Implement rebase --continue and --skip

For --continue, the Rebase command asserts that there are no unmerged
paths in the current repository. Then it checks if a commit is needed.
If yes, the commit message and author are taken from the author_script
and message files, respectively, and a commit is performed before the
next step is applied.
For --skip, the workspace is reset to the current HEAD before applying
the next step.

Includes some tests and a refactoring that extracts Strings in the
code into constants.


Change-Id: I72d9968535727046e737ec20e23239fe79976179
Signed-off-by: Mathias Kinzler <mathias.kinzler@sap.com>
Signed-off-by: Christian Halstrick <christian.halstrick@sap.com>

5 files changed, 728 insertions, 143 deletions

diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/RebaseCommandTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/RebaseCommandTest.java
index bddb9ed6e9..35b05e7195 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/RebaseCommandTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/RebaseCommandTest.java
@@ -51,10 +51,12 @@ import java.io.InputStreamReader;
 import org.eclipse.jgit.api.RebaseCommand.Operation;
 import org.eclipse.jgit.api.RebaseResult.Status;
 import org.eclipse.jgit.api.errors.RefNotFoundException;
+import org.eclipse.jgit.api.errors.UnmergedPathsException;
 import org.eclipse.jgit.api.errors.WrongRepositoryStateException;
 import org.eclipse.jgit.dircache.DirCacheCheckout;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.PersonIdent;
 import org.eclipse.jgit.lib.RefUpdate;
 import org.eclipse.jgit.lib.RepositoryState;
 import org.eclipse.jgit.lib.RepositoryTestCase;
@@ -62,6 +64,16 @@ import org.eclipse.jgit.revwalk.RevCommit;
 import org.eclipse.jgit.revwalk.RevWalk;
 
 public class RebaseCommandTest extends RepositoryTestCase {
+	private static final String FILE1 = "file1";
+
+	protected Git git;
+
+	@Override
+	protected void setUp() throws Exception {
+		super.setUp();
+		this.git = new Git(db);
+	}
+
 	private void createBranch(ObjectId objectId, String branchName)
 			throws IOException {
 		RefUpdate updateRef = db.updateRef(branchName);
@@ -88,8 +100,8 @@ public class RebaseCommandTest extends RepositoryTestCase {
 			IOException {
 		RevWalk walk = new RevWalk(db);
 		RevCommit head = walk.parseCommit(db.resolve(Constants.HEAD));
-		DirCacheCheckout dco = new DirCacheCheckout(db, head.getTree(),
-				db.lockDirCache(), commit.getTree());
+		DirCacheCheckout dco = new DirCacheCheckout(db, head.getTree(), db
+				.lockDirCache(), commit.getTree());
 		dco.setFailOnConflict(true);
 		dco.checkout();
 		walk.release();
@@ -100,14 +112,12 @@ public class RebaseCommandTest extends RepositoryTestCase {
 	}
 
 	public void testFastForwardWithNewFile() throws Exception {
-		Git git = new Git(db);
-
 		// create file1 on master
-		writeTrashFile("file1", "file1");
-		git.add().addFilepattern("file1").call();
+		writeTrashFile(FILE1, FILE1);
+		git.add().addFilepattern(FILE1).call();
 		RevCommit first = git.commit().setMessage("Add file1").call();
 
-		assertTrue(new File(db.getWorkTree(), "file1").exists());
+		assertTrue(new File(db.getWorkTree(), FILE1).exists());
 		// create a topic branch
 		createBranch(first, "refs/heads/topic");
 		// create file2 on master
@@ -124,32 +134,27 @@ public class RebaseCommandTest extends RepositoryTestCase {
 	}
 
 	public void testUpToDate() throws Exception {
-		Git git = new Git(db);
-
 		// create file1 on master
-		writeTrashFile("file1", "file1");
-		git.add().addFilepattern("file1").call();
+		writeTrashFile(FILE1, FILE1);
+		git.add().addFilepattern(FILE1).call();
 		RevCommit first = git.commit().setMessage("Add file1").call();
 
-		assertTrue(new File(db.getWorkTree(), "file1").exists());
+		assertTrue(new File(db.getWorkTree(), FILE1).exists());
 
 		RebaseResult res = git.rebase().setUpstream(first).call();
 		assertEquals(Status.UP_TO_DATE, res.getStatus());
 	}
 
 	public void testUnknownUpstream() throws Exception {
-		Git git = new Git(db);
-
 		// create file1 on master
-		writeTrashFile("file1", "file1");
-		git.add().addFilepattern("file1").call();
+		writeTrashFile(FILE1, FILE1);
+		git.add().addFilepattern(FILE1).call();
 		git.commit().setMessage("Add file1").call();
 
-		assertTrue(new File(db.getWorkTree(), "file1").exists());
+		assertTrue(new File(db.getWorkTree(), FILE1).exists());
 
 		try {
-			git.rebase().setUpstream("refs/heads/xyz")
-					.call();
+			git.rebase().setUpstream("refs/heads/xyz").call();
 			fail("expected exception was not thrown");
 		} catch (RefNotFoundException e) {
 			// expected exception
@@ -157,17 +162,15 @@ public class RebaseCommandTest extends RepositoryTestCase {
 	}
 
 	public void testConflictFreeWithSingleFile() throws Exception {
-		Git git = new Git(db);
-
 		// create file1 on master
-		File theFile = writeTrashFile("file1", "1\n2\n3\n");
-		git.add().addFilepattern("file1").call();
+		File theFile = writeTrashFile(FILE1, "1\n2\n3\n");
+		git.add().addFilepattern(FILE1).call();
 		RevCommit second = git.commit().setMessage("Add file1").call();
-		assertTrue(new File(db.getWorkTree(), "file1").exists());
+		assertTrue(new File(db.getWorkTree(), FILE1).exists());
 		// change first line in master and commit
-		writeTrashFile("file1", "1master\n2\n3\n");
+		writeTrashFile(FILE1, "1master\n2\n3\n");
 		checkFile(theFile, "1master\n2\n3\n");
-		git.add().addFilepattern("file1").call();
+		git.add().addFilepattern(FILE1).call();
 		RevCommit lastMasterChange = git.commit().setMessage(
 				"change file1 in master").call();
 
@@ -177,10 +180,10 @@ public class RebaseCommandTest extends RepositoryTestCase {
 		// we have the old content again
 		checkFile(theFile, "1\n2\n3\n");
 
-		assertTrue(new File(db.getWorkTree(), "file1").exists());
+		assertTrue(new File(db.getWorkTree(), FILE1).exists());
 		// change third line in topic branch
-		writeTrashFile("file1", "1\n2\n3\ntopic\n");
-		git.add().addFilepattern("file1").call();
+		writeTrashFile(FILE1, "1\n2\n3\ntopic\n");
+		git.add().addFilepattern(FILE1).call();
 		git.commit().setMessage("change file1 in topic").call();
 
