From 3b16f7a8e229a9f36ea48dee073e425ca7eadb2f Mon Sep 17 00:00:00 2001
From: Matthew Flatt <mflatt@racket-lang.org>
Date: Sun, 27 Mar 2011 11:21:28 -0600
Subject: [PATCH] win32: clipboard fix

original commit: 4e7281768818743ef9c9b779affef23448dff344
---
 collects/mred/private/wx/win32/clipboard.rkt | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/collects/mred/private/wx/win32/clipboard.rkt b/collects/mred/private/wx/win32/clipboard.rkt
index 5b212e28..e7b715f4 100644
--- a/collects/mred/private/wx/win32/clipboard.rkt
+++ b/collects/mred/private/wx/win32/clipboard.rkt
@@ -148,11 +148,12 @@
                            ;; no conversion:
                            d])))]
            [all-handles (for/list ([d (in-list all-data)])
-                          (let ([h (GlobalAlloc GHND (bytes-length d))])
-                            (let ([p (GlobalLock h)])
-                              (memcpy p d (bytes-length d)))
-                            (GlobalUnlock h)
-                            h))])
+			  (and d
+			       (let ([h (GlobalAlloc GHND (bytes-length d))])
+				 (let ([p (GlobalLock h)])
+				   (memcpy p d (bytes-length d)))
+				 (GlobalUnlock h)
+				 h)))])
       (if (null? types)
           (drop-client c)
           (atomically
@@ -161,7 +162,8 @@
                  (EmptyClipboard)
                  (for ([t (in-list type-ids)]
                        [h (in-list all-handles)])
-                   (SetClipboardData t h))
+		   (when h
+		     (SetClipboardData t h)))
                  (if (CloseClipboard)
                      (set! client c)
                      (drop-client c)))