Allow explicit configuration of git directory in InitCommand

Native git's "init" command allows to specify the location of the .git
folder with the option "--separate-git-dir". This allows for example to
setup repositories with a non-standard layout. E.g. .git folder under
/repos/a.git and the worktree under /home/git/a. Both directories
contain pointers to the other side: /repos/a.git/config contains
core.worktree=/home/git/a . And /home/git/a/.git is a file containing
"gitdir: /repos/a.git". This commit adds that option to InitCommand.
This feature is needed to support the new submodule layout where the
.git folder of the submodules is under .git/modules/<submodule>.

Change-Id: I0208f643808bf8f28e2c979d6e33662607775f1f

org.eclipse.jgit.junit/src/org/eclipse/jgit/junit/MockSystemReader.java

@@ -90,6 +90,7 @@ public MockSystemReader() {
 		init(Constants.GIT_AUTHOR_EMAIL_KEY);
 		init(Constants.GIT_COMMITTER_NAME_KEY);
 		init(Constants.GIT_COMMITTER_EMAIL_KEY);
+		setProperty(Constants.OS_USER_DIR, ".");
 		userGitConfig = new MockConfig(null, null);
 		systemGitConfig = new MockConfig(null, null);
 		setCurrentPlatform();

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

@@ -43,6 +43,7 @@
 package org.eclipse.jgit.api;
 
 import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 
 import java.io.File;
@@ -50,8 +51,12 @@
 
 import org.eclipse.jgit.api.errors.GitAPIException;
 import org.eclipse.jgit.api.errors.JGitInternalException;
+import org.eclipse.jgit.errors.NoWorkTreeException;
+import org.eclipse.jgit.junit.MockSystemReader;
 import org.eclipse.jgit.junit.RepositoryTestCase;
+import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.util.SystemReader;
 import org.junit.Before;
 import org.junit.Test;
 