 		RebaseResult res = git.rebase().setUpstream("refs/heads/master").call();
@@ -193,19 +196,17 @@ public class RebaseCommandTest extends RepositoryTestCase {
 	}
 
 	public void testDetachedHead() throws Exception {
-		Git git = new Git(db);
-
 		// create file1 on master
-		File theFile = writeTrashFile("file1", "1\n2\n3\n");
-		git.add().addFilepattern("file1").call();
+		File theFile = writeTrashFile(FILE1, "1\n2\n3\n");
+		git.add().addFilepattern(FILE1).call();
 		RevCommit second = git.commit().setMessage("Add file1").call();
-		assertTrue(new File(db.getWorkTree(), "file1").exists());
+		assertTrue(new File(db.getWorkTree(), FILE1).exists());
 		// change first line in master and commit
-		writeTrashFile("file1", "1master\n2\n3\n");
+		writeTrashFile(FILE1, "1master\n2\n3\n");
 		checkFile(theFile, "1master\n2\n3\n");
-		git.add().addFilepattern("file1").call();
-		RevCommit lastMasterChange = git.commit()
-				.setMessage("change file1 in master").call();
+		git.add().addFilepattern(FILE1).call();
+		RevCommit lastMasterChange = git.commit().setMessage(
+				"change file1 in master").call();
 
 		// create a topic branch based on second commit
 		createBranch(second, "refs/heads/topic");
@@ -213,10 +214,10 @@ public class RebaseCommandTest extends RepositoryTestCase {
 		// we have the old content again
 		checkFile(theFile, "1\n2\n3\n");
 
-		assertTrue(new File(db.getWorkTree(), "file1").exists());
+		assertTrue(new File(db.getWorkTree(), FILE1).exists());
 		// change third line in topic branch
-		writeTrashFile("file1", "1\n2\n3\ntopic\n");
-		git.add().addFilepattern("file1").call();
+		writeTrashFile(FILE1, "1\n2\n3\ntopic\n");
+		git.add().addFilepattern(FILE1).call();
 		RevCommit topicCommit = git.commit()
 				.setMessage("change file1 in topic").call();
 		checkoutBranch("refs/heads/master");
@@ -226,18 +227,15 @@ public class RebaseCommandTest extends RepositoryTestCase {
 		RebaseResult res = git.rebase().setUpstream("refs/heads/master").call();
 		assertEquals(Status.OK, res.getStatus());
 		checkFile(theFile, "1master\n2\n3\ntopic\n");
-		assertEquals(lastMasterChange,
-				new RevWalk(db).parseCommit(db.resolve(Constants.HEAD))
-						.getParent(0));
+		assertEquals(lastMasterChange, new RevWalk(db).parseCommit(
+				db.resolve(Constants.HEAD)).getParent(0));
 
 	}
 
 	public void testFilesAddedFromTwoBranches() throws Exception {
-		Git git = new Git(db);
-
 		// create file1 on master
-		writeTrashFile("file1", "file1");
-		git.add().addFilepattern("file1").call();
+		writeTrashFile(FILE1, FILE1);
+		git.add().addFilepattern(FILE1).call();
 		RevCommit masterCommit = git.commit().setMessage("Add file1 to master")
 				.call();
 
@@ -256,14 +254,14 @@ public class RebaseCommandTest extends RepositoryTestCase {
 		git.add().addFilepattern("file3").call();
 		git.commit().setMessage("Add file3 to branch file3").call();
 
-		assertTrue(new File(db.getWorkTree(), "file1").exists());
+		assertTrue(new File(db.getWorkTree(), FILE1).exists());
 		assertFalse(new File(db.getWorkTree(), "file2").exists());
 		assertTrue(new File(db.getWorkTree(), "file3").exists());
 
 		RebaseResult res = git.rebase().setUpstream("refs/heads/file2").call();
 		assertEquals(Status.OK, res.getStatus());
 
-		assertTrue(new File(db.getWorkTree(), "file1").exists());
+		assertTrue(new File(db.getWorkTree(), FILE1).exists());
 		assertTrue(new File(db.getWorkTree(), "file2").exists());
 		assertTrue(new File(db.getWorkTree(), "file3").exists());
 
@@ -273,54 +271,40 @@ public class RebaseCommandTest extends RepositoryTestCase {
 				db.resolve(Constants.HEAD)).getParent(0));
 
 		checkoutBranch("refs/heads/file2");
-		assertTrue(new File(db.getWorkTree(), "file1").exists());
+		assertTrue(new File(db.getWorkTree(), FILE1).exists());
 		assertTrue(new File(db.getWorkTree(), "file2").exists());
 		assertFalse(new File(db.getWorkTree(), "file3").exists());
 	}
 
-	public void testAbortOnConflict() throws Exception {
-		Git git = new Git(db);
-
+	public void testStopOnConflict() throws Exception {
 		// create file1 on master
-		File theFile = writeTrashFile("file1", "1\n2\n3\n");
-		git.add().addFilepattern("file1").call();
-		RevCommit firstInMaster = git.commit().setMessage("Add file1").call();
-		assertTrue(new File(db.getWorkTree(), "file1").exists());
-		// change first line in master and commit
-		writeTrashFile("file1", "1master\n2\n3\n");
-		checkFile(theFile, "1master\n2\n3\n");
-		git.add().addFilepattern("file1").call();
-		git.commit().setMessage("change file1 in master").call();
-
+		RevCommit firstInMaster = writeFileAndCommit(FILE1, "Add file1", "1",
+				"2", "3");
+		// change first line in master
+		writeFileAndCommit(FILE1, "change file1 in master", "1master", "2", "3");
+		checkFile(FILE1, "1master", "2", "3");
 		// create a topic branch based on second commit
 		createBranch(firstInMaster, "refs/heads/topic");
 		checkoutBranch("refs/heads/topic");
 		// we have the old content again
-		checkFile(theFile, "1\n2\n3\n");
+		checkFile(FILE1, "1", "2", "3");
 
-		assertTrue(new File(db.getWorkTree(), "file1").exists());
 		// add a line (non-conflicting)
-		writeTrashFile("file1", "1\n2\n3\ntopic4\n");
-		git.add().addFilepattern("file1").call();
-		git.commit().setMessage("add a line to file1 in topic").call();
+		writeFileAndCommit(FILE1, "add a line to file1 in topic", "1", "2",
+				"3", "topic4");
 
 		// change first line (conflicting)
-		writeTrashFile("file1", "1topic\n2\n3\ntopic4\n");
-		git.add().addFilepattern("file1").call();
-		RevCommit conflicting = git.commit()
-				.setMessage("change file1 in topic").call();
+		RevCommit conflicting = writeFileAndCommit(FILE1,
+				"change file1 in topic", "1topic", "2", "3", "topic4");
 
-		// change second line (not conflicting)
-		writeTrashFile("file1", "1topic\n2topic\n3\ntopic4\n");
-		git.add().addFilepattern("file1").call();
-		RevCommit lastTopicCommit = git.commit().setMessage(
-				"change file1 in topic again").call();
+		RevCommit lastTopicCommit = writeFileAndCommit(FILE1,
+				"change file1 in topic again", "1topic", "2", "3", "topic4");
 
