diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/CloneCommandTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/CloneCommandTest.java
index 2270a6a8b..b4abb53d8 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/CloneCommandTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/CloneCommandTest.java
@@ -646,25 +646,27 @@ public class CloneCommandTest extends RepositoryTestCase {
 		assertEquals(sub1Head, pathStatus.getHeadId());
 		assertEquals(sub1Head, pathStatus.getIndexId());
 
-		SubmoduleWalk walk = SubmoduleWalk.forIndex(git2.getRepository());
-		assertTrue(walk.next());
-		try (Repository clonedSub1 = walk.getRepository()) {
-			assertNotNull(clonedSub1);
-			assertEquals(new File(git2.getRepository().getWorkTree(),
-					walk.getPath()), clonedSub1.getWorkTree());
-			assertEquals(
-					new File(new File(git2.getRepository().getDirectory(),
-							"modules"), walk.getPath()),
-					clonedSub1.getDirectory());
-			status = new SubmoduleStatusCommand(clonedSub1);
-			statuses = status.call();
+		try (SubmoduleWalk walk = SubmoduleWalk
+				.forIndex(git2.getRepository())) {
+			assertTrue(walk.next());
+			try (Repository clonedSub1 = walk.getRepository()) {
+				assertNotNull(clonedSub1);
+				assertEquals(new File(git2.getRepository().getWorkTree(),
+						walk.getPath()), clonedSub1.getWorkTree());
+				assertEquals(
+						new File(new File(git2.getRepository().getDirectory(),
+								"modules"), walk.getPath()),
+						clonedSub1.getDirectory());
+				status = new SubmoduleStatusCommand(clonedSub1);
+				statuses = status.call();
+			}
+			assertFalse(walk.next());
 		}
 		pathStatus = statuses.get(path);
 		assertNotNull(pathStatus);
 		assertEquals(SubmoduleStatusType.INITIALIZED, pathStatus.getType());
 		assertEquals(sub2Head, pathStatus.getHeadId());
 		assertEquals(sub2Head, pathStatus.getIndexId());
-		assertFalse(walk.next());
 	}
 
 	@Test
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/CommitCommandTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/CommitCommandTest.java
index 3bde0eb33..b5661e844 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/CommitCommandTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/CommitCommandTest.java
@@ -148,9 +148,10 @@ public class CommitCommandTest extends RepositoryTestCase {
 		writeTrashFile(path, "content");
 		git.add().addFilepattern(path).call();
 		RevCommit commit1 = git.commit().setMessage("commit").call();
-		TreeWalk walk = TreeWalk.forPath(db, path, commit1.getTree());
-		assertNotNull(walk);
-		assertEquals(FileMode.EXECUTABLE_FILE, walk.getFileMode(0));
+		try (TreeWalk walk = TreeWalk.forPath(db, path, commit1.getTree())) {
+			assertNotNull(walk);
+			assertEquals(FileMode.EXECUTABLE_FILE, walk.getFileMode(0));
+		}
 
 		FS nonExecutableFs = new FS() {
 
@@ -204,9 +205,10 @@ public class CommitCommandTest extends RepositoryTestCase {
 		writeTrashFile(path, "content2");
 		RevCommit commit2 = git2.commit().setOnly(path).setMessage("commit2")
 				.call();
-		walk = TreeWalk.forPath(db, path, commit2.getTree());
-		assertNotNull(walk);
-		assertEquals(FileMode.EXECUTABLE_FILE, walk.getFileMode(0));
+		try (TreeWalk walk = TreeWalk.forPath(db, path, commit2.getTree())) {
+			assertNotNull(walk);
+			assertEquals(FileMode.EXECUTABLE_FILE, walk.getFileMode(0));
+		}
 	}
 
 	@Test
@@ -225,15 +227,16 @@ public class CommitCommandTest extends RepositoryTestCase {
 			assertNotNull(repo);
 			addRepoToClose(repo);
 
-			SubmoduleWalk generator = SubmoduleWalk.forIndex(db);
-			assertTrue(generator.next());
-			assertEquals(path, generator.getPath());
-			assertEquals(commit, generator.getObjectId());
-			assertEquals(uri, generator.getModulesUrl());
-			assertEquals(path, generator.getModulesPath());
-			assertEquals(uri, generator.getConfigUrl());
-			try (Repository subModRepo = generator.getRepository()) {
-				assertNotNull(subModRepo);
+			try (SubmoduleWalk generator = SubmoduleWalk.forIndex(db)) {
+				assertTrue(generator.next());
+				assertEquals(path, generator.getPath());
+				assertEquals(commit, generator.getObjectId());
+				assertEquals(uri, generator.getModulesUrl());
+				assertEquals(path, generator.getModulesPath());
+				assertEquals(uri, generator.getConfigUrl());
+				try (Repository subModRepo = generator.getRepository()) {
+					assertNotNull(subModRepo);
+				}
 			}
 			assertEquals(commit, repo.resolve(Constants.HEAD));
 
@@ -275,15 +278,16 @@ public class CommitCommandTest extends RepositoryTestCase {
 			assertNotNull(repo);
 			addRepoToClose(repo);
 
-			SubmoduleWalk generator = SubmoduleWalk.forIndex(db);
-			assertTrue(generator.next());
-			assertEquals(path, generator.getPath());
-			assertEquals(commit2, generator.getObjectId());
-			assertEquals(uri, generator.getModulesUrl());
-			assertEquals(path, generator.getModulesPath());
-			assertEquals(uri, generator.getConfigUrl());
-			try (Repository subModRepo = generator.getRepository()) {
-				assertNotNull(subModRepo);
+			try (SubmoduleWalk generator = SubmoduleWalk.forIndex(db)) {
+				assertTrue(generator.next());
+				assertEquals(path, generator.getPath());
+				assertEquals(commit2, generator.getObjectId());
+				assertEquals(uri, generator.getModulesUrl());
+				assertEquals(path, generator.getModulesPath());
+				assertEquals(uri, generator.getConfigUrl());
+				try (Repository subModRepo = generator.getRepository()) {
+					assertNotNull(subModRepo);
+				}
 			}
 			assertEquals(commit2, repo.resolve(Constants.HEAD));
 
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/EolRepositoryTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/EolRepositoryTest.java
index 47806cb99..d0dfd1ab9 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/EolRepositoryTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/EolRepositoryTest.java
@@ -142,8 +142,6 @@ public class EolRepositoryTest extends RepositoryTestCase {
 
 	protected String CONTENT_MIXED;
 
-	private TreeWalk walk;
-
 	/** work tree root .gitattributes */
 	private File dotGitattributes;
 
@@ -689,27 +687,25 @@ public class EolRepositoryTest extends RepositoryTestCase {
 
 	private void collectRepositoryState() throws Exception {
 		dirCache = db.readDirCache();
-		walk = beginWalk();
-		if (dotGitattributes != null)
-			collectEntryContentAndAttributes(F, ".gitattributes", null);
-		collectEntryContentAndAttributes(F, fileCRLF.getName(), entryCRLF);
-		collectEntryContentAndAttributes(F, fileLF.getName(), entryLF);
-		collectEntryContentAndAttributes(F, fileMixed.getName(), entryMixed);
-		endWalk();
-	}
-
-	private TreeWalk beginWalk() throws Exception {
-		TreeWalk newWalk = new TreeWalk(db);
-		newWalk.addTree(new FileTreeIterator(db));
-		newWalk.addTree(new DirCacheIterator(db.readDirCache()));
-		return newWalk;
-	}
-
-	private void endWalk() throws IOException {
-		assertFalse("Not all files tested", walk.next());
+		try (TreeWalk walk = new TreeWalk(db)) {
+			walk.addTree(new FileTreeIterator(db));
+			walk.addTree(new DirCacheIterator(db.readDirCache()));
+			if (dotGitattributes != null) {
+				collectEntryContentAndAttributes(walk, F, ".gitattributes",
+						null);
+			}
+			collectEntryContentAndAttributes(walk, F, fileCRLF.getName(),
+					entryCRLF);
+			collectEntryContentAndAttributes(walk, F, fileLF.getName(),
+					entryLF);
+			collectEntryContentAndAttributes(walk, F, fileMixed.getName(),
+					entryMixed);
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
-	private void collectEntryContentAndAttributes(FileMode type, String pathName,
+	private void collectEntryContentAndAttributes(TreeWalk walk, FileMode type,
+			String pathName,
 			ActualEntry e) throws IOException {
 		assertTrue("walk has entry", walk.next());
 
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/FetchAndPullCommandsRecurseSubmodulesTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/FetchAndPullCommandsRecurseSubmodulesTest.java
index 73a705b25..08ded559f 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/FetchAndPullCommandsRecurseSubmodulesTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/FetchAndPullCommandsRecurseSubmodulesTest.java
@@ -343,19 +343,22 @@ public class FetchAndPullCommandsRecurseSubmodulesTest extends RepositoryTestCas
 
 	private void assertSubmoduleFetchHeads(ObjectId expectedHead1,
 			ObjectId expectedHead2) throws Exception {
+		Object newHead1 = null;
+		ObjectId newHead2 = null;
 		try (SubmoduleWalk walk = SubmoduleWalk
 				.forIndex(git2.getRepository())) {
 			assertTrue(walk.next());
-			Repository r = walk.getRepository();
-			ObjectId newHead1 = r.resolve(Constants.FETCH_HEAD);
-			ObjectId newHead2;
-			try (SubmoduleWalk walk2 = SubmoduleWalk.forIndex(r)) {
-				assertTrue(walk2.next());
-				newHead2 = walk2.getRepository().resolve(Constants.FETCH_HEAD);
+			try (Repository r = walk.getRepository()) {
+				newHead1 = r.resolve(Constants.FETCH_HEAD);
+				try (SubmoduleWalk walk2 = SubmoduleWalk.forIndex(r)) {
+					assertTrue(walk2.next());
+					try (Repository r2 = walk2.getRepository()) {
+						newHead2 = r2.resolve(Constants.FETCH_HEAD);
+					}
+				}
 			}
-
-			assertEquals(expectedHead1, newHead1);
-			assertEquals(expectedHead2, newHead2);
 		}
+		assertEquals(expectedHead1, newHead1);
+		assertEquals(expectedHead2, newHead2);
 	}
 }
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/attributes/AttributesHandlerTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/attributes/AttributesHandlerTest.java
index 5868482c8..adc64d227 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/attributes/AttributesHandlerTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/attributes/AttributesHandlerTest.java
@@ -69,83 +69,90 @@ public class AttributesHandlerTest extends RepositoryTestCase {
 
 	private static final FileMode F = FileMode.REGULAR_FILE;
 
-	private TreeWalk walk;
-
 	@Test
 	public void testExpandNonMacro1() throws Exception {
 		setupRepo(null, null, null, "*.txt text");
 
-		walk = beginWalk();
-		assertIteration(D, "sub");
-		assertIteration(F, "sub/.gitattributes");
-		assertIteration(F, "sub/a.txt", attrs("text"));
-		endWalk();
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, D, "sub");
+			assertIteration(walk, F, "sub/.gitattributes");
+			assertIteration(walk, F, "sub/a.txt", attrs("text"));
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
 	@Test
 	public void testExpandNonMacro2() throws Exception {
 		setupRepo(null, null, null, "*.txt -text");
 
-		walk = beginWalk();
-		assertIteration(D, "sub");
-		assertIteration(F, "sub/.gitattributes");
-		assertIteration(F, "sub/a.txt", attrs("-text"));
-		endWalk();
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, D, "sub");
+			assertIteration(walk, F, "sub/.gitattributes");
+			assertIteration(walk, F, "sub/a.txt", attrs("-text"));
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
 	@Test
 	public void testExpandNonMacro3() throws Exception {
 		setupRepo(null, null, null, "*.txt !text");
 
-		walk = beginWalk();
-		assertIteration(D, "sub");
-		assertIteration(F, "sub/.gitattributes");
-		assertIteration(F, "sub/a.txt", attrs(""));
-		endWalk();
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, D, "sub");
+			assertIteration(walk, F, "sub/.gitattributes");
+			assertIteration(walk, F, "sub/a.txt", attrs(""));
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
 	@Test
 	public void testExpandNonMacro4() throws Exception {
 		setupRepo(null, null, null, "*.txt text=auto");
 
-		walk = beginWalk();
-		assertIteration(D, "sub");
-		assertIteration(F, "sub/.gitattributes");
-		assertIteration(F, "sub/a.txt", attrs("text=auto"));
-		endWalk();
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, D, "sub");
+			assertIteration(walk, F, "sub/.gitattributes");
+			assertIteration(walk, F, "sub/a.txt", attrs("text=auto"));
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
 	@Test
 	public void testExpandBuiltInMacro1() throws Exception {
 		setupRepo(null, null, null, "*.txt binary");
 
-		walk = beginWalk();
-		assertIteration(D, "sub");
-		assertIteration(F, "sub/.gitattributes");
-		assertIteration(F, "sub/a.txt", attrs("binary -diff -merge -text"));
-		endWalk();
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, D, "sub");
+			assertIteration(walk, F, "sub/.gitattributes");
+			assertIteration(walk, F, "sub/a.txt",
+					attrs("binary -diff -merge -text"));
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
 	@Test
 	public void testExpandBuiltInMacro2() throws Exception {
 		setupRepo(null, null, null, "*.txt -binary");
 
-		walk = beginWalk();
-		assertIteration(D, "sub");
-		assertIteration(F, "sub/.gitattributes");
-		assertIteration(F, "sub/a.txt", attrs("-binary diff merge text"));
-		endWalk();
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, D, "sub");
+			assertIteration(walk, F, "sub/.gitattributes");
+			assertIteration(walk, F, "sub/a.txt",
+					attrs("-binary diff merge text"));
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
 	@Test
 	public void testExpandBuiltInMacro3() throws Exception {
 		setupRepo(null, null, null, "*.txt !binary");
 
-		walk = beginWalk();
-		assertIteration(D, "sub");
-		assertIteration(F, "sub/.gitattributes");
-		assertIteration(F, "sub/a.txt", attrs(""));
-		endWalk();
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, D, "sub");
+			assertIteration(walk, F, "sub/.gitattributes");
+			assertIteration(walk, F, "sub/a.txt", attrs(""));
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
 	@Test
@@ -153,44 +160,48 @@ public class AttributesHandlerTest extends RepositoryTestCase {
 		setupRepo(
 				"[attr]foo a -b !c d=e", null, null, "*.txt foo");
 
-		walk = beginWalk();
-		assertIteration(D, "sub");
-		assertIteration(F, "sub/.gitattributes");
-		assertIteration(F, "sub/a.txt", attrs("foo a -b d=e"));
-		endWalk();
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, D, "sub");
+			assertIteration(walk, F, "sub/.gitattributes");
+			assertIteration(walk, F, "sub/a.txt", attrs("foo a -b d=e"));
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
 	@Test
 	public void testCustomGlobalMacro2() throws Exception {
 		setupRepo("[attr]foo a -b !c d=e", null, null, "*.txt -foo");
 
-		walk = beginWalk();
-		assertIteration(D, "sub");
-		assertIteration(F, "sub/.gitattributes");
-		assertIteration(F, "sub/a.txt", attrs("-foo -a b d=e"));
-		endWalk();
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, D, "sub");
+			assertIteration(walk, F, "sub/.gitattributes");
+			assertIteration(walk, F, "sub/a.txt", attrs("-foo -a b d=e"));
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
 	@Test
 	public void testCustomGlobalMacro3() throws Exception {
 		setupRepo("[attr]foo a -b !c d=e", null, null, "*.txt !foo");
 
-		walk = beginWalk();
-		assertIteration(D, "sub");
-		assertIteration(F, "sub/.gitattributes");
-		assertIteration(F, "sub/a.txt", attrs(""));
-		endWalk();
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, D, "sub");
+			assertIteration(walk, F, "sub/.gitattributes");
+			assertIteration(walk, F, "sub/a.txt", attrs(""));
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
 	@Test
 	public void testCustomGlobalMacro4() throws Exception {
 		setupRepo("[attr]foo a -b !c d=e", null, null, "*.txt foo=bar");
 
-		walk = beginWalk();
-		assertIteration(D, "sub");
-		assertIteration(F, "sub/.gitattributes");
-		assertIteration(F, "sub/a.txt", attrs("foo=bar a -b d=bar"));
-		endWalk();
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, D, "sub");
+			assertIteration(walk, F, "sub/.gitattributes");
+			assertIteration(walk, F, "sub/a.txt", attrs("foo=bar a -b d=bar"));
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
 	@Test
@@ -198,11 +209,12 @@ public class AttributesHandlerTest extends RepositoryTestCase {
 		setupRepo("[attr]foo bar1",
 				"[attr]foo bar2", null, "*.txt foo");
 
