/*
    * Copyright (C) 2008-2010, Google Inc.
    * Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org>
    * and other copyright owners as documented in the project's IP log.
    *
    * This program and the accompanying materials are made available
    * under the terms of the Eclipse Distribution License v1.0 which
    * accompanies this distribution, is reproduced below, and is
    * available at http://www.eclipse.org/org/documents/edl-v10.php
   *
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or
   * without modification, are permitted provided that the following
   * conditions are met:
   *
   * - Redistributions of source code must retain the above copyright
   *   notice, this list of conditions and the following disclaimer.
   *
   * - Redistributions in binary form must reproduce the above
   *   copyright notice, this list of conditions and the following
   *   disclaimer in the documentation and/or other materials provided
   *   with the distribution.
   *
   * - Neither the name of the Eclipse Foundation, Inc. nor the
   *   names of its contributors may be used to endorse or promote
   *   products derived from this software without specific prior
   *   written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
   * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
   * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
   * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
   * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
   * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  package org.eclipse.jgit.lib;
  
  import static java.lang.Integer.valueOf;
  import static java.lang.Long.valueOf;
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.fail;
  
  import java.io.UnsupportedEncodingException;
  import java.text.MessageFormat;
  
  import org.eclipse.jgit.errors.CorruptObjectException;
  import org.eclipse.jgit.internal.JGitText;
  import org.junit.Before;
  import org.junit.Test;
  
  public class ObjectCheckerTest {
  	private ObjectChecker checker;
  
  	@Before
  	public void setUp() throws Exception {
  		checker = new ObjectChecker();
  	}
  
  	@Test
  	public void testInvalidType() {
  		try {
  			checker.check(Constants.OBJ_BAD, new byte[0]);
  			fail("Did not throw CorruptObjectException");
  		} catch (CorruptObjectException e) {
  			final String m = e.getMessage();
  			assertEquals(MessageFormat.format(
  					JGitText.get().corruptObjectInvalidType2,
  					valueOf(Constants.OBJ_BAD)), m);
  		}
  	}
  
  	@Test
  	public void testCheckBlob() throws CorruptObjectException {
  		// Any blob should pass...
  		checker.checkBlob(new byte[0]);
  		checker.checkBlob(new byte[1]);
  
  		checker.check(Constants.OBJ_BLOB, new byte[0]);
  		checker.check(Constants.OBJ_BLOB, new byte[1]);
  	}
  
  	@Test
  	public void testValidCommitNoParent() throws CorruptObjectException {
  		final StringBuilder b = new StringBuilder();
  
  		b.append("tree ");
  		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
  		b.append('\n');
  
  		b.append("author A. U. Thor <author@localhost> 1 +0000\n");
 		b.append("committer A. U. Thor <author@localhost> 1 +0000\n");
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		checker.checkCommit(data);
 		checker.check(Constants.OBJ_COMMIT, data);
 	}
 
 	@Test
 	public void testValidCommitBlankAuthor() throws CorruptObjectException {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("tree ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		b.append("author <> 0 +0000\n");
 		b.append("committer <> 0 +0000\n");
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		checker.checkCommit(data);
 		checker.check(Constants.OBJ_COMMIT, data);
 	}
 
 	@Test
 	public void testCommitCorruptAuthor() throws CorruptObjectException {
 		StringBuilder b = new StringBuilder();
 		b.append("tree be9bfa841874ccc9f2ef7c48d0c76226f89b7189\n");
 		b.append("author b <b@c> <b@c> 0 +0000\n");
 		b.append("committer <> 0 +0000\n");
 
 		byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkCommit(data);
 			fail("Did not catch corrupt object");
 		} catch (CorruptObjectException e) {
 			assertEquals("invalid author", e.getMessage());
 		}
 		checker.setAllowInvalidPersonIdent(true);
 		checker.checkCommit(data);
 	}
 
 	@Test
 	public void testCommitCorruptCommitter() throws CorruptObjectException {
 		StringBuilder b = new StringBuilder();
 		b.append("tree be9bfa841874ccc9f2ef7c48d0c76226f89b7189\n");
 		b.append("author <> 0 +0000\n");
 		b.append("committer b <b@c> <b@c> 0 +0000\n");
 
 		byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkCommit(data);
 			fail("Did not catch corrupt object");
 		} catch (CorruptObjectException e) {
 			assertEquals("invalid committer", e.getMessage());
 		}
 		checker.setAllowInvalidPersonIdent(true);
 		checker.checkCommit(data);
 	}
 
 	@Test
 	public void testValidCommit1Parent() throws CorruptObjectException {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("tree ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		b.append("parent ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		b.append("author A. U. Thor <author@localhost> 1 +0000\n");
 		b.append("committer A. U. Thor <author@localhost> 1 +0000\n");
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		checker.checkCommit(data);
 		checker.check(Constants.OBJ_COMMIT, data);
 	}
 
 	@Test
 	public void testValidCommit2Parent() throws CorruptObjectException {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("tree ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		b.append("parent ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		b.append("parent ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		b.append("author A. U. Thor <author@localhost> 1 +0000\n");
 		b.append("committer A. U. Thor <author@localhost> 1 +0000\n");
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		checker.checkCommit(data);
 		checker.check(Constants.OBJ_COMMIT, data);
 	}
 
