/*
 * Copyright 2013 Rimero Solutions
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.rimerosolutions.ant.git.tasks;

import com.rimerosolutions.ant.git.AbstractGitRepoAwareTask;
import com.rimerosolutions.ant.git.GitBuildException;
import org.apache.tools.ant.BuildException;
import org.eclipse.jgit.api.MergeCommand;
import org.eclipse.jgit.api.MergeResult;

/**
 * Merge changes from a repository.
 *
 * <pre>{@code
 * <git:git directory="${testLocalRepoClient}" verbose="true" settingsRef="git.testing">
 *  <git:merge/>
 * </git:git>}</pre>
 *
 * <p><a href="http://www.kernel.org/pub/software/scm/git/docs/git-merge.html">Git documentation about merge</a></p>
 * <p><a href="http://download.eclipse.org/jgit/docs/latest/apidocs/org/eclipse/jgit/api/MergeCommand.html">JGit MergeCommand</a></p>
 *
 * @author Jonas Olsson
 */
public class MergeTask extends AbstractGitRepoAwareTask {

	private static final String TASK_NAME = "git-merge";
	private static final String MESSAGE_MERGE_FAILED = "Merge failed.";
	private static final String MESSAGE_MERGE_FAILED_WITH_STATUS = "Merge failed, status '%s'.";
	private static final String MESSAGE_MERGE_FAILED_WITH_URI = "Could not merge from uri '%s'.";
	private boolean squash = false;
	private String branchname = null;

	@Override
	public String getName() {
		return TASK_NAME;
	}

	/**
	* Set if merge should be squashed
	*
	* @param squash Whether or not to squash
	* @antdoc.notrequired
	*/
	public void setSquash(boolean squash) {
		this.squash = squash;
	}

	/**
	 * Set branch to merge
	 *
	 * @param branchname Branch to merge
	 */
	public void setBranchname(String branchname) {
		this.branchname = branchname;
	}

	@Override
	public void doExecute() {
		try {
			MergeCommand mergeCommand = git.merge().setSquash(squash);
			mergeCommand.include(mergeCommand.getRepository().getRef(branchname));

			setupCredentials(mergeCommand);
			MergeResult mergeResult = mergeCommand.call();

			if (!mergeResult.getMergeStatus().isSuccessful()) {

				if (mergeResult.getFailingPaths() != null && mergeResult.getFailingPaths().size() > 0) {
					throw new BuildException(String.format("%s - Failing paths: %s", MESSAGE_MERGE_FAILED, mergeResult.getFailingPaths()));
				}

				throw new BuildException(String.format(MESSAGE_MERGE_FAILED_WITH_STATUS, mergeResult.getMergeStatus().name()));
			}
		} catch (Exception e) {
			throw new GitBuildException(String.format(MESSAGE_MERGE_FAILED_WITH_URI, getUri()), e);
		}
	}

}

@@ -1042,16 +1042,47 @@
 it:merge
+ branchname=%22branchToMergeFrom%22
 /%3E%0A * %3C/

Update sample usage of merge task.