-		walk = beginWalk();
-		assertIteration(D, "sub");
-		assertIteration(F, "sub/.gitattributes");
-		assertIteration(F, "sub/a.txt", attrs("foo bar2"));
-		endWalk();
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, D, "sub");
+			assertIteration(walk, F, "sub/.gitattributes");
+			assertIteration(walk, F, "sub/a.txt", attrs("foo bar2"));
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
 	@Test
@@ -211,12 +223,13 @@ public class AttributesHandlerTest extends RepositoryTestCase {
 				null,
 				"[attr]foo bar3", "*.txt foo");
 
-		walk = beginWalk();
-		assertIteration(F, ".gitattributes");
-		assertIteration(D, "sub");
-		assertIteration(F, "sub/.gitattributes");
-		assertIteration(F, "sub/a.txt", attrs("foo bar3"));
-		endWalk();
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, F, ".gitattributes");
+			assertIteration(walk, D, "sub");
+			assertIteration(walk, F, "sub/.gitattributes");
+			assertIteration(walk, F, "sub/a.txt", attrs("foo bar3"));
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
 	@Test
@@ -224,12 +237,13 @@ public class AttributesHandlerTest extends RepositoryTestCase {
 		setupRepo("[attr]foo bar1",
 				"[attr]foo bar2", "[attr]foo bar3", "*.txt foo");
 
-		walk = beginWalk();
-		assertIteration(F, ".gitattributes");
-		assertIteration(D, "sub");
-		assertIteration(F, "sub/.gitattributes");
-		assertIteration(F, "sub/a.txt", attrs("foo bar2"));
-		endWalk();
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, F, ".gitattributes");
+			assertIteration(walk, D, "sub");
+			assertIteration(walk, F, "sub/.gitattributes");
+			assertIteration(walk, F, "sub/a.txt", attrs("foo bar2"));
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
 	@Test
@@ -238,11 +252,12 @@ public class AttributesHandlerTest extends RepositoryTestCase {
 				"[attr]foo x bar -foo",
 				null, null, "*.txt foo");
 
-		walk = beginWalk();
-		assertIteration(D, "sub");
-		assertIteration(F, "sub/.gitattributes");
-		assertIteration(F, "sub/a.txt", attrs("foo x bar"));
-		endWalk();
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, D, "sub");
+			assertIteration(walk, F, "sub/.gitattributes");
+			assertIteration(walk, F, "sub/a.txt", attrs("foo x bar"));
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
 	@Test
@@ -250,11 +265,12 @@ public class AttributesHandlerTest extends RepositoryTestCase {
 		setupRepo(
 				"[attr]foo x -bar\n[attr]bar y -foo", null, null, "*.txt foo");
 
-		walk = beginWalk();
-		assertIteration(D, "sub");
-		assertIteration(F, "sub/.gitattributes");
-		assertIteration(F, "sub/a.txt", attrs("foo x -bar -y"));
-		endWalk();
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, D, "sub");
+			assertIteration(walk, F, "sub/.gitattributes");
+			assertIteration(walk, F, "sub/a.txt", attrs("foo x -bar -y"));
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
 	@Test
@@ -266,23 +282,30 @@ public class AttributesHandlerTest extends RepositoryTestCase {
 		// apply to any of the files here. It would match for a
 		// further subdirectory sub/sub. The sub/ rules must match
 		// only for directories.
-		walk = beginWalk();
-		assertIteration(F, ".gitattributes");
-		assertIteration(D, "sub", attrs("global"));
-		assertIteration(F, "sub/.gitattributes", attrs("init top_sub"));
-		assertIteration(F, "sub/a.txt", attrs("init foo top top_sub"));
-		endWalk();
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, F, ".gitattributes");
+			assertIteration(walk, D, "sub", attrs("global"));
+			assertIteration(walk, F, "sub/.gitattributes",
+					attrs("init top_sub"));
+			assertIteration(walk, F, "sub/a.txt",
+					attrs("init foo top top_sub"));
+			assertFalse("Not all files tested", walk.next());
+		}
 		// All right, let's see that they *do* apply in sub/sub:
 		writeTrashFile("sub/sub/b.txt", "b");
-		walk = beginWalk();
-		assertIteration(F, ".gitattributes");
-		assertIteration(D, "sub", attrs("global"));
-		assertIteration(F, "sub/.gitattributes", attrs("init top_sub"));
-		assertIteration(F, "sub/a.txt", attrs("init foo top top_sub"));
-		assertIteration(D, "sub/sub", attrs("init subsub2 top_sub global"));
-		assertIteration(F, "sub/sub/b.txt",
-				attrs("init foo subsub top top_sub"));
-		endWalk();
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, F, ".gitattributes");
+			assertIteration(walk, D, "sub", attrs("global"));
+			assertIteration(walk, F, "sub/.gitattributes",
+					attrs("init top_sub"));
+			assertIteration(walk, F, "sub/a.txt",
+					attrs("init foo top top_sub"));
+			assertIteration(walk, D, "sub/sub",
+					attrs("init subsub2 top_sub global"));
+			assertIteration(walk, F, "sub/sub/b.txt",
+					attrs("init foo subsub top top_sub"));
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
 	@Test
@@ -293,16 +316,17 @@ public class AttributesHandlerTest extends RepositoryTestCase {
 		writeTrashFile("sub/b.jar", "bj");
 		writeTrashFile("sub/b.xml", "bx");
 		// On foo.xml/bar.jar we must not have 'xml'
-		walk = beginWalk();
-		assertIteration(F, ".gitattributes");
-		assertIteration(D, "foo.xml", attrs("xml"));
-		assertIteration(F, "foo.xml/bar.jar", attrs("jar"));
-		assertIteration(F, "foo.xml/bar.xml", attrs("xml"));
-		assertIteration(D, "sub");
-		assertIteration(F, "sub/a.txt");
-		assertIteration(F, "sub/b.jar", attrs("jar"));
-		assertIteration(F, "sub/b.xml", attrs("xml"));
-		endWalk();
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, F, ".gitattributes");
+			assertIteration(walk, D, "foo.xml", attrs("xml"));
+			assertIteration(walk, F, "foo.xml/bar.jar", attrs("jar"));
+			assertIteration(walk, F, "foo.xml/bar.xml", attrs("xml"));
+			assertIteration(walk, D, "sub");
+			assertIteration(walk, F, "sub/a.txt");
+			assertIteration(walk, F, "sub/b.jar", attrs("jar"));
+			assertIteration(walk, F, "sub/b.xml", attrs("xml"));
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
 	@Test
@@ -314,18 +338,19 @@ public class AttributesHandlerTest extends RepositoryTestCase {
 		writeTrashFile("sub/b.jar", "bj");
 		writeTrashFile("sub/b.xml", "bx");
 		writeTrashFile("sub/foo/b.jar", "bf");
-		walk = beginWalk();
-		assertIteration(F, ".gitattributes");
-		assertIteration(D, "foo", attrs("xml"));
-		assertIteration(F, "foo/bar.jar", attrs("jar"));
-		assertIteration(F, "foo/bar.xml");
-		assertIteration(D, "sub");
-		assertIteration(F, "sub/a.txt");
-		assertIteration(F, "sub/b.jar", attrs("jar"));
-		assertIteration(F, "sub/b.xml");
-		assertIteration(D, "sub/foo", attrs("sub xml"));
-		assertIteration(F, "sub/foo/b.jar", attrs("jar"));
-		endWalk();
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, F, ".gitattributes");
+			assertIteration(walk, D, "foo", attrs("xml"));
+			assertIteration(walk, F, "foo/bar.jar", attrs("jar"));
+			assertIteration(walk, F, "foo/bar.xml");
+			assertIteration(walk, D, "sub");
+			assertIteration(walk, F, "sub/a.txt");
+			assertIteration(walk, F, "sub/b.jar", attrs("jar"));
+			assertIteration(walk, F, "sub/b.xml");
+			assertIteration(walk, D, "sub/foo", attrs("sub xml"));
+			assertIteration(walk, F, "sub/foo/b.jar", attrs("jar"));
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
 	@Test
@@ -337,18 +362,19 @@ public class AttributesHandlerTest extends RepositoryTestCase {
 		writeTrashFile("sub/b.xml", "bx");
 		writeTrashFile("sub/foo/b.jar", "bf");
 		// On foo.xml/bar.jar we must not have 'xml'
-		walk = beginWalk();
-		assertIteration(F, ".gitattributes");
-		assertIteration(D, "foo");
-		assertIteration(F, "foo/bar.jar", attrs("jar xml"));
-		assertIteration(F, "foo/bar.xml", attrs("xml"));
-		assertIteration(D, "sub");
-		assertIteration(F, "sub/a.txt");
-		assertIteration(F, "sub/b.jar", attrs("jar"));
-		assertIteration(F, "sub/b.xml");
-		assertIteration(D, "sub/foo");
-		assertIteration(F, "sub/foo/b.jar", attrs("jar"));
-		endWalk();
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, F, ".gitattributes");
+			assertIteration(walk, D, "foo");
+			assertIteration(walk, F, "foo/bar.jar", attrs("jar xml"));
+			assertIteration(walk, F, "foo/bar.xml", attrs("xml"));
+			assertIteration(walk, D, "sub");
+			assertIteration(walk, F, "sub/a.txt");
+			assertIteration(walk, F, "sub/b.jar", attrs("jar"));
+			assertIteration(walk, F, "sub/b.xml");
+			assertIteration(walk, D, "sub/foo");
+			assertIteration(walk, F, "sub/foo/b.jar", attrs("jar"));
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
 	@Test
@@ -357,27 +383,29 @@ public class AttributesHandlerTest extends RepositoryTestCase {
 		writeTrashFile("sub/a.txt", "1");
 		writeTrashFile("foo/sext", "2");
 		writeTrashFile("foo/s.txt", "3");
-		walk = beginWalk();
-		assertIteration(F, ".gitattributes");
-		assertIteration(D, "foo");
-		assertIteration(F, "foo/s.txt", attrs("bar"));
-		assertIteration(F, "foo/sext", attrs("bar"));
-		assertIteration(D, "sub");
-		assertIteration(F, "sub/a.txt");
-		endWalk();
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, F, ".gitattributes");
+			assertIteration(walk, D, "foo");
+			assertIteration(walk, F, "foo/s.txt", attrs("bar"));
+			assertIteration(walk, F, "foo/sext", attrs("bar"));
+			assertIteration(walk, D, "sub");
+			assertIteration(walk, F, "sub/a.txt");
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
 	@Test
 	public void testPrefixMatchNot() throws Exception {
 		setupRepo(null, null, "sub/new bar", null);
 		writeTrashFile("sub/new/foo.txt", "1");
-		walk = beginWalk();
-		assertIteration(F, ".gitattributes");
-		assertIteration(D, "sub");
-		assertIteration(F, "sub/a.txt");
-		assertIteration(D, "sub/new", attrs("bar"));
-		assertIteration(F, "sub/new/foo.txt");
-		endWalk();
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, F, ".gitattributes");
+			assertIteration(walk, D, "sub");
+			assertIteration(walk, F, "sub/a.txt");
+			assertIteration(walk, D, "sub/new", attrs("bar"));
+			assertIteration(walk, F, "sub/new/foo.txt");
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
 	@Test
@@ -385,14 +413,15 @@ public class AttributesHandlerTest extends RepositoryTestCase {
 		setupRepo(null, null, "s[t-v]b/n[de]w bar", null);
 		writeTrashFile("sub/new/foo.txt", "1");
 		writeTrashFile("sub/ndw", "2");
-		walk = beginWalk();
-		assertIteration(F, ".gitattributes");
-		assertIteration(D, "sub");
-		assertIteration(F, "sub/a.txt");
-		assertIteration(F, "sub/ndw", attrs("bar"));
-		assertIteration(D, "sub/new", attrs("bar"));
-		assertIteration(F, "sub/new/foo.txt");
-		endWalk();
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, F, ".gitattributes");
+			assertIteration(walk, D, "sub");
+			assertIteration(walk, F, "sub/a.txt");
+			assertIteration(walk, F, "sub/ndw", attrs("bar"));
+			assertIteration(walk, D, "sub/new", attrs("bar"));
+			assertIteration(walk, F, "sub/new/foo.txt");
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
 	@Test
@@ -400,15 +429,16 @@ public class AttributesHandlerTest extends RepositoryTestCase {
 		setupRepo(null, null, "sub/new/* bar", null);
 		writeTrashFile("sub/new/foo.txt", "1");
 		writeTrashFile("sub/new/lower/foo.txt", "2");
-		walk = beginWalk();
-		assertIteration(F, ".gitattributes");
-		assertIteration(D, "sub");
-		assertIteration(F, "sub/a.txt");
-		assertIteration(D, "sub/new");
-		assertIteration(F, "sub/new/foo.txt", attrs("bar"));
-		assertIteration(D, "sub/new/lower", attrs("bar"));
-		assertIteration(F, "sub/new/lower/foo.txt");
-		endWalk();
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, F, ".gitattributes");
+			assertIteration(walk, D, "sub");
+			assertIteration(walk, F, "sub/a.txt");
+			assertIteration(walk, D, "sub/new");
+			assertIteration(walk, F, "sub/new/foo.txt", attrs("bar"));
+			assertIteration(walk, D, "sub/new/lower", attrs("bar"));
+			assertIteration(walk, F, "sub/new/lower/foo.txt");
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
 	@Test
@@ -417,20 +447,21 @@ public class AttributesHandlerTest extends RepositoryTestCase {
 		writeTrashFile("sub/new/foo.txt", "1");
 		writeTrashFile("foo/sub/new/foo.txt", "2");
 		writeTrashFile("sub/sub/new/foo.txt", "3");
-		walk = beginWalk();
-		assertIteration(F, ".gitattributes");
-		assertIteration(D, "foo");
-		assertIteration(D, "foo/sub");
-		assertIteration(D, "foo/sub/new");
-		assertIteration(F, "foo/sub/new/foo.txt");
-		assertIteration(D, "sub");
-		assertIteration(F, "sub/a.txt");
-		assertIteration(D, "sub/new", attrs("bar"));
-		assertIteration(F, "sub/new/foo.txt");
-		assertIteration(D, "sub/sub");
-		assertIteration(D, "sub/sub/new");
-		assertIteration(F, "sub/sub/new/foo.txt");
-		endWalk();
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, F, ".gitattributes");
+			assertIteration(walk, D, "foo");
+			assertIteration(walk, D, "foo/sub");
+			assertIteration(walk, D, "foo/sub/new");
+			assertIteration(walk, F, "foo/sub/new/foo.txt");
+			assertIteration(walk, D, "sub");
+			assertIteration(walk, F, "sub/a.txt");
+			assertIteration(walk, D, "sub/new", attrs("bar"));
+			assertIteration(walk, F, "sub/new/foo.txt");
+			assertIteration(walk, D, "sub/sub");
+			assertIteration(walk, D, "sub/sub/new");
+			assertIteration(walk, F, "sub/sub/new/foo.txt");
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
 	@Test
@@ -438,17 +469,18 @@ public class AttributesHandlerTest extends RepositoryTestCase {
 		setupRepo(null, null, "**/sub/new/ bar", null);
 		writeTrashFile("sub/new/foo.txt", "1");
 		writeTrashFile("foo/sub/new/foo.txt", "2");
-		walk = beginWalk();
-		assertIteration(F, ".gitattributes");
-		assertIteration(D, "foo");
-		assertIteration(D, "foo/sub");
-		assertIteration(D, "foo/sub/new", attrs("bar"));
-		assertIteration(F, "foo/sub/new/foo.txt");
-		assertIteration(D, "sub");
-		assertIteration(F, "sub/a.txt");
-		assertIteration(D, "sub/new", attrs("bar"));
-		assertIteration(F, "sub/new/foo.txt");
-		endWalk();
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, F, ".gitattributes");
+			assertIteration(walk, D, "foo");
+			assertIteration(walk, D, "foo/sub");
+			assertIteration(walk, D, "foo/sub/new", attrs("bar"));
+			assertIteration(walk, F, "foo/sub/new/foo.txt");
+			assertIteration(walk, D, "sub");
+			assertIteration(walk, F, "sub/a.txt");
+			assertIteration(walk, D, "sub/new", attrs("bar"));
+			assertIteration(walk, F, "sub/new/foo.txt");
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
 	@Test
@@ -457,20 +489,21 @@ public class AttributesHandlerTest extends RepositoryTestCase {
 		writeTrashFile("sub/new/foo.txt", "1");
 		writeTrashFile("foo/sub/new/foo.txt", "2");
 		writeTrashFile("sub/sub/new/foo.txt", "3");
-		walk = beginWalk();
-		assertIteration(F, ".gitattributes");
-		assertIteration(D, "foo");
-		assertIteration(D, "foo/sub");
-		assertIteration(D, "foo/sub/new", attrs("bar"));
-		assertIteration(F, "foo/sub/new/foo.txt");
-		assertIteration(D, "sub");
-		assertIteration(F, "sub/a.txt");
-		assertIteration(D, "sub/new", attrs("bar"));
-		assertIteration(F, "sub/new/foo.txt");
-		assertIteration(D, "sub/sub");
-		assertIteration(D, "sub/sub/new", attrs("bar"));
-		assertIteration(F, "sub/sub/new/foo.txt");
-		endWalk();
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, F, ".gitattributes");
+			assertIteration(walk, D, "foo");
+			assertIteration(walk, D, "foo/sub");
+			assertIteration(walk, D, "foo/sub/new", attrs("bar"));
+			assertIteration(walk, F, "foo/sub/new/foo.txt");
+			assertIteration(walk, D, "sub");
+			assertIteration(walk, F, "sub/a.txt");
+			assertIteration(walk, D, "sub/new", attrs("bar"));
+			assertIteration(walk, F, "sub/new/foo.txt");
+			assertIteration(walk, D, "sub/sub");
+			assertIteration(walk, D, "sub/sub/new", attrs("bar"));
+			assertIteration(walk, F, "sub/sub/new/foo.txt");
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
 	@Test
@@ -479,20 +512,21 @@ public class AttributesHandlerTest extends RepositoryTestCase {
 		writeTrashFile("sub/new/foo.txt", "1");
 		writeTrashFile("foo/sub/new/foo.txt", "2");
 		writeTrashFile("sub/sub/new/foo.txt", "3");
-		walk = beginWalk();
-		assertIteration(F, ".gitattributes");
-		assertIteration(D, "foo");
-		assertIteration(D, "foo/sub");
-		assertIteration(D, "foo/sub/new", attrs("bar"));
-		assertIteration(F, "foo/sub/new/foo.txt");
-		assertIteration(D, "sub");
-		assertIteration(F, "sub/a.txt");
-		assertIteration(D, "sub/new", attrs("bar"));
-		assertIteration(F, "sub/new/foo.txt");
-		assertIteration(D, "sub/sub");
-		assertIteration(D, "sub/sub/new", attrs("bar"));
-		assertIteration(F, "sub/sub/new/foo.txt");
-		endWalk();
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, F, ".gitattributes");
+			assertIteration(walk, D, "foo");
+			assertIteration(walk, D, "foo/sub");
+			assertIteration(walk, D, "foo/sub/new", attrs("bar"));
+			assertIteration(walk, F, "foo/sub/new/foo.txt");
+			assertIteration(walk, D, "sub");
+			assertIteration(walk, F, "sub/a.txt");
+			assertIteration(walk, D, "sub/new", attrs("bar"));
+			assertIteration(walk, F, "sub/new/foo.txt");
+			assertIteration(walk, D, "sub/sub");
+			assertIteration(walk, D, "sub/sub/new", attrs("bar"));
+			assertIteration(walk, F, "sub/sub/new/foo.txt");
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
 	@Test
@@ -500,17 +534,18 @@ public class AttributesHandlerTest extends RepositoryTestCase {
 		setupRepo(null, null, "s[uv]b/n*/ bar", null);
 		writeTrashFile("sub/new/foo.txt", "1");
 		writeTrashFile("foo/sub/new/foo.txt", "2");
-		walk = beginWalk();
-		assertIteration(F, ".gitattributes");
-		assertIteration(D, "foo");
-		assertIteration(D, "foo/sub");
-		assertIteration(D, "foo/sub/new");
-		assertIteration(F, "foo/sub/new/foo.txt");
-		assertIteration(D, "sub");
-		assertIteration(F, "sub/a.txt");
-		assertIteration(D, "sub/new", attrs("bar"));
-		assertIteration(F, "sub/new/foo.txt");
-		endWalk();
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, F, ".gitattributes");
+			assertIteration(walk, D, "foo");
+			assertIteration(walk, D, "foo/sub");
+			assertIteration(walk, D, "foo/sub/new");
+			assertIteration(walk, F, "foo/sub/new/foo.txt");
+			assertIteration(walk, D, "sub");
+			assertIteration(walk, F, "sub/a.txt");
+			assertIteration(walk, D, "sub/new", attrs("bar"));
+			assertIteration(walk, F, "sub/new/foo.txt");
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
 	@Test
@@ -519,30 +554,32 @@ public class AttributesHandlerTest extends RepositoryTestCase {
 		writeTrashFile("sub/new/foo.txt", "1");
 		writeTrashFile("foo/sub/new/foo.txt", "2");
 		writeTrashFile("foo/new", "3");
-		walk = beginWalk();
-		assertIteration(F, ".gitattributes");
-		assertIteration(D, "foo");
-		assertIteration(F, "foo/new");
-		assertIteration(D, "foo/sub");
-		assertIteration(D, "foo/sub/new", attrs("bar"));
-		assertIteration(F, "foo/sub/new/foo.txt");
-		assertIteration(D, "sub");
-		assertIteration(F, "sub/a.txt");
-		assertIteration(D, "sub/new", attrs("bar"));
-		assertIteration(F, "sub/new/foo.txt");
-		endWalk();
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, F, ".gitattributes");
+			assertIteration(walk, D, "foo");
+			assertIteration(walk, F, "foo/new");
+			assertIteration(walk, D, "foo/sub");
+			assertIteration(walk, D, "foo/sub/new", attrs("bar"));
+			assertIteration(walk, F, "foo/sub/new/foo.txt");
+			assertIteration(walk, D, "sub");
+			assertIteration(walk, F, "sub/a.txt");
+			assertIteration(walk, D, "sub/new", attrs("bar"));
+			assertIteration(walk, F, "sub/new/foo.txt");
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
 	private static Collection<Attribute> attrs(String s) {
 		return new AttributesRule("*", s).getAttributes();
 	}
 
