org.eclipse.jgit.test/tst/org/eclipse/jgit/treewalk/CanonicalTreeParserTest.java - jgit - Git at Google

 /*
  * Copyright (C) 2008-2009, Google Inc.
  * 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.treewalk;

 import static java.nio.charset.StandardCharsets.UTF_8;
 import static org.eclipse.jgit.lib.FileMode.REGULAR_FILE;
 import static org.eclipse.jgit.lib.FileMode.SYMLINK;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertSame;
 import static org.junit.Assert.assertTrue;

 import java.io.ByteArrayOutputStream;

 import org.eclipse.jgit.errors.CorruptObjectException;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.FileMode;
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.TreeFormatter;
 import org.eclipse.jgit.util.RawParseUtils;
 import org.junit.Before;
 import org.junit.Test;

 public class CanonicalTreeParserTest {
 	private final CanonicalTreeParser ctp = new CanonicalTreeParser();

 	private final FileMode m644 = FileMode.REGULAR_FILE;

 	private final FileMode mt = FileMode.TREE;

 	private final ObjectId hash_a = ObjectId
 			.fromString("6b9c715d21d5486e59083fb6071566aa6ecd4d42");

 	private final ObjectId hash_foo = ObjectId
 			.fromString("a213e8e25bb2442326e86cbfb9ef56319f482869");

 	private final ObjectId hash_sometree = ObjectId
 			.fromString("daf4bdb0d7bb24319810fe0e73aa317663448c93");

 	private byte[] tree1;

 	private byte[] tree2;

 	private byte[] tree3;

 	@Before
 	public void setUp() throws Exception {
 		tree1 = mktree(entry(m644, "a", hash_a));
 		tree2 = mktree(entry(m644, "a", hash_a), entry(m644, "foo", hash_foo));
 		tree3 = mktree(entry(m644, "a", hash_a), entry(mt, "b_sometree",
 				hash_sometree), entry(m644, "foo", hash_foo));
 	}

 	private static byte[] mktree(byte[]... data) throws Exception {
 		final ByteArrayOutputStream out = new ByteArrayOutputStream();
 		for (byte[] e : data)
 			out.write(e);
 		return out.toByteArray();
 	}

 	private static byte[] entry(final FileMode mode, final String name,
 			final ObjectId id) throws Exception {
 		final ByteArrayOutputStream out = new ByteArrayOutputStream();
 		mode.copyTo(out);
 		out.write(' ');
 		out.write(Constants.encode(name));
 		out.write(0);
 		id.copyRawTo(out);
 		return out.toByteArray();
 	}

 	private String path() {
 		return RawParseUtils.decode(UTF_8, ctp.path,
 				ctp.pathOffset, ctp.pathLen);
 	}

 	@Test
 	public void testEmptyTree_AtEOF() throws Exception {
 		ctp.reset(new byte[0]);
 		assertTrue(ctp.eof());
 	}

 	@Test
 	public void testOneEntry_Forward() throws Exception {
 		ctp.reset(tree1);

 		assertTrue(ctp.first());
 		assertFalse(ctp.eof());
 		assertEquals(m644.getBits(), ctp.mode);
 		assertEquals("a", path());
 		assertEquals(hash_a, ctp.getEntryObjectId());

 		ctp.next(1);
 		assertFalse(ctp.first());
 		assertTrue(ctp.eof());
 	}

 	@Test
 	public void testTwoEntries_ForwardOneAtATime() throws Exception {
 		ctp.reset(tree2);

 		assertTrue(ctp.first());
 		assertFalse(ctp.eof());
 		assertEquals(m644.getBits(), ctp.mode);
 		assertEquals("a", path());
 		assertEquals(hash_a, ctp.getEntryObjectId());

 		ctp.next(1);
 		assertFalse(ctp.eof());
 		assertEquals(m644.getBits(), ctp.mode);
 		assertEquals("foo", path());
 		assertEquals(hash_foo, ctp.getEntryObjectId());

 		ctp.next(1);
 		assertFalse(ctp.first());
 		assertTrue(ctp.eof());
 	}

 	@Test
 	public void testOneEntry_Seek1IsEOF() throws Exception {
 		ctp.reset(tree1);
 		ctp.next(1);
 		assertTrue(ctp.eof());
 	}

