Index: /trunk/src/org/openstreetmap/josm/Main.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/Main.java	(revision 12010)
+++ /trunk/src/org/openstreetmap/josm/Main.java	(revision 12011)
@@ -583,5 +583,5 @@
     protected abstract void initializeMainWindow();
 
-    private static class InitializationTask implements Callable<Void> {
+    static final class InitializationTask implements Callable<Void> {
 
         private final String name;
@@ -1231,4 +1231,12 @@
 
     /**
+     * Clears the network errors cache.
+     * @since 12011
+     */
+    public static void clearNetworkErrors() {
+        NETWORK_ERRORS.clear();
+    }
+
+    /**
      * Returns the JOSM website URL.
      * @return the josm website URL
Index: /trunk/test/unit/org/openstreetmap/josm/MainTest.java
===================================================================
--- /trunk/test/unit/org/openstreetmap/josm/MainTest.java	(revision 12010)
+++ /trunk/test/unit/org/openstreetmap/josm/MainTest.java	(revision 12011)
@@ -8,8 +8,11 @@
 import static org.junit.Assert.assertTrue;
 
+import java.awt.event.KeyEvent;
 import java.net.MalformedURLException;
+import java.net.URL;
 import java.nio.file.Paths;
 import java.util.Collection;
 import java.util.List;
+import java.util.Map;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Future;
@@ -20,8 +23,14 @@
 import org.junit.Test;
 import org.openstreetmap.josm.Main.DownloadParamType;
+import org.openstreetmap.josm.Main.InitStatusListener;
+import org.openstreetmap.josm.Main.InitializationTask;
+import org.openstreetmap.josm.actions.AboutAction;
 import org.openstreetmap.josm.data.osm.DataSet;
+import org.openstreetmap.josm.gui.MapFrameListener;
 import org.openstreetmap.josm.gui.ProgramArguments;
 import org.openstreetmap.josm.gui.layer.GpxLayer;
+import org.openstreetmap.josm.io.OnlineResource;
 import org.openstreetmap.josm.testutils.JOSMTestRules;
+import org.openstreetmap.josm.tools.Shortcut;
 