-	private void assertIteration(FileMode type, String pathName)
+	private void assertIteration(TreeWalk walk, FileMode type, String pathName)
 			throws IOException {
-		assertIteration(type, pathName, Collections.<Attribute> emptyList());
+		assertIteration(walk, type, pathName,
+				Collections.<Attribute> emptyList());
 	}
 
-	private void assertIteration(FileMode type, String pathName,
+	private void assertIteration(TreeWalk walk, FileMode type, String pathName,
 			Collection<Attribute> expectedAttrs) throws IOException {
 		assertTrue("walk has entry", walk.next());
 		assertEquals(pathName, walk.getPathString());
@@ -611,8 +648,4 @@ public class AttributesHandlerTest extends RepositoryTestCase {
 		newWalk.addTree(new FileTreeIterator(db));
 		return newWalk;
 	}
-
-	private void endWalk() throws IOException {
-		assertFalse("Not all files tested", walk.next());
-	}
 }
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/attributes/AttributesNodeDirCacheIteratorTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/attributes/AttributesNodeDirCacheIteratorTest.java
index 837de7481..cb37d8978 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/attributes/AttributesNodeDirCacheIteratorTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/attributes/AttributesNodeDirCacheIteratorTest.java
@@ -78,8 +78,6 @@ public class AttributesNodeDirCacheIteratorTest extends RepositoryTestCase {
 
 	private Git git;
 
-	private TreeWalk walk;
-
 	@Override
 	@Before
 	public void setUp() throws Exception {
@@ -105,23 +103,25 @@ public class AttributesNodeDirCacheIteratorTest extends RepositoryTestCase {
 		// Adds file to index
 		git.add().addFilepattern(".").call();
 
-		walk = beginWalk();
-
-		assertIteration(F, ".gitattributes");
-		assertIteration(F, "readme.txt", asList(EOL_LF));
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, F, ".gitattributes");
+			assertIteration(walk, F, "readme.txt", asList(EOL_LF));
 
-		assertIteration(D, "src");
+			assertIteration(walk, D, "src");
 
-		assertIteration(D, "src/config");
-		assertIteration(F, "src/config/.gitattributes");
-		assertIteration(F, "src/config/readme.txt", asList(DELTA_UNSET));
-		assertIteration(F, "src/config/windows.file", null);
-		assertIteration(F, "src/config/windows.txt", asList(DELTA_UNSET));
+			assertIteration(walk, D, "src/config");
+			assertIteration(walk, F, "src/config/.gitattributes");
+			assertIteration(walk, F, "src/config/readme.txt",
+					asList(DELTA_UNSET));
+			assertIteration(walk, F, "src/config/windows.file", null);
+			assertIteration(walk, F, "src/config/windows.txt",
+					asList(DELTA_UNSET));
 
-		assertIteration(F, "windows.file", null);
-		assertIteration(F, "windows.txt", asList(EOL_LF));
+			assertIteration(walk, F, "windows.file", null);
+			assertIteration(walk, F, "windows.txt", asList(EOL_LF));
 
-		endWalk();
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
 	/**
@@ -138,17 +138,18 @@ public class AttributesNodeDirCacheIteratorTest extends RepositoryTestCase {
 
 		// Adds file to index
 		git.add().addFilepattern(".").call();
-		walk = beginWalk();
 
-		assertIteration(F, "l0.txt");
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, F, "l0.txt");
 
-		assertIteration(D, "level1");
-		assertIteration(F, "level1/l1.txt");
+			assertIteration(walk, D, "level1");
+			assertIteration(walk, F, "level1/l1.txt");
 
-		assertIteration(D, "level1/level2");
-		assertIteration(F, "level1/level2/l2.txt");
+			assertIteration(walk, D, "level1/level2");
+			assertIteration(walk, F, "level1/level2/l2.txt");
 
-		endWalk();
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
 	/**
@@ -166,18 +167,19 @@ public class AttributesNodeDirCacheIteratorTest extends RepositoryTestCase {
 
 		// Adds file to index
 		git.add().addFilepattern(".").call();
-		walk = beginWalk();
 
-		assertIteration(F, ".gitattributes");
-		assertIteration(F, "l0.txt");
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, F, ".gitattributes");
+			assertIteration(walk, F, "l0.txt");
 
-		assertIteration(D, "level1");
-		assertIteration(F, "level1/l1.txt");
+			assertIteration(walk, D, "level1");
+			assertIteration(walk, F, "level1/l1.txt");
 
-		assertIteration(D, "level1/level2");
-		assertIteration(F, "level1/level2/l2.txt");
+			assertIteration(walk, D, "level1/level2");
+			assertIteration(walk, F, "level1/level2/l2.txt");
 
-		endWalk();
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
 	@Test
@@ -191,18 +193,19 @@ public class AttributesNodeDirCacheIteratorTest extends RepositoryTestCase {
 
 		// Adds file to index
 		git.add().addFilepattern(".").call();
-		walk = beginWalk();
 
-		assertIteration(F, ".gitattributes");
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, F, ".gitattributes");
 
-		assertIteration(D, "levelA");
-		assertIteration(F, "levelA/.gitattributes");
-		assertIteration(F, "levelA/lA.txt");
+			assertIteration(walk, D, "levelA");
+			assertIteration(walk, F, "levelA/.gitattributes");
+			assertIteration(walk, F, "levelA/lA.txt");
 
-		assertIteration(D, "levelB");
-		assertIteration(F, "levelB/.gitattributes");
+			assertIteration(walk, D, "levelB");
+			assertIteration(walk, F, "levelB/.gitattributes");
 
-		endWalk();
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
 	@Test
@@ -215,25 +218,27 @@ public class AttributesNodeDirCacheIteratorTest extends RepositoryTestCase {
 
 		// Adds file to index
 		git.add().addFilepattern(".").call();
-		walk = beginWalk();
 
-		assertIteration(F, "gitattributes");
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, F, "gitattributes");
 
-		assertIteration(F, "l0.txt");
+			assertIteration(walk, F, "l0.txt");
 
-		assertIteration(D, "levelA");
-		assertIteration(F, "levelA/file.gitattributes");
-		assertIteration(F, "levelA/lA.txt");
+			assertIteration(walk, D, "levelA");
+			assertIteration(walk, F, "levelA/file.gitattributes");
+			assertIteration(walk, F, "levelA/lA.txt");
 
-		endWalk();
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
-	private void assertIteration(FileMode type, String pathName)
+	private void assertIteration(TreeWalk walk, FileMode type, String pathName)
 			throws IOException {
-		assertIteration(type, pathName, Collections.<Attribute> emptyList());
+		assertIteration(walk, type, pathName,
+				Collections.<Attribute> emptyList());
 	}
 
-	private void assertIteration(FileMode type, String pathName,
+	private void assertIteration(TreeWalk walk, FileMode type, String pathName,
 			List<Attribute> nodeAttrs) throws IOException {
 		assertTrue("walk has entry", walk.next());
 		assertEquals(pathName, walk.getPathString());
@@ -243,14 +248,14 @@ public class AttributesNodeDirCacheIteratorTest extends RepositoryTestCase {
 
 		AttributesNode attributesNode = itr.getEntryAttributesNode(db
 				.newObjectReader());
-		assertAttributesNode(pathName, attributesNode, nodeAttrs);
+		assertAttributesNode(walk, pathName, attributesNode, nodeAttrs);
 
 		if (D.equals(type))
 			walk.enterSubtree();
 
 	}
 
-	private void assertAttributesNode(String pathName,
+	private void assertAttributesNode(TreeWalk walk, String pathName,
 			AttributesNode attributesNode, List<Attribute> nodeAttrs)
 					throws IOException {
 		if (attributesNode == null)
@@ -292,8 +297,4 @@ public class AttributesNodeDirCacheIteratorTest extends RepositoryTestCase {
 		newWalk.addTree(new DirCacheIterator(db.readDirCache()));
 		return newWalk;
 	}
-
-	private void endWalk() throws IOException {
-		assertFalse("Not all files tested", walk.next());
-	}
 }
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/attributes/AttributesNodeWorkingTreeIteratorTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/attributes/AttributesNodeWorkingTreeIteratorTest.java
index b159cca0d..9991ae59b 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/attributes/AttributesNodeWorkingTreeIteratorTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/attributes/AttributesNodeWorkingTreeIteratorTest.java
@@ -77,8 +77,6 @@ public class AttributesNodeWorkingTreeIteratorTest extends RepositoryTestCase {
 
 	private static Attribute DELTA_UNSET = new Attribute("delta", State.UNSET);
 
-	private TreeWalk walk;
-
 	@Test
 	public void testRules() throws Exception {
 
@@ -102,24 +100,26 @@ public class AttributesNodeWorkingTreeIteratorTest extends RepositoryTestCase {
 		writeTrashFile("src/config/windows.file", "");
 		writeTrashFile("src/config/windows.txt", "");
 
-		walk = beginWalk();
-
-		assertIteration(F, ".gitattributes");
-		assertIteration(F, "global.txt", asList(EOL_LF));
-		assertIteration(F, "readme.txt", asList(EOL_LF));
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, F, ".gitattributes");
+			assertIteration(walk, F, "global.txt", asList(EOL_LF));
+			assertIteration(walk, F, "readme.txt", asList(EOL_LF));
 
-		assertIteration(D, "src");
+			assertIteration(walk, D, "src");
 
-		assertIteration(D, "src/config");
-		assertIteration(F, "src/config/.gitattributes");
-		assertIteration(F, "src/config/readme.txt", asList(DELTA_UNSET));
-		assertIteration(F, "src/config/windows.file", null);
-		assertIteration(F, "src/config/windows.txt", asList(DELTA_UNSET));
+			assertIteration(walk, D, "src/config");
+			assertIteration(walk, F, "src/config/.gitattributes");
+			assertIteration(walk, F, "src/config/readme.txt",
+					asList(DELTA_UNSET));
+			assertIteration(walk, F, "src/config/windows.file", null);
+			assertIteration(walk, F, "src/config/windows.txt",
+					asList(DELTA_UNSET));
 
-		assertIteration(F, "windows.file", null);
-		assertIteration(F, "windows.txt", asList(EOL_LF));
+			assertIteration(walk, F, "windows.file", null);
+			assertIteration(walk, F, "windows.txt", asList(EOL_LF));
 
