Index: trunk/src/org/openstreetmap/josm/gui/io/importexport/AllFormatsImporter.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/io/importexport/AllFormatsImporter.java	(revision 14816)
+++ trunk/src/org/openstreetmap/josm/gui/io/importexport/AllFormatsImporter.java	(revision 14817)
@@ -35,5 +35,5 @@
         while (imp.hasNext()) {
             FileImporter fi = imp.next();
-            if (fi instanceof AllFormatsImporter) {
+            if (fi instanceof AllFormatsImporter || fi.filter == null) {
                 continue;
             }
Index: trunk/test/unit/org/openstreetmap/josm/data/validation/tests/DuplicateRelationTest.java
===================================================================
--- trunk/test/unit/org/openstreetmap/josm/data/validation/tests/DuplicateRelationTest.java	(revision 14817)
+++ trunk/test/unit/org/openstreetmap/josm/data/validation/tests/DuplicateRelationTest.java	(revision 14817)
@@ -0,0 +1,97 @@
+// License: GPL. For details, see LICENSE file.
+package org.openstreetmap.josm.data.validation.tests;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.openstreetmap.josm.TestUtils;
+import org.openstreetmap.josm.data.coor.LatLon;
+import org.openstreetmap.josm.data.osm.DataSet;
+import org.openstreetmap.josm.data.osm.Node;
+import org.openstreetmap.josm.data.osm.RelationMember;
+import org.openstreetmap.josm.data.validation.TestError;
+import org.openstreetmap.josm.gui.progress.NullProgressMonitor;
+import org.openstreetmap.josm.testutils.JOSMTestRules;
+
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
+
+/**
+ * JUnit Test of "Duplicate relation" validation test.
+ */
+public class DuplicateRelationTest {
+
+    /**
+     * Setup test by initializing JOSM preferences and projection.
+     */
+    @Rule
+    @SuppressFBWarnings(value = "URF_UNREAD_PUBLIC_OR_PROTECTED_FIELD")
+    public JOSMTestRules test = new JOSMTestRules().preferences();
+
+    static class ExpectedResult {
+        final int code;
+        final boolean fixable;
+        ExpectedResult(int code, boolean fixable) {
+            this.code = code;
+            this.fixable = fixable;
+        }
+    }
+
+    private void doTest(String tags1, String tags2, ExpectedResult... expectations) {
+        performTest(buildDataSet(tags1, tags2), expectations);
+    }
+
+    private void performTest(DataSet ds, ExpectedResult... expectations) {
+        final DuplicateRelation TEST = new DuplicateRelation();
+        TEST.startTest(NullProgressMonitor.INSTANCE);
+        TEST.visit(ds.allPrimitives());
+        TEST.endTest();
+
+        assertEquals(expectations.length, TEST.getErrors().size());
+        int i = 0;
+        for (TestError error : TEST.getErrors()) {
+            ExpectedResult expected = expectations[i++];
+            assertEquals(expected.code, error.getCode());
+            assertEquals(expected.fixable, error.isFixable());
+        }
+    }
+
+    private static DataSet buildDataSet(String tags1, String tags2) {
+        DataSet ds = new DataSet();
+
+        Node a = new Node(new LatLon(10.0, 5.0));
+        ds.addPrimitive(a);
+        ds.addPrimitive(TestUtils.newRelation(tags1, new RelationMember(null, a)));
+        ds.addPrimitive(TestUtils.newRelation(tags2, new RelationMember(null, a)));
+        return ds;
+    }
+
+    /**
+     * Test of "Duplicate relation" validation test - no tags.
+     */
+    @Test
+    public void testDuplicateRelationNoTags() {
+        doTest("", "",
+                new ExpectedResult(DuplicateRelation.DUPLICATE_RELATION, true),
+                new ExpectedResult(DuplicateRelation.SAME_RELATION, false));
+    }
+
+    /**
+     * Test of "Duplicate relation" validation test - same tags.
