RefTreeDatabase: Allow ORIG_HEAD, etc. on non-bare repositories

Store these in the bootstrap layer where they are using $GIT_DIR
as the storage directory for any reference that does not contain '/'.

Change-Id: I5595bf514e4475b7c7e799c2c79446597a3abb4a

org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/reftree/LocalDiskRefTreeDatabaseTest.java

@@ -0,0 +1,126 @@
+/*
+ * Copyright (C) 2016 Google Inc.
+ * and other copyright owners as documented in the project's IP log.
+ *
+ * This program and the accompanying materials are made available
+ * under the terms of the Eclipse Distribution License v1.0 which
+ * accompanies this distribution, is reproduced below, and is
+ * available at http://www.eclipse.org/org/documents/edl-v10.php
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ *   copyright notice, this list of conditions and the following
+ *   disclaimer in the documentation and/or other materials provided
+ *   with the distribution.
+ *
+ * - Neither the name of the Eclipse Foundation, Inc. nor the
+ *   names of its contributors may be used to endorse or promote
+ *   products derived from this software without specific prior
+ *   written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package org.eclipse.jgit.internal.storage.reftree;
+
+import static org.eclipse.jgit.lib.Constants.HEAD;
+import static org.eclipse.jgit.lib.Constants.MASTER;
+import static org.eclipse.jgit.lib.Constants.ORIG_HEAD;
+import static org.eclipse.jgit.lib.Constants.R_HEADS;
+import static org.eclipse.jgit.lib.RefDatabase.ALL;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.List;
+
+import org.eclipse.jgit.internal.storage.file.FileRepository;
+import org.eclipse.jgit.junit.LocalDiskRepositoryTestCase;
+import org.eclipse.jgit.junit.TestRepository;
+import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.Ref;
+import org.eclipse.jgit.lib.RefDatabase;
+import org.eclipse.jgit.lib.RefUpdate;
+import org.eclipse.jgit.revwalk.RevCommit;
+import org.eclipse.jgit.storage.file.FileBasedConfig;
+import org.eclipse.jgit.storage.file.FileRepositoryBuilder;
+import org.junit.Before;
+import org.junit.Test;
+
+public class LocalDiskRefTreeDatabaseTest extends LocalDiskRepositoryTestCase {
+	private FileRepository repo;
+	private RefTreeDatabase refdb;
+	private RefDatabase bootstrap;
+
+	private TestRepository<FileRepository> testRepo;
+	private RevCommit A;
+	private RevCommit B;
+
+	@Before
+	public void setUp() throws Exception {
+		FileRepository init = createWorkRepository();
+		FileBasedConfig cfg = init.getConfig();
+		cfg.setInt("core", null, "repositoryformatversion", 1);
+		cfg.setString("extensions", null, "refsStorage", "reftree");
+		cfg.save();
+
+		repo = (FileRepository) new FileRepositoryBuilder()
+				.setGitDir(init.getDirectory())
+				.build();
+		refdb = (RefTreeDatabase) repo.getRefDatabase();
+		bootstrap = refdb.getBootstrap();
+		addRepoToClose(repo);
+
+		RefUpdate head = refdb.newUpdate(HEAD, true);
+		head.link(R_HEADS + MASTER);
+
+		testRepo = new TestRepository<>(init);
+		A = testRepo.commit().create();
+		B = testRepo.commit(testRepo.getRevWalk().parseCommit(A));
+	}
+
+	@Test
+	public void testHeadOrigHead() throws IOException {
+		RefUpdate master = refdb.newUpdate(HEAD, false);
+		master.setExpectedOldObjectId(ObjectId.zeroId());
+		master.setNewObjectId(A);
+		assertEquals(RefUpdate.Result.NEW, master.update());
+		assertEquals(A, refdb.exactRef(HEAD).getObjectId());
+
+		RefUpdate orig = refdb.newUpdate(ORIG_HEAD, true);
+		orig.setNewObjectId(B);
+		assertEquals(RefUpdate.Result.NEW, orig.update());
+
+		File origFile = new File(repo.getDirectory(), ORIG_HEAD);
+		assertEquals(B.name() + '\n', read(origFile));
+		assertEquals(B, bootstrap.exactRef(ORIG_HEAD).getObjectId());
+		assertEquals(B, refdb.exactRef(ORIG_HEAD).getObjectId());
+		assertFalse(refdb.getRefs(ALL).containsKey(ORIG_HEAD));
+
+		List<Ref> addl = refdb.getAdditionalRefs();
+		assertEquals(2, addl.size());
+		assertEquals(ORIG_HEAD, addl.get(1).getName());
+		assertEquals(B, addl.get(1).getObjectId());
+	}
+}

org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/reftree/RefTreeDatabaseTest.java