 	@Test
 	public void testValidCommit128Parent() throws CorruptObjectException {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("tree ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		for (int i = 0; i < 128; i++) {
 			b.append("parent ");
 			b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 			b.append('\n');
 		}
 
 		b.append("author A. U. Thor <author@localhost> 1 +0000\n");
 		b.append("committer A. U. Thor <author@localhost> 1 +0000\n");
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		checker.checkCommit(data);
 		checker.check(Constants.OBJ_COMMIT, data);
 	}
 
 	@Test
 	public void testValidCommitNormalTime() throws CorruptObjectException {
 		final StringBuilder b = new StringBuilder();
 		final String when = "1222757360 -0730";
 
 		b.append("tree ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		b.append("author A. U. Thor <author@localhost> " + when + "\n");
 		b.append("committer A. U. Thor <author@localhost> " + when + "\n");
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		checker.checkCommit(data);
 		checker.check(Constants.OBJ_COMMIT, data);
 	}
 
 	@Test
 	public void testInvalidCommitNoTree1() {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("parent ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkCommit(data);
 			fail("Did not catch corrupt object");
 		} catch (CorruptObjectException e) {
 			assertEquals("no tree header", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidCommitNoTree2() {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("trie ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkCommit(data);
 			fail("Did not catch corrupt object");
 		} catch (CorruptObjectException e) {
 			assertEquals("no tree header", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidCommitNoTree3() {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("tree");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkCommit(data);
 			fail("Did not catch corrupt object");
 		} catch (CorruptObjectException e) {
 			assertEquals("no tree header", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidCommitNoTree4() {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("tree\t");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkCommit(data);
 			fail("Did not catch corrupt object");
 		} catch (CorruptObjectException e) {
 			assertEquals("no tree header", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidCommitInvalidTree1() {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("tree ");
 		b.append("zzzzfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkCommit(data);
 			fail("Did not catch corrupt object");
 		} catch (CorruptObjectException e) {
 			assertEquals("invalid tree", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidCommitInvalidTree2() {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("tree ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append("z\n");
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkCommit(data);
 			fail("Did not catch corrupt object");
 		} catch (CorruptObjectException e) {
 			assertEquals("invalid tree", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidCommitInvalidTree3() {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("tree ");
 		b.append("be9b");
 		b.append("\n");
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkCommit(data);
 			fail("Did not catch corrupt object");
 		} catch (CorruptObjectException e) {
 			assertEquals("invalid tree", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidCommitInvalidTree4() {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("tree  ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkCommit(data);
 			fail("Did not catch corrupt object");
 		} catch (CorruptObjectException e) {
 			assertEquals("invalid tree", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidCommitInvalidParent1() {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("tree ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		b.append("parent ");
 		b.append("\n");
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkCommit(data);
 			fail("Did not catch corrupt object");
 		} catch (CorruptObjectException e) {
 			assertEquals("invalid parent", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidCommitInvalidParent2() {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("tree ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		b.append("parent ");
 		b.append("zzzzfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append("\n");
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkCommit(data);
 			fail("Did not catch corrupt object");
 		} catch (CorruptObjectException e) {
 			assertEquals("invalid parent", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidCommitInvalidParent3() {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("tree ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		b.append("parent  ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append("\n");
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkCommit(data);
 			fail("Did not catch corrupt object");
 		} catch (CorruptObjectException e) {
 			assertEquals("invalid parent", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidCommitInvalidParent4() {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("tree ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		b.append("parent  ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append("z\n");
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkCommit(data);
 			fail("Did not catch corrupt object");
 		} catch (CorruptObjectException e) {
 			assertEquals("invalid parent", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidCommitInvalidParent5() {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("tree ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		b.append("parent\t");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append("\n");
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkCommit(data);
 			fail("Did not catch corrupt object");
 		} catch (CorruptObjectException e) {
 			// Yes, really, we complain about author not being
 			// found as the invalid parent line wasn't consumed.
 			assertEquals("no author", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidCommitNoAuthor() {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("tree ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		b.append("committer A. U. Thor <author@localhost> 1 +0000\n");
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkCommit(data);
 			fail("Did not catch corrupt object");
 		} catch (CorruptObjectException e) {
 			// Yes, really, we complain about author not being
 			// found as the invalid parent line wasn't consumed.
 			assertEquals("no author", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidCommitNoCommitter1() {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("tree ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		b.append("author A. U. Thor <author@localhost> 1 +0000\n");
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkCommit(data);
 			fail("Did not catch corrupt object");
 		} catch (CorruptObjectException e) {
 			// Yes, really, we complain about author not being
 			// found as the invalid parent line wasn't consumed.
 			assertEquals("no committer", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidCommitNoCommitter2() {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("tree ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		b.append("author A. U. Thor <author@localhost> 1 +0000\n");
 		b.append("\n");
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkCommit(data);
 			fail("Did not catch corrupt object");
 		} catch (CorruptObjectException e) {
 			// Yes, really, we complain about author not being
 			// found as the invalid parent line wasn't consumed.
 			assertEquals("no committer", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidCommitInvalidAuthor1() {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("tree ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		b.append("author A. U. Thor <foo 1 +0000\n");
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkCommit(data);
 			fail("Did not catch corrupt object");
 		} catch (CorruptObjectException e) {
 			// Yes, really, we complain about author not being
 			// found as the invalid parent line wasn't consumed.
 			assertEquals("invalid author", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidCommitInvalidAuthor2() {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("tree ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		b.append("author A. U. Thor foo> 1 +0000\n");
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkCommit(data);
 			fail("Did not catch corrupt object");
 		} catch (CorruptObjectException e) {
 			// Yes, really, we complain about author not being
 			// found as the invalid parent line wasn't consumed.
 			assertEquals("invalid author", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidCommitInvalidAuthor3() {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("tree ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		b.append("author 1 +0000\n");
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkCommit(data);
 			fail("Did not catch corrupt object");
 		} catch (CorruptObjectException e) {
 			// Yes, really, we complain about author not being
 			// found as the invalid parent line wasn't consumed.
 			assertEquals("invalid author", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidCommitInvalidAuthor4() {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("tree ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		b.append("author a <b> +0000\n");
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkCommit(data);
 			fail("Did not catch corrupt object");
 		} catch (CorruptObjectException e) {
 			// Yes, really, we complain about author not being
 			// found as the invalid parent line wasn't consumed.
 			assertEquals("invalid author", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidCommitInvalidAuthor5() {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("tree ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		b.append("author a <b>\n");
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkCommit(data);
 			fail("Did not catch corrupt object");
 		} catch (CorruptObjectException e) {
 			// Yes, really, we complain about author not being
 			// found as the invalid parent line wasn't consumed.
 			assertEquals("invalid author", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidCommitInvalidAuthor6() {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("tree ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		b.append("author a <b> z");
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkCommit(data);
 			fail("Did not catch corrupt object");
 		} catch (CorruptObjectException e) {
 			// Yes, really, we complain about author not being
 			// found as the invalid parent line wasn't consumed.
 			assertEquals("invalid author", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidCommitInvalidAuthor7() {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("tree ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		b.append("author a <b> 1 z");
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkCommit(data);
 			fail("Did not catch corrupt object");
 		} catch (CorruptObjectException e) {
 			// Yes, really, we complain about author not being
 			// found as the invalid parent line wasn't consumed.
 			assertEquals("invalid author", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidCommitInvalidCommitter() {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("tree ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		b.append("author a <b> 1 +0000\n");
 		b.append("committer a <");
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkCommit(data);
 			fail("Did not catch corrupt object");
 		} catch (CorruptObjectException e) {
 			// Yes, really, we complain about author not being
 			// found as the invalid parent line wasn't consumed.
 			assertEquals("invalid committer", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testValidTag() throws CorruptObjectException {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("object ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		b.append("type commit\n");
 		b.append("tag test-tag\n");
 		b.append("tagger A. U. Thor <author@localhost> 1 +0000\n");
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		checker.checkTag(data);
 		checker.check(Constants.OBJ_TAG, data);
 	}
 