@@ -101,4 +106,109 @@ public void testInitBareRepository() throws IOException,
 		assertNotNull(repository);
 		assertTrue(repository.isBare());
 	}
+
+	// non-bare repos where gitDir and directory is set. Same as
+	// "git init --separate-git-dir /tmp/a /tmp/b"
+	@Test
+	public void testInitWithExplicitGitDir() throws IOException,
+			JGitInternalException, GitAPIException {
+		File wt = createTempDirectory("testInitRepositoryWT");
+		File gitDir = createTempDirectory("testInitRepositoryGIT");
+		InitCommand command = new InitCommand();
+		command.setDirectory(wt);
+		command.setGitDir(gitDir);
+		Repository repository = command.call().getRepository();
+		addRepoToClose(repository);
+		assertNotNull(repository);
+		assertEqualsFile(wt, repository.getWorkTree());
+		assertEqualsFile(gitDir, repository.getDirectory());
+	}
+
+	// non-bare repos where only gitDir is set. Same as
+	// "git init --separate-git-dir /tmp/a"
+	@Test
+	public void testInitWithOnlyExplicitGitDir() throws IOException,
+			JGitInternalException, GitAPIException {
+		MockSystemReader reader = (MockSystemReader) SystemReader.getInstance();
+		reader.setProperty(Constants.OS_USER_DIR, getTemporaryDirectory()
+				.getAbsolutePath());
+		File gitDir = createTempDirectory("testInitRepository/.git");
+		InitCommand command = new InitCommand();
+		command.setGitDir(gitDir);
+		Repository repository = command.call().getRepository();
+		addRepoToClose(repository);
+		assertNotNull(repository);
+		assertEqualsFile(gitDir, repository.getDirectory());
+		assertEqualsFile(new File(reader.getProperty("user.dir")),
+				repository.getWorkTree());
+	}
+
+	// Bare repos where gitDir and directory is set will only work if gitDir and
+	// directory is pointing to same dir. Same as
+	// "git init --bare --separate-git-dir /tmp/a /tmp/b"
+	// (works in native git but I guess that's more a bug)
+	@Test(expected = IllegalStateException.class)
+	public void testInitBare_DirAndGitDirMustBeEqual() throws IOException,
+			JGitInternalException, GitAPIException {
+		File gitDir = createTempDirectory("testInitRepository.git");
+		InitCommand command = new InitCommand();
+		command.setBare(true);
+		command.setDirectory(gitDir);
+		command.setGitDir(new File(gitDir, ".."));
+		command.call();
+	}
+
+	// If neither directory nor gitDir is set in a non-bare repo make sure
+	// worktree and gitDir are set correctly. Standard case. Same as
+	// "git init"
+	@Test
+	public void testInitWithDefaultsNonBare() throws JGitInternalException,
+			GitAPIException, IOException {
+		MockSystemReader reader = (MockSystemReader) SystemReader.getInstance();
+		reader.setProperty(Constants.OS_USER_DIR, getTemporaryDirectory()
+				.getAbsolutePath());
+		InitCommand command = new InitCommand();
+		command.setBare(false);
+		Repository repository = command.call().getRepository();
+		addRepoToClose(repository);
+		assertNotNull(repository);
+		assertEqualsFile(new File(reader.getProperty("user.dir"), ".git"),
+				repository.getDirectory());
+		assertEqualsFile(new File(reader.getProperty("user.dir")),
+				repository.getWorkTree());
+	}
+
+	// If neither directory nor gitDir is set in a bare repo make sure
+	// worktree and gitDir are set correctly. Standard case. Same as
+	// "git init --bare"
+	@Test(expected = NoWorkTreeException.class)
+	public void testInitWithDefaultsBare() throws JGitInternalException,
+			GitAPIException, IOException {
+		MockSystemReader reader = (MockSystemReader) SystemReader.getInstance();
+		reader.setProperty(Constants.OS_USER_DIR, getTemporaryDirectory()
+				.getAbsolutePath());
+		InitCommand command = new InitCommand();
+		command.setBare(true);
+		Repository repository = command.call().getRepository();
+		addRepoToClose(repository);
+		assertNotNull(repository);
+		assertEqualsFile(new File(reader.getProperty("user.dir")),
+				repository.getDirectory());
+		assertNull(repository.getWorkTree());
+	}
+
+	// In a non-bare repo when directory and gitDir is set then they shouldn't
+	// point to the same dir. Same as
+	// "git init --separate-git-dir /tmp/a /tmp/a"
+	// (works in native git but I guess that's more a bug)
+	@Test(expected = IllegalStateException.class)
+	public void testInitNonBare_GitdirAndDirShouldntBeSame()
+			throws JGitInternalException, GitAPIException, IOException {
+		File gitDir = createTempDirectory("testInitRepository.git");
+		InitCommand command = new InitCommand();
+		command.setBare(false);
+		command.setGitDir(gitDir);
+		command.setDirectory(gitDir);
+		command.call().getRepository();
+	}
 }

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

@@ -249,6 +249,8 @@ indexFileIsInUse=Index file is in use
 indexFileIsTooLargeForJgit=Index file is too large for jgit
 indexSignatureIsInvalid=Index signature is invalid: {0}
 indexWriteException=Modified index could not be written
+initFailedBareRepoDifferentDirs=When initializing a bare repo with directory {0} and separate git-dir {1} specified both folders must point to the same location
+initFailedNonBareRepoSameDirs=When initializing a non-bare repo with directory {0} and separate git-dir {1} specified both folders should not point to the same location
 inMemoryBufferLimitExceeded=In-memory buffer limit exceeded
 inputStreamMustSupportMark=InputStream must support mark()
 integerValueOutOfRange=Integer value {0}.{1} out of range

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

@@ -44,13 +44,16 @@
 
 import java.io.File;
 import java.io.IOException;
+import java.text.MessageFormat;
 import java.util.concurrent.Callable;
 
 import org.eclipse.jgit.api.errors.GitAPIException;
 import org.eclipse.jgit.api.errors.JGitInternalException;
+import org.eclipse.jgit.internal.JGitText;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.lib.RepositoryBuilder;
+import org.eclipse.jgit.util.SystemReader;
 
