Enable LsRemoteCommand to work without local repository

It's supported by C Git and can be useful.

Bug: 413388
Change-Id: I12c6c10e791cc09ee271d89eb8b8d32f53e385db
Signed-off-by: Robin Stocker <robin@nibor.org>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

org.eclipse.jgit.test/tst/org/eclipse/jgit/api/LsRemoteCommandTest.java

 /*
- * Copyright (C) 2011, Chris Aniszczyk <caniszczyk@gmail.com>
+ * Copyright (C) 2011, 2013 Chris Aniszczyk <caniszczyk@gmail.com> and others.
  * and other copyright owners as documented in the project's IP log.
  *
  * This program and the accompanying materials are made available
 		assertEquals(2, refs.size());
 	}
 
+	@Test
+	public void testLsRemoteWithoutLocalRepository() throws Exception {
+		String uri = "file://" + git.getRepository().getWorkTree().getPath();
+		Collection<Ref> refs = Git.lsRemoteRepository().setRemote(uri).setHeads(true).call();
+		assertNotNull(refs);
+		assertEquals(2, refs.size());
+	}
+
 }

org.eclipse.jgit/src/org/eclipse/jgit/api/Git.java

 		return new CloneCommand();
 	}
 
+	/**
+	 * Returns a command to list remote branches/tags without a local
+	 * repository.
+	 *
+	 * @return a {@link LsRemoteCommand}
+	 * @since 3.1
+	 */
+	public static LsRemoteCommand lsRemoteRepository() {
+		return new LsRemoteCommand(null);
+	}
+
 	/**
 	 * Returns a command object to execute a {@code init} command
 	 *

org.eclipse.jgit/src/org/eclipse/jgit/api/LsRemoteCommand.java

 import org.eclipse.jgit.transport.FetchConnection;
 import org.eclipse.jgit.transport.RefSpec;
 import org.eclipse.jgit.transport.Transport;
+import org.eclipse.jgit.transport.URIish;
 
 /**
  * The ls-remote command
 
 	/**
 	 * @param repo
+	 *            local repository or null for operation without local
+	 *            repository
 	 */
 	public LsRemoteCommand(Repository repo) {
 		super(repo);
 		Transport transport = null;
 		FetchConnection fc = null;
 		try {
-			transport = Transport.open(repo, remote);
+			if (repo != null)
+				transport = Transport.open(repo, remote);
+			else
+				transport = Transport.open(new URIish(remote));
 			transport.setOptionUploadPack(uploadPack);
 			configure(transport);
 			Collection<RefSpec> refSpecs = new ArrayList<RefSpec>(1);