Close TreeWalks in tests

Note that TreeWalk.forPath() needs not be closed; the ObjectReader
_is_ closed when that method returns.

Change-Id: I6e022e4a2fde0c88d610a82de092ea541b33f75c
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

11 files changed, 689 insertions, 600 deletions

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 47806cb99d..d0dfd1ab92 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/attributes/AttributesHandlerTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/attributes/AttributesHandlerTest.java
index 5868482c88..adc64d227e 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 837de74818..cb37d8978a 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 b159cca0d5..9991ae59b0 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 d6aead4a52..0291fcc1e9 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 cbc0761463..45046a3999 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 19f6dcbc59..aa4392fcac 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 dd2c2e84b6..6c0b165a4f 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/treewalk/FileTreeIteratorTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/treewalk/FileTreeIteratorTest.java
index a3ce4ae94f..c6de2ceac9 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 54c217276d..e6a5322374 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 2f797e361a..964ffcaa83 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 {