Support relative submodule URLs on init/add/sync

Interpret submodule URLs that start with './' or '../' as
relative to either the configured remote for the HEAD branch,
or 'origin', or the parent repository working directory if no
remote URL is configured

Bug: 368536
Change-Id: Id4985824023b75cd45cd64a4dd9d421166391e10

org.eclipse.jgit.test/tst/org/eclipse/jgit/submodule/SubmoduleAddTest.java

@@ -47,6 +47,7 @@ import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
+import java.io.File;
 import java.text.MessageFormat;
 
 import org.eclipse.jgit.JGitText;
@@ -58,6 +59,7 @@ import org.eclipse.jgit.dircache.DirCache;
 import org.eclipse.jgit.dircache.DirCacheEditor;
 import org.eclipse.jgit.dircache.DirCacheEditor.PathEdit;
 import org.eclipse.jgit.dircache.DirCacheEntry;
+import org.eclipse.jgit.lib.ConfigConstants;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.FileMode;
 import org.eclipse.jgit.lib.ObjectId;
@@ -169,4 +171,45 @@ public class SubmoduleAddTest extends RepositoryTestCase {
 					e.getMessage());
 		}
 	}
+
+	@Test
+	public void addSubmoduleWithRelativeUri() throws Exception {
+		Git git = new Git(db);
+		writeTrashFile("file.txt", "content");
+		git.add().addFilepattern("file.txt").call();
+		RevCommit commit = git.commit().setMessage("create file").call();
+
+		SubmoduleAddCommand command = new SubmoduleAddCommand(db);
+		String path = "sub";
+		String uri = "./.git";
+		command.setPath(path);
+		command.setURI(uri);
+		Repository repo = command.call();
+		assertNotNull(repo);
+
+		SubmoduleWalk generator = SubmoduleWalk.forIndex(db);
+		assertTrue(generator.next());
+		assertEquals(path, generator.getPath());
+		assertEquals(commit, generator.getObjectId());
+		assertEquals(uri, generator.getModulesUrl());
+		assertEquals(path, generator.getModulesPath());
+		String fullUri = db.getDirectory().getAbsolutePath();
+		if (File.separatorChar == '\\')
+			fullUri = fullUri.replace('\\', '/');
+		assertEquals(fullUri, generator.getConfigUrl());
+		assertNotNull(generator.getRepository());
+		assertEquals(
+				fullUri,
+				generator
+						.getRepository()
+						.getConfig()
+						.getString(ConfigConstants.CONFIG_REMOTE_SECTION,
+								Constants.DEFAULT_REMOTE_NAME,
+								ConfigConstants.CONFIG_KEY_URL));
+		assertEquals(commit, repo.resolve(Constants.HEAD));
+
+		Status status = Git.wrap(db).status().call();
+		assertTrue(status.getAdded().contains(Constants.DOT_GIT_MODULES));
+		assertTrue(status.getAdded().contains(path));
+	}
 }

org.eclipse.jgit.test/tst/org/eclipse/jgit/submodule/SubmoduleInitTest.java

@@ -46,12 +46,14 @@ import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
 
 import java.io.File;
 import java.io.IOException;
 import java.util.Collection;
 
 import org.eclipse.jgit.api.SubmoduleInitCommand;
+import org.eclipse.jgit.api.errors.JGitInternalException;
 import org.eclipse.jgit.dircache.DirCache;
 import org.eclipse.jgit.dircache.DirCacheEditor;
 import org.eclipse.jgit.dircache.DirCacheEditor.PathEdit;
@@ -81,19 +83,7 @@ public class SubmoduleInitTest extends RepositoryTestCase {
 	@Test
 	public void repositoryWithUninitializedModule() throws IOException,
 			ConfigInvalidException {
-		final ObjectId id = ObjectId
-				.fromString("abcd1234abcd1234abcd1234abcd1234abcd1234");
-		final String path = "sub";
-		DirCache cache = db.lockDirCache();
-		DirCacheEditor editor = cache.editor();
-		editor.add(new PathEdit(path) {
-
-			public void apply(DirCacheEntry ent) {
-				ent.setFileMode(FileMode.GITLINK);
-				ent.setObjectId(id);
-			}
-		});
-		editor.commit();
+		final String path = addSubmoduleToIndex();
 