 	@Test
 	public void testInvalidTagNoObject1() {
 		final StringBuilder b = new StringBuilder();
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTag(data);
 			fail("incorrectly accepted invalid tag");
 		} catch (CorruptObjectException e) {
 			assertEquals("no object header", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTagNoObject2() {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("object\t");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTag(data);
 			fail("incorrectly accepted invalid tag");
 		} catch (CorruptObjectException e) {
 			assertEquals("no object header", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTagNoObject3() {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("obejct ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTag(data);
 			fail("incorrectly accepted invalid tag");
 		} catch (CorruptObjectException e) {
 			assertEquals("no object header", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTagNoObject4() {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("object ");
 		b.append("zz9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTag(data);
 			fail("incorrectly accepted invalid tag");
 		} catch (CorruptObjectException e) {
 			assertEquals("invalid object", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTagNoObject5() {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("object ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append(" \n");
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTag(data);
 			fail("incorrectly accepted invalid tag");
 		} catch (CorruptObjectException e) {
 			assertEquals("invalid object", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTagNoObject6() {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("object ");
 		b.append("be9");
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTag(data);
 			fail("incorrectly accepted invalid tag");
 		} catch (CorruptObjectException e) {
 			assertEquals("invalid object", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTagNoType1() {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("object ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTag(data);
 			fail("incorrectly accepted invalid tag");
 		} catch (CorruptObjectException e) {
 			assertEquals("no type header", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTagNoType2() {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("object ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		b.append("type\tcommit\n");
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTag(data);
 			fail("incorrectly accepted invalid tag");
 		} catch (CorruptObjectException e) {
 			assertEquals("no type header", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTagNoType3() {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("object ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		b.append("tpye commit\n");
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTag(data);
 			fail("incorrectly accepted invalid tag");
 		} catch (CorruptObjectException e) {
 			assertEquals("no type header", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTagNoType4() {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("object ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		b.append("type commit");
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTag(data);
 			fail("incorrectly accepted invalid tag");
 		} catch (CorruptObjectException e) {
 			assertEquals("no tag header", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTagNoTagHeader1() {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("object ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		b.append("type commit\n");
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTag(data);
 			fail("incorrectly accepted invalid tag");
 		} catch (CorruptObjectException e) {
 			assertEquals("no tag header", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTagNoTagHeader2() {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("object ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		b.append("type commit\n");
 		b.append("tag\tfoo\n");
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTag(data);
 			fail("incorrectly accepted invalid tag");
 		} catch (CorruptObjectException e) {
 			assertEquals("no tag header", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTagNoTagHeader3() {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("object ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		b.append("type commit\n");
 		b.append("tga foo\n");
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTag(data);
 			fail("incorrectly accepted invalid tag");
 		} catch (CorruptObjectException e) {
 			assertEquals("no tag header", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testValidTagHasNoTaggerHeader() throws CorruptObjectException {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("object ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		b.append("type commit\n");
 		b.append("tag foo\n");
 