 /**
  * Create an empty git repository or reinitalize an existing one
@@ -61,6 +64,8 @@
 public class InitCommand implements Callable<Git> {
 	private File directory;
 
+	private File gitDir;
+
 	private boolean bare;
 
 	/**
@@ -74,18 +79,36 @@ public Git call() throws GitAPIException {
 			if (bare)
 				builder.setBare();
 			builder.readEnvironment();
+			if (gitDir != null)
+				builder.setGitDir(gitDir);
+			else
+				gitDir = builder.getGitDir();
 			if (directory != null) {
-				File d = directory;
-				if (!bare)
-					d = new File(d, Constants.DOT_GIT);
-				builder.setGitDir(d);
+				if (bare)
+					builder.setGitDir(directory);
+				else {
+					builder.setWorkTree(directory);
+					if (gitDir == null)
+						builder.setGitDir(new File(directory, Constants.DOT_GIT));
+				}
 			} else if (builder.getGitDir() == null) {
-				File d = new File("."); //$NON-NLS-1$
-				if (d.getParentFile() != null)
-					d = d.getParentFile();
+				String dStr = SystemReader.getInstance()
+						.getProperty("user.dir"); //$NON-NLS-1$
+				if (dStr == null)
+					dStr = "."; //$NON-NLS-1$
+				File d = new File(dStr);
 				if (!bare)
 					d = new File(d, Constants.DOT_GIT);
 				builder.setGitDir(d);
+			} else {
+				// directory was not set but gitDir was set
+				if (!bare) {
+					String dStr = SystemReader.getInstance().getProperty(
+							"user.dir"); //$NON-NLS-1$
+					if (dStr == null)
+						dStr = "."; //$NON-NLS-1$
+					builder.setWorkTree(new File(dStr));
+				}
 			}
 			Repository repository = builder.build();
 			if (!repository.getObjectDatabase().exists())
@@ -103,20 +126,67 @@ public Git call() throws GitAPIException {
 	 * @param directory
 	 *            the directory to init to
 	 * @return this instance
+	 * @throws IllegalStateException
+	 *             if the combination of directory, gitDir and bare is illegal.
+	 *             E.g. if for a non-bare repository directory and gitDir point
+	 *             to the same directory of if for a bare repository both
+	 *             directory and gitDir are specified
 	 */
-	public InitCommand setDirectory(File directory) {
+	public InitCommand setDirectory(File directory)
+			throws IllegalStateException {
+		validateDirs(directory, gitDir, bare);
 		this.directory = directory;
 		return this;
 	}
 
 	/**
-	 * @param bare
-	 *            whether the repository is bare or not
+	 * @param gitDir
+	 *            the repository meta directory
 	 * @return this instance
+	 * @throws IllegalStateException
+	 *             if the combination of directory, gitDir and bare is illegal.
+	 *             E.g. if for a non-bare repository directory and gitDir point
+	 *             to the same directory of if for a bare repository both
+	 *             directory and gitDir are specified
+	 * @since 3.6
 	 */
-	public InitCommand setBare(boolean bare) {
-		this.bare = bare;
+	public InitCommand setGitDir(File gitDir)
+			throws IllegalStateException {
+		validateDirs(directory, gitDir, bare);
+		this.gitDir = gitDir;
 		return this;
 	}
 