 		SubmoduleWalk generator = SubmoduleWalk.forIndex(db);
 		assertTrue(generator.next());
@@ -123,4 +113,220 @@ public class SubmoduleInitTest extends RepositoryTestCase {
 		assertEquals(url, generator.getConfigUrl());
 		assertEquals(update, generator.getConfigUpdate());
 	}
+
+	@Test
+	public void resolveSameLevelRelativeUrl() throws Exception {
+		final String path = addSubmoduleToIndex();
+
+		String base = "git://server/repo.git";
+		FileBasedConfig config = db.getConfig();
+		config.setString(ConfigConstants.CONFIG_REMOTE_SECTION,
+				Constants.DEFAULT_REMOTE_NAME, ConfigConstants.CONFIG_KEY_URL,
+				base);
+		config.save();
+
+		SubmoduleWalk generator = SubmoduleWalk.forIndex(db);
+		assertTrue(generator.next());
+		assertNull(generator.getConfigUrl());
+		assertNull(generator.getConfigUpdate());
+
+		FileBasedConfig modulesConfig = new FileBasedConfig(new File(
+				db.getWorkTree(), Constants.DOT_GIT_MODULES), db.getFS());
+		modulesConfig.setString(ConfigConstants.CONFIG_SUBMODULE_SECTION, path,
+				ConfigConstants.CONFIG_KEY_PATH, path);
+		String url = "./sub.git";
+		modulesConfig.setString(ConfigConstants.CONFIG_SUBMODULE_SECTION, path,
+				ConfigConstants.CONFIG_KEY_URL, url);
+		String update = "rebase";
+		modulesConfig.setString(ConfigConstants.CONFIG_SUBMODULE_SECTION, path,
+				ConfigConstants.CONFIG_KEY_UPDATE, update);
+		modulesConfig.save();
+
+		SubmoduleInitCommand command = new SubmoduleInitCommand(db);
+		Collection<String> modules = command.call();
+		assertNotNull(modules);
+		assertEquals(1, modules.size());
+		assertEquals(path, modules.iterator().next());
+
+		generator = SubmoduleWalk.forIndex(db);
+		assertTrue(generator.next());
+		assertEquals("git://server/repo.git/sub.git", generator.getConfigUrl());
+		assertEquals(update, generator.getConfigUpdate());
+	}
+
+	@Test
+	public void resolveOneLevelHigherRelativeUrl() throws IOException,
+			ConfigInvalidException {
+		final String path = addSubmoduleToIndex();
+
+		String base = "git://server/repo.git";
+		FileBasedConfig config = db.getConfig();
+		config.setString(ConfigConstants.CONFIG_REMOTE_SECTION,
+				Constants.DEFAULT_REMOTE_NAME, ConfigConstants.CONFIG_KEY_URL,
+				base);
+		config.save();
+
+		SubmoduleWalk generator = SubmoduleWalk.forIndex(db);
+		assertTrue(generator.next());
+		assertNull(generator.getConfigUrl());
+		assertNull(generator.getConfigUpdate());
+
+		FileBasedConfig modulesConfig = new FileBasedConfig(new File(
+				db.getWorkTree(), Constants.DOT_GIT_MODULES), db.getFS());
+		modulesConfig.setString(ConfigConstants.CONFIG_SUBMODULE_SECTION, path,
+				ConfigConstants.CONFIG_KEY_PATH, path);
+		String url = "../sub.git";
+		modulesConfig.setString(ConfigConstants.CONFIG_SUBMODULE_SECTION, path,
+				ConfigConstants.CONFIG_KEY_URL, url);
+		String update = "rebase";
+		modulesConfig.setString(ConfigConstants.CONFIG_SUBMODULE_SECTION, path,
+				ConfigConstants.CONFIG_KEY_UPDATE, update);
+		modulesConfig.save();
+
+		SubmoduleInitCommand command = new SubmoduleInitCommand(db);
+		Collection<String> modules = command.call();
+		assertNotNull(modules);
+		assertEquals(1, modules.size());
+		assertEquals(path, modules.iterator().next());
+
+		generator = SubmoduleWalk.forIndex(db);
+		assertTrue(generator.next());
+		assertEquals("git://server/sub.git", generator.getConfigUrl());
+		assertEquals(update, generator.getConfigUpdate());
+	}
+
+	@Test
+	public void resolveTwoLevelHigherRelativeUrl() throws IOException,
+			ConfigInvalidException {
+		final String path = addSubmoduleToIndex();
+
+		String base = "git://server/repo.git";
+		FileBasedConfig config = db.getConfig();
+		config.setString(ConfigConstants.CONFIG_REMOTE_SECTION,
+				Constants.DEFAULT_REMOTE_NAME, ConfigConstants.CONFIG_KEY_URL,
+				base);
+		config.save();
+
+		SubmoduleWalk generator = SubmoduleWalk.forIndex(db);
+		assertTrue(generator.next());
+		assertNull(generator.getConfigUrl());
+		assertNull(generator.getConfigUpdate());
+
+		FileBasedConfig modulesConfig = new FileBasedConfig(new File(
+				db.getWorkTree(), Constants.DOT_GIT_MODULES), db.getFS());
