p): Accept format string args.
+
 2011-01-07  Glenn Morris  <rgm@gnu.org>
 
         * emacs.c (no_site_lisp): New int.
diff --git a/src/fns.c b/src/fns.c
index 8d54b73586f..3282b300f49 100644
--- a/src/fns.c
+++ b/src/fns.c
@@ -2460,7 +2460,7 @@ do_yes_or_no_p (Lisp_Object prompt)
 
 /* Anything that calls this function must protect from GC!  */
 
-DEFUN ("yes-or-no-p", Fyes_or_no_p, Syes_or_no_p, 1, 1, 0,
+DEFUN ("yes-or-no-p", Fyes_or_no_p, Syes_or_no_p, 1, MANY, 0,
        doc: /* Ask user a yes-or-no question.  Return t if answer is yes.
 Takes one argument, which is the string to display to ask the question.
 It should end in a space; `yes-or-no-p' adds `(yes or no) ' to it.
@@ -2469,13 +2469,11 @@ and can edit it until it has been confirmed.
 
 Under a windowing system a dialog box will be used if `last-nonmenu-event'
 is nil, and `use-dialog-box' is non-nil.  */)
-  (Lisp_Object prompt)
+  (int nargs, Lisp_Object *args)
 {
   register Lisp_Object ans;
-  Lisp_Object args[2];
   struct gcpro gcpro1;
-
-  CHECK_STRING (prompt);
+  Lisp_Object prompt = Fformat (nargs, args);
 
 #ifdef HAVE_MENUS
   if (FRAME_WINDOW_P (SELECTED_FRAME ())
@@ -2496,10 +2494,7 @@ is nil, and `use-dialog-box' is non-nil.  */)
     }
 #endif /* HAVE_MENUS */
 
-  args[0] = prompt;
-  args[1] = build_string ("(yes or no) ");
-  prompt = Fconcat (2, args);
-
+  prompt = concat2 (prompt, build_string ("(yes or no) "));
   GCPRO1 (prompt);
 
   while (1)