+	private static void validateDirs(File directory, File gitDir, boolean bare)
+			throws IllegalStateException {
+		if (directory != null) {
+			if (bare) {
+				if (gitDir != null && !gitDir.equals(directory))
+					throw new IllegalStateException(MessageFormat.format(
+							JGitText.get().initFailedBareRepoDifferentDirs,
+							gitDir, directory));
+			} else {
+				if (gitDir != null && gitDir.equals(directory))
+					throw new IllegalStateException(MessageFormat.format(
+							JGitText.get().initFailedNonBareRepoSameDirs,
+							gitDir, directory));
+			}
+		}
+	}
+
+	/**
+	 * @param bare
+	 *            whether the repository is bare or not
+	 * @throws IllegalStateException
+	 *             if the combination of directory, gitDir and bare is illegal.
+	 *             E.g. if for a non-bare repository directory and gitDir point
+	 *             to the same directory of if for a bare repository both
+	 *             directory and gitDir are specified
+	 * @return this instance
+	 */
+	public InitCommand setBare(boolean bare) {
+		validateDirs(directory, gitDir, bare);
+		this.bare = bare;
+		return this;
+	}
 }

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

@@ -308,6 +308,8 @@ public static JGitText get() {
 	/***/ public String indexFileIsTooLargeForJgit;
 	/***/ public String indexSignatureIsInvalid;
 	/***/ public String indexWriteException;
+	/***/ public String initFailedBareRepoDifferentDirs;
+	/***/ public String initFailedNonBareRepoSameDirs;
 	/***/ public String inMemoryBufferLimitExceeded;
 	/***/ public String inputStreamMustSupportMark;
 	/***/ public String integerValueOutOfRange;

org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/FileRepository.java

@@ -273,7 +273,8 @@ public void create(boolean bare) throws IOException {
 				ConfigConstants.CONFIG_CORE_SECTION, null,
 				ConfigConstants.CONFIG_KEY_HIDEDOTFILES,
 				HideDotFiles.DOTGITONLY);
-		if (hideDotFiles != HideDotFiles.FALSE && !isBare())
+		if (hideDotFiles != HideDotFiles.FALSE && !isBare()
+				&& getDirectory().getName().startsWith(".")) //$NON-NLS-1$
 			getFS().setHidden(getDirectory(), true);
 		refs.create();
 		objectDatabase.create();
@@ -329,6 +330,25 @@ public void create(boolean bare) throws IOException {
 			// Java has no other way
 			cfg.setBoolean(ConfigConstants.CONFIG_CORE_SECTION, null,
 					ConfigConstants.CONFIG_KEY_PRECOMPOSEUNICODE, true);
+		if (!bare) {
+			File workTree = getWorkTree();
+			if (!getDirectory().getParentFile().equals(workTree)) {
+				cfg.setString(ConfigConstants.CONFIG_CORE_SECTION, null,
+						ConfigConstants.CONFIG_KEY_WORKTREE, getWorkTree()
+								.getAbsolutePath());
+				LockFile dotGitLockFile = new LockFile(new File(workTree,
+						Constants.DOT_GIT), getFS());
+				try {
+					if (dotGitLockFile.lock()) {
+						dotGitLockFile.write(Constants.encode(Constants.GITDIR
+								+ getDirectory().getAbsolutePath()));
+						dotGitLockFile.commit();
+					}
+				} finally {
+					dotGitLockFile.unlock();
+				}
+			}
+		}
 		cfg.save();
 	}
 

org.eclipse.jgit/src/org/eclipse/jgit/lib/Constants.java

@@ -272,7 +272,14 @@ public final class Constants {
 	 */
 	public static final String INFO_EXCLUDE = "info/exclude";
 
-	/** The environment variable that contains the system user name */
+	/**
+	 * The system property that contains the system user name
+	 *
+	 * @since 3.6
+	 */
+	public static final String OS_USER_DIR = "user.dir";
+
+	/** The system property that contains the system user name */
 	public static final String OS_USER_NAME_KEY = "user.name";
 
 	/** The environment variable that contains the author's name */
@@ -358,6 +365,13 @@ public final class Constants {
 	/** Name of the .git/shallow file */
 	public static final String SHALLOW = "shallow";
 
+	/**
+	 * Prefix of the first line in a ".git" file
+	 *
+	 * @since 3.6
+	 */
+	public static final String GITDIR = "gitdir: ";
+
 	/**
 	 * Create a new digest function for objects.
 	 *