+		modulesConfig.setString(ConfigConstants.CONFIG_SUBMODULE_SECTION, path,
+				ConfigConstants.CONFIG_KEY_PATH, path);
+		String url = "../../server2/sub.git";
+		modulesConfig.setString(ConfigConstants.CONFIG_SUBMODULE_SECTION, path,
+				ConfigConstants.CONFIG_KEY_URL, url);
+		String update = "rebase";
+		modulesConfig.setString(ConfigConstants.CONFIG_SUBMODULE_SECTION, path,
+				ConfigConstants.CONFIG_KEY_UPDATE, update);
+		modulesConfig.save();
+
+		SubmoduleInitCommand command = new SubmoduleInitCommand(db);
+		Collection<String> modules = command.call();
+		assertNotNull(modules);
+		assertEquals(1, modules.size());
+		assertEquals(path, modules.iterator().next());
+
+		generator = SubmoduleWalk.forIndex(db);
+		assertTrue(generator.next());
+		assertEquals("git://server2/sub.git", generator.getConfigUrl());
+		assertEquals(update, generator.getConfigUpdate());
+	}
+
+	@Test
+	public void resolveWorkingDirectoryRelativeUrl() throws IOException,
+			ConfigInvalidException {
+		final String path = addSubmoduleToIndex();
+
+		String base = db.getWorkTree().getAbsolutePath();
+		if (File.separatorChar == '\\')
+			base = base.replace('\\', '/');
+		FileBasedConfig config = db.getConfig();
+		config.setString(ConfigConstants.CONFIG_REMOTE_SECTION,
+				Constants.DEFAULT_REMOTE_NAME, ConfigConstants.CONFIG_KEY_URL,
+				null);
+		config.save();
+
+		SubmoduleWalk generator = SubmoduleWalk.forIndex(db);
+		assertTrue(generator.next());
+		assertNull(generator.getConfigUrl());
+		assertNull(generator.getConfigUpdate());
+
+		FileBasedConfig modulesConfig = new FileBasedConfig(new File(
+				db.getWorkTree(), Constants.DOT_GIT_MODULES), db.getFS());
+		modulesConfig.setString(ConfigConstants.CONFIG_SUBMODULE_SECTION, path,
+				ConfigConstants.CONFIG_KEY_PATH, path);
+		String url = "./sub.git";
+		modulesConfig.setString(ConfigConstants.CONFIG_SUBMODULE_SECTION, path,
+				ConfigConstants.CONFIG_KEY_URL, url);
+		String update = "rebase";
+		modulesConfig.setString(ConfigConstants.CONFIG_SUBMODULE_SECTION, path,
+				ConfigConstants.CONFIG_KEY_UPDATE, update);
+		modulesConfig.save();
+
+		SubmoduleInitCommand command = new SubmoduleInitCommand(db);
+		Collection<String> modules = command.call();
+		assertNotNull(modules);
+		assertEquals(1, modules.size());
+		assertEquals(path, modules.iterator().next());
+
+		generator = SubmoduleWalk.forIndex(db);
+		assertTrue(generator.next());
+		assertEquals(base + "/sub.git", generator.getConfigUrl());
+		assertEquals(update, generator.getConfigUpdate());
+	}
+
+	@Test
+	public void resolveInvalidParentUrl() throws IOException,
+			ConfigInvalidException {
+		final String path = addSubmoduleToIndex();
+
+		String base = "no_slash";
+		FileBasedConfig config = db.getConfig();
+		config.setString(ConfigConstants.CONFIG_REMOTE_SECTION,
+				Constants.DEFAULT_REMOTE_NAME, ConfigConstants.CONFIG_KEY_URL,
+				base);
+		config.save();
+
+		SubmoduleWalk generator = SubmoduleWalk.forIndex(db);
+		assertTrue(generator.next());
+		assertNull(generator.getConfigUrl());
+		assertNull(generator.getConfigUpdate());
+
+		FileBasedConfig modulesConfig = new FileBasedConfig(new File(
+				db.getWorkTree(), Constants.DOT_GIT_MODULES), db.getFS());
+		modulesConfig.setString(ConfigConstants.CONFIG_SUBMODULE_SECTION, path,
+				ConfigConstants.CONFIG_KEY_PATH, path);
+		String url = "../sub.git";
+		modulesConfig.setString(ConfigConstants.CONFIG_SUBMODULE_SECTION, path,
+				ConfigConstants.CONFIG_KEY_URL, url);
+		modulesConfig.save();
+
+		try {
+			new SubmoduleInitCommand(db).call();
+			fail("Exception not thrown");
+		} catch (JGitInternalException e) {
+			assertTrue(e.getCause() instanceof IOException);
+		}
+	}
+
+	private String addSubmoduleToIndex() throws IOException {
+		final ObjectId id = ObjectId
+				.fromString("abcd1234abcd1234abcd1234abcd1234abcd1234");
+		final String path = "sub";
+		DirCache cache = db.lockDirCache();
+		DirCacheEditor editor = cache.editor();
+		editor.add(new PathEdit(path) {
+
+			public void apply(DirCacheEntry ent) {
+				ent.setFileMode(FileMode.GITLINK);
+				ent.setObjectId(id);
+			}
+		});
+		editor.commit();
+		return path;
+	}
 }