@@ -44,6 +44,7 @@
 package org.eclipse.jgit.internal.storage.reftree;
 
 import static org.eclipse.jgit.lib.Constants.HEAD;
+import static org.eclipse.jgit.lib.Constants.ORIG_HEAD;
 import static org.eclipse.jgit.lib.Constants.R_HEADS;
 import static org.eclipse.jgit.lib.Constants.R_TAGS;
 import static org.eclipse.jgit.lib.Ref.Storage.LOOSE;
@@ -467,6 +468,27 @@ public class RefTreeDatabaseTest {
 		assertEquals(txnId, getTxnCommitted());
 	}
 
+	@Test
+	public void testUpdate_RefusesOrigHeadOnBare() throws IOException {
+		assertTrue(refdb.getRepository().isBare());
+		ObjectId txnId = getTxnCommitted();
+
+		RefUpdate orig = refdb.newUpdate(ORIG_HEAD, true);
+		orig.setNewObjectId(B);
+		assertEquals(RefUpdate.Result.LOCK_FAILURE, orig.update());
+		assertEquals(txnId, getTxnCommitted());
+
+		ReceiveCommand cmd = command(null, B, ORIG_HEAD);
+		BatchRefUpdate batch = refdb.newBatchUpdate();
+		batch.addCommand(cmd);
+		batch.execute(new RevWalk(repo), NullProgressMonitor.INSTANCE);
+		assertEquals(REJECTED_OTHER_REASON, cmd.getResult());
+		assertEquals(
+				MessageFormat.format(JGitText.get().invalidRefName, ORIG_HEAD),
+				cmd.getMessage());
+		assertEquals(txnId, getTxnCommitted());
+	}
+
 	@Test
 	public void testBatchRefUpdate_NonFastForwardAborts() throws IOException {
 		update("refs/heads/master", A);

org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/reftree/RefTreeDatabase.java

@@ -43,6 +43,7 @@
 
 package org.eclipse.jgit.internal.storage.reftree;
 
+import static org.eclipse.jgit.lib.Constants.HEAD;
 import static org.eclipse.jgit.lib.Ref.Storage.LOOSE;
 import static org.eclipse.jgit.lib.Ref.Storage.PACKED;
 
@@ -189,12 +190,19 @@ public class RefTreeDatabase extends RefDatabase {
 
 	@Override
 	public Ref getRef(String name) throws IOException {
-		return findRef(getRefs(ALL), name);
+		String[] needle = new String[SEARCH_PATH.length];
+		for (int i = 0; i < SEARCH_PATH.length; i++) {
+			needle[i] = SEARCH_PATH[i] + name;
+		}
+		return firstExactRef(needle);
 	}
 
 	@Override
 	public Ref exactRef(String name) throws IOException {
-		if (conflictsWithBootstrap(name)) {
+		if (!repo.isBare() && name.indexOf('/') < 0 && !HEAD.equals(name)) {
+			// Pass through names like MERGE_HEAD, ORIG_HEAD, FETCH_HEAD.
+			return bootstrap.exactRef(name);
+		} else if (conflictsWithBootstrap(name)) {
 			return null;
 		}
 
@@ -311,6 +319,9 @@ public class RefTreeDatabase extends RefDatabase {
 
 	@Override
 	public RefUpdate newUpdate(String name, boolean detach) throws IOException {
+		if (!repo.isBare() && name.indexOf('/') < 0 && !HEAD.equals(name)) {
+			return bootstrap.newUpdate(name, detach);
+		}
 		if (conflictsWithBootstrap(name)) {
 			return new AlwaysFailUpdate(this, name);
 		}
@@ -345,7 +356,13 @@ public class RefTreeDatabase extends RefDatabase {
 			return true;
 		} else if (txnCommitted.equals(name)) {
 			return true;
-		} else if (name.length() > txnCommitted.length()
+		}
+
+		if (name.indexOf('/') < 0 && !HEAD.equals(name)) {
+			return true;
+		}
+
+		if (name.length() > txnCommitted.length()
 				&& name.charAt(txnCommitted.length()) == '/'
 				&& name.startsWith(txnCommitted)) {
 			return true;