 		checker.checkTag(Constants.encodeASCII(b.toString()));
 	}
 
 	@Test
 	public void testInvalidTagInvalidTaggerHeader1()
 			throws CorruptObjectException {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("object ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		b.append("type commit\n");
 		b.append("tag foo\n");
 		b.append("tagger \n");
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTag(data);
 			fail("incorrectly accepted invalid tag");
 		} catch (CorruptObjectException e) {
 			assertEquals("invalid tagger", e.getMessage());
 		}
 		checker.setAllowInvalidPersonIdent(true);
 		checker.checkTag(data);
 	}
 
 	@Test
 	public void testInvalidTagInvalidTaggerHeader3() {
 		final StringBuilder b = new StringBuilder();
 
 		b.append("object ");
 		b.append("be9bfa841874ccc9f2ef7c48d0c76226f89b7189");
 		b.append('\n');
 
 		b.append("type commit\n");
 		b.append("tag foo\n");
 		b.append("tagger a < 1 +000\n");
 
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTag(data);
 			fail("incorrectly accepted invalid tag");
 		} catch (CorruptObjectException e) {
 			assertEquals("invalid tagger", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testValidEmptyTree() throws CorruptObjectException {
 		checker.checkTree(new byte[0]);
 		checker.check(Constants.OBJ_TREE, new byte[0]);
 	}
 
 	@Test
 	public void testValidTree1() throws CorruptObjectException {
 		final StringBuilder b = new StringBuilder();
 		entry(b, "100644 regular-file");
 		final byte[] data = Constants.encodeASCII(b.toString());
 		checker.checkTree(data);
 	}
 
 	@Test
 	public void testValidTree2() throws CorruptObjectException {
 		final StringBuilder b = new StringBuilder();
 		entry(b, "100755 executable");
 		final byte[] data = Constants.encodeASCII(b.toString());
 		checker.checkTree(data);
 	}
 
 	@Test
 	public void testValidTree3() throws CorruptObjectException {
 		final StringBuilder b = new StringBuilder();
 		entry(b, "40000 tree");
 		final byte[] data = Constants.encodeASCII(b.toString());
 		checker.checkTree(data);
 	}
 
 	@Test
 	public void testValidTree4() throws CorruptObjectException {
 		final StringBuilder b = new StringBuilder();
 		entry(b, "120000 symlink");
 		final byte[] data = Constants.encodeASCII(b.toString());
 		checker.checkTree(data);
 	}
 
 	@Test
 	public void testValidTree5() throws CorruptObjectException {
 		final StringBuilder b = new StringBuilder();
 		entry(b, "160000 git link");
 		final byte[] data = Constants.encodeASCII(b.toString());
 		checker.checkTree(data);
 	}
 
 	@Test
 	public void testValidTree6() throws CorruptObjectException {
 		final StringBuilder b = new StringBuilder();
 		entry(b, "100644 .a");
 		final byte[] data = Constants.encodeASCII(b.toString());
 		checker.checkTree(data);
 	}
 
 	@Test
 	public void testValidPosixTree() throws CorruptObjectException {
 		checkOneName("a<b>c:d|e");
 		checkOneName("test ");
 		checkOneName("test.");
 		checkOneName("NUL");
 	}
 
 	@Test
 	public void testValidTreeSorting1() throws CorruptObjectException {
 		final StringBuilder b = new StringBuilder();
 		entry(b, "100644 fooaaa");
 		entry(b, "100755 foobar");
 		final byte[] data = Constants.encodeASCII(b.toString());
 		checker.checkTree(data);
 	}
 
 	@Test
 	public void testValidTreeSorting2() throws CorruptObjectException {
 		final StringBuilder b = new StringBuilder();
 		entry(b, "100755 fooaaa");
 		entry(b, "100644 foobar");
 		final byte[] data = Constants.encodeASCII(b.toString());
 		checker.checkTree(data);
 	}
 
 	@Test
 	public void testValidTreeSorting3() throws CorruptObjectException {
 		final StringBuilder b = new StringBuilder();
 		entry(b, "40000 a");
 		entry(b, "100644 b");
 		final byte[] data = Constants.encodeASCII(b.toString());
 		checker.checkTree(data);
 	}
 
 	@Test
 	public void testValidTreeSorting4() throws CorruptObjectException {
 		final StringBuilder b = new StringBuilder();
 		entry(b, "100644 a");
 		entry(b, "40000 b");
 		final byte[] data = Constants.encodeASCII(b.toString());
 		checker.checkTree(data);
 	}
 
 	@Test
 	public void testValidTreeSorting5() throws CorruptObjectException {
 		final StringBuilder b = new StringBuilder();
 		entry(b, "100644 a.c");
 		entry(b, "40000 a");
 		entry(b, "100644 a0c");
 		final byte[] data = Constants.encodeASCII(b.toString());
 		checker.checkTree(data);
 	}
 
 	@Test
 	public void testValidTreeSorting6() throws CorruptObjectException {
 		final StringBuilder b = new StringBuilder();
 		entry(b, "40000 a");
 		entry(b, "100644 apple");
 		final byte[] data = Constants.encodeASCII(b.toString());
 		checker.checkTree(data);
 	}
 
