improved serialization signature

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@15250 71c3de6d-444a-0410-be80-ed276b4c234a

core/src/main/java/hudson/model/Hudson.java

@@ -394,7 +394,7 @@ public final class Hudson extends AbstractModelObject implements ItemGroup<TopLe
      */
     public transient final List<AdministrativeMonitor> administrativeMonitors = new CopyOnWriteArrayList<AdministrativeMonitor>();
 
-    /*package*/ final Set<String> disabledAdministrativeMonitors = new CopyOnWriteArraySet<String>();
+    /*package*/ final CopyOnWriteArraySet<String> disabledAdministrativeMonitors = new CopyOnWriteArraySet<String>();
 
     /**
      * {@link AdjunctManager}

core/src/main/java/hudson/util/RobustCollectionConverter.java

@@ -34,6 +34,7 @@ import com.thoughtworks.xstream.XStream;
 
 import java.util.Collection;
 import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.concurrent.CopyOnWriteArraySet;
 
 /**
  * {@link CollectionConverter} that ignores {@link CannotResolveClassException}.
@@ -57,7 +58,7 @@ public class RobustCollectionConverter extends CollectionConverter {
     }
 
     public boolean canConvert(Class type) {
-        return super.canConvert(type) || type==CopyOnWriteArrayList.class;
+        return super.canConvert(type) || type==CopyOnWriteArrayList.class || type==CopyOnWriteArraySet.class;
     }
 
     public Object unmarshal(HierarchicalStreamReader reader, UnmarshallingContext context) {