Support insteadOf and pushInsteadOf URL replacement

Bug: 346873
Change-Id: I4116328f93f411da56a633bc32fd064b2ac083f2
Signed-off-by: Chris Aniszczyk <zx@twitter.com>

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

 import static org.junit.Assert.assertSame;
 import static org.junit.Assert.assertTrue;
 
+import java.util.Arrays;
 import java.util.List;
 
 import org.eclipse.jgit.errors.ConfigInvalidException;
 				+ "\tfetch = +refs/heads/*:refs/remotes/origin/*\n"
 				+ "\ttimeout = 60\n");
 	}
+
+	@Test
+	public void noInsteadOf() throws Exception {
+		config.setString("remote", "origin", "url", "short:project.git");
+		config.setString("url", "https://server/repos/", "name", "short:");
+		RemoteConfig rc = new RemoteConfig(config, "origin");
+		assertFalse(rc.getURIs().isEmpty());
+		assertEquals("short:project.git", rc.getURIs().get(0).toASCIIString());
+	}
+
+	@Test
+	public void singleInsteadOf() throws Exception {
+		config.setString("remote", "origin", "url", "short:project.git");
+		config.setString("url", "https://server/repos/", "insteadOf", "short:");
+		RemoteConfig rc = new RemoteConfig(config, "origin");
+		assertFalse(rc.getURIs().isEmpty());
+		assertEquals("https://server/repos/project.git", rc.getURIs().get(0)
+				.toASCIIString());
+	}
+
+	@Test
+	public void multipleInsteadOf() throws Exception {
+		config.setString("remote", "origin", "url", "prefixproject.git");
+		config.setStringList("url", "https://server/repos/", "insteadOf",
+				Arrays.asList("pre", "prefix", "pref", "perf"));
+		RemoteConfig rc = new RemoteConfig(config, "origin");
+		assertFalse(rc.getURIs().isEmpty());
+		assertEquals("https://server/repos/project.git", rc.getURIs().get(0)
+				.toASCIIString());
+	}
+
+	@Test
+	public void noPushInsteadOf() throws Exception {
+		config.setString("remote", "origin", "pushurl", "short:project.git");
+		config.setString("url", "https://server/repos/", "name", "short:");
+		RemoteConfig rc = new RemoteConfig(config, "origin");
+		assertFalse(rc.getPushURIs().isEmpty());
+		assertEquals("short:project.git", rc.getPushURIs().get(0)
+				.toASCIIString());
+	}
+
+	@Test
+	public void singlePushInsteadOf() throws Exception {
+		config.setString("remote", "origin", "pushurl", "short:project.git");
+		config.setString("url", "https://server/repos/", "pushInsteadOf",
+				"short:");
+		RemoteConfig rc = new RemoteConfig(config, "origin");
+		assertFalse(rc.getPushURIs().isEmpty());
+		assertEquals("https://server/repos/project.git", rc.getPushURIs()
+				.get(0).toASCIIString());
+	}
+
+	@Test
+	public void multiplePushInsteadOf() throws Exception {
+		config.setString("remote", "origin", "pushurl", "prefixproject.git");
+		config.setStringList("url", "https://server/repos/", "pushInsteadOf",
+				Arrays.asList("pre", "prefix", "pref", "perf"));
+		RemoteConfig rc = new RemoteConfig(config, "origin");
+		assertFalse(rc.getPushURIs().isEmpty());
+		assertEquals("https://server/repos/project.git", rc.getPushURIs()
+				.get(0).toASCIIString());
+	}
 }

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

 import java.net.URISyntaxException;
 import java.util.ArrayList;
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
 
 import org.eclipse.jgit.lib.Config;
 
 
 	private static final String KEY_TIMEOUT = "timeout";
 
+	private static final String KEY_INSTEADOF = "insteadof";
+
+	private static final String KEY_PUSHINSTEADOF = "pushinsteadof";
+
 	private static final boolean DEFAULT_MIRROR = false;
 
 	/** Default value for {@link #getUploadPack()} if not specified. */
 		String val;
 
 		vlst = rc.getStringList(SECTION, name, KEY_URL);
+		Map<String, String> insteadOf = getReplacements(rc, KEY_INSTEADOF);
 		uris = new ArrayList<URIish>(vlst.length);
 		for (final String s : vlst)
-			uris.add(new URIish(s));
+			uris.add(new URIish(replaceUri(s, insteadOf)));
 
+		Map<String, String> pushInsteadOf = getReplacements(rc,
+				KEY_PUSHINSTEADOF);
 		vlst = rc.getStringList(SECTION, name, KEY_PUSHURL);
 		pushURIs = new ArrayList<URIish>(vlst.length);
 		for (final String s : vlst)
-			pushURIs.add(new URIish(s));
+			pushURIs.add(new URIish(replaceUri(s, pushInsteadOf)));
 
 		vlst = rc.getStringList(SECTION, name, KEY_FETCH);
 		fetch = new ArrayList<RefSpec>(vlst.length);
 		rc.unset(SECTION, getName(), key);
 	}
 
+	private Map<String, String> getReplacements(final Config config,
+			final String keyName) {
+		final Map<String, String> replacements = new HashMap<String, String>();
+		for (String url : config.getSubsections(KEY_URL))
+			for (String insteadOf : config.getStringList(KEY_URL, url, keyName))
+				replacements.put(insteadOf, url);
+		return replacements;
+	}
+
+	private String replaceUri(final String uri,
+			final Map<String, String> replacements) {
+		if (replacements.isEmpty())
+			return uri;
+		Entry<String, String> match = null;
+		for (Entry<String, String> replacement : replacements.entrySet()) {
+			// Ignore current entry if not longer than previous match
+			if (match != null
+					&& match.getKey().length() > replacement.getKey().length())
+				continue;
+			if (!uri.startsWith(replacement.getKey()))
+				continue;
+			match = replacement;
+		}
+		if (match != null)
+			return match.getValue() + uri.substring(match.getKey().length());
+		else
+			return uri;
+	}
+
 	/**
 	 * Get the local name this remote configuration is recognized as.
 	 *