Index: trunk/test/unit/org/openstreetmap/josm/actions/PurgeActionTest.java
===================================================================
--- trunk/test/unit/org/openstreetmap/josm/actions/PurgeActionTest.java	(revision 8984)
+++ trunk/test/unit/org/openstreetmap/josm/actions/PurgeActionTest.java	(revision 8984)
@@ -0,0 +1,61 @@
+// License: GPL. For details, see LICENSE file.
+package org.openstreetmap.josm.actions;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.InputStream;
+
+import org.junit.BeforeClass;
+import org.junit.Test;
+import org.openstreetmap.josm.JOSMFixture;
+import org.openstreetmap.josm.Main;
+import org.openstreetmap.josm.TestUtils;
+import org.openstreetmap.josm.data.osm.DataSet;
+import org.openstreetmap.josm.data.osm.Way;
+import org.openstreetmap.josm.gui.layer.OsmDataLayer;
+import org.openstreetmap.josm.io.IllegalDataException;
+import org.openstreetmap.josm.io.OsmReader;
+
+/**
+ * Unit tests for class {@link PurgeAction}.
+ */
+public class PurgeActionTest {
+
+    /**
+     * Setup test.
+     */
+    @BeforeClass
+    public static void setUpBeforeClass() {
+        JOSMFixture.createUnitTestFixture().init(true);
+    }
+
+    /**
+     * Non-regression test for ticket #12038.
+     * @throws IOException if any I/O error occurs
+     * @throws FileNotFoundException if the data file cannot be found
+     * @throws IllegalDataException if OSM parsing fails
+     */
+    @Test
+    public void testCopyStringWayRelation() throws FileNotFoundException, IOException, IllegalDataException {
+        try (InputStream is = new FileInputStream(TestUtils.getRegressionDataFile(12038, "data.osm"))) {
+            DataSet ds = OsmReader.parseDataSet(is, null);
+            Main.map.mapView.addLayer(new OsmDataLayer(ds, null, null));
+            for (Way w : ds.getWays()) {
+                if (w.getId() == 222191929L) {
+                    ds.addSelected(w);
+                }
+            }
+            new PurgeAction().actionPerformed(null);
+            for (Way w : ds.getWays()) {
+                if (w.getId() == 222191929L) {
+                    assertTrue(w.isIncomplete());
+                    assertEquals(0, w.getNodesCount());
+                }
+            }
+        }
+    }
+}