win32: fix checkable menu item to toggle on selection

Closes PR 11985

collects/mred/private/wx/win32/frame.rkt

@@ -15,7 +15,8 @@
 	 "window.rkt"
          "wndclass.rkt"
          "hbitmap.rkt"
-         "cursor.rkt")
+         "cursor.rkt"
+	 "menu-item.rkt")
 
 (provide 
  (protect-out frame%
@@ -250,7 +251,10 @@
       0]
      [(and (= msg WM_COMMAND)
            (zero? (HIWORD wParam)))
-      (queue-window-event this (lambda () (on-menu-command (LOWORD wParam))))
+      (let ([id (LOWORD wParam)])
+	(let ([item (id-to-menu-item id)])
+	  (when item (send item auto-check)))
+	(queue-window-event this (lambda () (on-menu-command id))))
       0]
      [(= msg WM_INITMENU)
       (constrained-reply (get-eventspace)

collects/mred/private/wx/win32/menu-item.rkt

@@ -67,6 +67,10 @@
     (let ([s (GetMenuState hmenu pos MF_BYPOSITION)])
       (not (zero? (bitwise-and s MF_CHECKED)))))
 
+  (define/public (auto-check)
+    (when checkable?
+      (send parent auto-check id)))
+
   (public [get-id id])
   (define (get-id) id)
 

collects/mred/private/wx/win32/menu.rkt

@@ -126,6 +126,12 @@
      (lambda (i pos)
        (send i get-check hmenu pos))))
 
+  (define/public (auto-check id)
+    (with-item
+     id
+     (lambda (i pos)
+       (send i set-check hmenu pos (not (send i get-check hmenu pos))))))
+
   (define/private (remove-item! pos)
     (set! items 
           (append (take items pos)