 		RebaseResult res = git.rebase().setUpstream("refs/heads/master").call();
 		assertEquals(Status.STOPPED, res.getStatus());
 		assertEquals(conflicting, res.getCurrentCommit());
-		checkFile(theFile,
-				"<<<<<<< OURS\n1master\n=======\n1topic\n>>>>>>> THEIRS\n2\n3\ntopic4\n");
+		checkFile(FILE1,
+				"<<<<<<< OURS\n1master\n=======\n1topic\n>>>>>>> THEIRS\n2\n3\ntopic4");
 
 		assertEquals(RepositoryState.REBASING_INTERACTIVE, db
 				.getRepositoryState());
@@ -341,7 +325,7 @@ public class RebaseCommandTest extends RepositoryTestCase {
 		res = git.rebase().setOperation(Operation.ABORT).call();
 		assertEquals(res.getStatus(), Status.ABORTED);
 		assertEquals("refs/heads/topic", db.getFullBranch());
-		checkFile(theFile, "1topic\n2topic\n3\ntopic4\n");
+		checkFile(FILE1, "1topic", "2", "3", "topic4");
 		RevWalk rw = new RevWalk(db);
 		assertEquals(lastTopicCommit, rw
 				.parseCommit(db.resolve(Constants.HEAD)));
@@ -351,12 +335,335 @@ public class RebaseCommandTest extends RepositoryTestCase {
 		assertFalse(new File(db.getDirectory(), "rebase-merge").exists());
 	}
 
