InterIndexDiffFilterTest: Open TreeWalk in try-with-resource

Change-Id: Ie0046771b1ab1c9784d9a3bb597a9d76c6c3017d
Signed-off-by: David Pursehouse <david.pursehouse@sonymobile.com>

org.eclipse.jgit.test/tst/org/eclipse/jgit/treewalk/filter/InterIndexDiffFilterTest.java

 	public void testEmpty() throws IOException {
 		DirCache dc1 = DirCache.newInCore();
 		DirCache dc2 = DirCache.newInCore();
-		TreeWalk tw = new TreeWalk(db);
-		tw.addTree(new DirCacheIterator(dc1));
-		tw.addTree(new DirCacheIterator(dc2));
-		assertFalse(tw.next());
+		try (TreeWalk tw = new TreeWalk(db)) {
+			tw.addTree(new DirCacheIterator(dc1));
+			tw.addTree(new DirCacheIterator(dc2));
+			assertFalse(tw.next());
+		}
 	}
 
 	static final class AddEdit extends PathEdit {
 		editor.add(new AddEdit("a/a", FileMode.REGULAR_FILE, id("a"), 1, false));
 		editor.finish();
 
-		TreeWalk tw = new TreeWalk(db);
-		tw.setRecursive(true);
-		tw.addTree(new DirCacheIterator(dc1));
-		tw.addTree(new DirCacheIterator(dc2));
-		tw.setFilter(InterIndexDiffFilter.INSTANCE);
-		assertTrue(tw.next());
-		assertEquals("a/a", tw.getPathString());
-		assertFalse(tw.next());
+		try (TreeWalk tw = new TreeWalk(db)) {
+			tw.setRecursive(true);
+			tw.addTree(new DirCacheIterator(dc1));
+			tw.addTree(new DirCacheIterator(dc2));
+			tw.setFilter(InterIndexDiffFilter.INSTANCE);
+			assertTrue(tw.next());
+			assertEquals("a/a", tw.getPathString());
+			assertFalse(tw.next());
+		}
 	}
 
 	@Test
 		ed2.add(new AddEdit("a/a", FileMode.REGULAR_FILE, id("a"), 1, false));
 		ed2.finish();
 
-		TreeWalk tw = new TreeWalk(db);
-		tw.setRecursive(true);
-		tw.addTree(new DirCacheIterator(dc1));
-		tw.addTree(new DirCacheIterator(dc2));
-		tw.setFilter(InterIndexDiffFilter.INSTANCE);
+		try (TreeWalk tw = new TreeWalk(db)) {
+			tw.setRecursive(true);
+			tw.addTree(new DirCacheIterator(dc1));
+			tw.addTree(new DirCacheIterator(dc2));
+			tw.setFilter(InterIndexDiffFilter.INSTANCE);
 
-		assertFalse(tw.next());
+			assertFalse(tw.next());
+		}
 	}
 
 	@Test
 		ed2.add(new AddEdit("a/a", FileMode.REGULAR_FILE, id("a"), 1, true));
 		ed2.finish();
 
-		TreeWalk tw = new TreeWalk(db);
-		tw.setRecursive(true);
-		tw.addTree(new DirCacheIterator(dc1));
-		tw.addTree(new DirCacheIterator(dc2));
-		tw.setFilter(InterIndexDiffFilter.INSTANCE);
+		try (TreeWalk tw = new TreeWalk(db)) {
+			tw.setRecursive(true);
+			tw.addTree(new DirCacheIterator(dc1));
+			tw.addTree(new DirCacheIterator(dc2));
+			tw.setFilter(InterIndexDiffFilter.INSTANCE);
 
-		assertTrue(tw.next());
-		assertEquals("a/a", tw.getPathString());
-		assertFalse(tw.next());
+			assertTrue(tw.next());
+			assertEquals("a/a", tw.getPathString());
+			assertFalse(tw.next());
+		}
 	}
 
 	@Test
 		ed2.add(new AddEdit("a/a", FileMode.REGULAR_FILE, id("b"), 1, true));
 		ed2.finish();
 
-		TreeWalk tw = new TreeWalk(db);
-		tw.setRecursive(true);
-		tw.addTree(new DirCacheIterator(dc1));
-		tw.addTree(new DirCacheIterator(dc2));
-		tw.setFilter(InterIndexDiffFilter.INSTANCE);
+		try (TreeWalk tw = new TreeWalk(db)) {
+			tw.setRecursive(true);
+			tw.addTree(new DirCacheIterator(dc1));
+			tw.addTree(new DirCacheIterator(dc2));
+			tw.setFilter(InterIndexDiffFilter.INSTANCE);
 
-		assertFalse(tw.next());
+			assertFalse(tw.next());
+		}
 	}
 }