From 4430b7393438f9fa068523efe0fc111ef256c8e8 Mon Sep 17 00:00:00 2001
From: Robby Findler <robby@racket-lang.org>
Date: Fri, 19 Mar 2010 13:20:30 +0000
Subject: [PATCH] a bug found via random testing

svn: r18582

original commit: 1c72ed7a204567019a1e835c0c322b8f366781b9
---
 collects/framework/private/scheme.ss | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/collects/framework/private/scheme.ss b/collects/framework/private/scheme.ss
index 4625e8c7..6ce387d2 100644
--- a/collects/framework/private/scheme.ss
+++ b/collects/framework/private/scheme.ss
@@ -1154,7 +1154,9 @@
     (define/override (on-enable-surrogate text)
       (send text begin-edit-sequence)
       (super on-enable-surrogate text)
-      (send (send text get-keymap) chain-to-keymap keymap #f)
+      (let ([km (send text get-keymap)])
+        (when km
+          (send km chain-to-keymap keymap #f)))
       
       ;; I don't know about these editor flag settings.
       ;; maybe they belong in drscheme?