$NetBSD: patch-aa,v 1.4 2010/01/15 23:09:28 tnn Exp $

--- execute.c.orig	2008-03-20 00:21:49.000000000 +0000
+++ execute.c
@@ -730,7 +730,7 @@ ThreadUnwind (Value thread, int twixt, i
 #endif
 }
 
-#define ThreadBoxCheck(box,i) (BoxValueGet(box,i) == 0 ? ThreadBoxSetDefault(box,i,0) : 0)
+#define ThreadBoxCheck(box,i) (BoxValueGet(box,i) == 0 ? (ThreadBoxSetDefault(box,i,0) ,1) : 0)
 
 typedef struct _TypeChain {
     struct _TypeChain	*prev;