Do not try to serialize null header item.

diff --git a/mcs/class/System.ServiceModel/System.ServiceModel.Dispatcher/BaseMessagesFormatter.cs b/mcs/class/System.ServiceModel/System.ServiceModel.Dispatcher/BaseMessagesFormatter.cs
index c36e6f138a5db5375c3f63915bef2237279dec5b..1c38395c265d5627602e2dc84ee5f4f6f75fea7a 100644 (file)
--- a/mcs/class/System.ServiceModel/System.ServiceModel.Dispatcher/BaseMessagesFormatter.cs
+++ b/mcs/class/System.ServiceModel/System.ServiceModel.Dispatcher/BaseMessagesFormatter.cs
@@ -216,7 +216,8 @@ namespace System.ServiceModel.Dispatcher
                        var msg = PartsToMessage (md, version, action, parts);
                        if (headers != null)
                                foreach (var pair in headers)
-                                       msg.Headers.Add (MessageHeader.CreateHeader (pair.Key.Name, pair.Key.Namespace, pair.Value));
+                                       if (pair.Value != null)
+                                               msg.Headers.Add (MessageHeader.CreateHeader (pair.Key.Name, pair.Key.Namespace, pair.Value));
                        return msg;
                }