archive: Prepend a specified prefix to all entry filenames

Common practice when distributing tarballs is to prefix all entries
with a single directory name so when the tarball is extracted it all
falls neatly into a single directory.  Add a setPrefix() method to
ArchiveCommand to support this.

Change-Id: I16b2832ef98c30977f6b77b646728b83d93c196f
Signed-off-by: Jonathan Nieder <jrn@google.com>

org.eclipse.jgit.pgm.test/tst/org/eclipse/jgit/pgm/ArchiveTest.java

@@ -338,6 +338,99 @@ public void testTarWithSubdir() throws Exception {
 		assertArrayEquals(expect, actual);
 	}
 
+	private void commitBazAndFooSlashBar() throws Exception {
+		writeTrashFile("baz", "a file");
+		writeTrashFile("foo/bar", "another file");
+		git.add().addFilepattern("baz").call();
+		git.add().addFilepattern("foo").call();
+		git.commit().setMessage("sample commit").call();
+	}
+
+	@Test
+	public void testArchivePrefixOption() throws Exception {
+		commitBazAndFooSlashBar();
+		byte[] result = CLIGitCommand.rawExecute(
+				"git archive --prefix=x/ --format=zip master", db);
+		String[] expect = { "x/baz", "x/foo/bar" };
+		String[] actual = listZipEntries(result);
+
+		Arrays.sort(expect);
+		Arrays.sort(actual);
+		assertArrayEquals(expect, actual);
+	}
+
+	@Test
+	public void testTarPrefixOption() throws Exception {
+		commitBazAndFooSlashBar();
+		byte[] result = CLIGitCommand.rawExecute(
+				"git archive --prefix=x/ --format=tar master", db);
+		String[] expect = { "x/baz", "x/foo/bar" };
+		String[] actual = listTarEntries(result);
+
+		Arrays.sort(expect);
+		Arrays.sort(actual);
+		assertArrayEquals(expect, actual);
+	}
+
+	private void commitFoo() throws Exception {
+		writeTrashFile("foo", "a file");
+		git.add().addFilepattern("foo").call();
+		git.commit().setMessage("boring commit").call();
+	}
+
+	@Test
+	public void testPrefixDoesNotNormalizeDoubleSlash() throws Exception {
+		commitFoo();
+		byte[] result = CLIGitCommand.rawExecute(
+				"git archive --prefix=x// --format=zip master", db);
+		String[] expect = { "x//foo" };
+		assertArrayEquals(expect, listZipEntries(result));
+	}
+
+	@Test
+	public void testPrefixDoesNotNormalizeDoubleSlashInTar() throws Exception {
+		commitFoo();
+		final byte[] result = CLIGitCommand.rawExecute( //
+				"git archive --prefix=x// --format=tar master", db);
+		String[] expect = { "x//foo" };
+		assertArrayEquals(expect, listTarEntries(result));
+	}
+
+	/**
+	 * The prefix passed to "git archive" need not end with '/'.
+	 * In practice it is not very common to have a nonempty prefix
+	 * that does not name a directory (and hence end with /), but
+	 * since git has historically supported other prefixes, we do,
+	 * too.
+	 *
+	 * @throws Exception
+	 */
+	@Test
+	public void testPrefixWithoutTrailingSlash() throws Exception {
+		commitBazAndFooSlashBar();
+		byte[] result = CLIGitCommand.rawExecute(
+				"git archive --prefix=my- --format=zip master", db);
+		String[] expect = { "my-baz", "my-foo/bar" };
+		String[] actual = listZipEntries(result);
+
+		Arrays.sort(expect);
+		Arrays.sort(actual);
+		assertArrayEquals(expect, actual);
+	}
+
+	@Test
+	public void testTarPrefixWithoutTrailingSlash() throws Exception {
+		commitBazAndFooSlashBar();
+		final byte[] result = CLIGitCommand.rawExecute( //
+				"git archive --prefix=my- --format=tar master", db);
+		String[] expect = { "my-baz", "my-foo/bar" };
+		String[] actual = listTarEntries(result);
+
+		Arrays.sort(expect);
+		Arrays.sort(actual);
+		assertArrayEquals(expect, actual);
+	}
+
 	@Test
 	public void testArchivePreservesMode() throws Exception {
 		writeTrashFile("plain", "a file with content");

