A few tweaks
diff --git a/src/ProtocolBuffers.Test/TestUtil.cs b/src/ProtocolBuffers.Test/TestUtil.cs
index 70dd3c8..f27466b 100644
--- a/src/ProtocolBuffers.Test/TestUtil.cs
+++ b/src/ProtocolBuffers.Test/TestUtil.cs
@@ -37,6 +37,7 @@
         while (ancestor != null) {
           string candidate = Path.Combine(ancestor.FullName, "testdata");
           if (Directory.Exists(candidate)) {
+            testDataDirectory = candidate;
             return candidate;
           }
           ancestor = ancestor.Parent;