 	@Test
 	public void testTwoEntries_Seek2IsEOF() throws Exception {
 		ctp.reset(tree2);
 		ctp.next(2);
 		assertTrue(ctp.eof());
 	}

 	@Test
 	public void testThreeEntries_Seek3IsEOF() throws Exception {
 		ctp.reset(tree3);
 		ctp.next(3);
 		assertTrue(ctp.eof());
 	}

 	@Test
 	public void testThreeEntries_Seek2() throws Exception {
 		ctp.reset(tree3);

 		ctp.next(2);
 		assertFalse(ctp.eof());
 		assertFalse(ctp.eof());
 		assertEquals(m644.getBits(), ctp.mode);
 		assertEquals("foo", path());
 		assertEquals(hash_foo, ctp.getEntryObjectId());

 		ctp.next(1);
 		assertTrue(ctp.eof());
 	}

 	@Test
 	public void testOneEntry_Backwards() throws Exception {
 		ctp.reset(tree1);
 		ctp.next(1);
 		assertFalse(ctp.first());
 		assertTrue(ctp.eof());

 		ctp.back(1);
 		assertTrue(ctp.first());
 		assertFalse(ctp.eof());
 		assertEquals(m644.getBits(), ctp.mode);
 		assertEquals("a", path());
 		assertEquals(hash_a, ctp.getEntryObjectId());
 	}

 	@Test
 	public void testTwoEntries_BackwardsOneAtATime() throws Exception {
 		ctp.reset(tree2);
 		ctp.next(2);
 		assertTrue(ctp.eof());

 		ctp.back(1);
 		assertFalse(ctp.eof());
 		assertEquals(m644.getBits(), ctp.mode);
 		assertEquals("foo", path());
 		assertEquals(hash_foo, ctp.getEntryObjectId());

 		ctp.back(1);
 		assertFalse(ctp.eof());
 		assertEquals(m644.getBits(), ctp.mode);
 		assertEquals("a", path());
 		assertEquals(hash_a, ctp.getEntryObjectId());
 	}

 	@Test
 	public void testTwoEntries_BackwardsTwo() throws Exception {
 		ctp.reset(tree2);
 		ctp.next(2);
 		assertTrue(ctp.eof());

 		ctp.back(2);
 		assertFalse(ctp.eof());
 		assertEquals(m644.getBits(), ctp.mode);
 		assertEquals("a", path());
 		assertEquals(hash_a, ctp.getEntryObjectId());

 		ctp.next(1);
 		assertFalse(ctp.eof());
 		assertEquals(m644.getBits(), ctp.mode);
 		assertEquals("foo", path());
 		assertEquals(hash_foo, ctp.getEntryObjectId());

 		ctp.next(1);
 		assertTrue(ctp.eof());
 	}

 	@Test
 	public void testThreeEntries_BackwardsTwo() throws Exception {
 		ctp.reset(tree3);
 		ctp.next(3);
 		assertTrue(ctp.eof());

 		ctp.back(2);
 		assertFalse(ctp.eof());
 		assertEquals(mt.getBits(), ctp.mode);
 		assertEquals("b_sometree", path());
 		assertEquals(hash_sometree, ctp.getEntryObjectId());

 		ctp.next(1);
 		assertFalse(ctp.eof());
 		assertEquals(m644.getBits(), ctp.mode);
 		assertEquals("foo", path());
 		assertEquals(hash_foo, ctp.getEntryObjectId());

 		ctp.next(1);
 		assertTrue(ctp.eof());
 	}

 	@Test
 	public void testBackwards_ConfusingPathName() throws Exception {
 		final String aVeryConfusingName = "confusing 644 entry 755 and others";
 		ctp.reset(mktree(entry(m644, "a", hash_a), entry(mt, aVeryConfusingName,
 				hash_sometree), entry(m644, "foo", hash_foo)));
 		ctp.next(3);
 		assertTrue(ctp.eof());

 		ctp.back(2);
 		assertFalse(ctp.eof());
 		assertEquals(mt.getBits(), ctp.mode);
 		assertEquals(aVeryConfusingName, path());
 		assertEquals(hash_sometree, ctp.getEntryObjectId());

 		ctp.back(1);
 		assertFalse(ctp.eof());
 		assertEquals(m644.getBits(), ctp.mode);
 		assertEquals("a", path());
 		assertEquals(hash_a, ctp.getEntryObjectId());
 	}