-		endWalk();
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
 	/**
@@ -134,17 +134,17 @@ public class AttributesNodeWorkingTreeIteratorTest extends RepositoryTestCase {
 		writeTrashFile("level1/l1.txt", "");
 		writeTrashFile("level1/level2/l2.txt", "");
 
-		walk = beginWalk();
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, F, "l0.txt");
 
-		assertIteration(F, "l0.txt");
+			assertIteration(walk, D, "level1");
+			assertIteration(walk, F, "level1/l1.txt");
 
-		assertIteration(D, "level1");
-		assertIteration(F, "level1/l1.txt");
+			assertIteration(walk, D, "level1/level2");
+			assertIteration(walk, F, "level1/level2/l2.txt");
 
-		assertIteration(D, "level1/level2");
-		assertIteration(F, "level1/level2/l2.txt");
-
-		endWalk();
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
 	/**
@@ -160,18 +160,18 @@ public class AttributesNodeWorkingTreeIteratorTest extends RepositoryTestCase {
 		writeTrashFile("level1/l1.txt", "");
 		writeTrashFile("level1/level2/l2.txt", "");
 
-		walk = beginWalk();
-
-		assertIteration(F, ".gitattributes");
-		assertIteration(F, "l0.txt");
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, F, ".gitattributes");
+			assertIteration(walk, F, "l0.txt");
 
-		assertIteration(D, "level1");
-		assertIteration(F, "level1/l1.txt");
+			assertIteration(walk, D, "level1");
+			assertIteration(walk, F, "level1/l1.txt");
 
-		assertIteration(D, "level1/level2");
-		assertIteration(F, "level1/level2/l2.txt");
+			assertIteration(walk, D, "level1/level2");
+			assertIteration(walk, F, "level1/level2/l2.txt");
 
-		endWalk();
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
 	@Test
@@ -183,26 +183,27 @@ public class AttributesNodeWorkingTreeIteratorTest extends RepositoryTestCase {
 
 		writeTrashFile("levelA/lA.txt", "");
 
-		walk = beginWalk();
-
-		assertIteration(F, ".gitattributes");
+		try (TreeWalk walk = beginWalk()) {
+			assertIteration(walk, F, ".gitattributes");
 
-		assertIteration(D, "levelA");
-		assertIteration(F, "levelA/.gitattributes");
-		assertIteration(F, "levelA/lA.txt");
+			assertIteration(walk, D, "levelA");
+			assertIteration(walk, F, "levelA/.gitattributes");
+			assertIteration(walk, F, "levelA/lA.txt");
 
-		assertIteration(D, "levelB");
-		assertIteration(F, "levelB/.gitattributes");
+			assertIteration(walk, D, "levelB");
+			assertIteration(walk, F, "levelB/.gitattributes");
 
-		endWalk();
+			assertFalse("Not all files tested", walk.next());
+		}
 	}
 
-	private void assertIteration(FileMode type, String pathName)
+	private void assertIteration(TreeWalk walk, FileMode type, String pathName)
 			throws IOException {
-		assertIteration(type, pathName, Collections.<Attribute> emptyList());
+		assertIteration(walk, type, pathName,
+				Collections.<Attribute> emptyList());
 	}
 
-	private void assertIteration(FileMode type, String pathName,
+	private void assertIteration(TreeWalk walk, FileMode type, String pathName,
 			List<Attribute> nodeAttrs)
 			throws IOException {
 		assertTrue("walk has entry", walk.next());
@@ -212,13 +213,13 @@ public class AttributesNodeWorkingTreeIteratorTest extends RepositoryTestCase {
 		assertNotNull("has tree", itr);
 
 		AttributesNode attributesNode = itr.getEntryAttributesNode();
-		assertAttributesNode(pathName, attributesNode, nodeAttrs);
+		assertAttributesNode(walk, pathName, attributesNode, nodeAttrs);
 		if (D.equals(type))
 			walk.enterSubtree();
 
 	}
 
-	private void assertAttributesNode(String pathName,
+	private void assertAttributesNode(TreeWalk walk, String pathName,
 			AttributesNode attributesNode, List<Attribute> nodeAttrs)
 					throws IOException {
 		if (attributesNode == null)
@@ -259,8 +260,4 @@ public class AttributesNodeWorkingTreeIteratorTest extends RepositoryTestCase {
 		newWalk.addTree(new FileTreeIterator(db));
 		return newWalk;
 	}
-
-	private void endWalk() throws IOException {
-		assertFalse("Not all files tested", walk.next());
-	}
 }
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/attributes/TreeWalkAttributeTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/attributes/TreeWalkAttributeTest.java
index d6aead4a5..0291fcc1e 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/attributes/TreeWalkAttributeTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/attributes/TreeWalkAttributeTest.java
@@ -131,6 +131,12 @@ public class TreeWalkAttributeTest extends RepositoryTestCase {
 	@Override
 	@After
 	public void tearDown() throws Exception {
+		if (walk != null) {
+			walk.close();
+		}
+		if (ci_walk != null) {
+			ci_walk.close();
+		}
 		super.tearDown();
 		if (customAttributeFile != null)
 			customAttributeFile.delete();
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/ignore/IgnoreNodeTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/ignore/IgnoreNodeTest.java
index cbc076146..45046a399 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/ignore/IgnoreNodeTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/ignore/IgnoreNodeTest.java
@@ -63,6 +63,7 @@ import org.eclipse.jgit.treewalk.TreeWalk;
 import org.eclipse.jgit.treewalk.WorkingTreeIterator;
 import org.eclipse.jgit.util.FileUtils;
 import org.eclipse.jgit.util.SystemReader;
+import org.junit.After;
 import org.junit.Test;
 
 /**
@@ -79,6 +80,13 @@ public class IgnoreNodeTest extends RepositoryTestCase {
 
 	private TreeWalk walk;
 
+	@After
+	public void closeWalk() {
+		if (walk != null) {
+			walk.close();
+		}
+	}
+
 	@Test
 	public void testSimpleRootGitIgnoreGlobalIgnore() throws IOException {
 		writeIgnoreFile(".gitignore", "x");
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/merge/CherryPickTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/merge/CherryPickTest.java
index 19f6dcbc5..aa4392fca 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/merge/CherryPickTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/merge/CherryPickTest.java
@@ -106,23 +106,24 @@ public class CherryPickTest extends RepositoryTestCase {
 		boolean merge = twm.merge(new ObjectId[] { O, T });
 		assertTrue(merge);
 
-		final TreeWalk tw = new TreeWalk(db);
-		tw.setRecursive(true);
-		tw.reset(twm.getResultTreeId());
+		try (TreeWalk tw = new TreeWalk(db)) {
+			tw.setRecursive(true);
+			tw.reset(twm.getResultTreeId());
 
-		assertTrue(tw.next());
-		assertEquals("a", tw.getPathString());
-		assertCorrectId(treeO, tw);
+			assertTrue(tw.next());
+			assertEquals("a", tw.getPathString());
+			assertCorrectId(treeO, tw);
 
-		assertTrue(tw.next());
-		assertEquals("o", tw.getPathString());
-		assertCorrectId(treeO, tw);
+			assertTrue(tw.next());
+			assertEquals("o", tw.getPathString());
+			assertCorrectId(treeO, tw);
 
-		assertTrue(tw.next());
-		assertEquals("t", tw.getPathString());
-		assertCorrectId(treeT, tw);
+			assertTrue(tw.next());
+			assertEquals("t", tw.getPathString());
+			assertCorrectId(treeT, tw);
 
-		assertFalse(tw.next());
+			assertFalse(tw.next());
+		}
 	}
 
 	@Test
@@ -168,19 +169,20 @@ public class CherryPickTest extends RepositoryTestCase {
 		boolean merge = twm.merge(new ObjectId[] { B, T });
 		assertTrue(merge);
 
-		final TreeWalk tw = new TreeWalk(db);
-		tw.setRecursive(true);
-		tw.reset(twm.getResultTreeId());
+		try (TreeWalk tw = new TreeWalk(db)) {
+			tw.setRecursive(true);
+			tw.reset(twm.getResultTreeId());
 
-		assertTrue(tw.next());
-		assertEquals("a", tw.getPathString());
-		assertCorrectId(treeB, tw);
+			assertTrue(tw.next());
+			assertEquals("a", tw.getPathString());
+			assertCorrectId(treeB, tw);
 
-		assertTrue(tw.next());
-		assertEquals("t", tw.getPathString());
-		assertCorrectId(treeT, tw);
+			assertTrue(tw.next());
+			assertEquals("t", tw.getPathString());
+			assertCorrectId(treeT, tw);
 
-		assertFalse(tw.next());
+			assertFalse(tw.next());
+		}
 	}
 
 	private static void assertCorrectId(DirCache treeT, TreeWalk tw) {
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/merge/SimpleMergeTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/merge/SimpleMergeTest.java
index dd2c2e84b..6c0b165a4 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/merge/SimpleMergeTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/merge/SimpleMergeTest.java
@@ -174,23 +174,24 @@ public class SimpleMergeTest extends SampleDataRepositoryTestCase {
 		boolean merge = ourMerger.merge(new ObjectId[] { o, t });
 		assertTrue(merge);
 
-		final TreeWalk tw = new TreeWalk(db);
-		tw.setRecursive(true);
-		tw.reset(ourMerger.getResultTreeId());
+		try (TreeWalk tw = new TreeWalk(db)) {
+			tw.setRecursive(true);
+			tw.reset(ourMerger.getResultTreeId());
 
-		assertTrue(tw.next());
-		assertEquals("Makefile", tw.getPathString());
-		assertCorrectId(treeO, tw);
+			assertTrue(tw.next());
+			assertEquals("Makefile", tw.getPathString());
+			assertCorrectId(treeO, tw);
 
-		assertTrue(tw.next());
-		assertEquals("libelf-po/a", tw.getPathString());
-		assertCorrectId(treeO, tw);
+			assertTrue(tw.next());
+			assertEquals("libelf-po/a", tw.getPathString());
+			assertCorrectId(treeO, tw);
 
-		assertTrue(tw.next());
-		assertEquals("libelf/c", tw.getPathString());
-		assertCorrectId(treeT, tw);
+			assertTrue(tw.next());
+			assertEquals("libelf/c", tw.getPathString());
+			assertCorrectId(treeT, tw);
 
-		assertFalse(tw.next());
+			assertFalse(tw.next());
+		}
 	}
 
 	@Test
@@ -226,19 +227,20 @@ public class SimpleMergeTest extends SampleDataRepositoryTestCase {
 		boolean merge = ourMerger.merge(new ObjectId[] { o, t });
 		assertTrue(merge);
 
-		final TreeWalk tw = new TreeWalk(db);
-		tw.setRecursive(true);
-		tw.reset(ourMerger.getResultTreeId());
+		try (TreeWalk tw = new TreeWalk(db)) {
+			tw.setRecursive(true);
+			tw.reset(ourMerger.getResultTreeId());
 
-		assertTrue(tw.next());
-		assertEquals("d/o", tw.getPathString());
-		assertCorrectId(treeO, tw);
+			assertTrue(tw.next());
+			assertEquals("d/o", tw.getPathString());
+			assertCorrectId(treeO, tw);
 
-		assertTrue(tw.next());
-		assertEquals("d/t", tw.getPathString());
-		assertCorrectId(treeT, tw);
+			assertTrue(tw.next());
+			assertEquals("d/t", tw.getPathString());
+			assertCorrectId(treeT, tw);
 
-		assertFalse(tw.next());
+			assertFalse(tw.next());
+		}
 	}
 
 	@Test
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/submodule/SubmoduleAddTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/submodule/SubmoduleAddTest.java
index 1ff64a2e2..80e9e6b14 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/submodule/SubmoduleAddTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/submodule/SubmoduleAddTest.java
@@ -135,20 +135,20 @@ public class SubmoduleAddTest extends RepositoryTestCase {
 				subCommit = repo.resolve(Constants.HEAD);
 			}
 
-			SubmoduleWalk generator = SubmoduleWalk.forIndex(db);
-			generator.loadModulesConfig();
-			assertTrue(generator.next());
-			assertEquals(path, generator.getModuleName());
-			assertEquals(path, generator.getPath());
-			assertEquals(commit, generator.getObjectId());
-			assertEquals(uri, generator.getModulesUrl());
-			assertEquals(path, generator.getModulesPath());
-			assertEquals(uri, generator.getConfigUrl());
-			try (Repository subModRepo = generator.getRepository()) {
-				assertNotNull(subModRepo);
-				assertEquals(subCommit, commit);
+			try (SubmoduleWalk generator = SubmoduleWalk.forIndex(db)) {
+				generator.loadModulesConfig();
+				assertTrue(generator.next());
+				assertEquals(path, generator.getModuleName());
+				assertEquals(path, generator.getPath());
+				assertEquals(commit, generator.getObjectId());
+				assertEquals(uri, generator.getModulesUrl());
+				assertEquals(path, generator.getModulesPath());
+				assertEquals(uri, generator.getConfigUrl());
+				try (Repository subModRepo = generator.getRepository()) {
+					assertNotNull(subModRepo);
+					assertEquals(subCommit, commit);
+				}
 			}
-
 			Status status = Git.wrap(db).status().call();
 			assertTrue(status.getAdded().contains(Constants.DOT_GIT_MODULES));
 			assertTrue(status.getAdded().contains(path));
@@ -175,20 +175,20 @@ public class SubmoduleAddTest extends RepositoryTestCase {
 				subCommit = repo.resolve(Constants.HEAD);
 			}
 
-			SubmoduleWalk generator = SubmoduleWalk.forIndex(db);
-			generator.loadModulesConfig();
-			assertTrue(generator.next());
-			assertEquals(name, generator.getModuleName());
-			assertEquals(path, generator.getPath());
-			assertEquals(commit, generator.getObjectId());
-			assertEquals(uri, generator.getModulesUrl());
-			assertEquals(path, generator.getModulesPath());
-			assertEquals(uri, generator.getConfigUrl());
-			try (Repository subModRepo = generator.getRepository()) {
-				assertNotNull(subModRepo);
-				assertEquals(subCommit, commit);
+			try (SubmoduleWalk generator = SubmoduleWalk.forIndex(db)) {
+				generator.loadModulesConfig();
+				assertTrue(generator.next());
+				assertEquals(name, generator.getModuleName());
+				assertEquals(path, generator.getPath());
+				assertEquals(commit, generator.getObjectId());
+				assertEquals(uri, generator.getModulesUrl());
+				assertEquals(path, generator.getModulesPath());
+				assertEquals(uri, generator.getConfigUrl());
+				try (Repository subModRepo = generator.getRepository()) {
+					assertNotNull(subModRepo);
+					assertEquals(subCommit, commit);
+				}
 			}
-
 			Status status = Git.wrap(db).status().call();
 			assertTrue(status.getAdded().contains(Constants.DOT_GIT_MODULES));
 			assertTrue(status.getAdded().contains(path));
@@ -269,24 +269,25 @@ public class SubmoduleAddTest extends RepositoryTestCase {
 			assertNotNull(repo);
 			addRepoToClose(repo);
 
-			SubmoduleWalk generator = SubmoduleWalk.forIndex(db);
-			assertTrue(generator.next());
-			assertEquals(path, generator.getPath());
-			assertEquals(commit, generator.getObjectId());
-			assertEquals(uri, generator.getModulesUrl());
-			assertEquals(path, generator.getModulesPath());
-			String fullUri = db.getDirectory().getAbsolutePath();
-			if (File.separatorChar == '\\') {
-				fullUri = fullUri.replace('\\', '/');
-			}
-			assertEquals(fullUri, generator.getConfigUrl());
-			try (Repository subModRepo = generator.getRepository()) {
-				assertNotNull(subModRepo);
-				assertEquals(fullUri,
-						subModRepo.getConfig().getString(
-								ConfigConstants.CONFIG_REMOTE_SECTION,
-								Constants.DEFAULT_REMOTE_NAME,
-								ConfigConstants.CONFIG_KEY_URL));
+			try (SubmoduleWalk generator = SubmoduleWalk.forIndex(db)) {
+				assertTrue(generator.next());
+				assertEquals(path, generator.getPath());
+				assertEquals(commit, generator.getObjectId());
+				assertEquals(uri, generator.getModulesUrl());
+				assertEquals(path, generator.getModulesPath());
+				String fullUri = db.getDirectory().getAbsolutePath();
+				if (File.separatorChar == '\\') {
+					fullUri = fullUri.replace('\\', '/');
+				}
+				assertEquals(fullUri, generator.getConfigUrl());
+				try (Repository subModRepo = generator.getRepository()) {
+					assertNotNull(subModRepo);
+					assertEquals(fullUri,
+							subModRepo.getConfig().getString(
+									ConfigConstants.CONFIG_REMOTE_SECTION,
+									Constants.DEFAULT_REMOTE_NAME,
+									ConfigConstants.CONFIG_KEY_URL));
+				}
 			}
 			assertEquals(commit, repo.resolve(Constants.HEAD));
 
