Index: trunk/test/unit/org/openstreetmap/josm/data/osm/DataSetTest.java
===================================================================
--- trunk/test/unit/org/openstreetmap/josm/data/osm/DataSetTest.java	(revision 13496)
+++ trunk/test/unit/org/openstreetmap/josm/data/osm/DataSetTest.java	(revision 13497)
@@ -3,4 +3,5 @@
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 
@@ -14,4 +15,5 @@
 import org.junit.Test;
 import org.openstreetmap.josm.data.coor.LatLon;
+import org.openstreetmap.josm.data.osm.DataSet.DownloadPolicy;
 import org.openstreetmap.josm.data.osm.DataSet.UploadPolicy;
 import org.openstreetmap.josm.testutils.JOSMTestRules;
@@ -194,4 +196,39 @@
     }
 
+    /**
+     * Unit test for {@link DataSet#mergeFrom} - Policies.
+     */
+    @Test
+    public void testMergePolicies() {
+        DataSet ds1 = new DataSet();
+        DataSet ds2 = new DataSet();
+
+        ds1.setUploadPolicy(UploadPolicy.BLOCKED);
+        ds2.setUploadPolicy(UploadPolicy.NORMAL);
+        ds1.mergeFrom(ds2);
+        assertEquals(UploadPolicy.BLOCKED, ds1.getUploadPolicy());
+
+        ds1.setUploadPolicy(UploadPolicy.NORMAL);
+        ds2.setUploadPolicy(UploadPolicy.BLOCKED);
+        ds1.mergeFrom(ds2);
+        assertEquals(UploadPolicy.BLOCKED, ds1.getUploadPolicy());
+
+        ds1.setDownloadPolicy(DownloadPolicy.BLOCKED);
+        ds2.setDownloadPolicy(DownloadPolicy.NORMAL);
+        ds1.mergeFrom(ds2);
+        assertEquals(DownloadPolicy.BLOCKED, ds1.getDownloadPolicy());
+
+        ds1.setDownloadPolicy(DownloadPolicy.NORMAL);
+        ds2.setDownloadPolicy(DownloadPolicy.BLOCKED);
+        ds1.mergeFrom(ds2);
+        assertEquals(DownloadPolicy.BLOCKED, ds1.getDownloadPolicy());
+
+        ds2.lock();
+        assertFalse(ds1.isLocked());
+        assertTrue(ds2.isLocked());
+        ds1.mergeFrom(ds2);
+        assertTrue(ds1.isLocked());
+    }
+
     private static void assertEqualsDataSet(DataSet ds1, DataSet ds2) {
         assertEquals(new ArrayList<>(ds1.getNodes()), new ArrayList<>(ds2.getNodes()));
@@ -202,3 +239,14 @@
         assertEquals(ds1.getVersion(), ds2.getVersion());
     }
+
+    /**
+     * Checks that enum values are defined in the correct order.
+     */
+    @Test
+    public void testEnumOrder() {
+        assertTrue(DownloadPolicy.BLOCKED.compareTo(DownloadPolicy.NORMAL) > 0);
+        assertTrue(UploadPolicy.BLOCKED.compareTo(UploadPolicy.NORMAL) > 0);
+        assertTrue(UploadPolicy.BLOCKED.compareTo(UploadPolicy.DISCOURAGED) > 0);
+        assertTrue(UploadPolicy.DISCOURAGED.compareTo(UploadPolicy.NORMAL) > 0);
+    }
 }