Index: /trunk/src/org/openstreetmap/josm/data/osm/DataSet.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/data/osm/DataSet.java	(revision 12478)
+++ /trunk/src/org/openstreetmap/josm/data/osm/DataSet.java	(revision 12479)
@@ -234,5 +234,5 @@
             Collection<Relation> relations = copyFrom.getRelations();
             for (Relation r : relations) {
-                Relation newRelation = new Relation(r, r.isNew());
+                Relation newRelation = new Relation(r);
                 newRelation.setMembers(null);
                 primMap.put(r, newRelation);
@@ -251,4 +251,5 @@
             }
             version = copyFrom.version;
+            uploadPolicy = copyFrom.uploadPolicy;
         } finally {
             copyFrom.getReadLock().unlock();
Index: /trunk/test/unit/org/openstreetmap/josm/data/osm/DataSetTest.java
===================================================================
--- /trunk/test/unit/org/openstreetmap/josm/data/osm/DataSetTest.java	(revision 12478)
+++ /trunk/test/unit/org/openstreetmap/josm/data/osm/DataSetTest.java	(revision 12479)
@@ -14,4 +14,5 @@
 import org.junit.Test;
 import org.openstreetmap.josm.data.coor.LatLon;
+import org.openstreetmap.josm.data.osm.DataSet.UploadPolicy;
 import org.openstreetmap.josm.testutils.JOSMTestRules;
 
@@ -164,5 +165,40 @@
         ds.toggleSelected(n2.getPrimitiveId());
         assertEquals(Arrays.asList(n3, n1), new ArrayList<>(ds.getSelected()));
-
+    }
+
+    /**
+     * Unit test for {@link DataSet#DataSet(DataSet)}.
+     */
+    @Test
+    public void testCopyConstructor() {
+        DataSet ds = new DataSet();
+        assertEqualsDataSet(ds, new DataSet(ds));
+
+        ds.setVersion("fake_version");
+        ds.setUploadPolicy(UploadPolicy.BLOCKED);
+        Node n1 = new Node(LatLon.SOUTH_POLE);
+        Node n2 = new Node(LatLon.NORTH_POLE);
+        Way w = new Way(1);
+        w.setNodes(Arrays.asList(n1, n2));
+        ds.addPrimitive(n1);
+        ds.addPrimitive(n2);
+        ds.addPrimitive(w);
+        Relation r1 = new Relation(1);
+        Relation r2 = new Relation(2);
+        r2.addMember(new RelationMember("role1", n1));
+        r2.addMember(new RelationMember("role2", w));
+        r2.addMember(new RelationMember("role3", r1));
+        ds.addPrimitive(r1);
+        ds.addPrimitive(r2);
+        assertEqualsDataSet(ds, new DataSet(ds));
+    }
+
+    private static void assertEqualsDataSet(DataSet ds1, DataSet ds2) {
+        assertEquals(new ArrayList<>(ds1.getNodes()), new ArrayList<>(ds2.getNodes()));
+        assertEquals(new ArrayList<>(ds1.getWays()), new ArrayList<>(ds2.getWays()));
+        assertEquals(new ArrayList<>(ds1.getRelations()), new ArrayList<>(ds2.getRelations()));
+        assertEquals(new ArrayList<>(ds1.getDataSources()), new ArrayList<>(ds2.getDataSources()));
+        assertEquals(ds1.getUploadPolicy(), ds2.getUploadPolicy());
+        assertEquals(ds1.getVersion(), ds2.getVersion());
     }
 }