Provide an id for submodule entries.

Open a repository for submodule entries that have a child .git
directory and use the resolved HEAD commit as the entry's id.

Change-Id: I68d6e127f018b24ee865865a2dd3011a0e21453c
Signed-off-by: Kevin Sawicki <kevin@github.com>

org.eclipse.jgit.test/tst/org/eclipse/jgit/treewalk/FileTreeIteratorTest.java

@@ -45,19 +45,26 @@ package org.eclipse.jgit.treewalk;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
 
 import java.io.File;
 import java.security.MessageDigest;
 
 import org.eclipse.jgit.api.Git;
+import org.eclipse.jgit.dircache.DirCache;
 import org.eclipse.jgit.dircache.DirCacheCheckout;
+import org.eclipse.jgit.dircache.DirCacheEditor;
 import org.eclipse.jgit.dircache.DirCacheEntry;
+import org.eclipse.jgit.dircache.DirCacheIterator;
+import org.eclipse.jgit.dircache.DirCacheEditor.PathEdit;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.FileMode;
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.ObjectReader;
 import org.eclipse.jgit.lib.RepositoryTestCase;
+import org.eclipse.jgit.revwalk.RevCommit;
+import org.eclipse.jgit.treewalk.filter.PathFilter;
 import org.eclipse.jgit.util.FileUtils;
 import org.eclipse.jgit.util.RawParseUtils;
 import org.junit.Before;
@@ -208,6 +215,170 @@ public class FileTreeIteratorTest extends RepositoryTestCase {
 		assertFalse(fti.isModified(dce, false));
 	}
 