+     */
+    @Test
+    public void testDuplicateRelationSameTags() {
+        doTest("type=boundary", "type=boundary",
+                new ExpectedResult(DuplicateRelation.DUPLICATE_RELATION, true),
+                new ExpectedResult(DuplicateRelation.SAME_RELATION, false));
+    }
+
+    /**
+     * Test of "Duplicate relation" validation test - different tags.
+     */
+    @Test
+    public void testDuplicateRelationDifferentTags() {
+        doTest("type=boundary", "type=multipolygon",
+                new ExpectedResult(DuplicateRelation.SAME_RELATION, false));
+    }
+}
Index: trunk/test/unit/org/openstreetmap/josm/data/validation/tests/DuplicateWayTest.java
===================================================================
--- trunk/test/unit/org/openstreetmap/josm/data/validation/tests/DuplicateWayTest.java	(revision 14817)
+++ trunk/test/unit/org/openstreetmap/josm/data/validation/tests/DuplicateWayTest.java	(revision 14817)
@@ -0,0 +1,90 @@
+// License: GPL. For details, see LICENSE file.
+package org.openstreetmap.josm.data.validation.tests;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.openstreetmap.josm.TestUtils;
+import org.openstreetmap.josm.data.coor.LatLon;
+import org.openstreetmap.josm.data.osm.DataSet;
+import org.openstreetmap.josm.data.osm.Node;
+import org.openstreetmap.josm.data.validation.TestError;
+import org.openstreetmap.josm.gui.progress.NullProgressMonitor;
+import org.openstreetmap.josm.testutils.JOSMTestRules;
+
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
+
+/**
+ * JUnit Test of "Duplicate way" validation test.
+ */
+public class DuplicateWayTest {
+
+    /**
+     * Setup test by initializing JOSM preferences and projection.
+     */
+    @Rule
+    @SuppressFBWarnings(value = "URF_UNREAD_PUBLIC_OR_PROTECTED_FIELD")
+    public JOSMTestRules test = new JOSMTestRules();
+
+    private static final DuplicateWay TEST = new DuplicateWay();
+
+    private static void doTest(int code) {
+        doTest(code, "");
+    }
+
+    private static void doTest(int code, String tags) {
+        doTest(code, tags, tags, true);
+    }
+
+    private static void doTest(int code, String tags1, String tags2, boolean fixable) {
+        performTest(code, buildDataSet(tags1, tags2), fixable);
+    }
+
+    private static void performTest(int code, DataSet ds, boolean fixable) {
+        TEST.startTest(NullProgressMonitor.INSTANCE);
+        TEST.visit(ds.allPrimitives());
+        TEST.endTest();
+
+        assertEquals(1, TEST.getErrors().size());
+        TestError error = TEST.getErrors().iterator().next();
+        assertEquals(code, error.getCode());
+        assertEquals(fixable, error.isFixable());
+    }
+
+    private static DataSet buildDataSet(String tags1, String tags2) {
+        DataSet ds = new DataSet();
+
+        Node a = new Node(new LatLon(10.0, 5.0));
+        Node b = new Node(new LatLon(10.0, 6.0));
+        ds.addPrimitive(a);
+        ds.addPrimitive(b);
+        ds.addPrimitive(TestUtils.newWay(tags1, a, b));
+        ds.addPrimitive(TestUtils.newWay(tags2, a, b));
+        return ds;
+    }
+
+    /**
+     * Test of "Duplicate way" validation test - no tags.
+     */
+    @Test
+    public void testDuplicateWayNoTags() {
+        doTest(DuplicateWay.DUPLICATE_WAY);
+    }
+
+    /**
+     * Test of "Duplicate way" validation test - same tags.
+     */
+    @Test
+    public void testDuplicateWaySameTags() {
+        doTest(DuplicateWay.DUPLICATE_WAY, "highway=motorway");
+    }
+
+    /**
+     * Test of "Duplicate way" validation test - different tags.
+     */
+    @Test
+    public void testDuplicateWayDifferentTags() {
+        doTest(DuplicateWay.SAME_WAY, "highway=motorway", "highway=trunk", false);
+    }
+}