org.eclipse.jgit.test/tst/org/eclipse/jgit/submodule/SubmoduleSyncTest.java

@@ -137,4 +137,73 @@ public class SubmoduleSyncTest extends RepositoryTestCase {
 				ConfigConstants.CONFIG_REMOTE_SECTION,
 				Constants.DEFAULT_REMOTE_NAME, ConfigConstants.CONFIG_KEY_URL));
 	}
+
+	@Test
+	public void repositoryWithRelativeUriSubmodule() throws Exception {
+		writeTrashFile("file.txt", "content");
+		Git git = Git.wrap(db);
+		git.add().addFilepattern("file.txt").call();
+		git.commit().setMessage("create file").call();
+
+		final ObjectId id = ObjectId
+				.fromString("abcd1234abcd1234abcd1234abcd1234abcd1234");
+		final String path = "sub";
+		DirCache cache = db.lockDirCache();
+		DirCacheEditor editor = cache.editor();
+		editor.add(new PathEdit(path) {
+
+			public void apply(DirCacheEntry ent) {
+				ent.setFileMode(FileMode.GITLINK);
+				ent.setObjectId(id);
+			}
+		});
+		editor.commit();
+
+		String base = "git://server/repo.git";
+		FileBasedConfig config = db.getConfig();
+		config.setString(ConfigConstants.CONFIG_REMOTE_SECTION,
+				Constants.DEFAULT_REMOTE_NAME, ConfigConstants.CONFIG_KEY_URL,
+				base);
+		config.save();
+
+		FileBasedConfig modulesConfig = new FileBasedConfig(new File(
+				db.getWorkTree(), Constants.DOT_GIT_MODULES), db.getFS());
+		modulesConfig.setString(ConfigConstants.CONFIG_SUBMODULE_SECTION, path,
+				ConfigConstants.CONFIG_KEY_PATH, path);
+		String current = "git://server/repo.git";
+		modulesConfig.setString(ConfigConstants.CONFIG_SUBMODULE_SECTION, path,
+				ConfigConstants.CONFIG_KEY_URL, current);
+		modulesConfig.save();
+
+		Repository subRepo = Git.cloneRepository()
+				.setURI(db.getDirectory().toURI().toString())
+				.setDirectory(new File(db.getWorkTree(), path)).call()
+				.getRepository();
+		assertNotNull(subRepo);
+
+		SubmoduleWalk generator = SubmoduleWalk.forIndex(db);
+		assertTrue(generator.next());
+		assertNull(generator.getConfigUrl());
+		assertEquals(current, generator.getModulesUrl());
+
+		modulesConfig.setString(ConfigConstants.CONFIG_SUBMODULE_SECTION, path,
+				ConfigConstants.CONFIG_KEY_URL, "../sub.git");
+		modulesConfig.save();
+
+		SubmoduleSyncCommand command = new SubmoduleSyncCommand(db);
+		Map<String, String> synced = command.call();
+		assertNotNull(synced);
+		assertEquals(1, synced.size());
+		Entry<String, String> module = synced.entrySet().iterator().next();
+		assertEquals(path, module.getKey());
+		assertEquals("git://server/sub.git", module.getValue());
+
+		generator = SubmoduleWalk.forIndex(db);
+		assertTrue(generator.next());
+		assertEquals("git://server/sub.git", generator.getConfigUrl());
+		StoredConfig submoduleConfig = generator.getRepository().getConfig();
+		assertEquals("git://server/sub.git", submoduleConfig.getString(
+				ConfigConstants.CONFIG_REMOTE_SECTION,
+				Constants.DEFAULT_REMOTE_NAME, ConfigConstants.CONFIG_KEY_URL));
+	}
 }

