Ignore removed files with an assume-valid index entry

Bug: 347067
Change-Id: I5472e69dc77e26b5f248a4a04295775cf5051215
Signed-off-by: Chris Aniszczyk <zx@twitter.com>

org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/IndexDiffTest.java

@@ -466,19 +466,23 @@ public class IndexDiffTest extends RepositoryTestCase {
 		git.add().addFilepattern(path).call();
 		String path2 = "file2";
 		writeTrashFile(path2, "content");
-		git.add().addFilepattern(path2).call();
+		String path3 = "file3";
+		writeTrashFile(path3, "some content");
+		git.add().addFilepattern(path2).addFilepattern(path3).call();
 		git.commit().setMessage("commit").call();
 		assumeUnchanged(path2);
+		assumeUnchanged(path3);
 		writeTrashFile(path, "more content");
-		writeTrashFile(path2, "more content");
+		deleteTrashFile(path3);
 
 		FileTreeIterator iterator = new FileTreeIterator(db);
 		IndexDiff diff = new IndexDiff(db, Constants.HEAD, iterator);
 		diff.diff();
-		assertEquals(1, diff.getAssumeUnchanged().size());
+		assertEquals(2, diff.getAssumeUnchanged().size());
 		assertEquals(1, diff.getModified().size());
 		assertEquals(0, diff.getChanged().size());
 		assertTrue(diff.getAssumeUnchanged().contains("file2"));
+		assertTrue(diff.getAssumeUnchanged().contains("file3"));
 		assertTrue(diff.getModified().contains("file"));
 
 		git.add().addFilepattern(".").call();
@@ -486,10 +490,11 @@ public class IndexDiffTest extends RepositoryTestCase {
 		iterator = new FileTreeIterator(db);
 		diff = new IndexDiff(db, Constants.HEAD, iterator);
 		diff.diff();
-		assertEquals(1, diff.getAssumeUnchanged().size());
+		assertEquals(2, diff.getAssumeUnchanged().size());
 		assertEquals(0, diff.getModified().size());
 		assertEquals(1, diff.getChanged().size());
 		assertTrue(diff.getAssumeUnchanged().contains("file2"));
+		assertTrue(diff.getAssumeUnchanged().contains("file3"));
 		assertTrue(diff.getChanged().contains("file"));
 		assertEquals(Collections.EMPTY_SET, diff.getUntrackedFolders());
 	}

org.eclipse.jgit/src/org/eclipse/jgit/treewalk/filter/IndexDiffFilter.java

@@ -48,6 +48,7 @@ import java.util.LinkedList;
 import java.util.List;
 import java.util.Set;
 
+import org.eclipse.jgit.dircache.DirCacheEntry;
 import org.eclipse.jgit.dircache.DirCacheIterator;
 import org.eclipse.jgit.errors.IncorrectObjectTypeException;
 import org.eclipse.jgit.errors.MissingObjectException;
@@ -133,6 +134,14 @@ public class IndexDiffFilter extends TreeFilter {
 		final int wm = tw.getRawMode(workingTree);
 		String path = tw.getPathString();
 
+		DirCacheIterator di = tw.getTree(dirCache, DirCacheIterator.class);
+		if (di != null) {
+			DirCacheEntry dce = di.getDirCacheEntry();
+			if (dce != null)
+				if (dce.isAssumeValid())
+					return false;
+		}
+
 		if (!tw.isPostOrderTraversal()) {
 			// detect untracked Folders
 			// Whenever we enter a folder in the workingtree assume it will
@@ -153,7 +162,7 @@ public class IndexDiffFilter extends TreeFilter {
 			// it.
 			for (int i = 0; i < cnt; i++) {
 				int rmode = tw.getRawMode(i);
-				if (i != workingTree && rmode != 0
+				if (i != workingTree && rmode != FileMode.TYPE_MISSING
 						&& FileMode.TREE.equals(rmode)) {
 					untrackedParentFolders.clear();
 					break;
@@ -171,14 +180,14 @@ public class IndexDiffFilter extends TreeFilter {
 		// other tree.
 		final int dm = tw.getRawMode(dirCache);
 		WorkingTreeIterator wi = workingTree(tw);
-		if (dm == 0) {
+		if (dm == FileMode.TYPE_MISSING) {
 			if (honorIgnores && wi.isEntryIgnored()) {
 				ignoredPaths.add(wi.getEntryPathString());
 				int i = 0;
 				for (; i < cnt; i++) {
 					if (i == dirCache || i == workingTree)
 						continue;
-					if (tw.getRawMode(i) != 0)
+					if (tw.getRawMode(i) != FileMode.TYPE_MISSING)
 						break;
 				}
 
@@ -209,7 +218,6 @@ public class IndexDiffFilter extends TreeFilter {
 		// Only one chance left to detect a diff: between index and working
 		// tree. Make use of the WorkingTreeIterator#isModified() method to
 		// avoid computing SHA1 on filesystem content if not really needed.
-		DirCacheIterator di = tw.getTree(dirCache, DirCacheIterator.class);
 		return wi.isModified(di.getDirCacheEntry(), true);
 	}