Index: test/org/openstreetmap/josm/data/osm/DataSetTest.java
===================================================================
--- test/org/openstreetmap/josm/data/osm/DataSetTest.java	(revision 271)
+++ test/org/openstreetmap/josm/data/osm/DataSetTest.java	(revision 273)
@@ -73,4 +73,14 @@
 		assertTrue(node3.selected);
 		assertFalse(node2.selected);
+
+		ds.setSelected();
+		assertFalse(node3.selected || node2.selected);
+		
+		ds.setSelected(node1, way);
+		assertTrue(node1.selected && way.selected);
+		assertFalse(node3.selected);
+		
+		ds.setSelected((OsmPrimitive)null);
+		assertFalse(node1.selected || node2.selected || node3.selected || way.selected);
 	}