 	@Test
 	public void testValidTreeSorting7() throws CorruptObjectException {
 		final StringBuilder b = new StringBuilder();
 		entry(b, "40000 an orang");
 		entry(b, "40000 an orange");
 		final byte[] data = Constants.encodeASCII(b.toString());
 		checker.checkTree(data);
 	}
 
 	@Test
 	public void testValidTreeSorting8() throws CorruptObjectException {
 		final StringBuilder b = new StringBuilder();
 		entry(b, "100644 a");
 		entry(b, "100644 a0c");
 		entry(b, "100644 b");
 		final byte[] data = Constants.encodeASCII(b.toString());
 		checker.checkTree(data);
 	}
 
 	@Test
 	public void testAcceptTreeModeWithZero() throws CorruptObjectException {
 		StringBuilder b = new StringBuilder();
 		entry(b, "040000 a");
 		checker.setAllowLeadingZeroFileMode(true);
 		checker.checkTree(Constants.encodeASCII(b.toString()));
 	}
 
 	@Test
 	public void testInvalidTreeModeStartsWithZero1() {
 		final StringBuilder b = new StringBuilder();
 		entry(b, "0 a");
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTree(data);
 			fail("incorrectly accepted an invalid tree");
 		} catch (CorruptObjectException e) {
 			assertEquals("mode starts with '0'", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTreeModeStartsWithZero2() {
 		final StringBuilder b = new StringBuilder();
 		entry(b, "0100644 a");
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTree(data);
 			fail("incorrectly accepted an invalid tree");
 		} catch (CorruptObjectException e) {
 			assertEquals("mode starts with '0'", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTreeModeStartsWithZero3() {
 		final StringBuilder b = new StringBuilder();
 		entry(b, "040000 a");
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTree(data);
 			fail("incorrectly accepted an invalid tree");
 		} catch (CorruptObjectException e) {
 			assertEquals("mode starts with '0'", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTreeModeNotOctal1() {
 		final StringBuilder b = new StringBuilder();
 		entry(b, "8 a");
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTree(data);
 			fail("incorrectly accepted an invalid tree");
 		} catch (CorruptObjectException e) {
 			assertEquals("invalid mode character", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTreeModeNotOctal2() {
 		final StringBuilder b = new StringBuilder();
 		entry(b, "Z a");
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTree(data);
 			fail("incorrectly accepted an invalid tree");
 		} catch (CorruptObjectException e) {
 			assertEquals("invalid mode character", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTreeModeNotSupportedMode1() {
 		final StringBuilder b = new StringBuilder();
 		entry(b, "1 a");
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTree(data);
 			fail("incorrectly accepted an invalid tree");
 		} catch (CorruptObjectException e) {
 			assertEquals("invalid mode 1", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTreeModeNotSupportedMode2() {
 		final StringBuilder b = new StringBuilder();
 		entry(b, "170000 a");
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTree(data);
 			fail("incorrectly accepted an invalid tree");
 		} catch (CorruptObjectException e) {
 			assertEquals("invalid mode " + 0170000, e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTreeModeMissingName() {
 		final StringBuilder b = new StringBuilder();
 		b.append("100644");
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTree(data);
 			fail("incorrectly accepted an invalid tree");
 		} catch (CorruptObjectException e) {
 			assertEquals("truncated in mode", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTreeNameContainsSlash() {
 		final StringBuilder b = new StringBuilder();
 		entry(b, "100644 a/b");
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTree(data);
 			fail("incorrectly accepted an invalid tree");
 		} catch (CorruptObjectException e) {
 			assertEquals("name contains '/'", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTreeNameIsEmpty() {
 		final StringBuilder b = new StringBuilder();
 		entry(b, "100644 ");
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTree(data);
 			fail("incorrectly accepted an invalid tree");
 		} catch (CorruptObjectException e) {
 			assertEquals("zero length name", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTreeNameIsDot() {
 		final StringBuilder b = new StringBuilder();
 		entry(b, "100644 .");
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTree(data);
 			fail("incorrectly accepted an invalid tree");
 		} catch (CorruptObjectException e) {
 			assertEquals("invalid name '.'", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTreeNameIsDotDot() {
 		final StringBuilder b = new StringBuilder();
 		entry(b, "100644 ..");
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTree(data);
 			fail("incorrectly accepted an invalid tree");
 		} catch (CorruptObjectException e) {
 			assertEquals("invalid name '..'", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTreeNameIsGit() {
 		StringBuilder b = new StringBuilder();
 		entry(b, "100644 .git");
 		byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTree(data);
 			fail("incorrectly accepted an invalid tree");
 		} catch (CorruptObjectException e) {
 			assertEquals("invalid name '.git'", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTreeNameIsMixedCaseGit() {
 		StringBuilder b = new StringBuilder();
 		entry(b, "100644 .GiT");
 		byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTree(data);
 			fail("incorrectly accepted an invalid tree");
 		} catch (CorruptObjectException e) {
 			assertEquals("invalid name '.GiT'", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTreeNameIsMacHFSGit() {
 		StringBuilder b = new StringBuilder();
 		entry(b, "100644 .gi\u200Ct");
 		byte[] data = Constants.encode(b.toString());
 		try {
 			checker.setSafeForMacOS(true);
 			checker.checkTree(data);
 			fail("incorrectly accepted an invalid tree");
 		} catch (CorruptObjectException e) {
 			assertEquals(
 					"invalid name '.gi\u200Ct' contains ignorable Unicode characters",
 					e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTreeNameIsMacHFSGit2() {
 		StringBuilder b = new StringBuilder();
 		entry(b, "100644 \u206B.git");
 		byte[] data = Constants.encode(b.toString());
 		try {
 			checker.setSafeForMacOS(true);
 			checker.checkTree(data);
 			fail("incorrectly accepted an invalid tree");
 		} catch (CorruptObjectException e) {
 			assertEquals(
 					"invalid name '\u206B.git' contains ignorable Unicode characters",
 					e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTreeNameIsMacHFSGit3() {
 		StringBuilder b = new StringBuilder();
 		entry(b, "100644 .git\uFEFF");
 		byte[] data = Constants.encode(b.toString());
 		try {
 			checker.setSafeForMacOS(true);
 			checker.checkTree(data);
 			fail("incorrectly accepted an invalid tree");
 		} catch (CorruptObjectException e) {
 			assertEquals(
 					"invalid name '.git\uFEFF' contains ignorable Unicode characters",
 					e.getMessage());
 		}
 	}
 