 	@Test
 	public void testBackwords_Prebuilts1() throws Exception {
 		// What is interesting about this test is the ObjectId for the
 		// "darwin-x86" path entry ends in an octal digit (37 == '7').
 		// Thus when scanning backwards we could over scan and consume
 		// part of the SHA-1, and miss the path terminator.
 		//
 		final ObjectId common = ObjectId
 				.fromString("af7bf97cb9bce3f60f1d651a0ef862e9447dd8bc");
 		final ObjectId darwinx86 = ObjectId
 				.fromString("e927f7398240f78face99e1a738dac54ef738e37");
 		final ObjectId linuxx86 = ObjectId
 				.fromString("ac08dd97120c7cb7d06e98cd5b152011183baf21");
 		final ObjectId windows = ObjectId
 				.fromString("6c4c64c221a022bb973165192cca4812033479df");

 		ctp.reset(mktree(entry(mt, "common", common), entry(mt, "darwin-x86",
 				darwinx86), entry(mt, "linux-x86", linuxx86), entry(mt,
 				"windows", windows)));
 		ctp.next(3);
 		assertEquals("windows", ctp.getEntryPathString());
 		assertSame(mt, ctp.getEntryFileMode());
 		assertEquals(windows, ctp.getEntryObjectId());

 		ctp.back(1);
 		assertEquals("linux-x86", ctp.getEntryPathString());
 		assertSame(mt, ctp.getEntryFileMode());
 		assertEquals(linuxx86, ctp.getEntryObjectId());

 		ctp.next(1);
 		assertEquals("windows", ctp.getEntryPathString());
 		assertSame(mt, ctp.getEntryFileMode());
 		assertEquals(windows, ctp.getEntryObjectId());
 	}

 	@Test
 	public void testBackwords_Prebuilts2() throws Exception {
 		// What is interesting about this test is the ObjectId for the
 		// "darwin-x86" path entry ends in an octal digit (37 == '7').
 		// Thus when scanning backwards we could over scan and consume
 		// part of the SHA-1, and miss the path terminator.
 		//
 		final ObjectId common = ObjectId
 				.fromString("af7bf97cb9bce3f60f1d651a0ef862e9447dd8bc");
 		final ObjectId darwinx86 = ObjectId
 				.fromString("0000000000000000000000000000000000000037");
 		final ObjectId linuxx86 = ObjectId
 				.fromString("ac08dd97120c7cb7d06e98cd5b152011183baf21");
 		final ObjectId windows = ObjectId
 				.fromString("6c4c64c221a022bb973165192cca4812033479df");

 		ctp.reset(mktree(entry(mt, "common", common), entry(mt, "darwin-x86",
 				darwinx86), entry(mt, "linux-x86", linuxx86), entry(mt,
 				"windows", windows)));
 		ctp.next(3);
 		assertEquals("windows", ctp.getEntryPathString());
 		assertSame(mt, ctp.getEntryFileMode());
 		assertEquals(windows, ctp.getEntryObjectId());

 		ctp.back(1);
 		assertEquals("linux-x86", ctp.getEntryPathString());
 		assertSame(mt, ctp.getEntryFileMode());
 		assertEquals(linuxx86, ctp.getEntryObjectId());

 		ctp.next(1);
 		assertEquals("windows", ctp.getEntryPathString());
 		assertSame(mt, ctp.getEntryFileMode());
 		assertEquals(windows, ctp.getEntryObjectId());
 	}

