Index: trunk/test/unit/org/openstreetmap/josm/data/validation/tests/UnconnectedWaysTest.java
===================================================================
--- trunk/test/unit/org/openstreetmap/josm/data/validation/tests/UnconnectedWaysTest.java	(revision 15334)
+++ trunk/test/unit/org/openstreetmap/josm/data/validation/tests/UnconnectedWaysTest.java	(revision 15335)
@@ -14,5 +14,8 @@
 import org.junit.Test;
 import org.openstreetmap.josm.JOSMFixture;
+import org.openstreetmap.josm.TestUtils;
 import org.openstreetmap.josm.data.osm.DataSet;
+import org.openstreetmap.josm.gui.MainApplication;
+import org.openstreetmap.josm.gui.layer.OsmDataLayer;
 import org.openstreetmap.josm.gui.progress.NullProgressMonitor;
 import org.openstreetmap.josm.io.IllegalDataException;
@@ -35,5 +38,4 @@
         JOSMFixture.createUnitTestFixture().init();
         bib.initialize();
-        bib.startTest(null);
     }
 
@@ -48,4 +50,47 @@
         try (InputStream fis = Files.newInputStream(Paths.get("data_nodist/UnconnectedWaysTest.osm"))) {
             final DataSet ds = OsmReader.parseDataSet(fis, NullProgressMonitor.INSTANCE);
+            MainApplication.getLayerManager().addLayer(new OsmDataLayer(ds, null, null));
+
+            bib.startTest(null);
+            bib.visit(ds.allPrimitives());
+            bib.endTest();
+            assertThat(bib.getErrors(), isEmpty());
+        }
+    }
+
+    /**
+     * Non-regression test for <a href="https://josm.openstreetmap.de/ticket/6313">Bug #18051</a>.
+     * @throws IOException if any I/O error occurs
+     * @throws IllegalDataException if the OSM data cannot be parsed
+     * @throws FileNotFoundException if the data file cannot be found
+     */
+    @Test
+    public void testTicket18051() throws IOException, IllegalDataException, FileNotFoundException {
+        try (InputStream fis = TestUtils.getRegressionDataStream(18051, "modified-ways.osm.bz2")) {
+            final DataSet ds = OsmReader.parseDataSet(fis, NullProgressMonitor.INSTANCE);
+            MainApplication.getLayerManager().addLayer(new OsmDataLayer(ds, null, null));
+
+            bib.startTest(null);
+            bib.setBeforeUpload(true);
+            bib.visit(ds.allModifiedPrimitives());
+            bib.endTest();
+            assertThat(bib.getErrors(), isEmpty());
+        }
+    }
+
+    /**
+     * Non-regression test for <a href="https://josm.openstreetmap.de/ticket/6313">Bug #18106</a>.
+     * @throws IOException if any I/O error occurs
+     * @throws IllegalDataException if the OSM data cannot be parsed
+     * @throws FileNotFoundException if the data file cannot be found
+     */
+    @Test
+    public void testTicket18106() throws IOException, IllegalDataException, FileNotFoundException {
+        try (InputStream fis = TestUtils.getRegressionDataStream(18106, "uncon3.osm")) {
+            final DataSet ds = OsmReader.parseDataSet(fis, NullProgressMonitor.INSTANCE);
+            MainApplication.getLayerManager().addLayer(new OsmDataLayer(ds, null, null));
+
+            bib.startTest(null);
+            bib.setBeforeUpload(true);
             bib.visit(ds.allPrimitives());
             bib.endTest();