 	private static byte[] concat(byte[] b1, byte[] b2) {
 		byte[] data = new byte[b1.length + b2.length];
 		System.arraycopy(b1, 0, data, 0, b1.length);
 		System.arraycopy(b2, 0, data, b1.length, b2.length);
 		return data;
 	}
 
 	@Test
 	public void testInvalidTreeNameIsMacHFSGitCorruptUTF8AtEnd() {
 		byte[] data = concat(Constants.encode("100644 .git"),
 				new byte[] { (byte) 0xef });
 		StringBuilder b = new StringBuilder();
 		entry(b, "");
 		data = concat(data, Constants.encode(b.toString()));
 		try {
 			checker.setSafeForMacOS(true);
 			checker.checkTree(data);
 			fail("incorrectly accepted an invalid tree");
 		} catch (CorruptObjectException e) {
 			assertEquals(
 					"invalid name contains byte sequence '0xef' which is not a valid UTF-8 character",
 					e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTreeNameIsMacHFSGitCorruptUTF8AtEnd2() {
 		byte[] data = concat(Constants.encode("100644 .git"), new byte[] {
 				(byte) 0xe2, (byte) 0xab });
 		StringBuilder b = new StringBuilder();
 		entry(b, "");
 		data = concat(data, Constants.encode(b.toString()));
 		try {
 			checker.setSafeForMacOS(true);
 			checker.checkTree(data);
 			fail("incorrectly accepted an invalid tree");
 		} catch (CorruptObjectException e) {
 			assertEquals(
 					"invalid name contains byte sequence '0xe2ab' which is not a valid UTF-8 character",
 					e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTreeNameIsNotMacHFSGit()
 			throws CorruptObjectException {
 		StringBuilder b = new StringBuilder();
 		entry(b, "100644 .git\u200Cx");
 		byte[] data = Constants.encode(b.toString());
 		checker.setSafeForMacOS(true);
 		checker.checkTree(data);
 	}
 
 	@Test
 	public void testInvalidTreeNameIsNotMacHFSGit2()
 			throws CorruptObjectException {
 		StringBuilder b = new StringBuilder();
 		entry(b, "100644 .kit\u200C");
 		byte[] data = Constants.encode(b.toString());
 		checker.setSafeForMacOS(true);
 		checker.checkTree(data);
 	}
 
 	@Test
 	public void testInvalidTreeNameIsNotMacHFSGitOtherPlatform()
 			throws CorruptObjectException {
 		StringBuilder b = new StringBuilder();
 		entry(b, "100644 .git\u200C");
 		byte[] data = Constants.encode(b.toString());
 		checker.checkTree(data);
 	}
 
 	@Test
 	public void testInvalidTreeNameIsDotGitDot() {
 		StringBuilder b = new StringBuilder();
 		entry(b, "100644 .git.");
 		byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTree(data);
 			fail("incorrectly accepted an invalid tree");
 		} catch (CorruptObjectException e) {
 			assertEquals("invalid name '.git.'", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testValidTreeNameIsDotGitDotDot()
 			throws CorruptObjectException {
 		StringBuilder b = new StringBuilder();
 		entry(b, "100644 .git..");
 		checker.checkTree(Constants.encodeASCII(b.toString()));
 	}
 
 	@Test
 	public void testInvalidTreeNameIsDotGitSpace() {
 		StringBuilder b = new StringBuilder();
 		entry(b, "100644 .git ");
 		byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTree(data);
 			fail("incorrectly accepted an invalid tree");
 		} catch (CorruptObjectException e) {
 			assertEquals("invalid name '.git '", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTreeNameIsDotGitSomething()
 			throws CorruptObjectException {
 		StringBuilder b = new StringBuilder();
 		entry(b, "100644 .gitfoobar");
 		byte[] data = Constants.encodeASCII(b.toString());
 		checker.checkTree(data);
 	}
 
 	@Test
 	public void testInvalidTreeNameIsDotGitSomethingSpaceSomething()
 			throws CorruptObjectException {
 		StringBuilder b = new StringBuilder();
 		entry(b, "100644 .gitfoo bar");
 		byte[] data = Constants.encodeASCII(b.toString());
 		checker.checkTree(data);
 	}
 
