Remove AmbiguousObjectException from BranchCreateCommand.call()

We wanted to wrap all LowLevel JGit excpetions into a
JGitInternalException so that users of this high-level interface
don't have to explicitly catch all of them. This
was forgotten on BranchCreateCommand.call() and I added
it.

Change-Id: Ie140e99574fb004137c66e80fb92eb6c6d0fa5e1
Signed-off-by: Christian Halstrick <christian.halstrick@sap.com>

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

@@ -53,7 +53,6 @@ import org.eclipse.jgit.api.errors.JGitInternalException;
 import org.eclipse.jgit.api.errors.NotMergedException;
 import org.eclipse.jgit.api.errors.RefAlreadyExistsException;
 import org.eclipse.jgit.api.errors.RefNotFoundException;
-import org.eclipse.jgit.errors.AmbiguousObjectException;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.Ref;
 import org.eclipse.jgit.lib.RefUpdate;
@@ -404,7 +403,7 @@ public class BranchCommandTest extends RepositoryTestCase {
 	public Ref createBranch(Git actGit, String name, boolean force,
 			String startPoint, SetupUpstreamMode mode)
 			throws JGitInternalException, RefAlreadyExistsException,
-			AmbiguousObjectException, RefNotFoundException,
+			RefNotFoundException,
 			InvalidRefNameException {
 		CreateBranchCommand cmd = actGit.branchCreate();
 		cmd.setName(name);

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

@@ -114,16 +114,13 @@ public class CreateBranchCommand extends GitCommand<Ref> {
 	 *             that already exists
 	 * @throws RefNotFoundException
 	 *             if the start point can not be found
-	 * @throws AmbiguousObjectException
-	 *             if the start point is ambiguous
 	 * @throws InvalidRefNameException
 	 *             if the provided name is <code>null</code> or otherwise
 	 *             invalid
 	 * @return the newly created branch
 	 */
 	public Ref call() throws JGitInternalException, RefAlreadyExistsException,
-			RefNotFoundException, AmbiguousObjectException,
-			InvalidRefNameException {
+			RefNotFoundException, InvalidRefNameException {
 		checkCallable();
 		processOptions();
 		try {
@@ -267,8 +264,6 @@ public class CreateBranchCommand extends GitCommand<Ref> {
 				config.save();
 			}
 			return result;
-		} catch (AmbiguousObjectException e) {
-			throw e;
 		} catch (IOException ioe) {
 			throw new JGitInternalException(ioe.getMessage(), ioe);
 		}