Index: trunk/test/unit/org/openstreetmap/josm/data/osm/BBoxTest.java
===================================================================
--- trunk/test/unit/org/openstreetmap/josm/data/osm/BBoxTest.java	(revision 15480)
+++ trunk/test/unit/org/openstreetmap/josm/data/osm/BBoxTest.java	(revision 15483)
@@ -37,4 +37,24 @@
             .suppress(Warning.NONFINAL_FIELDS)
             .verify();
+    }
+
+    /**
+     * Unit test of method {@link BBox#bboxesAreFunctionallyEqual}
+     */
+    @Test
+    public void testBboxesAreFunctionallyEqual() {
+        BBox bbox1 = new BBox(0, 1, 1, 0);
+        BBox bbox2 = new BBox(0.1, 0.9, 0.9, 0.1);
+
+        assertFalse(BBox.bboxesAreFunctionallyEqual(bbox1, null, null));
+        assertFalse(BBox.bboxesAreFunctionallyEqual(null, bbox2, null));
+        assertFalse(BBox.bboxesAreFunctionallyEqual(null, null, null));
+
+        assertFalse(bbox1.bboxesAreFunctionallyEqual(bbox2, null));
+        assertTrue(bbox1.bboxesAreFunctionallyEqual(bbox2, 0.1));
+        bbox1.add(0, 1.1);
+        assertFalse(bbox1.bboxesAreFunctionallyEqual(bbox2, 0.1));
+        bbox1.add(2, 0);
+        assertFalse(bbox1.bboxesAreFunctionallyEqual(bbox2, 0.1));
     }