 	@Test
 	public void testInvalidTreeNameIsDotGitSomethingDot()
 			throws CorruptObjectException {
 		StringBuilder b = new StringBuilder();
 		entry(b, "100644 .gitfoobar.");
 		byte[] data = Constants.encodeASCII(b.toString());
 		checker.checkTree(data);
 	}
 
 	@Test
 	public void testInvalidTreeNameIsDotGitSomethingDotDot()
 			throws CorruptObjectException {
 		StringBuilder b = new StringBuilder();
 		entry(b, "100644 .gitfoobar..");
 		byte[] data = Constants.encodeASCII(b.toString());
 		checker.checkTree(data);
 	}
 
 	@Test
 	public void testInvalidTreeNameIsDotGitDotSpace() {
 		StringBuilder b = new StringBuilder();
 		entry(b, "100644 .git. ");
 		byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTree(data);
 			fail("incorrectly accepted an invalid tree");
 		} catch (CorruptObjectException e) {
 			assertEquals("invalid name '.git. '", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTreeNameIsDotGitSpaceDot() {
 		StringBuilder b = new StringBuilder();
 		entry(b, "100644 .git . ");
 		byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTree(data);
 			fail("incorrectly accepted an invalid tree");
 		} catch (CorruptObjectException e) {
 			assertEquals("invalid name '.git . '", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTreeNameIsGITTilde1() {
 		StringBuilder b = new StringBuilder();
 		entry(b, "100644 GIT~1");
 		byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTree(data);
 			fail("incorrectly accepted an invalid tree");
 		} catch (CorruptObjectException e) {
 			assertEquals("invalid name 'GIT~1'", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTreeNameIsGiTTilde1() {
 		StringBuilder b = new StringBuilder();
 		entry(b, "100644 GiT~1");
 		byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTree(data);
 			fail("incorrectly accepted an invalid tree");
 		} catch (CorruptObjectException e) {
 			assertEquals("invalid name 'GiT~1'", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testValidTreeNameIsGitTilde11() throws CorruptObjectException {
 		StringBuilder b = new StringBuilder();
 		entry(b, "100644 GIT~11");
 		byte[] data = Constants.encodeASCII(b.toString());
 		checker.checkTree(data);
 	}
 
 	@Test
 	public void testInvalidTreeTruncatedInName() {
 		final StringBuilder b = new StringBuilder();
 		b.append("100644 b");
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTree(data);
 			fail("incorrectly accepted an invalid tree");
 		} catch (CorruptObjectException e) {
 			assertEquals("truncated in name", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTreeTruncatedInObjectId() {
 		final StringBuilder b = new StringBuilder();
 		b.append("100644 b\0\1\2");
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTree(data);
 			fail("incorrectly accepted an invalid tree");
 		} catch (CorruptObjectException e) {
 			assertEquals("truncated in object id", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTreeBadSorting1() {
 		final StringBuilder b = new StringBuilder();
 		entry(b, "100644 foobar");
 		entry(b, "100644 fooaaa");
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTree(data);
 			fail("incorrectly accepted an invalid tree");
 		} catch (CorruptObjectException e) {
 			assertEquals("incorrectly sorted", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTreeBadSorting2() {
 		final StringBuilder b = new StringBuilder();
 		entry(b, "40000 a");
 		entry(b, "100644 a.c");
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTree(data);
 			fail("incorrectly accepted an invalid tree");
 		} catch (CorruptObjectException e) {
 			assertEquals("incorrectly sorted", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTreeBadSorting3() {
 		final StringBuilder b = new StringBuilder();
 		entry(b, "100644 a0c");
 		entry(b, "40000 a");
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTree(data);
 			fail("incorrectly accepted an invalid tree");
 		} catch (CorruptObjectException e) {
 			assertEquals("incorrectly sorted", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTreeDuplicateNames1() {
 		final StringBuilder b = new StringBuilder();
 		entry(b, "100644 a");
 		entry(b, "100644 a");
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTree(data);
 			fail("incorrectly accepted an invalid tree");
 		} catch (CorruptObjectException e) {
 			assertEquals("duplicate entry names", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTreeDuplicateNames2() {
 		final StringBuilder b = new StringBuilder();
 		entry(b, "100644 a");
 		entry(b, "100755 a");
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTree(data);
 			fail("incorrectly accepted an invalid tree");
 		} catch (CorruptObjectException e) {
 			assertEquals("duplicate entry names", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTreeDuplicateNames3() {
 		final StringBuilder b = new StringBuilder();
 		entry(b, "100644 a");
 		entry(b, "40000 a");
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTree(data);
 			fail("incorrectly accepted an invalid tree");
 		} catch (CorruptObjectException e) {
 			assertEquals("duplicate entry names", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTreeDuplicateNames4() {
 		final StringBuilder b = new StringBuilder();
 		entry(b, "100644 a");
 		entry(b, "100644 a.c");
 		entry(b, "100644 a.d");
 		entry(b, "100644 a.e");
 		entry(b, "40000 a");
 		entry(b, "100644 zoo");
 		final byte[] data = Constants.encodeASCII(b.toString());
 		try {
 			checker.checkTree(data);
 			fail("incorrectly accepted an invalid tree");
 		} catch (CorruptObjectException e) {
 			assertEquals("duplicate entry names", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTreeDuplicateNames5()
 			throws UnsupportedEncodingException {
 		StringBuilder b = new StringBuilder();
 		entry(b, "100644 a");
 		entry(b, "100644 A");
 		byte[] data = b.toString().getBytes("UTF-8");
 		try {
 			checker.setSafeForWindows(true);
 			checker.checkTree(data);
 			fail("incorrectly accepted an invalid tree");
 		} catch (CorruptObjectException e) {
 			assertEquals("duplicate entry names", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTreeDuplicateNames6()
 			throws UnsupportedEncodingException {
 		StringBuilder b = new StringBuilder();
 		entry(b, "100644 a");
 		entry(b, "100644 A");
 		byte[] data = b.toString().getBytes("UTF-8");
 		try {
 			checker.setSafeForMacOS(true);
 			checker.checkTree(data);
 			fail("incorrectly accepted an invalid tree");
 		} catch (CorruptObjectException e) {
 			assertEquals("duplicate entry names", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTreeDuplicateNames7()
 			throws UnsupportedEncodingException {
 		try {
 			Class.forName("java.text.Normalizer");
 		} catch (ClassNotFoundException e) {
 			// Ignore this test on Java 5 platform.
 			return;
 		}
 