org.eclipse.jgit/resources/org/eclipse/jgit/JGitText.properties

@@ -423,6 +423,7 @@ staleRevFlagsOn=Stale RevFlags on {0}
 startingReadStageWithoutWrittenRequestDataPendingIsNotSupported=Starting read stage without written request data pending is not supported
 statelessRPCRequiresOptionToBeEnabled=stateless RPC requires {0} to be enabled
 submoduleExists=Submodule ''{0}'' already exists in the index
+submoduleParentRemoteUrlInvalid=Cannot remove segment from remote url ''{0}''
 submodulesNotSupported=Submodules are not supported
 symlinkCannotBeWrittenAsTheLinkTarget=Symlink "{0}" cannot be written as the link target cannot be read from within Java.
 systemConfigFileInvalid=Systen wide config file {0} is invalid {1}

org.eclipse.jgit/src/org/eclipse/jgit/JGitText.java

@@ -484,6 +484,7 @@ public class JGitText extends TranslationBundle {
 	/***/ public String statelessRPCRequiresOptionToBeEnabled;
 	/***/ public String submoduleExists;
 	/***/ public String submodulesNotSupported;
+	/***/ public String submoduleParentRemoteUrlInvalid;
 	/***/ public String symlinkCannotBeWrittenAsTheLinkTarget;
 	/***/ public String systemConfigFileInvalid;
 	/***/ public String tagNameInvalid;

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

@@ -148,12 +148,18 @@ public class SubmoduleAddCommand extends
 			throw new JGitInternalException(e.getMessage(), e);
 		}
 
+		final String resolvedUri;
+		try {
+			resolvedUri = SubmoduleWalk.getSubmoduleRemoteUrl(repo, uri);
+		} catch (IOException e) {
+			throw new JGitInternalException(e.getMessage(), e);
+		}
 		// Clone submodule repository
 		File moduleDirectory = SubmoduleWalk.getSubmoduleDirectory(repo, path);
 		CloneCommand clone = Git.cloneRepository();
 		configure(clone);
 		clone.setDirectory(moduleDirectory);
-		clone.setURI(uri);
+		clone.setURI(resolvedUri);
 		if (monitor != null)
 			clone.setProgressMonitor(monitor);
 		Repository subRepo = clone.call().getRepository();
@@ -161,7 +167,7 @@ public class SubmoduleAddCommand extends
 		// Save submodule URL to parent repository's config
 		StoredConfig config = repo.getConfig();
 		config.setString(ConfigConstants.CONFIG_SUBMODULE_SECTION, path,
-				ConfigConstants.CONFIG_KEY_URL, uri);
+				ConfigConstants.CONFIG_KEY_URL, resolvedUri);
 		try {
 			config.save();
 		} catch (IOException e) {

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

@@ -106,7 +106,7 @@ public class SubmoduleInitCommand extends GitCommand<Collection<String>> {
 				String path = generator.getPath();
 				// Copy 'url' and 'update' fields from .gitmodules to config
 				// file
-				String url = generator.getModulesUrl();
+				String url = generator.getRemoteUrl();
 				String update = generator.getModulesUpdate();
 				if (url != null)
 					config.setString(ConfigConstants.CONFIG_SUBMODULE_SECTION,

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

@@ -116,7 +116,7 @@ public class SubmoduleSyncCommand extends GitCommand<Map<String, String>> {
 			Map<String, String> synced = new HashMap<String, String>();
 			StoredConfig config = repo.getConfig();
 			while (generator.next()) {
-				String remoteUrl = generator.getModulesUrl();
+				String remoteUrl = generator.getRemoteUrl();
 				if (remoteUrl == null)
 					continue;
 

org.eclipse.jgit/src/org/eclipse/jgit/submodule/SubmoduleWalk.java

@@ -44,7 +44,9 @@ package org.eclipse.jgit.submodule;
 
 import java.io.File;
 import java.io.IOException;
+import java.text.MessageFormat;
 
