Index: trunk/test/unit/org/openstreetmap/josm/io/session/SessionReaderTest.java
===================================================================
--- trunk/test/unit/org/openstreetmap/josm/io/session/SessionReaderTest.java	(revision 7326)
+++ trunk/test/unit/org/openstreetmap/josm/io/session/SessionReaderTest.java	(revision 7326)
@@ -0,0 +1,120 @@
+// License: GPL. For details, see LICENSE file.
+package org.openstreetmap.josm.io.session;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.List;
+
+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.gui.MainApplication;
+import org.openstreetmap.josm.gui.layer.GpxLayer;
+import org.openstreetmap.josm.gui.layer.Layer;
+import org.openstreetmap.josm.gui.layer.OsmDataLayer;
+import org.openstreetmap.josm.gui.layer.markerlayer.MarkerLayer;
+import org.openstreetmap.josm.gui.preferences.ToolbarPreferences;
+import org.openstreetmap.josm.gui.preferences.projection.ProjectionPreference;
+import org.openstreetmap.josm.io.IllegalDataException;
+
+/**
+ * Unit tests for Session reading.
+ */
+public class SessionReaderTest {
+
+    /**
+     * Setup tests.
+     */
+    @BeforeClass
+    public static void setUpBeforeClass() {
+        JOSMFixture.createUnitTestFixture().init();
+        ProjectionPreference.setProjection();
+        Main.toolbar = new ToolbarPreferences();
+        new MainApplication();
+        Main.main.createMapFrame(null, null);
+    }
+
+    private static String getSessionDataDir() {
+        return TestUtils.getTestDataRoot() + "/sessions";
+    }
+
+    private List<Layer> testRead(String sessionFileName) throws IOException, IllegalDataException {
+        boolean zip = sessionFileName.endsWith(".joz");
+        File file = new File(getSessionDataDir()+"/"+sessionFileName);
+        SessionReader reader = new SessionReader();
+        reader.loadSession(file, zip, null);
+        return reader.getLayers();
+    }
+
+    /**
+     * Tests to read an empty .jos or .joz file.
+     * @throws IOException if any I/O error occurs
+     * @throws IllegalDataException is the test file is considered as invalid
+     */
+    @Test
+    public void testReadEmpty() throws IOException, IllegalDataException {
+        assertTrue(testRead("empty.jos").isEmpty());
+        assertTrue(testRead("empty.joz").isEmpty());
+    }
+
+    /**
+     * Tests to read a .jos or .joz file containing OSM data.
+     * @throws IOException if any I/O error occurs
+     * @throws IllegalDataException is the test file is considered as invalid
+     */
+    @Test
+    public void testReadOsm() throws IOException, IllegalDataException {
+        for (String file : new String[]{"osm.jos", "osm.joz"}) {
+            List<Layer> layers = testRead(file);
+            assertTrue(layers.size() == 1);
+            assertTrue(layers.get(0) instanceof OsmDataLayer);
+            OsmDataLayer osm = (OsmDataLayer) layers.get(0);
+            assertEquals(osm.getName(), "OSM layer name");
+        }
+    }
+
+    /**
+     * Tests to read a .jos or .joz file containing GPX data.
+     * @throws IOException if any I/O error occurs
+     * @throws IllegalDataException is the test file is considered as invalid
+     */
+    @Test
+    public void testReadGpx() throws IOException, IllegalDataException {
+        for (String file : new String[]{"gpx.jos", "gpx.joz", "nmea.jos"}) {
+            List<Layer> layers = testRead(file);
+            assertTrue(layers.size() == 1);
+            assertTrue(layers.get(0) instanceof GpxLayer);
+            GpxLayer gpx = (GpxLayer) layers.get(0);
+            assertEquals(gpx.getName(), "GPX layer name");
+        }
+    }
+
+    /**
+     * Tests to read a .joz file containing GPX and marker data.
+     * @throws IOException if any I/O error occurs
+     * @throws IllegalDataException is the test file is considered as invalid
+     */
+    @Test
+    public void testReadGpxAndMarker() throws IOException, IllegalDataException {
+        List<Layer> layers = testRead("gpx_markers.joz");
+        assertTrue(layers.size() == 2);
+        GpxLayer gpx = null;
+        MarkerLayer marker = null;
+        for (Layer layer : layers) {
+            if (layer instanceof GpxLayer) {
+                gpx = (GpxLayer) layer;
+            } else if (layer instanceof MarkerLayer) {
+                marker = (MarkerLayer) layer;
+            }
+        }
+        assertTrue(gpx != null);
+        assertTrue(marker != null);
+        assertEquals(gpx.getName(), "GPX layer name");
+        assertEquals(marker.getName(), "Marker layer name");
+    }
+}
Index: trunk/test/unit/org/openstreetmap/josm/io/session/SessionWriterTest.java
===================================================================
--- trunk/test/unit/org/openstreetmap/josm/io/session/SessionWriterTest.java	(revision 7307)
+++ trunk/test/unit/org/openstreetmap/josm/io/session/SessionWriterTest.java	(revision 7326)
@@ -13,5 +13,7 @@
 import org.openstreetmap.josm.JOSMFixture;
 import org.openstreetmap.josm.Main;
+import org.openstreetmap.josm.data.coor.LatLon;
 import org.openstreetmap.josm.data.gpx.GpxData;
+import org.openstreetmap.josm.data.gpx.WayPoint;
 import org.openstreetmap.josm.data.osm.DataSet;
 import org.openstreetmap.josm.gui.MainApplication;
@@ -19,7 +21,9 @@
 import org.openstreetmap.josm.gui.layer.Layer;
 import org.openstreetmap.josm.gui.layer.OsmDataLayer;
+import org.openstreetmap.josm.gui.layer.markerlayer.MarkerLayer;
 import org.openstreetmap.josm.gui.preferences.ToolbarPreferences;
 import org.openstreetmap.josm.gui.preferences.projection.ProjectionPreference;
 import org.openstreetmap.josm.tools.MultiMap;
+import org.openstreetmap.josm.tools.Pair;
 