-	public void testAbortOnConflictFileCreationAndDeletion() throws Exception {
-		Git git = new Git(db);
+	public void testStopOnConflictAndContinue() throws Exception {
+		// create file1 on master
+		RevCommit firstInMaster = writeFileAndCommit(FILE1, "Add file1", "1",
+				"2", "3");
+		// change in master
+		writeFileAndCommit(FILE1, "change file1 in master", "1master", "2", "3");
+
+		checkFile(FILE1, "1master", "2", "3");
+		// create a topic branch based on the first commit
+		createBranch(firstInMaster, "refs/heads/topic");
+		checkoutBranch("refs/heads/topic");
+		// we have the old content again
+		checkFile(FILE1, "1", "2", "3");
+
+		// add a line (non-conflicting)
+		writeFileAndCommit(FILE1, "add a line to file1 in topic", "1", "2",
+				"3", "4topic");
+
+		// change first line (conflicting)
+		writeFileAndCommit(FILE1,
+				"change file1 in topic\n\nThis is conflicting", "1topic", "2",
+				"3", "4topic");
+
+		// change second line (not conflicting)
+		writeFileAndCommit(FILE1, "change file1 in topic again", "1topic",
+				"2topic", "3", "4topic");
+
+		RebaseResult res = git.rebase().setUpstream("refs/heads/master").call();
+		assertEquals(Status.STOPPED, res.getStatus());
+
+		// continue should throw a meaningful exception
+		try {
+			res = git.rebase().setOperation(Operation.CONTINUE).call();
+			fail("Expected Exception not thrown");
+		} catch (UnmergedPathsException e) {
+			// expected
+		}
+
+		// merge the file; the second topic commit should go through
+		writeFileAndAdd(FILE1, "1topic", "2", "3", "4topic");
+
+		res = git.rebase().setOperation(Operation.CONTINUE).call();
+		assertNotNull(res);
+		assertEquals(Status.OK, res.getStatus());
+		assertEquals(RepositoryState.SAFE, db.getRepositoryState());
+
+		ObjectId headId = db.resolve(Constants.HEAD);
+		RevWalk rw = new RevWalk(db);
+		RevCommit rc = rw.parseCommit(headId);
+		RevCommit parent = rw.parseCommit(rc.getParent(0));
+		assertEquals("change file1 in topic\n\nThis is conflicting", parent
+				.getFullMessage());
+	}
+
+	public void testStopOnConflictAndFailContinueIfFileIsDirty()
+			throws Exception {
+		// create file1 on master
+		RevCommit firstInMaster = writeFileAndCommit(FILE1, "Add file1", "1",
+				"2", "3");
+		// change in master
+		writeFileAndCommit(FILE1, "change file1 in master", "1master", "2", "3");
+
+		checkFile(FILE1, "1master", "2", "3");
+		// create a topic branch based on the first commit
+		createBranch(firstInMaster, "refs/heads/topic");
+		checkoutBranch("refs/heads/topic");
+		// we have the old content again
+		checkFile(FILE1, "1", "2", "3");
+
+		// add a line (non-conflicting)
+		writeFileAndCommit(FILE1, "add a line to file1 in topic", "1", "2",
+				"3", "4topic");
+
+		// change first line (conflicting)
+		writeFileAndCommit(FILE1,
+				"change file1 in topic\n\nThis is conflicting", "1topic", "2",
+				"3", "4topic");
+
+		// change second line (not conflicting)
+		writeFileAndCommit(FILE1, "change file1 in topic again", "1topic",
+				"2topic", "3", "4topic");
+
+		RebaseResult res = git.rebase().setUpstream("refs/heads/master").call();
+		assertEquals(Status.STOPPED, res.getStatus());
+
+		git.add().addFilepattern(FILE1).call();
+		File trashFile = writeTrashFile(FILE1, "Some local change");
+
+		res = git.rebase().setOperation(Operation.CONTINUE).call();
+		assertNotNull(res);
+		assertEquals(Status.STOPPED, res.getStatus());
+		checkFile(trashFile, "Some local change");
+	}
+
+	public void testStopOnLastConflictAndContinue() throws Exception {
+		// create file1 on master
+		RevCommit firstInMaster = writeFileAndCommit(FILE1, "Add file1", "1",
+				"2", "3");
+		// change in master
+		writeFileAndCommit(FILE1, "change file1 in master", "1master", "2", "3");
+
+		checkFile(FILE1, "1master", "2", "3");
+		// create a topic branch based on the first commit
+		createBranch(firstInMaster, "refs/heads/topic");
+		checkoutBranch("refs/heads/topic");
+		// we have the old content again
+		checkFile(FILE1, "1", "2", "3");
+
+		// add a line (non-conflicting)
+		writeFileAndCommit(FILE1, "add a line to file1 in topic", "1", "2",
+				"3", "4topic");
+
+		// change first line (conflicting)
+		writeFileAndCommit(FILE1,
+				"change file1 in topic\n\nThis is conflicting", "1topic", "2",
+				"3", "4topic");
+
+		RebaseResult res = git.rebase().setUpstream("refs/heads/master").call();
+		assertEquals(Status.STOPPED, res.getStatus());
+
+		// merge the file; the second topic commit should go through
+		writeFileAndAdd(FILE1, "1topic", "2", "3", "4topic");
+
+		res = git.rebase().setOperation(Operation.CONTINUE).call();
+		assertNotNull(res);
+		assertEquals(Status.OK, res.getStatus());
+		assertEquals(RepositoryState.SAFE, db.getRepositoryState());
+	}
+
+	public void testStopOnLastConflictAndSkip() throws Exception {
+		// create file1 on master
+		RevCommit firstInMaster = writeFileAndCommit(FILE1, "Add file1", "1",
+				"2", "3");
+		// change in master
+		writeFileAndCommit(FILE1, "change file1 in master", "1master", "2", "3");
+
+		checkFile(FILE1, "1master", "2", "3");
+		// create a topic branch based on the first commit
+		createBranch(firstInMaster, "refs/heads/topic");
+		checkoutBranch("refs/heads/topic");
+		// we have the old content again
+		checkFile(FILE1, "1", "2", "3");
+
+		// add a line (non-conflicting)
+		writeFileAndCommit(FILE1, "add a line to file1 in topic", "1", "2",
+				"3", "4topic");
+
+		// change first line (conflicting)
+		writeFileAndCommit(FILE1,
+				"change file1 in topic\n\nThis is conflicting", "1topic", "2",
+				"3", "4topic");
+
+		RebaseResult res = git.rebase().setUpstream("refs/heads/master").call();
+		assertEquals(Status.STOPPED, res.getStatus());
+
+		// merge the file; the second topic commit should go through
+		writeFileAndAdd(FILE1, "1topic", "2", "3", "4topic");
+
+		res = git.rebase().setOperation(Operation.SKIP).call();
+		assertNotNull(res);
+		assertEquals(Status.OK, res.getStatus());
+		assertEquals(RepositoryState.SAFE, db.getRepositoryState());
+	}
+
+	public void testStopOnConflictAndSkipNoConflict() throws Exception {
+		// create file1 on master
+		RevCommit firstInMaster = writeFileAndCommit(FILE1, "Add file1", "1",
+				"2", "3");
+		// change in master
+		writeFileAndCommit(FILE1, "change file1 in master", "1master", "2", "3");
+
+		checkFile(FILE1, "1master", "2", "3");
+		// create a topic branch based on the first commit
+		createBranch(firstInMaster, "refs/heads/topic");
+		checkoutBranch("refs/heads/topic");
+		// we have the old content again
+		checkFile(FILE1, "1", "2", "3");
+
+		// add a line (non-conflicting)
+		writeFileAndCommit(FILE1, "add a line to file1 in topic", "1", "2",
+				"3", "4topic");
+
+		// change first line (conflicting)
+		writeFileAndCommit(FILE1,
+				"change file1 in topic\n\nThis is conflicting", "1topic", "2",
+				"3", "4topic");
+
+		// change third line (not conflicting)
+		writeFileAndCommit(FILE1, "change file1 in topic again", "1topic", "2",
+				"3topic", "4topic");
+
+		RebaseResult res = git.rebase().setUpstream("refs/heads/master").call();
+		assertEquals(Status.STOPPED, res.getStatus());
+
+		res = git.rebase().setOperation(Operation.SKIP).call();
+
+		checkFile(FILE1, "1master", "2", "3topic", "4topic");
+		assertEquals(Status.OK, res.getStatus());
+	}
+
+	public void testStopOnConflictAndSkipWithConflict() throws Exception {
+		// create file1 on master
+		RevCommit firstInMaster = writeFileAndCommit(FILE1, "Add file1", "1",
+				"2", "3", "4");
+		// change in master
+		writeFileAndCommit(FILE1, "change file1 in master", "1master", "2",
+				"3master", "4");
+
+		checkFile(FILE1, "1master", "2", "3master", "4");
+		// create a topic branch based on the first commit
+		createBranch(firstInMaster, "refs/heads/topic");
+		checkoutBranch("refs/heads/topic");
+		// we have the old content again
+		checkFile(FILE1, "1", "2", "3", "4");
+
+		// add a line (non-conflicting)
+		writeFileAndCommit(FILE1, "add a line to file1 in topic", "1", "2",
+				"3", "4", "5topic");
+
+		// change first line (conflicting)
+		writeFileAndCommit(FILE1,
+				"change file1 in topic\n\nThis is conflicting", "1topic", "2",
+				"3", "4", "5topic");
+
+		// change third line (conflicting)
+		writeFileAndCommit(FILE1, "change file1 in topic again", "1topic", "2",
+				"3topic", "4", "5topic");
+
+		RebaseResult res = git.rebase().setUpstream("refs/heads/master").call();
+		assertEquals(Status.STOPPED, res.getStatus());
+
+		res = git.rebase().setOperation(Operation.SKIP).call();
+		// TODO is this correct? It is what the command line returns
+		checkFile(FILE1,
+				"1master\n2\n<<<<<<< OURS\n3master\n=======\n3topic\n>>>>>>> THEIRS\n4\n5topic");
+		assertEquals(Status.STOPPED, res.getStatus());
+	}
+
+	public void testStopOnConflictCommitAndContinue() throws Exception {
+		// create file1 on master
+		RevCommit firstInMaster = writeFileAndCommit(FILE1, "Add file1", "1",
+				"2", "3");
+		// change in master
+		writeFileAndCommit(FILE1, "change file1 in master", "1master", "2", "3");
+
+		checkFile(FILE1, "1master", "2", "3");
+		// create a topic branch based on the first commit
+		createBranch(firstInMaster, "refs/heads/topic");
+		checkoutBranch("refs/heads/topic");
+		// we have the old content again
+		checkFile(FILE1, "1", "2", "3");
+
+		// add a line (non-conflicting)
+		writeFileAndCommit(FILE1, "add a line to file1 in topic", "1", "2",
+				"3", "4topic");
+
+		// change first line (conflicting)
+		writeFileAndCommit(FILE1,
+				"change file1 in topic\n\nThis is conflicting", "1topic", "2",
+				"3", "4topic");
+
+		// change second line (not conflicting)
+		writeFileAndCommit(FILE1, "change file1 in topic again", "1topic", "2",
+				"3topic", "4topic");
+
+		RebaseResult res = git.rebase().setUpstream("refs/heads/master").call();
+		assertEquals(Status.STOPPED, res.getStatus());
+
+		// continue should throw a meaningful exception
+		try {
+			res = git.rebase().setOperation(Operation.CONTINUE).call();
+			fail("Expected Exception not thrown");
+		} catch (UnmergedPathsException e) {
+			// expected
+		}
+
+		// merge the file; the second topic commit should go through
+		writeFileAndCommit(FILE1, "A different commit message", "1topic", "2",
+				"3", "4topic");
+
+		res = git.rebase().setOperation(Operation.CONTINUE).call();
+		assertNotNull(res);
+		assertEquals(Status.OK, res.getStatus());
+		assertEquals(RepositoryState.SAFE, db.getRepositoryState());
+
+		ObjectId headId = db.resolve(Constants.HEAD);
+		RevWalk rw = new RevWalk(db);
+		RevCommit rc = rw.parseCommit(headId);
+		RevCommit parent = rw.parseCommit(rc.getParent(0));
+		assertEquals("A different commit message", parent.getFullMessage());
+	}
+
+	private RevCommit writeFileAndCommit(String fileName, String commitMessage,
+			String... lines) throws Exception {
+		StringBuilder sb = new StringBuilder();
+		for (String line : lines) {
+			sb.append(line);
+			sb.append('\n');
+		}
+		writeTrashFile(fileName, sb.toString());
+		git.add().addFilepattern(fileName).call();
+		return git.commit().setMessage(commitMessage).call();
+	}
 