 	@Test
 	public void testFreakingHugePathName() throws Exception {
 		final int n = AbstractTreeIterator.DEFAULT_PATH_SIZE * 4;
 		final StringBuilder b = new StringBuilder(n);
 		for (int i = 0; i < n; i++)
 			b.append('q');
 		final String name = b.toString();
 		ctp.reset(entry(m644, name, hash_a));
 		assertFalse(ctp.eof());
 		assertEquals(name, RawParseUtils.decode(UTF_8, ctp.path,
 				ctp.pathOffset, ctp.pathLen));
 	}

 	@Test
 	public void testFindAttributesWhenFirst() throws CorruptObjectException {
 		TreeFormatter tree = new TreeFormatter();
 		tree.append(".gitattributes", REGULAR_FILE, hash_a);
 		ctp.reset(tree.toByteArray());

 		assertTrue(ctp.findFile(".gitattributes"));
 		assertEquals(REGULAR_FILE.getBits(), ctp.getEntryRawMode());
 		assertEquals(".gitattributes", ctp.getEntryPathString());
 		assertEquals(hash_a, ctp.getEntryObjectId());
 	}

 	@Test
 	public void testFindAttributesWhenSecond() throws CorruptObjectException {
 		TreeFormatter tree = new TreeFormatter();
 		tree.append(".config", SYMLINK, hash_a);
 		tree.append(".gitattributes", REGULAR_FILE, hash_foo);
 		ctp.reset(tree.toByteArray());

 		assertTrue(ctp.findFile(".gitattributes"));
 		assertEquals(REGULAR_FILE.getBits(), ctp.getEntryRawMode());
 		assertEquals(".gitattributes", ctp.getEntryPathString());
 		assertEquals(hash_foo, ctp.getEntryObjectId());
 	}

 	@Test
 	public void testFindAttributesWhenMissing() throws CorruptObjectException {
 		TreeFormatter tree = new TreeFormatter();
 		tree.append("src", REGULAR_FILE, hash_a);
 		tree.append("zoo", REGULAR_FILE, hash_foo);
 		ctp.reset(tree.toByteArray());

 		assertFalse(ctp.findFile(".gitattributes"));
 		assertEquals(11, ctp.idOffset()); // Did not walk the entire tree.
 		assertEquals("src", ctp.getEntryPathString());
 	}
 }
	/*
	* Copyright (C) 2008-2009, Google Inc.
	* 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.treewalk;

	import static java.nio.charset.StandardCharsets.UTF_8;
	import static org.eclipse.jgit.lib.FileMode.REGULAR_FILE;
	import static org.eclipse.jgit.lib.FileMode.SYMLINK;
	import static org.junit.Assert.assertEquals;
	import static org.junit.Assert.assertFalse;
	import static org.junit.Assert.assertSame;
	import static org.junit.Assert.assertTrue;

	import java.io.ByteArrayOutputStream;

	import org.eclipse.jgit.errors.CorruptObjectException;
	import org.eclipse.jgit.lib.Constants;
	import org.eclipse.jgit.lib.FileMode;
	import org.eclipse.jgit.lib.ObjectId;
	import org.eclipse.jgit.lib.TreeFormatter;
	import org.eclipse.jgit.util.RawParseUtils;
	import org.junit.Before;
	import org.junit.Test;

	public class CanonicalTreeParserTest {
	private final CanonicalTreeParser ctp = new CanonicalTreeParser();

	private final FileMode m644 = FileMode.REGULAR_FILE;

	private final FileMode mt = FileMode.TREE;

	private final ObjectId hash_a = ObjectId
	.fromString("6b9c715d21d5486e59083fb6071566aa6ecd4d42");

	private final ObjectId hash_foo = ObjectId
	.fromString("a213e8e25bb2442326e86cbfb9ef56319f482869");

	private final ObjectId hash_sometree = ObjectId
	.fromString("daf4bdb0d7bb24319810fe0e73aa317663448c93");

	private byte[] tree1;

	private byte[] tree2;

	private byte[] tree3;

