.

original commit: cd0b455f0c081298d17fc1b770baf4708f9a4fb7

collects/mred/mred.ss

@@ -1347,15 +1347,21 @@
 (define (app-handler-orig ah)
   (app-handler-ref ah 1))
 
-(let ([f (entry-point
+(let* ([running-quit? #f]
+       [f (entry-point
 	   (lambda ()
+	     (unless running-quit?
 	       (let ([af active-main-frame])
 		 (when af
+		   (set! running-quit? #t)
 		   (queue-window-callback
 		    af
 		    (entry-point
 		     (lambda ()
-		    (send af on-exit))))))))])
+		       (dynamic-wind
+			   void
+			   (lambda () (send af on-exit))
+			   (lambda () (set! running-quit? #t)))))))))))])
   (wx:application-quit-handler (make-app-handler f f)))
 
 (define (set-handler! who proc param)