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/submodule/SubmoduleDeinitTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/submodule/SubmoduleDeinitTest.java
index 815ce9b35..bb0085106 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/submodule/SubmoduleDeinitTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/submodule/SubmoduleDeinitTest.java
@@ -107,7 +107,6 @@ public class SubmoduleDeinitTest extends RepositoryTestCase {
 		assertEquals(1, updated.size());
 
 		File submoduleDir = assertSubmoduleIsInitialized();
-		SubmoduleWalk generator;
 
 		write(new File(submoduleDir, "untracked"), "untracked");
 
@@ -115,8 +114,9 @@ public class SubmoduleDeinitTest extends RepositoryTestCase {
 		assertEquals(path, result.getPath());
 		assertEquals(SubmoduleDeinitCommand.SubmoduleDeinitStatus.DIRTY, result.getStatus());
 
-		generator = SubmoduleWalk.forIndex(db);
-		assertTrue(generator.next());
+		try (SubmoduleWalk generator = SubmoduleWalk.forIndex(db)) {
+			assertTrue(generator.next());
+		}
 		assertTrue(submoduleDir.isDirectory());
 		assertNotEquals(0, submoduleDir.list().length);
 	}
@@ -132,33 +132,36 @@ public class SubmoduleDeinitTest extends RepositoryTestCase {
 		assertEquals(1, updated.size());
 
 		File submoduleDir = assertSubmoduleIsInitialized();
-		SubmoduleWalk generator = SubmoduleWalk.forIndex(db);
-		generator.next();
-
-		//want to create a commit inside the repo...
-		try (Repository submoduleLocalRepo = generator.getRepository()) {
-			JGitTestUtil.writeTrashFile(submoduleLocalRepo, "file.txt",
-					"new data");
-			Git.wrap(submoduleLocalRepo).commit().setAll(true)
-					.setMessage("local commit").call();
+		try (SubmoduleWalk generator = SubmoduleWalk.forIndex(db)) {
+			generator.next();
+
+			// want to create a commit inside the repo...
+			try (Repository submoduleLocalRepo = generator.getRepository()) {
+				JGitTestUtil.writeTrashFile(submoduleLocalRepo, "file.txt",
+						"new data");
+				Git.wrap(submoduleLocalRepo).commit().setAll(true)
+						.setMessage("local commit").call();
+			}
 		}
 		SubmoduleDeinitResult result = runDeinit(new SubmoduleDeinitCommand(db).addPath("sub"));
 		assertEquals(path, result.getPath());
 		assertEquals(SubmoduleDeinitCommand.SubmoduleDeinitStatus.DIRTY, result.getStatus());
 
-		generator = SubmoduleWalk.forIndex(db);
-		assertTrue(generator.next());
+		try (SubmoduleWalk generator = SubmoduleWalk.forIndex(db)) {
+			assertTrue(generator.next());
+		}
 		assertTrue(submoduleDir.isDirectory());
 		assertNotEquals(0, submoduleDir.list().length);
 	}
 
 	private File assertSubmoduleIsInitialized() throws IOException {
-		SubmoduleWalk generator = SubmoduleWalk.forIndex(db);
-		assertTrue(generator.next());
-		File submoduleDir = new File(db.getWorkTree(), generator.getPath());
-		assertTrue(submoduleDir.isDirectory());
-		assertNotEquals(0, submoduleDir.list().length);
-		return submoduleDir;
+		try (SubmoduleWalk generator = SubmoduleWalk.forIndex(db)) {
+			assertTrue(generator.next());
+			File submoduleDir = new File(db.getWorkTree(), generator.getPath());
+			assertTrue(submoduleDir.isDirectory());
+			assertNotEquals(0, submoduleDir.list().length);
+			return submoduleDir;
+		}
 	}
 
 	@Test
@@ -180,8 +183,9 @@ public class SubmoduleDeinitTest extends RepositoryTestCase {
 		assertEquals(path, result.getPath());
 		assertEquals(SubmoduleDeinitCommand.SubmoduleDeinitStatus.FORCED, result.getStatus());
 
-		SubmoduleWalk generator = SubmoduleWalk.forIndex(db);
-		assertTrue(generator.next());
+		try (SubmoduleWalk generator = SubmoduleWalk.forIndex(db)) {
+			assertTrue(generator.next());
+		}
 		assertTrue(submoduleDir.isDirectory());
 		assertEquals(0, submoduleDir.list().length);
 	}
@@ -202,8 +206,9 @@ public class SubmoduleDeinitTest extends RepositoryTestCase {
 		assertEquals(path, result.getPath());
 		assertEquals(SubmoduleDeinitCommand.SubmoduleDeinitStatus.SUCCESS, result.getStatus());
 
-		SubmoduleWalk generator = SubmoduleWalk.forIndex(db);
-		assertTrue(generator.next());
+		try (SubmoduleWalk generator = SubmoduleWalk.forIndex(db)) {
+			assertTrue(generator.next());
+		}
 		assertTrue(submoduleDir.isDirectory());
 		assertEquals(0, submoduleDir.list().length);
 	}
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/submodule/SubmoduleInitTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/submodule/SubmoduleInitTest.java
index c7a009c5b..9fe2fc6fd 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/submodule/SubmoduleInitTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/submodule/SubmoduleInitTest.java
@@ -86,11 +86,11 @@ public class SubmoduleInitTest extends RepositoryTestCase {
 			ConfigInvalidException, GitAPIException {
 		final String path = addSubmoduleToIndex();
 
-		SubmoduleWalk generator = SubmoduleWalk.forIndex(db);
-		assertTrue(generator.next());
-		assertNull(generator.getConfigUrl());
-		assertNull(generator.getConfigUpdate());
-
+		try (SubmoduleWalk generator = SubmoduleWalk.forIndex(db)) {
+			assertTrue(generator.next());
+			assertNull(generator.getConfigUrl());
+			assertNull(generator.getConfigUpdate());
+		}
 		FileBasedConfig modulesConfig = new FileBasedConfig(new File(
 				db.getWorkTree(), Constants.DOT_GIT_MODULES), db.getFS());
 		modulesConfig.setString(ConfigConstants.CONFIG_SUBMODULE_SECTION, path,
@@ -109,10 +109,11 @@ public class SubmoduleInitTest extends RepositoryTestCase {
 		assertEquals(1, modules.size());
 		assertEquals(path, modules.iterator().next());
 
-		generator = SubmoduleWalk.forIndex(db);
-		assertTrue(generator.next());
-		assertEquals(url, generator.getConfigUrl());
-		assertEquals(update, generator.getConfigUpdate());
+		try (SubmoduleWalk generator = SubmoduleWalk.forIndex(db)) {
+			assertTrue(generator.next());
+			assertEquals(url, generator.getConfigUrl());
+			assertEquals(update, generator.getConfigUpdate());
+		}
 	}
 
 	@Test
@@ -126,11 +127,11 @@ public class SubmoduleInitTest extends RepositoryTestCase {
 				base);
 		config.save();
 
-		SubmoduleWalk generator = SubmoduleWalk.forIndex(db);
-		assertTrue(generator.next());
-		assertNull(generator.getConfigUrl());
-		assertNull(generator.getConfigUpdate());
-
+		try (SubmoduleWalk generator = SubmoduleWalk.forIndex(db)) {
+			assertTrue(generator.next());
+			assertNull(generator.getConfigUrl());
+			assertNull(generator.getConfigUpdate());
+		}
 		FileBasedConfig modulesConfig = new FileBasedConfig(new File(
 				db.getWorkTree(), Constants.DOT_GIT_MODULES), db.getFS());
 		modulesConfig.setString(ConfigConstants.CONFIG_SUBMODULE_SECTION, path,
@@ -149,10 +150,12 @@ public class SubmoduleInitTest extends RepositoryTestCase {
 		assertEquals(1, modules.size());
 		assertEquals(path, modules.iterator().next());
 
-		generator = SubmoduleWalk.forIndex(db);
-		assertTrue(generator.next());
-		assertEquals("git://server/repo.git/sub.git", generator.getConfigUrl());
-		assertEquals(update, generator.getConfigUpdate());
+		try (SubmoduleWalk generator = SubmoduleWalk.forIndex(db)) {
+			assertTrue(generator.next());
+			assertEquals("git://server/repo.git/sub.git",
+					generator.getConfigUrl());
+			assertEquals(update, generator.getConfigUpdate());
+		}
 	}
 
 	@Test
@@ -167,11 +170,11 @@ public class SubmoduleInitTest extends RepositoryTestCase {
 				base);
 		config.save();
 
-		SubmoduleWalk generator = SubmoduleWalk.forIndex(db);
-		assertTrue(generator.next());
-		assertNull(generator.getConfigUrl());
-		assertNull(generator.getConfigUpdate());
-
+		try (SubmoduleWalk generator = SubmoduleWalk.forIndex(db)) {
+			assertTrue(generator.next());
+			assertNull(generator.getConfigUrl());
+			assertNull(generator.getConfigUpdate());
+		}
 		FileBasedConfig modulesConfig = new FileBasedConfig(new File(
 				db.getWorkTree(), Constants.DOT_GIT_MODULES), db.getFS());
 		modulesConfig.setString(ConfigConstants.CONFIG_SUBMODULE_SECTION, path,
@@ -190,10 +193,11 @@ public class SubmoduleInitTest extends RepositoryTestCase {
 		assertEquals(1, modules.size());
 		assertEquals(path, modules.iterator().next());
 
-		generator = SubmoduleWalk.forIndex(db);
-		assertTrue(generator.next());
-		assertEquals("git://server/sub.git", generator.getConfigUrl());
-		assertEquals(update, generator.getConfigUpdate());
+		try (SubmoduleWalk generator = SubmoduleWalk.forIndex(db)) {
+			assertTrue(generator.next());
+			assertEquals("git://server/sub.git", generator.getConfigUrl());
+			assertEquals(update, generator.getConfigUpdate());
+		}
 	}
 
 	@Test
@@ -208,11 +212,11 @@ public class SubmoduleInitTest extends RepositoryTestCase {
 				base);
 		config.save();
 
-		SubmoduleWalk generator = SubmoduleWalk.forIndex(db);
-		assertTrue(generator.next());
-		assertNull(generator.getConfigUrl());
-		assertNull(generator.getConfigUpdate());
-
+		try (SubmoduleWalk generator = SubmoduleWalk.forIndex(db)) {
+			assertTrue(generator.next());
+			assertNull(generator.getConfigUrl());
+			assertNull(generator.getConfigUpdate());
+		}
 		FileBasedConfig modulesConfig = new FileBasedConfig(new File(
 				db.getWorkTree(), Constants.DOT_GIT_MODULES), db.getFS());
 		modulesConfig.setString(ConfigConstants.CONFIG_SUBMODULE_SECTION, path,
@@ -231,10 +235,11 @@ public class SubmoduleInitTest extends RepositoryTestCase {
 		assertEquals(1, modules.size());
 		assertEquals(path, modules.iterator().next());
 
-		generator = SubmoduleWalk.forIndex(db);
-		assertTrue(generator.next());
-		assertEquals("git://server2/sub.git", generator.getConfigUrl());
-		assertEquals(update, generator.getConfigUpdate());
+		try (SubmoduleWalk generator = SubmoduleWalk.forIndex(db)) {
+			assertTrue(generator.next());
+			assertEquals("git://server2/sub.git", generator.getConfigUrl());
+			assertEquals(update, generator.getConfigUpdate());
+		}
 	}
 
 	@Test
@@ -250,11 +255,11 @@ public class SubmoduleInitTest extends RepositoryTestCase {
 				Constants.DEFAULT_REMOTE_NAME, ConfigConstants.CONFIG_KEY_URL);
 		config.save();
 
-		SubmoduleWalk generator = SubmoduleWalk.forIndex(db);
-		assertTrue(generator.next());
-		assertNull(generator.getConfigUrl());
-		assertNull(generator.getConfigUpdate());
-
+		try (SubmoduleWalk generator = SubmoduleWalk.forIndex(db)) {
+			assertTrue(generator.next());
+			assertNull(generator.getConfigUrl());
+			assertNull(generator.getConfigUpdate());
+		}
 		FileBasedConfig modulesConfig = new FileBasedConfig(new File(
 				db.getWorkTree(), Constants.DOT_GIT_MODULES), db.getFS());
 		modulesConfig.setString(ConfigConstants.CONFIG_SUBMODULE_SECTION, path,
@@ -273,10 +278,11 @@ public class SubmoduleInitTest extends RepositoryTestCase {
 		assertEquals(1, modules.size());
 		assertEquals(path, modules.iterator().next());
 
-		generator = SubmoduleWalk.forIndex(db);
-		assertTrue(generator.next());
-		assertEquals(base + "/sub.git", generator.getConfigUrl());
-		assertEquals(update, generator.getConfigUpdate());
+		try (SubmoduleWalk generator = SubmoduleWalk.forIndex(db)) {
+			assertTrue(generator.next());
+			assertEquals(base + "/sub.git", generator.getConfigUrl());
+			assertEquals(update, generator.getConfigUpdate());
+		}
 	}
 
 	@Test
@@ -291,11 +297,11 @@ public class SubmoduleInitTest extends RepositoryTestCase {
 				base);
 		config.save();
 
-		SubmoduleWalk generator = SubmoduleWalk.forIndex(db);
-		assertTrue(generator.next());
-		assertNull(generator.getConfigUrl());
-		assertNull(generator.getConfigUpdate());
-
+		try (SubmoduleWalk generator = SubmoduleWalk.forIndex(db)) {
+			assertTrue(generator.next());
+			assertNull(generator.getConfigUrl());
+			assertNull(generator.getConfigUpdate());
+		}
 		FileBasedConfig modulesConfig = new FileBasedConfig(new File(
 				db.getWorkTree(), Constants.DOT_GIT_MODULES), db.getFS());
 		modulesConfig.setString(ConfigConstants.CONFIG_SUBMODULE_SECTION, path,
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/submodule/SubmoduleSyncTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/submodule/SubmoduleSyncTest.java
index 6f3b52f7b..1053e31bc 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/submodule/SubmoduleSyncTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/submodule/SubmoduleSyncTest.java
@@ -119,11 +119,11 @@ public class SubmoduleSyncTest extends RepositoryTestCase {
 		addRepoToClose(subRepo);
 		assertNotNull(subRepo);
 
-		SubmoduleWalk generator = SubmoduleWalk.forIndex(db);
-		assertTrue(generator.next());
-		assertNull(generator.getConfigUrl());
-		assertEquals(url, generator.getModulesUrl());
-
+		try (SubmoduleWalk generator = SubmoduleWalk.forIndex(db)) {
+			assertTrue(generator.next());
+			assertNull(generator.getConfigUrl());
+			assertEquals(url, generator.getModulesUrl());
+		}
 		SubmoduleSyncCommand command = new SubmoduleSyncCommand(db);
 		Map<String, String> synced = command.call();
 		assertNotNull(synced);
@@ -132,16 +132,17 @@ public class SubmoduleSyncTest extends RepositoryTestCase {
 		assertEquals(path, module.getKey());
 		assertEquals(url, module.getValue());
 
-		generator = SubmoduleWalk.forIndex(db);
-		assertTrue(generator.next());
-		assertEquals(url, generator.getConfigUrl());
-		try (Repository subModRepository = generator.getRepository()) {
-			StoredConfig submoduleConfig = subModRepository.getConfig();
-			assertEquals(url,
-					submoduleConfig.getString(
-							ConfigConstants.CONFIG_REMOTE_SECTION,
-							Constants.DEFAULT_REMOTE_NAME,
-							ConfigConstants.CONFIG_KEY_URL));
+		try (SubmoduleWalk generator = SubmoduleWalk.forIndex(db)) {
+			assertTrue(generator.next());
+			assertEquals(url, generator.getConfigUrl());
+			try (Repository subModRepository = generator.getRepository()) {
+				StoredConfig submoduleConfig = subModRepository.getConfig();
+				assertEquals(url,
+						submoduleConfig.getString(
+								ConfigConstants.CONFIG_REMOTE_SECTION,
+								Constants.DEFAULT_REMOTE_NAME,
+								ConfigConstants.CONFIG_KEY_URL));
+			}
 		}
 	}
 
