Fix Check for FF_ONLY merges again

Added more FF-mode tests

Change-Id: I33eed5737d9411cc1cf214da62ce719916a1b736

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

@@ -204,28 +204,6 @@ public class MergeCommandTest extends RepositoryTestCase {
 		}
 	}
 
-	@Test
-	public void testMergeCannotDoRequiredFastForward() throws Exception {
-		Git git = new Git(db);
-
-		RevCommit first = git.commit().setMessage("first").call();
-		createBranch(first, "refs/heads/side");
-
-		writeTrashFile("a", "a");
-		git.add().addFilepattern("a").call();
-		git.commit().setMessage("second").call();
-
-		checkoutBranch("refs/heads/side");
-		writeTrashFile("b", "b");
-		git.add().addFilepattern("b").call();
-		git.commit().setMessage("third").call();
-
-		MergeResult result = git.merge().include(db.getRef(Constants.MASTER))
-				.setFastForward(FastForwardMode.NO_FF)
-				.call();
-		assertEquals(MergeStatus.ABORTED, result.getMergeStatus());
-	}
-
 	@Theory
 	public void testMergeSuccessAllStrategies(MergeStrategy mergeStrategy)
 			throws Exception {
@@ -1367,6 +1345,41 @@ public class MergeCommandTest extends RepositoryTestCase {
 
 		assertEquals(MergeStatus.FAST_FORWARD, result.getMergeStatus());
 	}
+	@Test
+	public void testNoFastForward() throws Exception {
+		Git git = new Git(db);
+		RevCommit initialCommit = git.commit().setMessage("initial commit")
+				.call();
+		createBranch(initialCommit, "refs/heads/branch1");
+		git.commit().setMessage("second commit").call();
+		checkoutBranch("refs/heads/branch1");
+
+		MergeCommand merge = git.merge();
+		merge.setFastForward(FastForwardMode.NO_FF);
+		merge.include(db.getRef(Constants.MASTER));
+		MergeResult result = merge.call();
+
+		assertEquals(MergeStatus.MERGED, result.getMergeStatus());
+	}
+
+	@Test
+	public void testFastForwardOnlyNotPossible() throws Exception {
+		Git git = new Git(db);
+		RevCommit initialCommit = git.commit().setMessage("initial commit")
+				.call();
+		createBranch(initialCommit, "refs/heads/branch1");
+		git.commit().setMessage("second commit").call();
+		checkoutBranch("refs/heads/branch1");
+		writeTrashFile("file1", "branch1");
+		git.add().addFilepattern("file").call();
+		git.commit().setMessage("second commit on branch1").call();
+		MergeCommand merge = git.merge();
+		merge.setFastForward(FastForwardMode.FF_ONLY);
+		merge.include(db.getRef(Constants.MASTER));
+		MergeResult result = merge.call();
+
+		assertEquals(MergeStatus.ABORTED, result.getMergeStatus());
+	}
 	private static void setExecutable(Git git, String path, boolean executable) {
 		FS.DETECTED.setExecute(
 				new File(git.getRepository().getWorkTree(), path), executable);

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

@@ -300,7 +300,7 @@ public class MergeCommand extends GitCommand<MergeResult> {
 						headCommit, srcCommit }, mergeStatus, mergeStrategy,
 						null, msg);
 			} else {
-				if (fastForwardMode == FastForwardMode.NO_FF) {
+				if (fastForwardMode == FastForwardMode.FF_ONLY) {
 					return new MergeResult(headCommit, srcCommit,
 							new ObjectId[] { headCommit, srcCommit },
 							MergeStatus.ABORTED, mergeStrategy, null, null);