Add support for rebase interactive 'edit' command

The 'edit' command allows you to change arbitrary commit
content and the message of any commit in the repository.

Bug: 394577
Change-Id: I43a44782cdb10b29f13784fa75ab37fe5d4da01b
Signed-off-by: Dariusz Luksza <dariusz@luksza.org>
Signed-off-by: Chris Aniszczyk <zx@twitter.com>

org.eclipse.jgit.test/tst/org/eclipse/jgit/api/RebaseCommandTest.java

@@ -1581,6 +1581,58 @@ public class RebaseCommandTest extends RepositoryTestCase {
 		assertEquals("rewritten commit message", actualCommitMag);
 	}
 
+	@Test
+	public void testRebaseInteractiveEdit() throws Exception {
+		// create file1 on master
+		writeTrashFile(FILE1, FILE1);
+		git.add().addFilepattern(FILE1).call();
+		git.commit().setMessage("Add file1").call();
+		assertTrue(new File(db.getWorkTree(), FILE1).exists());
+
+		// create file2 on master
+		writeTrashFile("file2", "file2");
+		git.add().addFilepattern("file2").call();
+		git.commit().setMessage("Add file2").call();
+		assertTrue(new File(db.getWorkTree(), "file2").exists());
+
+		// update FILE1 on master
+		writeTrashFile(FILE1, "blah");
+		git.add().addFilepattern(FILE1).call();
+		git.commit().setMessage("updated file1 on master").call();
+
+		writeTrashFile("file2", "more change");
+		git.add().addFilepattern("file2").call();
+		git.commit().setMessage("update file2 on side").call();
+
+		RebaseResult res = git.rebase().setUpstream("HEAD~2")
+				.runInteractively(new InteractiveHandler() {
+					public void prepareSteps(List<Step> steps) {
+						steps.get(0).action = Action.EDIT;
+					}
+
+					public String modifyCommitMessage(String commit) {
+						return ""; // not used
+					}
+				}).call();
+		assertEquals(Status.STOPPED, res.getStatus());
+		RevCommit toBeEditted = git.log().call().iterator().next();
+		assertEquals("updated file1 on master", toBeEditted.getFullMessage());
+
+		// change file and commit with new commit message
+		writeTrashFile("file1", "edited");
+		git.commit().setAll(true).setAmend(true)
+				.setMessage("edited commit message").call();
+		// resume rebase
+		res = git.rebase().setOperation(Operation.CONTINUE).call();
+
+		checkFile(new File(db.getWorkTree(), "file1"), "edited");
+		assertEquals(Status.OK, res.getStatus());
+		Iterator<RevCommit> logIterator = git.log().all().call().iterator();
+		logIterator.next(); // skip first commit;
+		String actualCommitMag = logIterator.next().getShortMessage();
+		assertEquals("edited commit message", actualCommitMag);
+	}
+
 	private File getTodoFile() {
 		File todoFile = new File(db.getDirectory(),
 				"rebase-merge/git-rebase-todo");

org.eclipse.jgit/src/org/eclipse/jgit/api/RebaseCommand.java

@@ -143,6 +143,8 @@ public class RebaseCommand extends GitCommand<RebaseResult> {
 
 	private static final String REBASE_HEAD = "head";
 
+	private static final String AMEND = "amend";
+
 	/**
 	 * The available operations
 	 */
@@ -240,7 +242,12 @@ public class RebaseCommand extends GitCommand<RebaseResult> {
 			if (operation == Operation.CONTINUE) {
 				newHead = continueRebase();
 
-				if (newHead == null) {
+				File amendFile = new File(rebaseDir, AMEND);
+				boolean amendExists = amendFile.exists();
+				if (amendExists) {
+					FileUtils.delete(amendFile);
+				}
+				if (newHead == null && !amendExists) {
 					// continueRebase() returns null only if no commit was
 					// neccessary. This means that no changes where left over
 					// after resolving all conflicts. In this case, cgit stops
@@ -331,6 +338,9 @@ public class RebaseCommand extends GitCommand<RebaseResult> {
 						newHead = new Git(repo).commit().setMessage(newMessage)
 								.setAmend(true).call();
 						continue;
+					case EDIT:
+						createFile(rebaseDir, AMEND, commitToPick.name());
+						return stop(commitToPick);
 					}
 				} finally {
 					monitor.endTask();
@@ -1070,7 +1080,9 @@ public class RebaseCommand extends GitCommand<RebaseResult> {
 		/** Use commit */
 		PICK("pick", "p"),
 		/** Use commit, but edit the commit message */
-		REWORD("reword", "r"); // later add SQUASH, EDIT, etc.
+		REWORD("reword", "r"),
+		/** Use commit, but stop for amending */
+		EDIT("edit", "e"); // later add SQUASH, FIXUP, etc.
 
 		private final String token;
 
@@ -1094,13 +1106,14 @@ public class RebaseCommand extends GitCommand<RebaseResult> {
 		}
 
 		static Action parse(String token) {
-			if (token.equals(PICK.token) || token.equals(PICK.shortToken))
-				return PICK;
-			if (token.equals(REWORD.token) || token.equals(REWORD.shortToken))
-				return REWORD;
+			for (Action action : Action.values()) {
+				if (action.token.equals(token)
+						|| action.shortToken.equals(token))
+					return action;
+			}
 			throw new JGitInternalException(MessageFormat.format(
 					JGitText.get().unknownOrUnsupportedCommand, token,
-					PICK.toToken()));
+					Action.values()));
 		}
 	}