@@ -190,11 +191,11 @@ public class SubmoduleSyncTest extends RepositoryTestCase {
 		assertNotNull(subRepo);
 		addRepoToClose(subRepo);
 
-		SubmoduleWalk generator = SubmoduleWalk.forIndex(db);
-		assertTrue(generator.next());
-		assertNull(generator.getConfigUrl());
-		assertEquals(current, generator.getModulesUrl());
-
+		try (SubmoduleWalk generator = SubmoduleWalk.forIndex(db)) {
+			assertTrue(generator.next());
+			assertNull(generator.getConfigUrl());
+			assertEquals(current, generator.getModulesUrl());
+		}
 		modulesConfig.setString(ConfigConstants.CONFIG_SUBMODULE_SECTION, path,
 				ConfigConstants.CONFIG_KEY_URL, "../sub.git");
 		modulesConfig.save();
@@ -207,16 +208,17 @@ public class SubmoduleSyncTest extends RepositoryTestCase {
 		assertEquals(path, module.getKey());
 		assertEquals("git://server/sub.git", module.getValue());
 
-		generator = SubmoduleWalk.forIndex(db);
-		assertTrue(generator.next());
-		assertEquals("git://server/sub.git", generator.getConfigUrl());
-		try (Repository subModRepository1 = generator.getRepository()) {
-			StoredConfig submoduleConfig = subModRepository1.getConfig();
-			assertEquals("git://server/sub.git",
-					submoduleConfig.getString(
-							ConfigConstants.CONFIG_REMOTE_SECTION,
-							Constants.DEFAULT_REMOTE_NAME,
-							ConfigConstants.CONFIG_KEY_URL));
+		try (SubmoduleWalk generator = SubmoduleWalk.forIndex(db)) {
+			assertTrue(generator.next());
+			assertEquals("git://server/sub.git", generator.getConfigUrl());
+			try (Repository subModRepository1 = generator.getRepository()) {
+				StoredConfig submoduleConfig = subModRepository1.getConfig();
+				assertEquals("git://server/sub.git",
+						submoduleConfig.getString(
+								ConfigConstants.CONFIG_REMOTE_SECTION,
+								Constants.DEFAULT_REMOTE_NAME,
+								ConfigConstants.CONFIG_KEY_URL));
+			}
 		}
 	}
 }
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/submodule/SubmoduleUpdateTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/submodule/SubmoduleUpdateTest.java
index bbce413ef..6f358b47f 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/submodule/SubmoduleUpdateTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/submodule/SubmoduleUpdateTest.java
@@ -119,11 +119,12 @@ public class SubmoduleUpdateTest extends RepositoryTestCase {
 		assertEquals(1, updated.size());
 		assertEquals(path, updated.iterator().next());
 
-		SubmoduleWalk generator = SubmoduleWalk.forIndex(db);
-		assertTrue(generator.next());
-		try (Repository subRepo = generator.getRepository()) {
-			assertNotNull(subRepo);
-			assertEquals(commit, subRepo.resolve(Constants.HEAD));
+		try (SubmoduleWalk generator = SubmoduleWalk.forIndex(db)) {
+			assertTrue(generator.next());
+			try (Repository subRepo = generator.getRepository()) {
+				assertNotNull(subRepo);
+				assertEquals(commit, subRepo.resolve(Constants.HEAD));
+			}
 		}
 	}
 
@@ -181,10 +182,11 @@ public class SubmoduleUpdateTest extends RepositoryTestCase {
 		});
 		editor.commit();
 
-		Repository subRepo = Git.init().setBare(false)
+		try (Repository subRepo = Git.init().setBare(false)
 				.setDirectory(new File(db.getWorkTree(), path)).call()
-				.getRepository();
-		assertNotNull(subRepo);
+				.getRepository()) {
+			assertNotNull(subRepo);
+		}
 
 		SubmoduleUpdateCommand command = new SubmoduleUpdateCommand(db);
 		Collection<String> updated = command.call();
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/submodule/SubmoduleWalkTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/submodule/SubmoduleWalkTest.java
index ea1ace364..0b6047f88 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/submodule/SubmoduleWalkTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/submodule/SubmoduleWalkTest.java
@@ -98,10 +98,11 @@ public class SubmoduleWalkTest extends RepositoryTestCase {
 
 	@Test
 	public void repositoryWithNoSubmodules() throws IOException {
-		SubmoduleWalk gen = SubmoduleWalk.forIndex(db);
-		assertFalse(gen.next());
-		assertNull(gen.getPath());
-		assertEquals(ObjectId.zeroId(), gen.getObjectId());
+		try (SubmoduleWalk gen = SubmoduleWalk.forIndex(db)) {
+			assertFalse(gen.next());
+			assertNull(gen.getPath());
+			assertEquals(ObjectId.zeroId(), gen.getObjectId());
+		}
 	}
 
 	@Test
@@ -129,20 +130,21 @@ public class SubmoduleWalkTest extends RepositoryTestCase {
 		});
 		editor.commit();
 
-		SubmoduleWalk gen = SubmoduleWalk.forIndex(db);
-		assertTrue(gen.next());
-		assertEquals(path, gen.getPath());
-		assertEquals(id, gen.getObjectId());
-		assertEquals(new File(db.getWorkTree(), path), gen.getDirectory());
-		assertNull(gen.getConfigUpdate());
-		assertNull(gen.getConfigUrl());
-		assertNull(gen.getModulesPath());
-		assertNull(gen.getModulesUpdate());
-		assertNull(gen.getModulesUrl());
-		assertNull(gen.getRepository());
+		try (SubmoduleWalk gen = SubmoduleWalk.forIndex(db)) {
+			assertTrue(gen.next());
+			assertEquals(path, gen.getPath());
+			assertEquals(id, gen.getObjectId());
+			assertEquals(new File(db.getWorkTree(), path), gen.getDirectory());
+			assertNull(gen.getConfigUpdate());
+			assertNull(gen.getConfigUrl());
+			assertNull(gen.getModulesPath());
+			assertNull(gen.getModulesUpdate());
+			assertNull(gen.getModulesUrl());
+			assertNull(gen.getRepository());
+			assertFalse(gen.next());
+		}
 		Status status = Git.wrap(db).status().call();
-		assertTrue(!status.isClean());
-		assertFalse(gen.next());
+		assertFalse(status.isClean());
 	}
 
 	@Test
@@ -178,24 +180,25 @@ public class SubmoduleWalkTest extends RepositoryTestCase {
 		});
 		editor.commit();
 
-		SubmoduleWalk gen = SubmoduleWalk.forIndex(db);
-		assertTrue(gen.next());
-		assertEquals(path, gen.getPath());
-		assertEquals(id, gen.getObjectId());
-		assertEquals(new File(db.getWorkTree(), path), gen.getDirectory());
-		assertNull(gen.getConfigUpdate());
-		assertNull(gen.getConfigUrl());
-		assertNull(gen.getModulesPath());
-		assertNull(gen.getModulesUpdate());
-		assertNull(gen.getModulesUrl());
-		try (Repository subRepo = gen.getRepository()) {
-			assertNotNull(subRepo);
-			assertEquals(modulesGitDir.getAbsolutePath(),
-					subRepo.getDirectory().getAbsolutePath());
-			assertEquals(new File(db.getWorkTree(), path).getAbsolutePath(),
-					subRepo.getWorkTree().getAbsolutePath());
+		try (SubmoduleWalk gen = SubmoduleWalk.forIndex(db)) {
+			assertTrue(gen.next());
+			assertEquals(path, gen.getPath());
+			assertEquals(id, gen.getObjectId());
+			assertEquals(new File(db.getWorkTree(), path), gen.getDirectory());
+			assertNull(gen.getConfigUpdate());
+			assertNull(gen.getConfigUrl());
+			assertNull(gen.getModulesPath());
+			assertNull(gen.getModulesUpdate());
+			assertNull(gen.getModulesUrl());
+			try (Repository subRepo = gen.getRepository()) {
+				assertNotNull(subRepo);
+				assertEquals(modulesGitDir.getAbsolutePath(),
+						subRepo.getDirectory().getAbsolutePath());
+				assertEquals(new File(db.getWorkTree(), path).getAbsolutePath(),
+						subRepo.getWorkTree().getAbsolutePath());
+			}
+			assertFalse(gen.next());
 		}
-		assertFalse(gen.next());
 	}
 
 	@Test
@@ -232,23 +235,24 @@ public class SubmoduleWalkTest extends RepositoryTestCase {
 		});
 		editor.commit();
 
-		SubmoduleWalk gen = SubmoduleWalk.forIndex(db);
-		assertTrue(gen.next());
-		assertEquals(path, gen.getPath());
-		assertEquals(id, gen.getObjectId());
-		assertEquals(new File(db.getWorkTree(), path), gen.getDirectory());
-		assertNull(gen.getConfigUpdate());
-		assertNull(gen.getConfigUrl());
-		assertNull(gen.getModulesPath());
-		assertNull(gen.getModulesUpdate());
-		assertNull(gen.getModulesUrl());
-		try (Repository subRepo = gen.getRepository()) {
-			assertNotNull(subRepo);
-			assertEqualsFile(modulesGitDir, subRepo.getDirectory());
-			assertEqualsFile(new File(db.getWorkTree(), path),
-					subRepo.getWorkTree());
-			subRepo.close();
-			assertFalse(gen.next());
+		try (SubmoduleWalk gen = SubmoduleWalk.forIndex(db)) {
+			assertTrue(gen.next());
+			assertEquals(path, gen.getPath());
+			assertEquals(id, gen.getObjectId());
+			assertEquals(new File(db.getWorkTree(), path), gen.getDirectory());
+			assertNull(gen.getConfigUpdate());
+			assertNull(gen.getConfigUrl());
+			assertNull(gen.getModulesPath());
+			assertNull(gen.getModulesUpdate());
+			assertNull(gen.getModulesUrl());
+			try (Repository subRepo = gen.getRepository()) {
+				assertNotNull(subRepo);
+				assertEqualsFile(modulesGitDir, subRepo.getDirectory());
+				assertEqualsFile(new File(db.getWorkTree(), path),
+						subRepo.getWorkTree());
+				subRepo.close();
+				assertFalse(gen.next());
+			}
 		}
 	}
 
@@ -270,18 +274,19 @@ public class SubmoduleWalkTest extends RepositoryTestCase {
 		});
 		editor.commit();
 
-		SubmoduleWalk gen = SubmoduleWalk.forIndex(db);
-		assertTrue(gen.next());
-		assertEquals(path, gen.getPath());
-		assertEquals(id, gen.getObjectId());
-		assertEquals(new File(db.getWorkTree(), path), gen.getDirectory());
-		assertNull(gen.getConfigUpdate());
-		assertNull(gen.getConfigUrl());
-		assertNull(gen.getModulesPath());
-		assertNull(gen.getModulesUpdate());
-		assertNull(gen.getModulesUrl());
-		assertNull(gen.getRepository());
-		assertFalse(gen.next());
+		try (SubmoduleWalk gen = SubmoduleWalk.forIndex(db)) {
+			assertTrue(gen.next());
+			assertEquals(path, gen.getPath());
+			assertEquals(id, gen.getObjectId());
+			assertEquals(new File(db.getWorkTree(), path), gen.getDirectory());
+			assertNull(gen.getConfigUpdate());
+			assertNull(gen.getConfigUrl());
+			assertNull(gen.getModulesPath());
+			assertNull(gen.getModulesUpdate());
+			assertNull(gen.getModulesUrl());
+			assertNull(gen.getRepository());
+			assertFalse(gen.next());
+		}
 	}
 
 	@Test
@@ -312,12 +317,13 @@ public class SubmoduleWalkTest extends RepositoryTestCase {
 		});
 		editor.commit();
 
-		SubmoduleWalk gen = SubmoduleWalk.forIndex(db);
-		gen.setFilter(PathFilter.create(path1));
-		assertTrue(gen.next());
-		assertEquals(path1, gen.getPath());
-		assertEquals(id1, gen.getObjectId());
-		assertFalse(gen.next());
+		try (SubmoduleWalk gen = SubmoduleWalk.forIndex(db)) {
+			gen.setFilter(PathFilter.create(path1));
+			assertTrue(gen.next());
+			assertEquals(path1, gen.getPath());
+			assertEquals(id1, gen.getObjectId());
+			assertFalse(gen.next());
+		}
 	}
 
 	@Test
@@ -358,18 +364,19 @@ public class SubmoduleWalkTest extends RepositoryTestCase {
 		});
 		editor.commit();
 
-		SubmoduleWalk gen = SubmoduleWalk.forIndex(db);
-		assertTrue(gen.next());
-		assertEquals(path, gen.getPath());
-		assertEquals(subId, gen.getObjectId());
-		assertEquals(new File(db.getWorkTree(), path), gen.getDirectory());
-		assertNull(gen.getConfigUpdate());
-		assertNull(gen.getConfigUrl());
-		assertEquals("sub", gen.getModulesPath());
-		assertNull(gen.getModulesUpdate());
-		assertEquals("git://example.com/sub", gen.getModulesUrl());
-		assertNull(gen.getRepository());
-		assertFalse(gen.next());
+		try (SubmoduleWalk gen = SubmoduleWalk.forIndex(db)) {
+			assertTrue(gen.next());
+			assertEquals(path, gen.getPath());
+			assertEquals(subId, gen.getObjectId());
+			assertEquals(new File(db.getWorkTree(), path), gen.getDirectory());
+			assertNull(gen.getConfigUpdate());
+			assertNull(gen.getConfigUrl());
+			assertEquals("sub", gen.getModulesPath());
+			assertNull(gen.getModulesUpdate());
+			assertEquals("git://example.com/sub", gen.getModulesUrl());
+			assertNull(gen.getRepository());
+			assertFalse(gen.next());
+		}
 	}
 
 	@Test
@@ -397,17 +404,19 @@ public class SubmoduleWalkTest extends RepositoryTestCase {
 						})
 				.create());
 
-		SubmoduleWalk gen = SubmoduleWalk.forPath(db, commit.getTree(), "sub");
-		assertEquals(path, gen.getPath());
-		assertEquals(subId, gen.getObjectId());
-		assertEquals(new File(db.getWorkTree(), path), gen.getDirectory());
-		assertNull(gen.getConfigUpdate());
-		assertNull(gen.getConfigUrl());
-		assertEquals("sub", gen.getModulesPath());
-		assertNull(gen.getModulesUpdate());
-		assertEquals("git://example.com/sub", gen.getModulesUrl());
-		assertNull(gen.getRepository());
-		assertFalse(gen.next());
+		try (SubmoduleWalk gen = SubmoduleWalk.forPath(db, commit.getTree(),
+				"sub")) {
+			assertEquals(path, gen.getPath());
+			assertEquals(subId, gen.getObjectId());
+			assertEquals(new File(db.getWorkTree(), path), gen.getDirectory());
+			assertNull(gen.getConfigUpdate());
+			assertNull(gen.getConfigUrl());
+			assertEquals("sub", gen.getModulesPath());
+			assertNull(gen.getModulesUpdate());
+			assertEquals("git://example.com/sub", gen.getModulesUrl());
+			assertNull(gen.getRepository());
+			assertFalse(gen.next());
+		}
 	}
 
 	@Test
@@ -437,17 +446,18 @@ public class SubmoduleWalkTest extends RepositoryTestCase {
 
 		final CanonicalTreeParser p = new CanonicalTreeParser();
 		p.reset(testDb.getRevWalk().getObjectReader(), commit.getTree());
-		SubmoduleWalk gen = SubmoduleWalk.forPath(db, p, "sub");
-		assertEquals(path, gen.getPath());
-		assertEquals(subId, gen.getObjectId());
-		assertEquals(new File(db.getWorkTree(), path), gen.getDirectory());
-		assertNull(gen.getConfigUpdate());
-		assertNull(gen.getConfigUrl());
-		assertEquals("sub", gen.getModulesPath());
-		assertNull(gen.getModulesUpdate());
-		assertEquals("git://example.com/sub", gen.getModulesUrl());
-		assertNull(gen.getRepository());
-		assertFalse(gen.next());
+		try (SubmoduleWalk gen = SubmoduleWalk.forPath(db, p, "sub")) {
+			assertEquals(path, gen.getPath());
+			assertEquals(subId, gen.getObjectId());
+			assertEquals(new File(db.getWorkTree(), path), gen.getDirectory());
+			assertNull(gen.getConfigUpdate());
+			assertNull(gen.getConfigUrl());
+			assertEquals("sub", gen.getModulesPath());
+			assertNull(gen.getModulesUpdate());
+			assertEquals("git://example.com/sub", gen.getModulesUrl());
+			assertNull(gen.getRepository());
+			assertFalse(gen.next());
+		}
 	}
 
