From a6600997b13d6f6002e491c8463b38cdeb788450 Mon Sep 17 00:00:00 2001
From: Solomon Foster <colomon@gmail.com>
Date: Tue, 12 Jun 2012 06:57:49 -0400
Subject: [PATCH] Handle null strings returned from CLR using sorear++'s
 suggestion.

---
 lib/NieczaCLR.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/NieczaCLR.cs b/lib/NieczaCLR.cs
index ec7240ec..ffc51be3 100644
--- a/lib/NieczaCLR.cs
+++ b/lib/NieczaCLR.cs
@@ -788,7 +788,7 @@ public class CLRWrapperProvider {
             if (cty == typeof(bool))
                 return Kernel.BoxAnyMO((bool)ret, Kernel.BoolMO);
             if (cty == typeof(string))
-                return Kernel.BoxAnyMO((string)ret, Kernel.StrMO);
+                return ret == null ? Kernel.StrMO.typeObj : Kernel.BoxAnyMO((string)ret, Kernel.StrMO);
             if (cty == typeof(Variable))
                 return (Variable)ret;
             if (cty == typeof(P6any))