+import org.eclipse.jgit.JGitText;
 import org.eclipse.jgit.dircache.DirCacheIterator;
 import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.eclipse.jgit.errors.CorruptObjectException;
@@ -176,6 +178,83 @@ public class SubmoduleWalk {
 		return new File(getSubmoduleDirectory(parent, path), Constants.DOT_GIT);
 	}
 
+	/**
+	 * Resolve submodule repository URL.
+	 * <p>
+	 * This handles relative URLs that are typically specified in the
+	 * '.gitmodules' file by resolving them against the remote URL of the parent
+	 * repository.
+	 * <p>
+	 * Relative URLs will be resolved against the parent repository's working
+	 * directory if the parent repository has no configured remote URL.
+	 *
+	 * @param parent
+	 *            parent repository
+	 * @param url
+	 *            absolute or relative URL of the submodule repository
+	 * @return resolved URL
+	 * @throws IOException
+	 */
+	public static String getSubmoduleRemoteUrl(final Repository parent,
+			final String url) throws IOException {
+		if (!url.startsWith("./") && !url.startsWith("../"))
+			return url;
+
+		String remoteName = null;
+		// Look up remote URL associated wit HEAD ref
+		Ref ref = parent.getRef(Constants.HEAD);
+		if (ref != null) {
+			if (ref.isSymbolic())
+				ref = ref.getLeaf();
+			remoteName = parent.getConfig().getString(
+					ConfigConstants.CONFIG_BRANCH_SECTION,
+					Repository.shortenRefName(ref.getName()),
+					ConfigConstants.CONFIG_KEY_REMOTE);
+		}
+
+		// Fall back to 'origin' if current HEAD ref has no remote URL
+		if (remoteName == null)
+			remoteName = Constants.DEFAULT_REMOTE_NAME;
+
+		String remoteUrl = parent.getConfig().getString(
+				ConfigConstants.CONFIG_REMOTE_SECTION, remoteName,
+				ConfigConstants.CONFIG_KEY_URL);
+
+		// Fall back to parent repository's working directory if no remote URL
+		if (remoteUrl == null) {
+			remoteUrl = parent.getWorkTree().getAbsolutePath();
+			// Normalize slashes to '/'
+			if ('\\' == File.separatorChar)
+				remoteUrl = remoteUrl.replace('\\', '/');
+		}
+
+		// Remove trailing '/'
+		if (remoteUrl.charAt(remoteUrl.length() - 1) == '/')
+			remoteUrl = remoteUrl.substring(0, remoteUrl.length() - 1);
+
+		char separator = '/';
+		String submoduleUrl = url;
+		while (submoduleUrl.length() > 0) {
+			if (submoduleUrl.startsWith("./"))
+				submoduleUrl = submoduleUrl.substring(2);
+			else if (submoduleUrl.startsWith("../")) {
+				int lastSeparator = remoteUrl.lastIndexOf('/');
+				if (lastSeparator < 1) {
+					lastSeparator = remoteUrl.lastIndexOf(':');
+					separator = ':';
+				}
+				if (lastSeparator < 1)
+					throw new IOException(MessageFormat.format(
+							JGitText.get().submoduleParentRemoteUrlInvalid,
+							remoteUrl));
+				remoteUrl = remoteUrl.substring(0, lastSeparator);
+				submoduleUrl = submoduleUrl.substring(3);
+			} else
+				break;
+		}
+		return remoteUrl + separator + submoduleUrl;
+	}
+
 	private final Repository repository;
 
 	private final TreeWalk walk;
@@ -432,4 +511,19 @@ public class SubmoduleWalk {
 		Ref head = subRepo.getRef(Constants.HEAD);
 		return head != null ? head.getLeaf().getName() : null;
 	}
+
+	/**
+	 * Get the resolved remote URL for the current submodule.
+	 * <p>
+	 * This method resolves the value of {@link #getModulesUrl()} to an absolute
+	 * URL
+	 *
+	 * @return resolved remote URL
+	 * @throws IOException
+	 * @throws ConfigInvalidException
+	 */
+	public String getRemoteUrl() throws IOException, ConfigInvalidException {
+		String url = getModulesUrl();
+		return url != null ? getSubmoduleRemoteUrl(repository, url) : null;
+	}
 }