+	private void writeFileAndAdd(String fileName, String... lines)
+			throws Exception {
+		StringBuilder sb = new StringBuilder();
+		for (String line : lines) {
+			sb.append(line);
+			sb.append('\n');
+		}
+		writeTrashFile(fileName, sb.toString());
+		git.add().addFilepattern(fileName).call();
+	}
+
+	private void checkFile(String fileName, String... lines) throws Exception {
+		File file = new File(db.getWorkTree(), fileName);
+		StringBuilder sb = new StringBuilder();
+		for (String line : lines) {
+			sb.append(line);
+			sb.append('\n');
+		}
+		checkFile(file, sb.toString());
+	}
+
+	public void testStopOnConflictFileCreationAndDeletion() throws Exception {
 		// create file1 on master
-		writeTrashFile("file1", "Hello World");
-		git.add().addFilepattern("file1").call();
+		writeTrashFile(FILE1, "Hello World");
+		git.add().addFilepattern(FILE1).call();
 		// create file2 on master
 		File file2 = writeTrashFile("file2", "Hello World 2");
 		git.add().addFilepattern("file2").call();
@@ -378,10 +685,8 @@ public class RebaseCommandTest extends RepositoryTestCase {
 		writeTrashFile("folder6/file1", "Hello World folder6");
 		git.add().addFilepattern("folder6/file1").call();
 
-		git.commit()
-				.setMessage(
-						"Add file 4 and folder folder6, delete file2 on master")
-				.call();
+		git.commit().setMessage(
+				"Add file 4 and folder folder6, delete file2 on master").call();
 
 		// create a topic branch based on second commit
 		createBranch(firstInMaster, "refs/heads/topic");
@@ -403,9 +708,8 @@ public class RebaseCommandTest extends RepositoryTestCase {
 
 		deleteTrashFile("file5");
 		git.add().setUpdate(true).addFilepattern("file5").call();
-		RevCommit conflicting = git.commit()
-				.setMessage("Delete file5, add file folder6 and file7 in topic")
-				.call();
+		RevCommit conflicting = git.commit().setMessage(
+				"Delete file5, add file folder6 and file7 in topic").call();
 
 		RebaseResult res = git.rebase().setUpstream("refs/heads/master").call();
 		assertEquals(Status.STOPPED, res.getStatus());
@@ -429,8 +733,7 @@ public class RebaseCommandTest extends RepositoryTestCase {
 		assertEquals(res.getStatus(), Status.ABORTED);
 		assertEquals("refs/heads/topic", db.getFullBranch());
 		RevWalk rw = new RevWalk(db);
-		assertEquals(conflicting,
-				rw.parseCommit(db.resolve(Constants.HEAD)));
+		assertEquals(conflicting, rw.parseCommit(db.resolve(Constants.HEAD)));
 		assertEquals(RepositoryState.SAFE, db.getRepositoryState());
 
 		// rebase- dir in .git must be deleted
@@ -444,6 +747,62 @@ public class RebaseCommandTest extends RepositoryTestCase {
 