 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
@@ -64,7 +73,9 @@
         Main.error(new Exception("exception_error"));
         Main.error("Error message on one line");
+        Main.error("Error message with {0}", "param");
         Main.error("First line of error message on several lines\nline2\nline3\nline4");
         Collection<String> errors = Main.getLastErrorAndWarnings();
         assertTrue(errors.contains("E: java.lang.Exception: exception_error"));
+        assertTrue(errors.contains("E: Error message with param"));
         assertTrue(errors.contains("E: Error message on one line"));
         assertTrue(errors.contains("E: First line of error message on several lines"));
@@ -72,8 +83,10 @@
         // Correct behaviour with warnings
         Main.warn(new Exception("exception_warn", new Exception("root_cause")));
+        Main.warn(new Exception("exception_warn_bool"), true);
         Main.warn("Warning message on one line");
         Main.warn("First line of warning message on several lines\nline2\nline3\nline4");
         Collection<String> warnings = Main.getLastErrorAndWarnings();
         assertTrue(warnings.contains("W: java.lang.Exception: exception_warn. Cause: java.lang.Exception: root_cause"));
+        assertTrue(warnings.contains("W: java.lang.Exception: exception_warn_bool"));
         assertTrue(warnings.contains("W: Warning message on one line"));
         assertTrue(warnings.contains("W: First line of warning message on several lines"));
@@ -174,3 +187,105 @@
         TestUtils.superficialEnumCodeCoverage(DownloadParamType.class);
     }
+
+    /**
+     * Unit test of {@link Main#getBaseUserUrl}.
+     */
+    @Test
+    public void testGetBaseUserUrl() {
+        assertEquals("http://api06.dev.openstreetmap.org/user", Main.getBaseUserUrl());
+    }
+
+    /**
+     * Unit test of {@link Main#addNetworkError}, {@link Main#getNetworkErrors} and {@link Main#clearNetworkErrors}.
+     * @throws MalformedURLException if any error occurs
+     */
+    @Test
+    public void testNetworkErrors() throws MalformedURLException {
+        Main.clearNetworkErrors();
+        assertTrue(Main.getNetworkErrors().isEmpty());
+        Main.addNetworkError("http://url1", new Exception("exception_1"));
+        Main.addNetworkError(new URL("http://url2"), new Exception("exception_2"));
+        Map<String, Throwable> errors = Main.getNetworkErrors();
+        assertEquals(2, errors.size());
+        assertEquals("exception_1", errors.get("http://url1").getMessage());
+        assertEquals("exception_2", errors.get("http://url2").getMessage());
+        Main.clearNetworkErrors();
+        assertTrue(Main.getNetworkErrors().isEmpty());
+    }
+
+    /**
+     * Unit test of {@link Main#setOffline} and {@link Main#getOfflineResources}.
+     */
+    @Test
+    public void testOfflineRessources() {
+        Main.setOnline(OnlineResource.ALL);
+        assertTrue(Main.getOfflineResources().isEmpty());
+        assertFalse(Main.isOffline(OnlineResource.JOSM_WEBSITE));
+        Main.setOffline(OnlineResource.JOSM_WEBSITE);
+        assertTrue(Main.isOffline(OnlineResource.JOSM_WEBSITE));
+        Main.setOnline(OnlineResource.JOSM_WEBSITE);
+        assertFalse(Main.isOffline(OnlineResource.JOSM_WEBSITE));
+        Main.setOffline(OnlineResource.ALL);
+        assertTrue(Main.isOffline(OnlineResource.JOSM_WEBSITE));
+        assertTrue(Main.isOffline(OnlineResource.OSM_API));
+        Main.setOnline(OnlineResource.ALL);
+    }
+
+    /**
+     * Unit test of {@link Main#getRegisteredActionShortcut}.
+     */
+    @Test
+    public void testGetRegisteredActionShortcut() {
+        Shortcut noKeystroke = Shortcut.registerShortcut("no", "keystroke", 0, 0);
+        assertNull(noKeystroke.getKeyStroke());
+        assertNull(Main.getRegisteredActionShortcut(noKeystroke));
+        Shortcut noAction = Shortcut.registerShortcut("foo", "bar", KeyEvent.VK_AMPERSAND, Shortcut.SHIFT);
+        assertNotNull(noAction.getKeyStroke());
+        assertNull(Main.getRegisteredActionShortcut(noAction));
+        AboutAction about = new AboutAction();
+        assertEquals(about, Main.getRegisteredActionShortcut(about.getShortcut()));
+    }
+
+    /**
+     * Unit test of {@link Main#addMapFrameListener} and {@link Main#removeMapFrameListener}.
+     */
+    @Test
+    public void testMapFrameListener() {
+        MapFrameListener listener = (o, n) -> { };
+        assertTrue(Main.addMapFrameListener(listener));
+        assertFalse(Main.addMapFrameListener(null));
+        assertTrue(Main.removeMapFrameListener(listener));
+        assertFalse(Main.removeMapFrameListener(null));
+    }
+
+    private static class InitStatusListenerStub implements InitStatusListener {
+
+        boolean updated;
+        boolean finished;
+
+        @Override
+        public Object updateStatus(String event) {
+            updated = true;
+            return null;
+        }
+
+        @Override
+        public void finish(Object status) {
+            finished = true;
+        }
+    }
+
+    /**
+     * Unit test of {@link Main#setInitStatusListener}.
+     */
+    @Test
+    public void testSetInitStatusListener() {
+        InitStatusListenerStub listener = new InitStatusListenerStub();
+        Main.setInitStatusListener(listener);
+        assertFalse(listener.updated);
+        assertFalse(listener.finished);
+        new InitializationTask("", () -> { }).call();
+        assertTrue(listener.updated);
+        assertTrue(listener.finished);
+    }
 }