 	@Test
@@ -477,16 +487,17 @@ public class SubmoduleWalkTest extends RepositoryTestCase {
 
 		final CanonicalTreeParser p = new CanonicalTreeParser();
 		p.reset(testDb.getRevWalk().getObjectReader(), commit.getTree());
-		SubmoduleWalk gen = SubmoduleWalk.forPath(db, p, "sub");
-		assertEquals(path, gen.getPath());
-		assertEquals(subId, gen.getObjectId());
-		assertEquals(new File(db.getWorkTree(), path), gen.getDirectory());
-		assertNull(gen.getConfigUpdate());
-		assertNull(gen.getConfigUrl());
-		assertEquals("sub", gen.getModulesPath());
-		assertNull(gen.getModulesUpdate());
-		assertEquals("git://example.com/sub", gen.getModulesUrl());
-		assertNull(gen.getRepository());
-		assertFalse(gen.next());
+		try (SubmoduleWalk gen = SubmoduleWalk.forPath(db, p, "sub")) {
+			assertEquals(path, gen.getPath());
+			assertEquals(subId, gen.getObjectId());
+			assertEquals(new File(db.getWorkTree(), path), gen.getDirectory());
+			assertNull(gen.getConfigUpdate());
+			assertNull(gen.getConfigUrl());
+			assertEquals("sub", gen.getModulesPath());
+			assertNull(gen.getModulesUpdate());
+			assertEquals("git://example.com/sub", gen.getModulesUrl());
+			assertNull(gen.getRepository());
+			assertFalse(gen.next());
+		}
 	}
 }
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/treewalk/FileTreeIteratorTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/treewalk/FileTreeIteratorTest.java
index a3ce4ae94..c6de2ceac 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/treewalk/FileTreeIteratorTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/treewalk/FileTreeIteratorTest.java
@@ -272,22 +272,23 @@ public class FileTreeIteratorTest extends RepositoryTestCase {
 			git.add().addFilepattern("file").call();
 		}
 		DirCacheEntry dce = db.readDirCache().getEntry("file");
-		TreeWalk tw = new TreeWalk(db);
-		FileTreeIterator fti = new FileTreeIterator(trash, db.getFS(), db
-				.getConfig().get(WorkingTreeOptions.KEY));
-		tw.addTree(fti);
-		DirCacheIterator dci = new DirCacheIterator(db.readDirCache());
-		tw.addTree(dci);
-		fti.setDirCacheIterator(tw, 1);
-		while (tw.next() && !tw.getPathString().equals("file")) {
-			//
-		}
-		assertEquals(MetadataDiff.EQUAL, fti.compareMetadata(dce));
-		ObjectId fromRaw = ObjectId.fromRaw(fti.idBuffer(), fti.idOffset());
-		assertEquals("6b584e8ece562ebffc15d38808cd6b98fc3d97ea",
-				fromRaw.getName());
-		try (ObjectReader objectReader = db.newObjectReader()) {
-			assertFalse(fti.isModified(dce, false, objectReader));
+		try (TreeWalk tw = new TreeWalk(db)) {
+			FileTreeIterator fti = new FileTreeIterator(trash, db.getFS(),
+					db.getConfig().get(WorkingTreeOptions.KEY));
+			tw.addTree(fti);
+			DirCacheIterator dci = new DirCacheIterator(db.readDirCache());
+			tw.addTree(dci);
+			fti.setDirCacheIterator(tw, 1);
+			while (tw.next() && !tw.getPathString().equals("file")) {
+				//
+			}
+			assertEquals(MetadataDiff.EQUAL, fti.compareMetadata(dce));
+			ObjectId fromRaw = ObjectId.fromRaw(fti.idBuffer(), fti.idOffset());
+			assertEquals("6b584e8ece562ebffc15d38808cd6b98fc3d97ea",
+					fromRaw.getName());
+			try (ObjectReader objectReader = db.newObjectReader()) {
+				assertFalse(fti.isModified(dce, false, objectReader));
+			}
 		}
 	}
 
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/treewalk/NameConflictTreeWalkTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/treewalk/NameConflictTreeWalkTest.java
index 54c217276..e6a532237 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/treewalk/NameConflictTreeWalkTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/treewalk/NameConflictTreeWalkTest.java
@@ -84,16 +84,17 @@ public class NameConflictTreeWalkTest extends RepositoryTestCase {
 			assertEquals(1, tree1.getEntryCount());
 		}
 
-		final TreeWalk tw = new TreeWalk(db);
-		tw.addTree(new DirCacheIterator(tree0));
-		tw.addTree(new DirCacheIterator(tree1));
-
-		assertModes("a", REGULAR_FILE, MISSING, tw);
-		assertModes("a.b", EXECUTABLE_FILE, MISSING, tw);
-		assertModes("a", MISSING, TREE, tw);
-		tw.enterSubtree();
-		assertModes("a/b", MISSING, REGULAR_FILE, tw);
-		assertModes("a0b", SYMLINK, MISSING, tw);
+		try (TreeWalk tw = new TreeWalk(db)) {
+			tw.addTree(new DirCacheIterator(tree0));
+			tw.addTree(new DirCacheIterator(tree1));
+
+			assertModes("a", REGULAR_FILE, MISSING, tw);
+			assertModes("a.b", EXECUTABLE_FILE, MISSING, tw);
+			assertModes("a", MISSING, TREE, tw);
+			tw.enterSubtree();
+			assertModes("a/b", MISSING, REGULAR_FILE, tw);
+			assertModes("a0b", SYMLINK, MISSING, tw);
+		}
 	}
 
 	@Test
@@ -115,20 +116,21 @@ public class NameConflictTreeWalkTest extends RepositoryTestCase {
 			assertEquals(1, tree1.getEntryCount());
 		}
 
-		final NameConflictTreeWalk tw = new NameConflictTreeWalk(db);
-		tw.addTree(new DirCacheIterator(tree0));
-		tw.addTree(new DirCacheIterator(tree1));
-
-		assertModes("a", REGULAR_FILE, TREE, tw);
-		assertTrue(tw.isDirectoryFileConflict());
-		assertTrue(tw.isSubtree());
-		tw.enterSubtree();
-		assertModes("a/b", MISSING, REGULAR_FILE, tw);
-		assertTrue(tw.isDirectoryFileConflict());
-		assertModes("a.b", EXECUTABLE_FILE, MISSING, tw);
-		assertFalse(tw.isDirectoryFileConflict());
-		assertModes("a0b", SYMLINK, MISSING, tw);
-		assertFalse(tw.isDirectoryFileConflict());
+		try (NameConflictTreeWalk tw = new NameConflictTreeWalk(db)) {
+			tw.addTree(new DirCacheIterator(tree0));
+			tw.addTree(new DirCacheIterator(tree1));
+
+			assertModes("a", REGULAR_FILE, TREE, tw);
+			assertTrue(tw.isDirectoryFileConflict());
+			assertTrue(tw.isSubtree());
+			tw.enterSubtree();
+			assertModes("a/b", MISSING, REGULAR_FILE, tw);
+			assertTrue(tw.isDirectoryFileConflict());
+			assertModes("a.b", EXECUTABLE_FILE, MISSING, tw);
+			assertFalse(tw.isDirectoryFileConflict());
+			assertModes("a0b", SYMLINK, MISSING, tw);
+			assertFalse(tw.isDirectoryFileConflict());
+		}
 	}
 
 	@Test
@@ -151,20 +153,21 @@ public class NameConflictTreeWalkTest extends RepositoryTestCase {
 			assertEquals(2, tree1.getEntryCount());
 		}
 
-		final NameConflictTreeWalk tw = new NameConflictTreeWalk(db);
-		tw.addTree(new DirCacheIterator(tree0));
-		tw.addTree(new DirCacheIterator(tree1));
-
-		assertModes("a", REGULAR_FILE, TREE, tw);
-		assertTrue(tw.isSubtree());
-		assertTrue(tw.isDirectoryFileConflict());
-		tw.enterSubtree();
-		assertModes("a/b", MISSING, REGULAR_FILE, tw);
-		assertTrue(tw.isDirectoryFileConflict());
-		assertModes("a.b", EXECUTABLE_FILE, EXECUTABLE_FILE, tw);
-		assertFalse(tw.isDirectoryFileConflict());
-		assertModes("a0b", SYMLINK, MISSING, tw);
-		assertFalse(tw.isDirectoryFileConflict());
+		try (NameConflictTreeWalk tw = new NameConflictTreeWalk(db)) {
+			tw.addTree(new DirCacheIterator(tree0));
+			tw.addTree(new DirCacheIterator(tree1));
+
+			assertModes("a", REGULAR_FILE, TREE, tw);
+			assertTrue(tw.isSubtree());
+			assertTrue(tw.isDirectoryFileConflict());
+			tw.enterSubtree();
+			assertModes("a/b", MISSING, REGULAR_FILE, tw);
+			assertTrue(tw.isDirectoryFileConflict());
+			assertModes("a.b", EXECUTABLE_FILE, EXECUTABLE_FILE, tw);
+			assertFalse(tw.isDirectoryFileConflict());
+			assertModes("a0b", SYMLINK, MISSING, tw);
+			assertFalse(tw.isDirectoryFileConflict());
+		}
 	}
 
 	@Test
@@ -187,20 +190,21 @@ public class NameConflictTreeWalkTest extends RepositoryTestCase {
 			assertEquals(3, tree1.getEntryCount());
 		}
 
-		final NameConflictTreeWalk tw = new NameConflictTreeWalk(db);
-		tw.addTree(new DirCacheIterator(tree0));
-		tw.addTree(new DirCacheIterator(tree1));
-
-		assertModes("a", REGULAR_FILE, TREE, tw);
-		assertTrue(tw.isSubtree());
-		assertTrue(tw.isDirectoryFileConflict());
-		tw.enterSubtree();
-		assertModes("a/b", MISSING, REGULAR_FILE, tw);
-		assertTrue(tw.isDirectoryFileConflict());
-		assertModes("a.b", MISSING, EXECUTABLE_FILE, tw);
-		assertFalse(tw.isDirectoryFileConflict());
-		assertModes("a0b", SYMLINK, SYMLINK, tw);
-		assertFalse(tw.isDirectoryFileConflict());
+		try (NameConflictTreeWalk tw = new NameConflictTreeWalk(db)) {
+			tw.addTree(new DirCacheIterator(tree0));
+			tw.addTree(new DirCacheIterator(tree1));
+
+			assertModes("a", REGULAR_FILE, TREE, tw);
+			assertTrue(tw.isSubtree());
+			assertTrue(tw.isDirectoryFileConflict());
+			tw.enterSubtree();
+			assertModes("a/b", MISSING, REGULAR_FILE, tw);
+			assertTrue(tw.isDirectoryFileConflict());
+			assertModes("a.b", MISSING, EXECUTABLE_FILE, tw);
+			assertFalse(tw.isDirectoryFileConflict());
+			assertModes("a0b", SYMLINK, SYMLINK, tw);
+			assertFalse(tw.isDirectoryFileConflict());
+		}
 	}
 
 	@Test
@@ -224,26 +228,27 @@ public class NameConflictTreeWalkTest extends RepositoryTestCase {
 			assertEquals(4, tree1.getEntryCount());
 		}
 
-		final NameConflictTreeWalk tw = new NameConflictTreeWalk(db);
-		tw.addTree(new DirCacheIterator(tree0));
-		tw.addTree(new DirCacheIterator(tree1));
-
-		assertModes("0", REGULAR_FILE, REGULAR_FILE, tw);
-		assertFalse(tw.isDirectoryFileConflict());
-		assertModes("a", REGULAR_FILE, TREE, tw);
-		assertTrue(tw.isSubtree());
-		assertTrue(tw.isDirectoryFileConflict());
-		tw.enterSubtree();
-		assertModes("a/b", MISSING, REGULAR_FILE, tw);
-		assertTrue(tw.isDirectoryFileConflict());
-		assertModes("a/c", MISSING, TREE, tw);
-		assertTrue(tw.isDirectoryFileConflict());
-		tw.enterSubtree();
-		assertModes("a/c/e", MISSING, REGULAR_FILE, tw);
-		assertTrue(tw.isDirectoryFileConflict());
-
-		assertModes("a.b", MISSING, REGULAR_FILE, tw);
-		assertFalse(tw.isDirectoryFileConflict());
+		try (NameConflictTreeWalk tw = new NameConflictTreeWalk(db)) {
+			tw.addTree(new DirCacheIterator(tree0));
+			tw.addTree(new DirCacheIterator(tree1));
+
+			assertModes("0", REGULAR_FILE, REGULAR_FILE, tw);
+			assertFalse(tw.isDirectoryFileConflict());
+			assertModes("a", REGULAR_FILE, TREE, tw);
+			assertTrue(tw.isSubtree());
+			assertTrue(tw.isDirectoryFileConflict());
+			tw.enterSubtree();
+			assertModes("a/b", MISSING, REGULAR_FILE, tw);
+			assertTrue(tw.isDirectoryFileConflict());
+			assertModes("a/c", MISSING, TREE, tw);
+			assertTrue(tw.isDirectoryFileConflict());
+			tw.enterSubtree();
+			assertModes("a/c/e", MISSING, REGULAR_FILE, tw);
+			assertTrue(tw.isDirectoryFileConflict());
+
+			assertModes("a.b", MISSING, REGULAR_FILE, tw);
+			assertFalse(tw.isDirectoryFileConflict());
+		}
 	}
 
 	private static void assertModes(final String path, final FileMode mode0,
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/treewalk/filter/IndexDiffFilterTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/treewalk/filter/IndexDiffFilterTest.java
index 2f797e361..964ffcaa8 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/treewalk/filter/IndexDiffFilterTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/treewalk/filter/IndexDiffFilterTest.java
@@ -101,13 +101,14 @@ public class IndexDiffFilterTest extends RepositoryTestCase {
 		RevCommit commit = writeFileInFolderAndCommit();
 		deleteAll();
 		writeFileWithFolderName();
-		TreeWalk treeWalk = createTreeWalk(commit);
 
-		assertTrue(treeWalk.next());
-		assertEquals("folder", treeWalk.getPathString());
-		assertTrue(treeWalk.next());
-		assertEquals("folder/file", treeWalk.getPathString());
-		assertFalse(treeWalk.next());
+		try (TreeWalk treeWalk = createTreeWalk(commit)) {
+			assertTrue(treeWalk.next());
+			assertEquals("folder", treeWalk.getPathString());
+			assertTrue(treeWalk.next());
+			assertEquals("folder/file", treeWalk.getPathString());
+			assertFalse(treeWalk.next());
+		}
 	}
 
 	@Test
@@ -115,24 +116,26 @@ public class IndexDiffFilterTest extends RepositoryTestCase {
 		RevCommit commit = writeFileInFolderAndCommit();
 		deleteAll();
 		writeFileWithFolderName();
-		TreeWalk treeWalk = createNonRecursiveTreeWalk(commit);
-
-		assertTrue(treeWalk.next());
-		assertEquals("folder", treeWalk.getPathString());
-		assertTrue(treeWalk.next());
-		assertEquals("folder", treeWalk.getPathString());
-		assertTrue(treeWalk.isSubtree());
-		treeWalk.enterSubtree();
-		assertTrue(treeWalk.next());
-		assertEquals("folder/file", treeWalk.getPathString());
-		assertFalse(treeWalk.next());
+
+		try (TreeWalk treeWalk = createNonRecursiveTreeWalk(commit)) {
+			assertTrue(treeWalk.next());
+			assertEquals("folder", treeWalk.getPathString());
+			assertTrue(treeWalk.next());
+			assertEquals("folder", treeWalk.getPathString());
+			assertTrue(treeWalk.isSubtree());
+			treeWalk.enterSubtree();
+			assertTrue(treeWalk.next());
+			assertEquals("folder/file", treeWalk.getPathString());
+			assertFalse(treeWalk.next());
+		}
 	}
 
 	@Test
 	public void testFileCommitted() throws Exception {
 		RevCommit commit = writeFileAndCommit();
-		TreeWalk treeWalk = createTreeWalk(commit);
-		assertFalse(treeWalk.next());
+		try (TreeWalk treeWalk = createTreeWalk(commit)) {
+			assertFalse(treeWalk.next());
+		}
 	}
 