 	}
 
+	public void testAuthorScriptConverter() throws Exception {
+		// -1 h timezone offset
+		PersonIdent ident = new PersonIdent("Author name", "a.mail@some.com",
+				123456789123L, -60);
+		String convertedAuthor = git.rebase().toAuthorScript(ident);
+		String[] lines = convertedAuthor.split("\n");
+		assertEquals("GIT_AUTHOR_NAME='Author name'", lines[0]);
+		assertEquals("GIT_AUTHOR_EMAIL='a.mail@some.com'", lines[1]);
+		assertEquals("GIT_AUTHOR_DATE='123456789 -0100'", lines[2]);
+
+		PersonIdent parsedIdent = git.rebase().parseAuthor(
+				convertedAuthor.getBytes("UTF-8"));
+		assertEquals(ident.getName(), parsedIdent.getName());
+		assertEquals(ident.getEmailAddress(), parsedIdent.getEmailAddress());
+		// this is rounded to the last second
+		assertEquals(123456789000L, parsedIdent.getWhen().getTime());
+		assertEquals(ident.getTimeZoneOffset(), parsedIdent.getTimeZoneOffset());
+
+		// + 9.5h timezone offset
+		ident = new PersonIdent("Author name", "a.mail@some.com",
+				123456789123L, +570);
+		convertedAuthor = git.rebase().toAuthorScript(ident);
+		lines = convertedAuthor.split("\n");
+		assertEquals("GIT_AUTHOR_NAME='Author name'", lines[0]);
+		assertEquals("GIT_AUTHOR_EMAIL='a.mail@some.com'", lines[1]);
+		assertEquals("GIT_AUTHOR_DATE='123456789 +0930'", lines[2]);
+
+		parsedIdent = git.rebase().parseAuthor(
+				convertedAuthor.getBytes("UTF-8"));
+		assertEquals(ident.getName(), parsedIdent.getName());
+		assertEquals(ident.getEmailAddress(), parsedIdent.getEmailAddress());
+		assertEquals(123456789000L, parsedIdent.getWhen().getTime());
+		assertEquals(ident.getTimeZoneOffset(), parsedIdent.getTimeZoneOffset());
+	}
+
+	public void testRepositoryStateChecks() throws Exception {
+		try {
+			git.rebase().setOperation(Operation.ABORT).call();
+			fail("Expected Exception not thrown");
+		} catch (WrongRepositoryStateException e) {
+			// expected
+		}
+		try {
+			git.rebase().setOperation(Operation.SKIP).call();
+			fail("Expected Exception not thrown");
+		} catch (WrongRepositoryStateException e) {
+			// expected
+		}
+		try {
+			git.rebase().setOperation(Operation.CONTINUE).call();
+			fail("Expected Exception not thrown");
+		} catch (WrongRepositoryStateException e) {
+			// expected
+		}
+	}
+
 	private int countPicks() throws IOException {
 		int count = 0;
 		File todoFile = new File(db.getDirectory(),
diff --git a/org.eclipse.jgit/resources/org/eclipse/jgit/JGitText.properties b/org.eclipse.jgit/resources/org/eclipse/jgit/JGitText.properties
index 7c5e981199..07f0cb1d7d 100644
--- a/org.eclipse.jgit/resources/org/eclipse/jgit/JGitText.properties
+++ b/org.eclipse.jgit/resources/org/eclipse/jgit/JGitText.properties
@@ -69,6 +69,7 @@ cannotReadFile=Cannot read file {0}
 cannotReadHEAD=cannot read HEAD: {0} {1}
 cannotReadObject=Cannot read object
 cannotReadTree=Cannot read tree {0}
+cannotRebaseWithoutCurrentHead=Can not rebase without a current HEAD
 cannotResolveLocalTrackingRefForUpdating=Cannot resolve local tracking ref {0} for updating.
 cannotStoreObjects=cannot store objects
 cannotUnloadAModifiedTree=Cannot unload a modified tree.
@@ -426,6 +427,7 @@ unknownRepositoryFormat=Unknown repository format
 unknownZlibError=Unknown zlib error.
 unpackException=Exception while parsing pack stream
 unmergedPath=Unmerged path: {0}
+unmergedPaths=Repository contains unmerged paths
 unreadablePackIndex=Unreadable pack index: {0}
 unrecognizedRef=Unrecognized ref: {0}
 unsupportedCommand0=unsupported command 0
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/JGitText.java b/org.eclipse.jgit/src/org/eclipse/jgit/JGitText.java
index e34d0a58b0..87053a8c95 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/JGitText.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/JGitText.java
@@ -129,6 +129,7 @@ public class JGitText extends TranslationBundle {
 	/***/ public String cannotReadHEAD;
 	/***/ public String cannotReadObject;
 	/***/ public String cannotReadTree;
+	/***/ public String cannotRebaseWithoutCurrentHead;
 	/***/ public String cannotResolveLocalTrackingRefForUpdating;
 	/***/ public String cannotStoreObjects;
 	/***/ public String cannotUnloadAModifiedTree;
@@ -485,6 +486,7 @@ public class JGitText extends TranslationBundle {
 	/***/ public String unknownRepositoryFormat;
 	/***/ public String unknownZlibError;
 	/***/ public String unmergedPath;
+	/***/ public String unmergedPaths;	
 	/***/ public String unpackException;
 	/***/ public String unreadablePackIndex;
 	/***/ public String unrecognizedRef;
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/api/RebaseCommand.java b/org.eclipse.jgit/src/org/eclipse/jgit/api/RebaseCommand.java
index eaa96f578a..6629c4f8ee 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/api/RebaseCommand.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/api/RebaseCommand.java
@@ -47,6 +47,7 @@ import java.io.BufferedWriter;
 import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.FileInputStream;
+import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStreamReader;
@@ -55,7 +56,9 @@ import java.text.MessageFormat;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 
 import org.eclipse.jgit.JGitText;
 import org.eclipse.jgit.api.RebaseResult.Status;
@@ -63,14 +66,18 @@ import org.eclipse.jgit.api.errors.GitAPIException;
 import org.eclipse.jgit.api.errors.JGitInternalException;
 import org.eclipse.jgit.api.errors.NoHeadException;
 import org.eclipse.jgit.api.errors.RefNotFoundException;
+import org.eclipse.jgit.api.errors.UnmergedPathsException;
 import org.eclipse.jgit.api.errors.WrongRepositoryStateException;
 import org.eclipse.jgit.diff.DiffFormatter;
+import org.eclipse.jgit.dircache.DirCache;
 import org.eclipse.jgit.dircache.DirCacheCheckout;
+import org.eclipse.jgit.dircache.DirCacheIterator;
 import org.eclipse.jgit.lib.AbbreviatedObjectId;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.NullProgressMonitor;
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.ObjectReader;
+import org.eclipse.jgit.lib.PersonIdent;
 import org.eclipse.jgit.lib.ProgressMonitor;
 import org.eclipse.jgit.lib.Ref;
 import org.eclipse.jgit.lib.RefUpdate;
@@ -78,6 +85,8 @@ import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.lib.RefUpdate.Result;
 import org.eclipse.jgit.revwalk.RevCommit;
 import org.eclipse.jgit.revwalk.RevWalk;
+import org.eclipse.jgit.treewalk.TreeWalk;
+import org.eclipse.jgit.treewalk.filter.TreeFilter;
 import org.eclipse.jgit.util.FileUtils;
 import org.eclipse.jgit.util.IO;
 import org.eclipse.jgit.util.RawParseUtils;
@@ -95,6 +104,40 @@ import org.eclipse.jgit.util.RawParseUtils;
  */
 public class RebaseCommand extends GitCommand<RebaseResult> {
 	/**
+	 * The name of the "rebase-merge" folder
+	 */
+	public static final String REBASE_MERGE = "rebase-merge";
+
+	/**
+	 * The name of the "stopped-sha" file
+	 */
+	public static final String STOPPED_SHA = "stopped-sha";
+
+	private static final String AUTHOR_SCRIPT = "author-script";
+
+	private static final String DONE = "done";
+
+	private static final String GIT_AUTHOR_DATE = "GIT_AUTHOR_DATE";
+
+	private static final String GIT_AUTHOR_EMAIL = "GIT_AUTHOR_EMAIL";
+
+	private static final String GIT_AUTHOR_NAME = "GIT_AUTHOR_NAME";
+
+	private static final String GIT_REBASE_TODO = "git-rebase-todo";
+
+	private static final String HEAD_NAME = "head-name";
+
+	private static final String INTERACTIVE = "interactive";
+
+	private static final String MESSAGE = "message";
+
+	private static final String ONTO = "onto";
+
+	private static final String PATCH = "patch";
+
+	private static final String REBASE_HEAD = "head";
+
+	/**
 	 * The available operations
 	 */
 	public enum Operation {
@@ -132,7 +175,7 @@ public class RebaseCommand extends GitCommand<RebaseResult> {
 	protected RebaseCommand(Repository repo) {
 		super(repo);
 		walk = new RevWalk(repo);
-		rebaseDir = new File(repo.getDirectory(), "rebase-merge");
+		rebaseDir = new File(repo.getDirectory(), REBASE_MERGE);
 	}
 
 	/**
@@ -145,6 +188,7 @@ public class RebaseCommand extends GitCommand<RebaseResult> {
 	 */
 	public RebaseResult call() throws NoHeadException, RefNotFoundException,
 			JGitInternalException, GitAPIException {
+		RevCommit newHead = null;
 		checkCallable();
 		checkParameters();
 		try {
@@ -158,7 +202,7 @@ public class RebaseCommand extends GitCommand<RebaseResult> {
 			case SKIP:
 				// fall through
 			case CONTINUE:
-				String upstreamCommitName = readFile(rebaseDir, "onto");
+				String upstreamCommitName = readFile(rebaseDir, ONTO);
 				this.upstreamCommit = walk.parseCommit(repo
 						.resolve(upstreamCommitName));
 				break;
@@ -172,16 +216,13 @@ public class RebaseCommand extends GitCommand<RebaseResult> {
 				return abort();
 
 			if (this.operation == Operation.CONTINUE)
-				throw new UnsupportedOperationException(
-						"--continue Not yet implemented");
+				newHead = continueRebase();
 
-			if (this.operation == Operation.SKIP)
-				throw new UnsupportedOperationException(
-						"--skip Not yet implemented");
+			List<Step> steps = loadSteps();
 
-			RevCommit newHead = null;
+			if (this.operation == Operation.SKIP && !steps.isEmpty())
+				checkoutCurrentHead();
 
-			List<Step> steps = loadSteps();
 			ObjectReader or = repo.newObjectReader();
 			int stepsToPop = 0;
 