 		StringBuilder b = new StringBuilder();
 		entry(b, "100644 \u0065\u0301");
 		entry(b, "100644 \u00e9");
 		byte[] data = b.toString().getBytes("UTF-8");
 		try {
 			checker.setSafeForMacOS(true);
 			checker.checkTree(data);
 			fail("incorrectly accepted an invalid tree");
 		} catch (CorruptObjectException e) {
 			assertEquals("duplicate entry names", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testInvalidTreeDuplicateNames8()
 			throws UnsupportedEncodingException, CorruptObjectException {
 		StringBuilder b = new StringBuilder();
 		entry(b, "100644 A");
 		checker.setSafeForMacOS(true);
 		checker.checkTree(b.toString().getBytes("UTF-8"));
 	}
 
 	@Test
 	public void testRejectNulInPathSegment() {
 		try {
 			checker.checkPathSegment(Constants.encodeASCII("a\u0000b"), 0, 3);
 			fail("incorrectly accepted NUL in middle of name");
 		} catch (CorruptObjectException e) {
 			assertEquals("name contains byte 0x00", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testRejectSpaceAtEndOnWindows() {
 		checker.setSafeForWindows(true);
 		try {
 			checkOneName("test ");
 			fail("incorrectly accepted space at end");
 		} catch (CorruptObjectException e) {
 			assertEquals("invalid name ends with ' '", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testRejectDotAtEndOnWindows() {
 		checker.setSafeForWindows(true);
 		try {
 			checkOneName("test.");
 			fail("incorrectly accepted dot at end");
 		} catch (CorruptObjectException e) {
 			assertEquals("invalid name ends with '.'", e.getMessage());
 		}
 	}
 
 	@Test
 	public void testRejectDevicesOnWindows() {
 		checker.setSafeForWindows(true);
 
 		String[] bad = { "CON", "PRN", "AUX", "NUL", "COM1", "COM2", "COM3",
 				"COM4", "COM5", "COM6", "COM7", "COM8", "COM9", "LPT1", "LPT2",
 				"LPT3", "LPT4", "LPT5", "LPT6", "LPT7", "LPT8", "LPT9" };
 		for (String b : bad) {
 			try {
 				checkOneName(b);
 				fail("incorrectly accepted " + b);
 			} catch (CorruptObjectException e) {
 				assertEquals("invalid name '" + b + "'", e.getMessage());
 			}
 			try {
 				checkOneName(b + ".txt");
 				fail("incorrectly accepted " + b + ".txt");
 			} catch (CorruptObjectException e) {
 				assertEquals("invalid name '" + b + "'", e.getMessage());
 			}
 		}
 	}
 
 	@Test
 	public void testRejectInvalidWindowsCharacters() {
 		checker.setSafeForWindows(true);
 		rejectName('<');
 		rejectName('>');
 		rejectName(':');
 		rejectName('"');
 		rejectName('/');
 		rejectName('\\');
 		rejectName('|');
 		rejectName('?');
 		rejectName('*');
 
 		for (int i = 1; i <= 31; i++)
 			rejectName((byte) i);
 	}
 
 	private void rejectName(char c) {
 		try {
 			checkOneName("te" + c + "st");
 			fail("incorrectly accepted with " + c);
 		} catch (CorruptObjectException e) {
 			assertEquals("name contains '" + c + "'", e.getMessage());
 		}
 	}
 
 	private void rejectName(byte c) {
 		String h = Integer.toHexString(c);
 		try {
 			checkOneName("te" + ((char) c) + "st");
 			fail("incorrectly accepted with 0x" + h);
 		} catch (CorruptObjectException e) {
 			assertEquals("name contains byte 0x" + h, e.getMessage());
 		}
 	}
 
 	private void checkOneName(String name) throws CorruptObjectException {
 		StringBuilder b = new StringBuilder();
 		entry(b, "100644 " + name);
 		checker.checkTree(Constants.encodeASCII(b.toString()));
 	}
 
 	private static void entry(final StringBuilder b, final String modeName) {
 		b.append(modeName);
 		b.append('\0');
 		for (int i = 0; i < Constants.OBJECT_ID_LENGTH; i++)
 			b.append((char) i);
 	}
 }