+	@Test
+	public void submoduleHeadMatchesIndex() throws Exception {
+		Git git = new Git(db);
+		writeTrashFile("file.txt", "content");
+		git.add().addFilepattern("file.txt").call();
+		final RevCommit id = git.commit().setMessage("create file").call();
+		final String path = "sub";
+		DirCache cache = db.lockDirCache();
+		DirCacheEditor editor = cache.editor();
+		editor.add(new PathEdit(path) {
+
+			public void apply(DirCacheEntry ent) {
+				ent.setFileMode(FileMode.GITLINK);
+				ent.setObjectId(id);
+			}
+		});
+		editor.commit();
+
+		Git.cloneRepository().setURI(db.getDirectory().toURI().toString())
+				.setDirectory(new File(db.getWorkTree(), path)).call();
+
+		TreeWalk walk = new TreeWalk(db);
+		DirCacheIterator indexIter = new DirCacheIterator(db.readDirCache());
+		FileTreeIterator workTreeIter = new FileTreeIterator(db);
+		walk.addTree(indexIter);
+		walk.addTree(workTreeIter);
+		walk.setFilter(PathFilter.create(path));
+
+		assertTrue(walk.next());
+		assertTrue(indexIter.idEqual(workTreeIter));
+	}
+
+	@Test
+	public void submoduleWithNoGitDirectory() throws Exception {
+		Git git = new Git(db);
+		writeTrashFile("file.txt", "content");
+		git.add().addFilepattern("file.txt").call();
+		final RevCommit id = git.commit().setMessage("create file").call();
+		final String path = "sub";
+		DirCache cache = db.lockDirCache();
+		DirCacheEditor editor = cache.editor();
+		editor.add(new PathEdit(path) {
+
+			public void apply(DirCacheEntry ent) {
+				ent.setFileMode(FileMode.GITLINK);
+				ent.setObjectId(id);
+			}
+		});
+		editor.commit();
+
+		File submoduleRoot = new File(db.getWorkTree(), path);
+		assertTrue(submoduleRoot.mkdir());
+		assertTrue(new File(submoduleRoot, Constants.DOT_GIT).mkdir());
+
+		TreeWalk walk = new TreeWalk(db);
+		DirCacheIterator indexIter = new DirCacheIterator(db.readDirCache());
+		FileTreeIterator workTreeIter = new FileTreeIterator(db);
+		walk.addTree(indexIter);
+		walk.addTree(workTreeIter);
+		walk.setFilter(PathFilter.create(path));
+
+		assertTrue(walk.next());
+		assertFalse(indexIter.idEqual(workTreeIter));
+		assertEquals(ObjectId.zeroId(), workTreeIter.getEntryObjectId());
+	}
+
+	@Test
+	public void submoduleWithNoHead() throws Exception {
+		Git git = new Git(db);
+		writeTrashFile("file.txt", "content");
+		git.add().addFilepattern("file.txt").call();
+		final RevCommit id = git.commit().setMessage("create file").call();
+		final String path = "sub";
+		DirCache cache = db.lockDirCache();
+		DirCacheEditor editor = cache.editor();
+		editor.add(new PathEdit(path) {
+
+			public void apply(DirCacheEntry ent) {
+				ent.setFileMode(FileMode.GITLINK);
+				ent.setObjectId(id);
+			}
+		});
+		editor.commit();
+
+		assertNotNull(Git.init().setDirectory(new File(db.getWorkTree(), path))
+				.call().getRepository());
+
+		TreeWalk walk = new TreeWalk(db);
+		DirCacheIterator indexIter = new DirCacheIterator(db.readDirCache());
+		FileTreeIterator workTreeIter = new FileTreeIterator(db);
+		walk.addTree(indexIter);
+		walk.addTree(workTreeIter);
+		walk.setFilter(PathFilter.create(path));
+
+		assertTrue(walk.next());
+		assertFalse(indexIter.idEqual(workTreeIter));
+		assertEquals(ObjectId.zeroId(), workTreeIter.getEntryObjectId());
+	}
+
+	@Test
+	public void submoduleDirectoryIterator() throws Exception {
+		Git git = new Git(db);
+		writeTrashFile("file.txt", "content");
+		git.add().addFilepattern("file.txt").call();
+		final RevCommit id = git.commit().setMessage("create file").call();
+		final String path = "sub";
+		DirCache cache = db.lockDirCache();
+		DirCacheEditor editor = cache.editor();
+		editor.add(new PathEdit(path) {
+
+			public void apply(DirCacheEntry ent) {
+				ent.setFileMode(FileMode.GITLINK);
+				ent.setObjectId(id);
+			}
+		});
+		editor.commit();
+
+		Git.cloneRepository().setURI(db.getDirectory().toURI().toString())
+				.setDirectory(new File(db.getWorkTree(), path)).call();
+
+		TreeWalk walk = new TreeWalk(db);
+		DirCacheIterator indexIter = new DirCacheIterator(db.readDirCache());
+		FileTreeIterator workTreeIter = new FileTreeIterator(db.getWorkTree(),
+				db.getFS(), db.getConfig().get(WorkingTreeOptions.KEY));
+		walk.addTree(indexIter);
+		walk.addTree(workTreeIter);
+		walk.setFilter(PathFilter.create(path));
+
+		assertTrue(walk.next());
+		assertTrue(indexIter.idEqual(workTreeIter));
+	}
+
+	@Test
+	public void submoduleNestedWithHeadMatchingIndex() throws Exception {
+		Git git = new Git(db);
+		writeTrashFile("file.txt", "content");
+		git.add().addFilepattern("file.txt").call();
+		final RevCommit id = git.commit().setMessage("create file").call();
+		final String path = "sub/dir1/dir2";
+		DirCache cache = db.lockDirCache();
+		DirCacheEditor editor = cache.editor();
+		editor.add(new PathEdit(path) {
+
+			public void apply(DirCacheEntry ent) {
+				ent.setFileMode(FileMode.GITLINK);
+				ent.setObjectId(id);
+			}
+		});
+		editor.commit();
+
+		Git.cloneRepository().setURI(db.getDirectory().toURI().toString())
+				.setDirectory(new File(db.getWorkTree(), path)).call();
+
+		TreeWalk walk = new TreeWalk(db);
+		DirCacheIterator indexIter = new DirCacheIterator(db.readDirCache());
+		FileTreeIterator workTreeIter = new FileTreeIterator(db);
+		walk.addTree(indexIter);
+		walk.addTree(workTreeIter);
+		walk.setFilter(PathFilter.create(path));
+
+		assertTrue(walk.next());
+		assertTrue(indexIter.idEqual(workTreeIter));
+	}
+
 	private static String nameOf(final AbstractTreeIterator i) {
 		return RawParseUtils.decode(Constants.CHARSET, i.path, 0, i.pathLen);
 	}