@@ -211,16 +252,21 @@ public class RebaseCommand extends GitCommand<RebaseResult> {
 				}
 				stepsToPop++;
 			}
-			if (newHead != null) {
+			if (newHead != null || steps.isEmpty()) {
 				// point the previous head (if any) to the new commit
-				String headName = readFile(rebaseDir, "head-name");
+				String headName = readFile(rebaseDir, HEAD_NAME);
 				if (headName.startsWith(Constants.R_REFS)) {
 					RefUpdate rup = repo.updateRef(headName);
-					rup.setNewObjectId(newHead);
-					rup.forceUpdate();
+					if (newHead != null) {
+						rup.setNewObjectId(newHead);
+						rup.forceUpdate();
+					}
 					rup = repo.updateRef(Constants.HEAD);
 					rup.link(headName);
 				}
+				if (this.operation == Operation.SKIP && steps.isEmpty()) {
+					checkoutCurrentHead();
+				}
 				FileUtils.delete(rebaseDir, FileUtils.RECURSIVE);
 				return new RebaseResult(Status.OK);
 			}
@@ -230,29 +276,118 @@ public class RebaseCommand extends GitCommand<RebaseResult> {
 		}
 	}
 
+	private void checkoutCurrentHead() throws IOException, NoHeadException,
+			JGitInternalException {
+		ObjectId headTree = repo.resolve(Constants.HEAD + "^{tree}");
+		if (headTree == null)
+			throw new NoHeadException(
+					JGitText.get().cannotRebaseWithoutCurrentHead);
+		DirCache dc = repo.lockDirCache();
+		try {
+			DirCacheCheckout dco = new DirCacheCheckout(repo, dc, headTree);
+			dco.setFailOnConflict(false);
+			boolean needsDeleteFiles = dco.checkout();
+			if (needsDeleteFiles) {
+				List<String> fileList = dco.getToBeDeleted();
+				for (String filePath : fileList) {
+					File fileToDelete = new File(repo.getWorkTree(), filePath);
+					if (fileToDelete.exists())
+						FileUtils.delete(fileToDelete, FileUtils.RECURSIVE
+								| FileUtils.RETRY);
+				}
+			}
+		} finally {
+			dc.unlock();
+		}
+	}
+
+	/**
+	 * @return the commit if we had to do a commit, otherwise null
+	 * @throws GitAPIException
+	 * @throws IOException
+	 */
+	private RevCommit continueRebase() throws GitAPIException, IOException {
+		// if there are still conflicts, we throw a specific Exception
+		DirCache dc = repo.readDirCache();
+		boolean hasUnmergedPaths = dc.hasUnmergedPaths();
+		if (hasUnmergedPaths)
+			throw new UnmergedPathsException();
+
+		// determine whether we need to commit
+		TreeWalk treeWalk = new TreeWalk(repo);
+		treeWalk.reset();
+		treeWalk.setRecursive(true);
+		treeWalk.addTree(new DirCacheIterator(dc));
+		ObjectId id = repo.resolve(Constants.HEAD + "^{tree}");
+		if (id == null)
+			throw new NoHeadException(
+					JGitText.get().cannotRebaseWithoutCurrentHead);
+
+		treeWalk.addTree(id);
+
+		treeWalk.setFilter(TreeFilter.ANY_DIFF);
+
+		boolean needsCommit = treeWalk.next();
+		treeWalk.release();
+
+		if (needsCommit) {
+			CommitCommand commit = new Git(repo).commit();
+			commit.setMessage(readFile(rebaseDir, MESSAGE));
+			commit.setAuthor(parseAuthor());
+			return commit.call();
+		}
+		return null;
+	}
+
+	private PersonIdent parseAuthor() throws IOException {
+		File authorScriptFile = new File(rebaseDir, AUTHOR_SCRIPT);
+		byte[] raw;
+		try {
+			raw = IO.readFully(authorScriptFile);
+		} catch (FileNotFoundException notFound) {
+			return null;
+		}
+		return parseAuthor(raw);
+	}
+
 	private RebaseResult stop(RevCommit commitToPick) throws IOException {
-		StringBuilder sb = new StringBuilder(100);
-		sb.append("GIT_AUTHOR_NAME='");
-		sb.append(commitToPick.getAuthorIdent().getName());
-		sb.append("'\n");
-		sb.append("GIT_AUTHOR_EMAIL='");
-		sb.append(commitToPick.getAuthorIdent().getEmailAddress());
-		sb.append("'\n");
-		sb.append("GIT_AUTHOR_DATE='");
-		sb.append(commitToPick.getAuthorIdent().getWhen());
-		sb.append("'\n");
-		createFile(rebaseDir, "author-script", sb.toString());
-		createFile(rebaseDir, "message", commitToPick.getShortMessage());
+		PersonIdent author = commitToPick.getAuthorIdent();
+		String authorScript = toAuthorScript(author);
+		createFile(rebaseDir, AUTHOR_SCRIPT, authorScript);
+		createFile(rebaseDir, MESSAGE, commitToPick.getFullMessage());
 		ByteArrayOutputStream bos = new ByteArrayOutputStream();
 		DiffFormatter df = new DiffFormatter(bos);
 		df.setRepository(repo);
 		df.format(commitToPick.getParent(0), commitToPick);
-		createFile(rebaseDir, "patch", new String(bos.toByteArray(), "UTF-8"));
-		createFile(rebaseDir, "stopped-sha", repo.newObjectReader().abbreviate(
+		createFile(rebaseDir, PATCH, new String(bos.toByteArray(),
+				Constants.CHARACTER_ENCODING));
+		createFile(rebaseDir, STOPPED_SHA, repo.newObjectReader().abbreviate(
 				commitToPick).name());
 		return new RebaseResult(commitToPick);
 	}
 
+	String toAuthorScript(PersonIdent author) {
+		StringBuilder sb = new StringBuilder(100);
+		sb.append(GIT_AUTHOR_NAME);
+		sb.append("='");
+		sb.append(author.getName());
+		sb.append("'\n");
+		sb.append(GIT_AUTHOR_EMAIL);
+		sb.append("='");
+		sb.append(author.getEmailAddress());
+		sb.append("'\n");
+		// the command line uses the "external String"
+		// representation for date and timezone
+		sb.append(GIT_AUTHOR_DATE);
+		sb.append("='");
+		String externalString = author.toExternalString();
+		sb
+				.append(externalString.substring(externalString
+						.lastIndexOf('>') + 2));
+		sb.append("'\n");
+		return sb.toString();
+	}
+
 	/**
 	 * Removes the number of lines given in the parameter from the
 	 * <code>git-rebase-todo</code> file but preserves comments and other lines
@@ -266,10 +401,10 @@ public class RebaseCommand extends GitCommand<RebaseResult> {
 			return;
 		List<String> todoLines = new ArrayList<String>();
 		List<String> poppedLines = new ArrayList<String>();
-		File todoFile = new File(rebaseDir, "git-rebase-todo");
-		File doneFile = new File(rebaseDir, "done");
+		File todoFile = new File(rebaseDir, GIT_REBASE_TODO);
+		File doneFile = new File(rebaseDir, DONE);
 		BufferedReader br = new BufferedReader(new InputStreamReader(
-				new FileInputStream(todoFile), "UTF-8"));
+				new FileInputStream(todoFile), Constants.CHARACTER_ENCODING));
 		try {
 			// check if the line starts with a action tag (pick, skip...)
 			while (poppedLines.size() < numSteps) {
@@ -297,7 +432,7 @@ public class RebaseCommand extends GitCommand<RebaseResult> {
 		}
 
