Index: trunk/src/org/openstreetmap/josm/data/osm/MultipolygonBuilder.java
===================================================================
--- trunk/src/org/openstreetmap/josm/data/osm/MultipolygonBuilder.java	(revision 9770)
+++ trunk/src/org/openstreetmap/josm/data/osm/MultipolygonBuilder.java	(revision 9774)
@@ -6,4 +6,7 @@
 import java.awt.Rectangle;
 import java.awt.geom.Area;
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
 import java.util.ArrayList;
 import java.util.Collection;
@@ -308,4 +311,7 @@
     private static class Worker extends RecursiveTask<List<PolygonLevel>> {
 
+        // Needed for Findbugs / Coverity because parent class is serializable
+        private static final long serialVersionUID = 1L;
+
         private final transient List<JoinedPolygon> input;
         private final int from;
@@ -403,4 +409,14 @@
             return output;
         }
+
+        private void readObject(ObjectInputStream ois) throws ClassNotFoundException, IOException {
+            // Needed for Findbugs / Coverity because parent class is serializable
+            ois.defaultReadObject();
+        }
+
+        private void writeObject(ObjectOutputStream oos) throws IOException {
+            // Needed for Findbugs / Coverity because parent class is serializable
+            oos.defaultWriteObject();
+        }
     }
 }
Index: trunk/src/org/openstreetmap/josm/gui/dialogs/RelationListDialog.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/dialogs/RelationListDialog.java	(revision 9770)
+++ trunk/src/org/openstreetmap/josm/gui/dialogs/RelationListDialog.java	(revision 9774)
@@ -124,5 +124,5 @@
     private final transient HighlightHelper highlightHelper = new HighlightHelper();
     private final boolean highlightEnabled = Main.pref.getBoolean("draw.target-highlight", true);
-    private RecentRelationsAction recentRelationsAction;
+    private transient RecentRelationsAction recentRelationsAction;
 
     /**