(winner-pending-undo-ring): Defvar before first use.

(winner-undo-counter): Likewise.

lisp/winner.el

@@ -129,6 +129,11 @@ With arg, turn Winner mode on if and only if arg is positive."
     (force-mode-line-update)))
 
 ;; Inspired by undo (simple.el)
+
+(defvar winner-pending-undo-ring nil)
+
+(defvar winner-undo-counter nil)
+
 (defun winner-undo (arg)
   "Switch back to an earlier window configuration saved by Winner mode.
 In other words, \"undo\" changes in window configuration."
@@ -147,10 +152,6 @@ In other words, \"undo\" changes in window configuration."
       (message "Winner undo (%d)!" winner-undo-counter)
       (setq this-command 'winner-undo))))
 
-(defvar winner-pending-undo-ring nil)
-
-(defvar winner-undo-counter nil)
-
 (defun winner-undo-more (count)
   "Undo N window configuration changes beyond what was already undone.
 Call `winner-undo-start' to get ready to undo recent changes,