424051 - Using --list-config can result in NPE

+ Adding protection for no-manifest
+ Adding bad-jar tests for no-manifest, not-a-jar, and zero-length

jetty-start/src/main/java/org/eclipse/jetty/start/JarVersion.java

@@ -148,6 +148,11 @@ public class JarVersion
             String version = null;
 
             Manifest manifest = jar.getManifest();
+            
+            if (manifest == null)
+            {
+                return "(none specified)";
+            }
 
             version = getMainManifestImplVersion(manifest);
             if (version != null)
@@ -173,7 +178,7 @@ public class JarVersion
                 return version;
             }
 
-            return "(not specified)";
+            return "(none specified)";
         }
         catch (IOException e)
         {

jetty-start/src/test/java/org/eclipse/jetty/start/JarVersionTest.java

@@ -0,0 +1,54 @@
+//
+//  ========================================================================
+//  Copyright (c) 1995-2013 Mort Bay Consulting Pty. Ltd.
+//  ------------------------------------------------------------------------
+//  All rights reserved. This program and the accompanying materials
+//  are made available under the terms of the Eclipse Public License v1.0
+//  and Apache License v2.0 which accompanies this distribution.
+//
+//      The Eclipse Public License is available at
+//      http://www.eclipse.org/legal/epl-v10.html
+//
+//      The Apache License v2.0 is available at
+//      http://www.opensource.org/licenses/apache2.0.php
+//
+//  You may elect to redistribute this code under either of these licenses.
+//  ========================================================================
+//
+
+package org.eclipse.jetty.start;
+
+import static org.hamcrest.Matchers.*;
+
+import java.io.File;
+
+import org.eclipse.jetty.toolchain.test.MavenTestingUtils;
+import org.junit.Assert;
+import org.junit.Test;
+
+public class JarVersionTest
+{
+    private void assertJarVersion(String jarname, String expectedVersion)
+    {
+        File jarfile = MavenTestingUtils.getTestResourceFile(jarname);
+        Assert.assertThat("Jar: " + jarname,JarVersion.getVersion(jarfile),containsString(expectedVersion));
+    }
+
+    @Test
+    public void testNoManifestJar()
+    {
+        assertJarVersion("bad-libs/no-manifest.jar","(none specified)");
+    }
+
+    @Test
+    public void testNotAJar()
+    {
+        assertJarVersion("bad-libs/not-a.jar","(error: ZipException ");
+    }
+
+    @Test
+    public void testZeroLengthJar()
+    {
+        assertJarVersion("bad-libs/zero-length.jar","(error: ZipException ");
+    }
+}