	@Before
	public void setUp() throws Exception {
	tree1 = mktree(entry(m644, "a", hash_a));
	tree2 = mktree(entry(m644, "a", hash_a), entry(m644, "foo", hash_foo));
	tree3 = mktree(entry(m644, "a", hash_a), entry(mt, "b_sometree",
	hash_sometree), entry(m644, "foo", hash_foo));
	}

	private static byte[] mktree(byte[]... data) throws Exception {
	final ByteArrayOutputStream out = new ByteArrayOutputStream();
	for (byte[] e : data)
	out.write(e);
	return out.toByteArray();
	}

	private static byte[] entry(final FileMode mode, final String name,
	final ObjectId id) throws Exception {
	final ByteArrayOutputStream out = new ByteArrayOutputStream();
	mode.copyTo(out);
	out.write(' ');
	out.write(Constants.encode(name));
	out.write(0);
	id.copyRawTo(out);
	return out.toByteArray();
	}

	private String path() {
	return RawParseUtils.decode(UTF_8, ctp.path,
	ctp.pathOffset, ctp.pathLen);
	}

	@Test
	public void testEmptyTree_AtEOF() throws Exception {
	ctp.reset(new byte[0]);
	assertTrue(ctp.eof());
	}

	@Test
	public void testOneEntry_Forward() throws Exception {
	ctp.reset(tree1);

	assertTrue(ctp.first());
	assertFalse(ctp.eof());
	assertEquals(m644.getBits(), ctp.mode);
	assertEquals("a", path());
	assertEquals(hash_a, ctp.getEntryObjectId());

	ctp.next(1);
	assertFalse(ctp.first());
	assertTrue(ctp.eof());
	}

	@Test
	public void testTwoEntries_ForwardOneAtATime() throws Exception {
	ctp.reset(tree2);

	assertTrue(ctp.first());
	assertFalse(ctp.eof());
	assertEquals(m644.getBits(), ctp.mode);
	assertEquals("a", path());
	assertEquals(hash_a, ctp.getEntryObjectId());

	ctp.next(1);
	assertFalse(ctp.eof());
	assertEquals(m644.getBits(), ctp.mode);
	assertEquals("foo", path());
	assertEquals(hash_foo, ctp.getEntryObjectId());

	ctp.next(1);
	assertFalse(ctp.first());
	assertTrue(ctp.eof());
	}

	@Test
	public void testOneEntry_Seek1IsEOF() throws Exception {
	ctp.reset(tree1);
	ctp.next(1);
	assertTrue(ctp.eof());
	}

	@Test
	public void testTwoEntries_Seek2IsEOF() throws Exception {
	ctp.reset(tree2);
	ctp.next(2);
	assertTrue(ctp.eof());
	}

	@Test
	public void testThreeEntries_Seek3IsEOF() throws Exception {
	ctp.reset(tree3);
	ctp.next(3);
	assertTrue(ctp.eof());
	}

	@Test
	public void testThreeEntries_Seek2() throws Exception {
	ctp.reset(tree3);

	ctp.next(2);
	assertFalse(ctp.eof());
	assertFalse(ctp.eof());
	assertEquals(m644.getBits(), ctp.mode);
	assertEquals("foo", path());
	assertEquals(hash_foo, ctp.getEntryObjectId());

	ctp.next(1);
	assertTrue(ctp.eof());
	}

	@Test
	public void testOneEntry_Backwards() throws Exception {
	ctp.reset(tree1);
	ctp.next(1);
	assertFalse(ctp.first());
	assertTrue(ctp.eof());

	ctp.back(1);
	assertTrue(ctp.first());
	assertFalse(ctp.eof());
	assertEquals(m644.getBits(), ctp.mode);
	assertEquals("a", path());
	assertEquals(hash_a, ctp.getEntryObjectId());
	}

