From 196ac13bdd3e20d2a82e9175c6982c56b58ac35f Mon Sep 17 00:00:00 2001
From: Matthew Flatt <mflatt@racket-lang.org>
Date: Wed, 20 Jul 2011 13:57:52 -0600
Subject: [PATCH] fix bug in .zo writing

The bug showed up in the "racket/embed.rktl" test.

Merge to 5.1.2
(cherry picked from commit 5b8a892fbba0afc56deeda1d4e3a24a3ddb048b5)
---
 src/racket/src/marshal.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/racket/src/marshal.c b/src/racket/src/marshal.c
index c8a0a20343..725ab5dfd8 100644
--- a/src/racket/src/marshal.c
+++ b/src/racket/src/marshal.c
@@ -923,7 +923,10 @@ static Scheme_Object *write_variable(Scheme_Object *obj)
   sym = (Scheme_Object *)(SCHEME_VAR_BUCKET(obj))->key;
     
   home = scheme_get_bucket_home((Scheme_Bucket *)obj);
-  m = home->module;
+  if (home)
+    m = home->module;
+  else
+    m = NULL;
     
   /* If we get a writeable variable (instead of a module variable),
      it must be a reference to a module referenced directly by its