push: support per-ref force-with-lease

When rebasing, force-pushing has a race condition: someone else might
have pushed a commit since the one you just rewrote. The force-with-lease
option prevents this by ensuring that the ref's old value is the one
that you expected.

Change-Id: I97ca9f8395396c76332bdd07c486e60549ca4401
Signed-off-by: David Turner <dturner@twosigma.com>

2 files changed, 95 insertions, 0 deletions

diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/PushCommandTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/PushCommandTest.java
index 2a325405e8..eaf64b649f 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/PushCommandTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/PushCommandTest.java
@@ -66,8 +66,10 @@ import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.lib.StoredConfig;
 import org.eclipse.jgit.revwalk.RevCommit;
 import org.eclipse.jgit.transport.PushResult;
+import org.eclipse.jgit.transport.RefLeaseSpec;
 import org.eclipse.jgit.transport.RefSpec;
 import org.eclipse.jgit.transport.RemoteConfig;
+import org.eclipse.jgit.transport.RemoteRefUpdate;
 import org.eclipse.jgit.transport.TrackingRefUpdate;
 import org.eclipse.jgit.transport.URIish;
 import org.eclipse.jgit.util.FS;
@@ -379,4 +381,56 @@ public class PushCommandTest extends RepositoryTestCase {
 					db2.resolve(commit3.getId().getName() + "^{commit}"));
 		}
 	}
+
+	@Test
+	public void testPushWithLease() throws JGitInternalException, IOException,
+			GitAPIException, URISyntaxException {
+
+		// create other repository
+		Repository db2 = createWorkRepository();
+
+		// setup the first repository
+		final StoredConfig config = db.getConfig();
+		RemoteConfig remoteConfig = new RemoteConfig(config, "test");
+		URIish uri = new URIish(db2.getDirectory().toURI().toURL());
+		remoteConfig.addURI(uri);
+		remoteConfig.update(config);
+		config.save();
+
+		try (Git git1 = new Git(db)) {
+			// create one commit and push it
+			RevCommit commit = git1.commit().setMessage("initial commit").call();
+			Ref branchRef = git1.branchCreate().setName("initial").call();
+
+			RefSpec spec = new RefSpec("refs/heads/master:refs/heads/x");
+			git1.push().setRemote("test").setRefSpecs(spec)
+					.call();
+
+			assertEquals(commit.getId(),
+					db2.resolve(commit.getId().getName() + "^{commit}"));
+			//now try to force-push a new commit, with a good lease
+
+			RevCommit commit2 = git1.commit().setMessage("second commit").call();
+			Iterable<PushResult> results =
+					git1.push().setRemote("test").setRefSpecs(spec)
+							.setRefLeaseSpecs(new RefLeaseSpec("refs/heads/x", "initial"))
+							.call();
+			for (PushResult result : results) {
+				RemoteRefUpdate update = result.getRemoteUpdate("refs/heads/x");
+				assertEquals(update.getStatus(), RemoteRefUpdate.Status.OK);
+			}
+
+			RevCommit commit3 = git1.commit().setMessage("third commit").call();
+			//now try to force-push a new commit, with a bad lease
+
+			results =
+					git1.push().setRemote("test").setRefSpecs(spec)
+							.setRefLeaseSpecs(new RefLeaseSpec("refs/heads/x", "initial"))
+							.call();
+			for (PushResult result : results) {
+				RemoteRefUpdate update = result.getRemoteUpdate("refs/heads/x");
+				assertEquals(update.getStatus(), RemoteRefUpdate.Status.REJECTED_REMOTE_CHANGED);
+			}
+		}
+	}
 }
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/TransportTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/TransportTest.java
index 5519f61ac2..d4c47d37e3 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/TransportTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/TransportTest.java
@@ -53,7 +53,9 @@ import java.io.IOException;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 
 import org.eclipse.jgit.lib.Config;
 import org.eclipse.jgit.lib.Constants;
@@ -209,6 +211,45 @@ public class TransportTest extends SampleDataRepositoryTestCase {
 		assertEquals(ObjectId.zeroId(), tru.getOldObjectId());
 	}
 
+	/**
+	 * Test RefSpec to RemoteRefUpdate conversion with leases.
+	 *
+	 * @throws IOException
+	 */
+	@Test
+	public void testFindRemoteRefUpdatesWithLeases() throws IOException {
+		final RefSpec specA = new RefSpec("+refs/heads/a:refs/heads/b");
+		final RefSpec specC = new RefSpec("+refs/heads/c:refs/heads/d");
+		final Collection<RefSpec> specs = Arrays.asList(specA, specC);
+		final Map<String, RefLeaseSpec> leases = new HashMap<>();
+		leases.put("refs/heads/b",
+				new RefLeaseSpec("refs/heads/b", "refs/heads/c"));
+
+		Collection<RemoteRefUpdate> result;
+		try (Transport transport = Transport.open(db, remoteConfig)) {
+			result = transport.findRemoteRefUpdatesFor(specs, leases);
+		}
+
+		assertEquals(2, result.size());
+		boolean foundA = false;
+		boolean foundC = false;
+		for (final RemoteRefUpdate rru : result) {
+			if ("refs/heads/a".equals(rru.getSrcRef())
+					&& "refs/heads/b".equals(rru.getRemoteName())) {
+				foundA = true;
+				assertEquals(db.exactRef("refs/heads/c").getObjectId(),
+						rru.getExpectedOldObjectId());
+			}
+			if ("refs/heads/c".equals(rru.getSrcRef())
+					&& "refs/heads/d".equals(rru.getRemoteName())) {
+				foundC = true;
+				assertNull(rru.getExpectedOldObjectId());
+			}
+		}
+		assertTrue(foundA);
+		assertTrue(foundC);
+	}
+
 	@Test
 	public void testLocalTransportWithRelativePath() throws Exception {
 		Repository other = createWorkRepository();