 	@Test
@@ -153,89 +156,100 @@ public class IndexDiffFilterTest extends RepositoryTestCase {
 				"<<<<<<< HEAD\nside\n=======\nmaster\n>>>>>>> master\n");
 		writeTrashFile(FILE, "master");
 
-		TreeWalk treeWalk = createTreeWalk(side);
-		int count = 0;
-		while (treeWalk.next())
-			count++;
-		assertEquals(2, count);
+		try (TreeWalk treeWalk = createTreeWalk(side)) {
+			int count = 0;
+			while (treeWalk.next())
+				count++;
+			assertEquals(2, count);
+		}
 	}
 
 	@Test
 	public void testFileInFolderCommitted() throws Exception {
 		RevCommit commit = writeFileInFolderAndCommit();
-		TreeWalk treeWalk = createTreeWalk(commit);
-		assertFalse(treeWalk.next());
+		try (TreeWalk treeWalk = createTreeWalk(commit)) {
+			assertFalse(treeWalk.next());
+		}
 	}
 
 	@Test
 	public void testEmptyFolderCommitted() throws Exception {
 		RevCommit commit = createEmptyFolderAndCommit();
-		TreeWalk treeWalk = createTreeWalk(commit);
-		assertFalse(treeWalk.next());
+		try (TreeWalk treeWalk = createTreeWalk(commit)) {
+			assertFalse(treeWalk.next());
+		}
 	}
 
 	@Test
 	public void testFileCommittedChangedNotModified() throws Exception {
 		RevCommit commit = writeFileAndCommit();
 		writeFile();
-		TreeWalk treeWalk = createTreeWalk(commit);
-		assertFalse(treeWalk.next());
+		try (TreeWalk treeWalk = createTreeWalk(commit)) {
+			assertFalse(treeWalk.next());
+		}
 	}
 
 	@Test
 	public void testFileInFolderCommittedChangedNotModified() throws Exception {
 		RevCommit commit = writeFileInFolderAndCommit();
 		writeFileInFolder();
-		TreeWalk treeWalk = createTreeWalk(commit);
-		assertFalse(treeWalk.next());
+		try (TreeWalk treeWalk = createTreeWalk(commit)) {
+			assertFalse(treeWalk.next());
+		}
 	}
 
 	@Test
 	public void testFileCommittedModified() throws Exception {
 		RevCommit commit = writeFileAndCommit();
 		writeFileModified();
-		TreeWalk treeWalk = createTreeWalk(commit);
-		assertPaths(treeWalk, FILE);
+		try (TreeWalk treeWalk = createTreeWalk(commit)) {
+			assertPaths(treeWalk, FILE);
+		}
 	}
 
 	@Test
 	public void testFileInFolderCommittedModified() throws Exception {
 		RevCommit commit = writeFileInFolderAndCommit();
 		writeFileInFolderModified();
-		TreeWalk treeWalk = createTreeWalk(commit);
-		assertPaths(treeWalk, FILE_IN_FOLDER);
+		try (TreeWalk treeWalk = createTreeWalk(commit)) {
+			assertPaths(treeWalk, FILE_IN_FOLDER);
+		}
 	}
 
 	@Test
 	public void testFileCommittedDeleted() throws Exception {
 		RevCommit commit = writeFileAndCommit();
 		deleteFile();
-		TreeWalk treeWalk = createTreeWalk(commit);
-		assertPaths(treeWalk, FILE);
+		try (TreeWalk treeWalk = createTreeWalk(commit)) {
+			assertPaths(treeWalk, FILE);
+		}
 	}
 
 	@Test
 	public void testFileInFolderCommittedDeleted() throws Exception {
 		RevCommit commit = writeFileInFolderAndCommit();
 		deleteFileInFolder();
-		TreeWalk treeWalk = createTreeWalk(commit);
-		assertPaths(treeWalk, FILE_IN_FOLDER);
+		try (TreeWalk treeWalk = createTreeWalk(commit)) {
+			assertPaths(treeWalk, FILE_IN_FOLDER);
+		}
 	}
 
 	@Test
 	public void testFileInFolderCommittedAllDeleted() throws Exception {
 		RevCommit commit = writeFileInFolderAndCommit();
 		deleteAll();
-		TreeWalk treeWalk = createTreeWalk(commit);
-		assertPaths(treeWalk, FILE_IN_FOLDER);
+		try (TreeWalk treeWalk = createTreeWalk(commit)) {
+			assertPaths(treeWalk, FILE_IN_FOLDER);
+		}
 	}
 
 	@Test
 	public void testEmptyFolderCommittedDeleted() throws Exception {
 		RevCommit commit = createEmptyFolderAndCommit();
 		deleteFolder();
-		TreeWalk treeWalk = createTreeWalk(commit);
-		assertFalse(treeWalk.next());
+		try (TreeWalk treeWalk = createTreeWalk(commit)) {
+			assertFalse(treeWalk.next());
+		}
 	}
 
 	@Test
@@ -243,8 +257,9 @@ public class IndexDiffFilterTest extends RepositoryTestCase {
 			throws Exception {
 		RevCommit commit = writeFileAndCommit();
 		writeFileModifiedAndCommit();
-		TreeWalk treeWalk = createTreeWalk(commit);
-		assertPaths(treeWalk, FILE);
+		try (TreeWalk treeWalk = createTreeWalk(commit)) {
+			assertPaths(treeWalk, FILE);
+		}
 	}
 
 	@Test
@@ -252,8 +267,9 @@ public class IndexDiffFilterTest extends RepositoryTestCase {
 			throws Exception {
 		RevCommit commit = writeFileInFolderAndCommit();
 		writeFileInFolderModifiedAndCommit();
-		TreeWalk treeWalk = createTreeWalk(commit);
-		assertPaths(treeWalk, FILE_IN_FOLDER);
+		try (TreeWalk treeWalk = createTreeWalk(commit)) {
+			assertPaths(treeWalk, FILE_IN_FOLDER);
+		}
 	}
 
 	@Test
@@ -261,8 +277,9 @@ public class IndexDiffFilterTest extends RepositoryTestCase {
 			throws Exception {
 		RevCommit commit = writeFileAndCommit();
 		deleteFileAndCommit();
-		TreeWalk treeWalk = createTreeWalk(commit);
-		assertPaths(treeWalk, FILE);
+		try (TreeWalk treeWalk = createTreeWalk(commit)) {
+			assertPaths(treeWalk, FILE);
+		}
 	}
 
 	@Test
@@ -270,8 +287,9 @@ public class IndexDiffFilterTest extends RepositoryTestCase {
 			throws Exception {
 		RevCommit commit = writeFileInFolderAndCommit();
 		deleteFileInFolderAndCommit();
-		TreeWalk treeWalk = createTreeWalk(commit);
-		assertPaths(treeWalk, FILE_IN_FOLDER);
+		try (TreeWalk treeWalk = createTreeWalk(commit)) {
+			assertPaths(treeWalk, FILE_IN_FOLDER);
+		}
 	}
 
 	@Test
@@ -279,8 +297,9 @@ public class IndexDiffFilterTest extends RepositoryTestCase {
 			throws Exception {
 		RevCommit commit = writeFileInFolderAndCommit();
 		deleteAllAndCommit();
-		TreeWalk treeWalk = createTreeWalk(commit);
-		assertPaths(treeWalk, FILE_IN_FOLDER);
+		try (TreeWalk treeWalk = createTreeWalk(commit)) {
+			assertPaths(treeWalk, FILE_IN_FOLDER);
+		}
 	}
 
 	@Test
@@ -288,96 +307,108 @@ public class IndexDiffFilterTest extends RepositoryTestCase {
 			throws Exception {
 		RevCommit commit = createEmptyFolderAndCommit();
 		deleteFolderAndCommit();
-		TreeWalk treeWalk = createTreeWalk(commit);
-		assertFalse(treeWalk.next());
+		try (TreeWalk treeWalk = createTreeWalk(commit)) {
+			assertFalse(treeWalk.next());
+		}
 	}
 
 	@Test
 	public void testFileUntracked() throws Exception {
 		RevCommit commit = writeFileAndCommit();
 		writeFileUntracked();
-		TreeWalk treeWalk = createTreeWalk(commit);
-		assertPaths(treeWalk, UNTRACKED_FILE);
+		try (TreeWalk treeWalk = createTreeWalk(commit)) {
+			assertPaths(treeWalk, UNTRACKED_FILE);
+		}
 	}
 
 	@Test
 	public void testFileInFolderUntracked() throws Exception {
 		RevCommit commit = writeFileInFolderAndCommit();
 		writeFileInFolderUntracked();
-		TreeWalk treeWalk = createTreeWalk(commit);
-		assertPaths(treeWalk, UNTRACKED_FILE_IN_FOLDER);
+		try (TreeWalk treeWalk = createTreeWalk(commit)) {
+			assertPaths(treeWalk, UNTRACKED_FILE_IN_FOLDER);
+		}
 	}
 
 	@Test
 	public void testEmptyFolderUntracked() throws Exception {
 		RevCommit commit = createEmptyFolderAndCommit();
 		createEmptyFolderUntracked();
-		TreeWalk treeWalk = createTreeWalk(commit);
-		assertFalse(treeWalk.next());
+		try (TreeWalk treeWalk = createTreeWalk(commit)) {
+			assertFalse(treeWalk.next());
+		}
 	}
 
 	@Test
 	public void testFileIgnored() throws Exception {
 		RevCommit commit = writeFileAndCommit();
 		writeFileIgnored();
-		TreeWalk treeWalk = createTreeWalk(commit);
-		assertFalse(treeWalk.next());
+		try (TreeWalk treeWalk = createTreeWalk(commit)) {
+			assertFalse(treeWalk.next());
+		}
 	}
 
 	@Test
 	public void testFileInFolderIgnored() throws Exception {
 		RevCommit commit = writeFileInFolderAndCommit();
 		writeFileInFolderIgnored();
-		TreeWalk treeWalk = createTreeWalk(commit);
-		assertFalse(treeWalk.next());
+		try (TreeWalk treeWalk = createTreeWalk(commit)) {
+			assertFalse(treeWalk.next());
+		}
 	}
 
 	@Test
 	public void testFileInFolderAllIgnored() throws Exception {
 		RevCommit commit = writeFileInFolderAndCommit();
 		writeFileInFolderAllIgnored();
-		TreeWalk treeWalk = createTreeWalk(commit);
-		assertFalse(treeWalk.next());
+		try (TreeWalk treeWalk = createTreeWalk(commit)) {
+			assertFalse(treeWalk.next());
+		}
 	}
 
 	@Test
 	public void testEmptyFolderIgnored() throws Exception {
 		RevCommit commit = createEmptyFolderAndCommit();
 		createEmptyFolderIgnored();
-		TreeWalk treeWalk = createTreeWalk(commit);
-		assertFalse(treeWalk.next());
+		try (TreeWalk treeWalk = createTreeWalk(commit)) {
+			assertFalse(treeWalk.next());
+		}
 	}
 
 	@Test
 	public void testFileIgnoredNotHonored() throws Exception {
 		RevCommit commit = writeFileAndCommit();
 		writeFileIgnored();
-		TreeWalk treeWalk = createTreeWalkDishonorIgnores(commit);
-		assertPaths(treeWalk, IGNORED_FILE, GITIGNORE);
+		try (TreeWalk treeWalk = createTreeWalkDishonorIgnores(commit)) {
+			assertPaths(treeWalk, IGNORED_FILE, GITIGNORE);
+		}
 	}
 
 	@Test
 	public void testFileCommittedModifiedIgnored() throws Exception {
 		RevCommit commit = writeFileAndCommit();
 		writeFileModifiedIgnored();
-		TreeWalk treeWalk = createTreeWalk(commit);
-		assertPaths(treeWalk, FILE);
+		try (TreeWalk treeWalk = createTreeWalk(commit)) {
+			assertPaths(treeWalk, FILE);
+		}
 	}
 
 	@Test
 	public void testFileInFolderCommittedModifiedIgnored() throws Exception {
 		RevCommit commit = writeFileInFolderAndCommit();
 		writeFileInFolderModifiedIgnored();
-		TreeWalk treeWalk = createTreeWalk(commit);
-		assertPaths(treeWalk, FILE_IN_FOLDER);
+		try (TreeWalk treeWalk = createTreeWalk(commit)) {
+			assertPaths(treeWalk, FILE_IN_FOLDER);
+		}
 	}
 
 	@Test
 	public void testFileInFolderCommittedModifiedAllIgnored() throws Exception {
 		RevCommit commit = writeFileInFolderAndCommit();
 		writeFileInFolderModifiedAllIgnored();
-		TreeWalk treeWalk = createTreeWalk(commit);
-		assertPaths(treeWalk, FILE_IN_FOLDER);
+		try (TreeWalk treeWalk = createTreeWalk(commit)) {
+			assertPaths(treeWalk, FILE_IN_FOLDER);
+		}
 	}
 
 	@Test
@@ -386,8 +417,9 @@ public class IndexDiffFilterTest extends RepositoryTestCase {
 		RevCommit commit = writeFileAndCommit();
 		deleteFileAndCommit();
 		rewriteFileIgnored();
-		TreeWalk treeWalk = createTreeWalk(commit);
-		assertPaths(treeWalk, FILE);
+		try (TreeWalk treeWalk = createTreeWalk(commit)) {
+			assertPaths(treeWalk, FILE);
+		}
 	}
 
 	@Test
@@ -396,8 +428,9 @@ public class IndexDiffFilterTest extends RepositoryTestCase {
 		RevCommit commit = writeFileInFolderAndCommit();
 		deleteFileInFolderAndCommit();
 		rewriteFileInFolderIgnored();
-		TreeWalk treeWalk = createTreeWalk(commit);
-		assertPaths(treeWalk, FILE_IN_FOLDER);
+		try (TreeWalk treeWalk = createTreeWalk(commit)) {
+			assertPaths(treeWalk, FILE_IN_FOLDER);
+		}
 	}
 
 	@Test
@@ -406,8 +439,9 @@ public class IndexDiffFilterTest extends RepositoryTestCase {
 		RevCommit commit = writeFileInFolderAndCommit();
 		deleteAllAndCommit();
 		rewriteFileInFolderAllIgnored();
-		TreeWalk treeWalk = createTreeWalk(commit);
-		assertPaths(treeWalk, FILE_IN_FOLDER);
+		try (TreeWalk treeWalk = createTreeWalk(commit)) {
+			assertPaths(treeWalk, FILE_IN_FOLDER);
+		}
 	}
 
 	@Test
@@ -416,15 +450,17 @@ public class IndexDiffFilterTest extends RepositoryTestCase {
 		RevCommit commit = createEmptyFolderAndCommit();
 		deleteFolderAndCommit();
 		recreateEmptyFolderIgnored();
-		TreeWalk treeWalk = createTreeWalk(commit);
-		assertFalse(treeWalk.next());
+		try (TreeWalk treeWalk = createTreeWalk(commit)) {
+			assertFalse(treeWalk.next());
+		}
 	}
 
 	@Test
 	public void testFileInFolderCommittedNonRecursive() throws Exception {
 		RevCommit commit = writeFileInFolderAndCommit();
-		TreeWalk treeWalk = createNonRecursiveTreeWalk(commit);
-		assertPaths(treeWalk, FOLDER);
+		try (TreeWalk treeWalk = createNonRecursiveTreeWalk(commit)) {
+			assertPaths(treeWalk, FOLDER);
+		}
 	}
 
 	@Test
@@ -432,8 +468,9 @@ public class IndexDiffFilterTest extends RepositoryTestCase {
 		RevCommit commit = writeFileInFolderAndCommit();
 		deleteAll();
 		writeFileWithFolderName();
-		TreeWalk treeWalk = createTreeWalk(commit);
-		assertPaths(treeWalk, FOLDER, FILE_IN_FOLDER);
+		try (TreeWalk treeWalk = createTreeWalk(commit)) {
+			assertPaths(treeWalk, FOLDER, FILE_IN_FOLDER);
+		}
 	}
 
 	@Test
@@ -442,8 +479,9 @@ public class IndexDiffFilterTest extends RepositoryTestCase {
 		RevCommit commit = writeFileInFolderAndCommit();
 		deleteAll();
 		writeFileWithFolderNameAndCommit();
-		TreeWalk treeWalk = createTreeWalk(commit);
-		assertPaths(treeWalk, FOLDER, FILE_IN_FOLDER);
+		try (TreeWalk treeWalk = createTreeWalk(commit)) {
+			assertPaths(treeWalk, FOLDER, FILE_IN_FOLDER);
+		}
 	}
 
 	private void writeFile() throws Exception {