org.eclipse.jgit/src/org/eclipse/jgit/treewalk/FileTreeIterator.java

@@ -223,4 +223,11 @@ public class FileTreeIterator extends WorkingTreeIterator {
 	public File getEntryFile() {
 		return ((FileEntry) current()).getFile();
 	}
+
+	@Override
+	protected byte[] idSubmodule(final Entry e) {
+		if (repository == null)
+			return idSubmodule(getDirectory(), e);
+		return super.idSubmodule(e);
+	}
 }

org.eclipse.jgit/src/org/eclipse/jgit/treewalk/WorkingTreeIterator.java

@@ -67,12 +67,15 @@ import org.eclipse.jgit.dircache.DirCache;
 import org.eclipse.jgit.dircache.DirCacheEntry;
 import org.eclipse.jgit.dircache.DirCacheIterator;
 import org.eclipse.jgit.errors.CorruptObjectException;
+import org.eclipse.jgit.errors.NoWorkTreeException;
 import org.eclipse.jgit.ignore.IgnoreNode;
 import org.eclipse.jgit.ignore.IgnoreRule;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.CoreConfig;
 import org.eclipse.jgit.lib.FileMode;
+import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.lib.RepositoryBuilder;
 import org.eclipse.jgit.util.FS;
 import org.eclipse.jgit.util.IO;
 import org.eclipse.jgit.util.io.EolCanonicalizingInputStream;
@@ -122,6 +125,9 @@ public abstract class WorkingTreeIterator extends AbstractTreeIterator {
 	/** If there is a .gitignore file present, the parsed rules from it. */
 	private IgnoreNode ignoreNode;
 
+	/** Repository that is the root level being iterated over */
+	protected Repository repository;
+
 	/**
 	 * Create a new iterator with no parent.
 	 *
@@ -177,6 +183,7 @@ public abstract class WorkingTreeIterator extends AbstractTreeIterator {
 	 *            the repository.
 	 */
 	protected void initRootIterator(Repository repo) {
+		repository = repo;
 		Entry entry;
 		if (ignoreNode instanceof PerDirectoryIgnoreNode)
 			entry = ((PerDirectoryIgnoreNode) ignoreNode).entry;
@@ -239,13 +246,66 @@ public abstract class WorkingTreeIterator extends AbstractTreeIterator {
 			//
 			return zeroid;
 		case FileMode.TYPE_GITLINK:
-			// TODO: Support obtaining current HEAD SHA-1 from nested repository
-			//
-			return zeroid;
+			contentIdFromPtr = ptr;
+			return contentId = idSubmodule(entries[ptr]);
 		}
 		return zeroid;
 	}
 
+	/**
+	 * Get submodule id for given entry.
+	 *
+	 * @param e
+	 * @return non-null submodule id
+	 */
+	protected byte[] idSubmodule(Entry e) {
+		if (repository == null)
+			return zeroid;
+		File directory;
+		try {
+			directory = repository.getWorkTree();
+		} catch (NoWorkTreeException nwte) {
+			return zeroid;
+		}
+		return idSubmodule(directory, e);
+	}
+
+	/**
+	 * Get submodule id using the repository at the location of the entry
+	 * relative to the directory.
+	 *
+	 * @param directory
+	 * @param e
+	 * @return non-null submodule id
+	 */
+	protected byte[] idSubmodule(File directory, Entry e) {
+		final String gitDirPath = e.getName() + "/" + Constants.DOT_GIT;
+		final File submoduleGitDir = new File(directory, gitDirPath);
+		if (!submoduleGitDir.isDirectory())
+			return zeroid;
+		final Repository submoduleRepo;
+		try {
+			FS fs = repository != null ? repository.getFS() : FS.DETECTED;
+			submoduleRepo = new RepositoryBuilder().setGitDir(submoduleGitDir)
+					.setMustExist(true).setFS(fs).build();
+		} catch (IOException exception) {
+			return zeroid;
+		}
+		final ObjectId head;
+		try {
+			head = submoduleRepo.resolve(Constants.HEAD);
+		} catch (IOException exception) {
+			return zeroid;
+		} finally {
+			submoduleRepo.close();
+		}
+		if (head == null)
+			return zeroid;
+		final byte[] id = new byte[Constants.OBJECT_ID_LENGTH];
+		head.copyRawTo(id, 0);
+		return id;
+	}
+
 	private static final byte[] digits = { '0', '1', '2', '3', '4', '5', '6',
 			'7', '8', '9' };