	@Test
	public void testTwoEntries_BackwardsOneAtATime() throws Exception {
	ctp.reset(tree2);
	ctp.next(2);
	assertTrue(ctp.eof());

	ctp.back(1);
	assertFalse(ctp.eof());
	assertEquals(m644.getBits(), ctp.mode);
	assertEquals("foo", path());
	assertEquals(hash_foo, ctp.getEntryObjectId());

	ctp.back(1);
	assertFalse(ctp.eof());
	assertEquals(m644.getBits(), ctp.mode);
	assertEquals("a", path());
	assertEquals(hash_a, ctp.getEntryObjectId());
	}

	@Test
	public void testTwoEntries_BackwardsTwo() throws Exception {
	ctp.reset(tree2);
	ctp.next(2);
	assertTrue(ctp.eof());

	ctp.back(2);
	assertFalse(ctp.eof());
	assertEquals(m644.getBits(), ctp.mode);
	assertEquals("a", path());
	assertEquals(hash_a, ctp.getEntryObjectId());

	ctp.next(1);
	assertFalse(ctp.eof());
	assertEquals(m644.getBits(), ctp.mode);
	assertEquals("foo", path());
	assertEquals(hash_foo, ctp.getEntryObjectId());

	ctp.next(1);
	assertTrue(ctp.eof());
	}

	@Test
	public void testThreeEntries_BackwardsTwo() throws Exception {
	ctp.reset(tree3);
	ctp.next(3);
	assertTrue(ctp.eof());

	ctp.back(2);
	assertFalse(ctp.eof());
	assertEquals(mt.getBits(), ctp.mode);
	assertEquals("b_sometree", path());
	assertEquals(hash_sometree, ctp.getEntryObjectId());

	ctp.next(1);
	assertFalse(ctp.eof());
	assertEquals(m644.getBits(), ctp.mode);
	assertEquals("foo", path());
	assertEquals(hash_foo, ctp.getEntryObjectId());

	ctp.next(1);
	assertTrue(ctp.eof());
	}

	@Test
	public void testBackwards_ConfusingPathName() throws Exception {
	final String aVeryConfusingName = "confusing 644 entry 755 and others";
	ctp.reset(mktree(entry(m644, "a", hash_a), entry(mt, aVeryConfusingName,
	hash_sometree), entry(m644, "foo", hash_foo)));
	ctp.next(3);
	assertTrue(ctp.eof());

	ctp.back(2);
	assertFalse(ctp.eof());
	assertEquals(mt.getBits(), ctp.mode);
	assertEquals(aVeryConfusingName, path());
	assertEquals(hash_sometree, ctp.getEntryObjectId());

	ctp.back(1);
	assertFalse(ctp.eof());
	assertEquals(m644.getBits(), ctp.mode);
	assertEquals("a", path());
	assertEquals(hash_a, ctp.getEntryObjectId());
	}

	@Test
	public void testBackwords_Prebuilts1() throws Exception {
	// What is interesting about this test is the ObjectId for the
	// "darwin-x86" path entry ends in an octal digit (37 == '7').
	// Thus when scanning backwards we could over scan and consume
	// part of the SHA-1, and miss the path terminator.
	//
	final ObjectId common = ObjectId
	.fromString("af7bf97cb9bce3f60f1d651a0ef862e9447dd8bc");
	final ObjectId darwinx86 = ObjectId
	.fromString("e927f7398240f78face99e1a738dac54ef738e37");
	final ObjectId linuxx86 = ObjectId
	.fromString("ac08dd97120c7cb7d06e98cd5b152011183baf21");
	final ObjectId windows = ObjectId
	.fromString("6c4c64c221a022bb973165192cca4812033479df");

	ctp.reset(mktree(entry(mt, "common", common), entry(mt, "darwin-x86",
	darwinx86), entry(mt, "linux-x86", linuxx86), entry(mt,
	"windows", windows)));
	ctp.next(3);
	assertEquals("windows", ctp.getEntryPathString());
	assertSame(mt, ctp.getEntryFileMode());
	assertEquals(windows, ctp.getEntryObjectId());

	ctp.back(1);
	assertEquals("linux-x86", ctp.getEntryPathString());
	assertSame(mt, ctp.getEntryFileMode());
	assertEquals(linuxx86, ctp.getEntryObjectId());

	ctp.next(1);
	assertEquals("windows", ctp.getEntryPathString());
	assertSame(mt, ctp.getEntryFileMode());
	assertEquals(windows, ctp.getEntryObjectId());
	}