org.eclipse.jgit.pgm/resources/org/eclipse/jgit/pgm/internal/CLIText.properties

@@ -74,6 +74,7 @@ mergeWentWellStoppedBeforeCommitting=Automatic merge went well; stopped before c
 metaVar_DAG=DAG
 metaVar_KEY=KEY
 metaVar_archiveFormat=format
+metaVar_archivePrefix=prefix/
 metaVar_arg=ARG
 metaVar_author=AUTHOR
 metaVar_base=base
@@ -229,6 +230,7 @@ usage_approveDestructionOfRepository=approve destruction of repository
 usage_archive=zip up files from the named tree
 usage_archiveFormat=archive format. Currently supported formats: 'tar', 'zip', 'tgz', 'tbz2', 'txz'
 usage_archiveOutput=output file to write the archive to
+usage_archivePrefix=string to prepend to each pathname in the archive
 usage_blameLongRevision=show long revision
 usage_blameRange=annotate only the given range
 usage_blameRawTimestamp=show raw timestamp

org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/Archive.java

@@ -69,6 +69,9 @@ class Archive extends TextBuiltin {
 	@Option(name = "--format", metaVar = "metaVar_archiveFormat", usage = "usage_archiveFormat")
 	private String format;
 
+	@Option(name = "--prefix", metaVar = "metaVar_archivePrefix", usage = "usage_archivePrefix")
+	private String prefix;
+
 	@Option(name = "--output", aliases = { "-o" }, metaVar = "metaVar_file", usage = "usage_archiveOutput")
 	private String output;
 
@@ -88,6 +91,7 @@ protected void run() throws Exception {
 				ArchiveCommand cmd = new Git(db).archive()
 					.setTree(tree)
 					.setFormat(format)
+					.setPrefix(prefix)
 					.setOutputStream(stream);
 				if (output != null)
 					cmd.setFilename(output);

org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/internal/CLIText.java

@@ -143,6 +143,7 @@ public static String formatLine(String line) {
 	/***/ public String mergeWentWellStoppedBeforeCommitting;
 	/***/ public String metaVar_KEY;
 	/***/ public String metaVar_archiveFormat;
+	/***/ public String metaVar_archivePrefix;
 	/***/ public String metaVar_arg;
 	/***/ public String metaVar_author;
 	/***/ public String metaVar_bucket;

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

@@ -250,6 +250,7 @@ private static Format<?> lookupFormat(String formatName) throws UnsupportedForma
 
 	private OutputStream out;
 	private ObjectId tree;
+	private String prefix;
 	private String format;
 
 	/** Filename suffix, for automatically choosing a format. */
@@ -264,6 +265,7 @@ public ArchiveCommand(Repository repo) {
 	}
 
 	private <T extends Closeable> OutputStream writeArchive(Format<T> fmt) {
+		final String pfx = prefix == null ? "" : prefix;
 		final TreeWalk walk = new TreeWalk(repo);
 		try {
 			final T outa = fmt.createArchiveOutputStream(out);
@@ -275,7 +277,7 @@ private <T extends Closeable> OutputStream writeArchive(Format<T> fmt) {
 				walk.reset(rw.parseTree(tree));
 				walk.setRecursive(true);
 				while (walk.next()) {
-					final String name = walk.getPathString();
+					final String name = pfx + walk.getPathString();
 					final FileMode mode = walk.getFileMode(0);
 
 					if (mode == FileMode.TREE)
@@ -329,6 +331,18 @@ public ArchiveCommand setTree(ObjectId tree) {
 		return this;
 	}
 
+	/**
+	 * @param prefix
+	 *            string prefixed to filenames in archive (e.g., "master/").
+	 *            null means to not use any leading prefix.
+	 * @return this
+	 * @since 3.3
+	 */
+	public ArchiveCommand setPrefix(String prefix) {
+		this.prefix = prefix;
+		return this;
+	}
+
 	/**
 	 * Set the intended filename for the produced archive. Currently the only
 	 * effect is to determine the default archive format when none is specified