From 571fec95aa37cb160f9de909cc39dce286a793f0 Mon Sep 17 00:00:00 2001
From: Matthias Felleisen <matthias@racket-lang.org>
Date: Mon, 30 Nov 2009 18:22:38 +0000
Subject: [PATCH] stop the world and let me get off (2)

svn: r17112
---
 collects/2htdp/private/world.ss | 35 +++++++++++++++++++--------------
 collects/2htdp/universe.ss      |  2 +-
 2 files changed, 21 insertions(+), 16 deletions(-)

diff --git a/collects/2htdp/private/world.ss b/collects/2htdp/private/world.ss
index 59480ffe1a..f3e13348f5 100644
--- a/collects/2htdp/private/world.ss
+++ b/collects/2htdp/private/world.ss
@@ -215,26 +215,31 @@
           (queue-callback 
            (lambda ()
              (with-handlers ([exn? (handler #t)])
-	       (define stop-it #f)
                (define tag (format "~a callback" 'transform))
                (define nw (transform (send world get) arg ...))
                (when (package? nw)
                  (broadcast (package-message nw))
                  (set! nw (package-world nw)))
-               (printf "~s\n" nw)
-	       (when (stop-the-world? nw)
-		 (set! nw (stop-the-world-world nw))
-		 (set! stop-it #t))
-               (let ([changed-world? (send world set tag nw)])
-                 (unless changed-world?
-                   (when draw (pdraw))
-                   (when (or stop-it (pstop))
-                     (when last-picture 
-                       (set! draw last-picture)
-                       (pdraw))
-                     (callback-stop! 'name)
-                     (enable-images-button)))
-                 changed-world?))))))
+               (if (stop-the-world? nw)
+		   (begin
+		     (set! nw (stop-the-world-world nw))
+		     (send world set tag nw)
+		     (when last-picture
+		       (set! draw last-picture))
+		     (when draw (pdraw))
+		     (callback-stop! 'name)
+		     (enable-images-button))
+		   (let ([changed-world? (send world set tag nw)])
+		     (unless changed-world?
+		       (when draw (pdraw))
+		       (when (pstop)
+			 (printf "!stop!\n")
+			 (when last-picture 
+			   (set! draw last-picture)
+			   (pdraw))
+			 (callback-stop! 'name)
+			 (enable-images-button)))
+		     changed-world?)))))))
       
       ;; tick, tock : deal with a tick event for this world 
       (def/pub-cback (ptock) tick)
diff --git a/collects/2htdp/universe.ss b/collects/2htdp/universe.ss
index a13d4fd3ee..be9d563852 100644
--- a/collects/2htdp/universe.ss
+++ b/collects/2htdp/universe.ss
@@ -24,7 +24,7 @@
 (provide (all-from-out "private/image.ss"))
 
 (provide 
- (rename-out (make-stop-the-world STOP!))) ;; World -> STOP!
+ (rename-out (make-stop-the-world stop-with))) ;; World -> STOP
 
 (provide
  launch-many-worlds