 		BufferedWriter todoWriter = new BufferedWriter(new OutputStreamWriter(
-				new FileOutputStream(todoFile), "UTF-8"));
+				new FileOutputStream(todoFile), Constants.CHARACTER_ENCODING));
 		try {
 			for (String writeLine : todoLines) {
 				todoWriter.write(writeLine);
@@ -311,7 +446,8 @@ public class RebaseCommand extends GitCommand<RebaseResult> {
 			// append here
 			BufferedWriter doneWriter = new BufferedWriter(
 					new OutputStreamWriter(
-							new FileOutputStream(doneFile, true), "UTF-8"));
+							new FileOutputStream(doneFile, true),
+							Constants.CHARACTER_ENCODING));
 			try {
 				for (String writeLine : poppedLines) {
 					doneWriter.write(writeLine);
@@ -363,14 +499,14 @@ public class RebaseCommand extends GitCommand<RebaseResult> {
 		// create the folder for the meta information
 		rebaseDir.mkdir();
 
-		createFile(repo.getDirectory(), "ORIG_HEAD", headId.name());
-		createFile(rebaseDir, "head", headId.name());
-		createFile(rebaseDir, "head-name", headName);
-		createFile(rebaseDir, "onto", upstreamCommit.name());
-		createFile(rebaseDir, "interactive", "");
+		createFile(repo.getDirectory(), Constants.ORIG_HEAD, headId.name());
+		createFile(rebaseDir, REBASE_HEAD, headId.name());
+		createFile(rebaseDir, HEAD_NAME, headName);
+		createFile(rebaseDir, ONTO, upstreamCommit.name());
+		createFile(rebaseDir, INTERACTIVE, "");
 		BufferedWriter fw = new BufferedWriter(new OutputStreamWriter(
-				new FileOutputStream(new File(rebaseDir, "git-rebase-todo")),
-				"UTF-8"));
+				new FileOutputStream(new File(rebaseDir, GIT_REBASE_TODO)),
+				Constants.CHARACTER_ENCODING));
 		fw.write("# Created by EGit: rebasing " + upstreamCommit.name()
 				+ " onto " + headId.name());
 		fw.newLine();
@@ -404,13 +540,7 @@ public class RebaseCommand extends GitCommand<RebaseResult> {
 		if (this.operation != Operation.BEGIN) {
 			// these operations are only possible while in a rebasing state
 			switch (repo.getRepositoryState()) {
-			case REBASING:
-				// fall through
 			case REBASING_INTERACTIVE:
-				// fall through
-			case REBASING_MERGE:
-				// fall through
-			case REBASING_REBASING:
 				break;
 			default:
 				throw new WrongRepositoryStateException(MessageFormat.format(
@@ -438,7 +568,7 @@ public class RebaseCommand extends GitCommand<RebaseResult> {
 		File file = new File(parentDir, name);
 		FileOutputStream fos = new FileOutputStream(file);
 		try {
-			fos.write(content.getBytes("UTF-8"));
+			fos.write(content.getBytes(Constants.CHARACTER_ENCODING));
 			fos.write('\n');
 		} finally {
 			fos.close();
@@ -447,7 +577,7 @@ public class RebaseCommand extends GitCommand<RebaseResult> {
 
 	private RebaseResult abort() throws IOException {
 		try {
-			String commitId = readFile(repo.getDirectory(), "ORIG_HEAD");
+			String commitId = readFile(repo.getDirectory(), Constants.ORIG_HEAD);
 			monitor.beginTask(MessageFormat.format(
 					JGitText.get().abortingRebase, commitId),
 					ProgressMonitor.UNKNOWN);
@@ -463,7 +593,7 @@ public class RebaseCommand extends GitCommand<RebaseResult> {
 			monitor.endTask();
 		}
 		try {
-			String headName = readFile(rebaseDir, "head-name");
+			String headName = readFile(rebaseDir, HEAD_NAME);
 			if (headName.startsWith(Constants.R_REFS)) {
 				monitor.beginTask(MessageFormat.format(
 						JGitText.get().resettingHead, headName),
@@ -527,7 +657,7 @@ public class RebaseCommand extends GitCommand<RebaseResult> {
 	}
 
 	private List<Step> loadSteps() throws IOException {
-		byte[] buf = IO.readFully(new File(rebaseDir, "git-rebase-todo"));
+		byte[] buf = IO.readFully(new File(rebaseDir, GIT_REBASE_TODO));
 		int ptr = 0;
 		int tokenBegin = 0;
 		ArrayList<Step> r = new ArrayList<Step>();
@@ -656,4 +786,42 @@ public class RebaseCommand extends GitCommand<RebaseResult> {
 			this.action = action;
 		}
 	}
+
+	PersonIdent parseAuthor(byte[] raw) {
+		if (raw.length == 0)
+			return null;
+
+		Map<String, String> keyValueMap = new HashMap<String, String>();
+		for (int p = 0; p < raw.length;) {
+			int end = RawParseUtils.nextLF(raw, p);
+			if (end == p)
+				break;
+			int equalsIndex = RawParseUtils.next(raw, p, '=');
+			if (equalsIndex == end)
+				break;
+			String key = RawParseUtils.decode(raw, p, equalsIndex - 1);
+			String value = RawParseUtils.decode(raw, equalsIndex + 1, end - 2);
+			p = end;
+			keyValueMap.put(key, value);
+		}
+
+		String name = keyValueMap.get(GIT_AUTHOR_NAME);
+		String email = keyValueMap.get(GIT_AUTHOR_EMAIL);
+		String time = keyValueMap.get(GIT_AUTHOR_DATE);
+
+		// the time is saved as <seconds since 1970> <timezone offset>
+		long when = Long.parseLong(time.substring(0, time.indexOf(' '))) * 1000;
+		String tzOffsetString = time.substring(time.indexOf(' ') + 1);
+		int multiplier = -1;
+		if (tzOffsetString.charAt(0) == '+')
+			multiplier = 1;
+		int hours = Integer.parseInt(tzOffsetString.substring(1, 3));
+		int minutes = Integer.parseInt(tzOffsetString.substring(3, 5));
+		// this is in format (+/-)HHMM (hours and minutes)
+		// we need to convert into minutes
+		int tz = (hours * 60 + minutes) * multiplier;
+		if (name != null && email != null)
+			return new PersonIdent(name, email, when, tz);
+		return null;
+	}
 }
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/api/errors/UnmergedPathsException.java b/org.eclipse.jgit/src/org/eclipse/jgit/api/errors/UnmergedPathsException.java
new file mode 100644
index 0000000000..ab078663b2
--- /dev/null
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/api/errors/UnmergedPathsException.java
@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2010,Mathias Kinzler <mathias.kinzler@sap.com> 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.api.errors;
+
+import org.eclipse.jgit.JGitText;
+
+/**
+ * Thrown when branch deletion fails due to unmerged data
+ */
+public class UnmergedPathsException extends GitAPIException {
+	private static final long serialVersionUID = 1L;
+
+	/**
+	 * The default constructor with a default message
+	 */
+	public UnmergedPathsException() {
+		super(JGitText.get().unmergedPaths);
+	}
+}