	@Test
	public void testBackwords_Prebuilts2() throws Exception {
	// What is interesting about this test is the ObjectId for the
	// "darwin-x86" path entry ends in an octal digit (37 == '7').
	// Thus when scanning backwards we could over scan and consume
	// part of the SHA-1, and miss the path terminator.
	//
	final ObjectId common = ObjectId
	.fromString("af7bf97cb9bce3f60f1d651a0ef862e9447dd8bc");
	final ObjectId darwinx86 = ObjectId
	.fromString("0000000000000000000000000000000000000037");
	final ObjectId linuxx86 = ObjectId
	.fromString("ac08dd97120c7cb7d06e98cd5b152011183baf21");
	final ObjectId windows = ObjectId
	.fromString("6c4c64c221a022bb973165192cca4812033479df");

	ctp.reset(mktree(entry(mt, "common", common), entry(mt, "darwin-x86",
	darwinx86), entry(mt, "linux-x86", linuxx86), entry(mt,
	"windows", windows)));
	ctp.next(3);
	assertEquals("windows", ctp.getEntryPathString());
	assertSame(mt, ctp.getEntryFileMode());
	assertEquals(windows, ctp.getEntryObjectId());

	ctp.back(1);
	assertEquals("linux-x86", ctp.getEntryPathString());
	assertSame(mt, ctp.getEntryFileMode());
	assertEquals(linuxx86, ctp.getEntryObjectId());

	ctp.next(1);
	assertEquals("windows", ctp.getEntryPathString());
	assertSame(mt, ctp.getEntryFileMode());
	assertEquals(windows, ctp.getEntryObjectId());
	}

	@Test
	public void testFreakingHugePathName() throws Exception {
	final int n = AbstractTreeIterator.DEFAULT_PATH_SIZE * 4;
	final StringBuilder b = new StringBuilder(n);
	for (int i = 0; i < n; i++)
	b.append('q');
	final String name = b.toString();
	ctp.reset(entry(m644, name, hash_a));
	assertFalse(ctp.eof());
	assertEquals(name, RawParseUtils.decode(UTF_8, ctp.path,
	ctp.pathOffset, ctp.pathLen));
	}

	@Test
	public void testFindAttributesWhenFirst() throws CorruptObjectException {
	TreeFormatter tree = new TreeFormatter();
	tree.append(".gitattributes", REGULAR_FILE, hash_a);
	ctp.reset(tree.toByteArray());

	assertTrue(ctp.findFile(".gitattributes"));
	assertEquals(REGULAR_FILE.getBits(), ctp.getEntryRawMode());
	assertEquals(".gitattributes", ctp.getEntryPathString());
	assertEquals(hash_a, ctp.getEntryObjectId());
	}

	@Test
	public void testFindAttributesWhenSecond() throws CorruptObjectException {
	TreeFormatter tree = new TreeFormatter();
	tree.append(".config", SYMLINK, hash_a);
	tree.append(".gitattributes", REGULAR_FILE, hash_foo);
	ctp.reset(tree.toByteArray());

	assertTrue(ctp.findFile(".gitattributes"));
	assertEquals(REGULAR_FILE.getBits(), ctp.getEntryRawMode());
	assertEquals(".gitattributes", ctp.getEntryPathString());
	assertEquals(hash_foo, ctp.getEntryObjectId());
	}

	@Test
	public void testFindAttributesWhenMissing() throws CorruptObjectException {
	TreeFormatter tree = new TreeFormatter();
	tree.append("src", REGULAR_FILE, hash_a);
	tree.append("zoo", REGULAR_FILE, hash_foo);
	ctp.reset(tree.toByteArray());

	assertFalse(ctp.findFile(".gitattributes"));
	assertEquals(11, ctp.idOffset()); // Did not walk the entire tree.
	assertEquals("src", ctp.getEntryPathString());
	}
	}