Index: trunk/test/unit/org/openstreetmap/josm/data/osm/visitor/MergeSourceBuildingVisitorTest.java
===================================================================
--- trunk/test/unit/org/openstreetmap/josm/data/osm/visitor/MergeSourceBuildingVisitorTest.java	(revision 10201)
+++ trunk/test/unit/org/openstreetmap/josm/data/osm/visitor/MergeSourceBuildingVisitorTest.java	(revision 10202)
@@ -13,4 +13,5 @@
 import org.openstreetmap.josm.JOSMFixture;
 import org.openstreetmap.josm.data.coor.LatLon;
+import org.openstreetmap.josm.data.osm.Changeset;
 import org.openstreetmap.josm.data.osm.DataSet;
 import org.openstreetmap.josm.data.osm.Node;
@@ -409,3 +410,11 @@
         assertTrue(r2.getMembers().contains(new RelationMember("relation-1", r1)));
     }
+
+    /**
+     * Unit test of {@code AbstractVisitor#visit(org.openstreetmap.josm.data.osm.Changeset)}.
+     */
+    @Test
+    public void testVisitChangeset() {
+        new MergeSourceBuildingVisitor(new DataSet()).visit(new Changeset());
+    }
 }
Index: trunk/test/unit/org/openstreetmap/josm/data/validation/routines/EmailValidatorTest.java
===================================================================
--- trunk/test/unit/org/openstreetmap/josm/data/validation/routines/EmailValidatorTest.java	(revision 10201)
+++ trunk/test/unit/org/openstreetmap/josm/data/validation/routines/EmailValidatorTest.java	(revision 10202)
@@ -60,4 +60,5 @@
     public void testEmail()  {
         assertTrue(validator.isValid("jsmith@apache.org"));
+        assertFalse(validator.isValid(null));
     }