URIish: fall back to host as humanish name

When we have a URI that contains an empty path component (that is
it only contains a "/") we want to fall back to the host as
humanish name.

This change is according to the behavior of upstream git, which
falls back on the hostname when guessing directory names for
newly cloned repositories (see [1] for the discussion).

[1] http://article.gmane.org/gmane.comp.version-control.git/274669

Change-Id: I44400c6ab72a2722d2155d53d63671bd867d6c44
Signed-off-by: Patrick Steinhardt <ps@pks.im>

org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/URIishTest.java

  * Copyright (C) 2008, Robin Rosenberg <robin.rosenberg@dewire.com>
  * Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org>
  * Copyright (C) 2013, Robin Stocker <robin@nibor.org>
+ * Copyright (C) 2015, Patrick Steinhardt <ps@pks.im>
  * and other copyright owners as documented in the project's IP log.
  *
  * This program and the accompanying materials are made available
 		assertEquals(u, new URIish(str));
 	}
 
+	@Test
+	public void testSshProtoHostOnly() throws Exception {
+		final String str = "ssh://example.com/";
+		URIish u = new URIish(str);
+		assertEquals("ssh", u.getScheme());
+		assertTrue(u.isRemote());
+		assertEquals("/", u.getRawPath());
+		assertEquals("/", u.getPath());
+		assertEquals("example.com", u.getHost());
+		assertEquals(-1, u.getPort());
+		assertEquals("ssh://example.com/", u.toString());
+		assertEquals("ssh://example.com/", u.toASCIIString());
+		assertEquals("example.com", u.getHumanishName());
+		assertEquals(u, new URIish(str));
+	}
+
+	@Test
+	public void testSshProtoHostWithAuthentication() throws Exception {
+		final String str = "ssh://user:secret@pass@example.com/";
+		URIish u = new URIish(str);
+		assertEquals("ssh", u.getScheme());
+		assertTrue(u.isRemote());
+		assertEquals("/", u.getRawPath());
+		assertEquals("/", u.getPath());
+		assertEquals("example.com", u.getHost());
+		assertEquals(-1, u.getPort());
+		assertEquals("ssh://user@example.com/", u.toString());
+		assertEquals("ssh://user@example.com/", u.toASCIIString());
+		assertEquals("example.com", u.getHumanishName());
+		assertEquals("user", u.getUser());
+		assertEquals("secret@pass", u.getPass());
+		assertEquals(u, new URIish(str));
+	}
+
+	@Test
+	public void testSshProtoHostWithPort() throws Exception {
+		final String str = "ssh://example.com:2222/";
+		URIish u = new URIish(str);
+		assertEquals("ssh", u.getScheme());
+		assertTrue(u.isRemote());
+		assertEquals("/", u.getRawPath());
+		assertEquals("/", u.getPath());
+		assertEquals("example.com", u.getHost());
+		assertEquals(2222, u.getPort());
+		assertEquals("ssh://example.com:2222/", u.toString());
+		assertEquals("ssh://example.com:2222/", u.toASCIIString());
+		assertEquals("example.com", u.getHumanishName());
+		assertEquals(u, new URIish(str));
+	}
+
 	@Test
 	public void testSshProtoWithUserAndPort() throws Exception {
 		final String str = "ssh://user@example.com:33/some/p ath";
 		assertEquals("abc", humanishName);
 	}
 
+	@Test
+	public void testGetEmptyHumanishNameWithAuthorityOnly() throws IllegalArgumentException,
+			URISyntaxException {
+		String humanishName = new URIish(GIT_SCHEME + "abc").getHumanishName();
+		assertEquals("abc", humanishName);
+	}
+
 	@Test
 	public void testGetValidSlashHumanishName()
 			throws IllegalArgumentException, URISyntaxException {

org.eclipse.jgit/src/org/eclipse/jgit/transport/URIish.java

  * Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org>
  * Copyright (C) 2010, Christian Halstrick <christian.halstrick@sap.com>
  * Copyright (C) 2013, Robin Stocker <robin@nibor.org>
+ * Copyright (C) 2015, Patrick Steinhardt <ps@pks.im>
  * and other copyright owners as documented in the project's IP log.
  *
  * This program and the accompanying materials are made available
 			+ OPT_USER_PWD_P //
 			+ HOST_P //
 			+ OPT_PORT_P //
-			+ "(" // open a catpuring group the the user-home-dir part //$NON-NLS-1$
-			+ (USER_HOME_P + "?") // //$NON-NLS-1$
-			+ "[\\\\/])" // //$NON-NLS-1$
+			+ "(" // open a group capturing the user-home-dir-part //$NON-NLS-1$
+			+ (USER_HOME_P + "?") //$NON-NLS-1$
+			+ "[\\\\/])" //$NON-NLS-1$
 			+ ")?" // close the optional group containing hostname //$NON-NLS-1$
-			+ "(.+)?" // //$NON-NLS-1$
+			+ "(.+)?" //$NON-NLS-1$
 			+ "$"); //$NON-NLS-1$
 
 	/**
 	 * <td><code>/path/to/repo/</code></td>
 	 * </tr>
 	 * <tr>
+	 * <td><code>localhost</code></td>
+	 * <td><code>ssh://localhost/</code></td>
+	 * </tr>
+	 * <tr>
 	 * <td><code>/path//to</code></td>
 	 * <td>an empty string</td>
 	 * </tr>
 	 * @see #getPath
 	 */
 	public String getHumanishName() throws IllegalArgumentException {
-		if ("".equals(getPath()) || getPath() == null) //$NON-NLS-1$
-			throw new IllegalArgumentException();
 		String s = getPath();
+		if ("/".equals(s)) //$NON-NLS-1$
+			s = getHost();
+		if ("".equals(s) || s == null) //$NON-NLS-1$
+			throw new IllegalArgumentException();
+
 		String[] elements;
 		if ("file".equals(scheme) || LOCAL_FILE.matcher(s).matches()) //$NON-NLS-1$
 			elements = s.split("[\\" + File.separatorChar + "/]"); //$NON-NLS-1$ //$NON-NLS-2$