 /**
@@ -106,5 +110,5 @@
 
     private OsmDataLayer createOsmLayer() {
-        OsmDataLayer layer = new OsmDataLayer(new DataSet(), null, null);
+        OsmDataLayer layer = new OsmDataLayer(new DataSet(), "OSM layer name", null);
         layer.setAssociatedFile(new File("data.osm"));
         return layer;
@@ -112,7 +116,14 @@
 
     private GpxLayer createGpxLayer() {
-        GpxLayer layer = new GpxLayer(new GpxData());
+        GpxData data = new GpxData();
+        data.waypoints.add(new WayPoint(new LatLon(42.72665, -0.00747)));
+        data.waypoints.add(new WayPoint(new LatLon(42.72659, -0.00749)));
+        GpxLayer layer = new GpxLayer(data, "GPX layer name");
         layer.setAssociatedFile(new File("data.gpx"));
         return layer;
+    }
+
+    private MarkerLayer createMarkerLayer(GpxLayer gpx) {
+        return new MarkerLayer(gpx.data, "Marker layer name", gpx.getAssociatedFile(), gpx);
     }
 
@@ -170,3 +181,13 @@
         testWrite(Collections.<Layer>singletonList(createGpxLayer()), true);
     }
+
+    /**
+     * Tests to write a .joz file containing GPX and marker data.
+     * @throws IOException if any I/O error occurs
+     */
+    @Test
+    public void testWriteGpxAndMarkerJoz() throws IOException {
+        GpxLayer gpx = createGpxLayer();
+        testWrite(Pair.toArrayList(new Pair<Layer, Layer>(gpx, createMarkerLayer(gpx))), true);
+    }
 }