Add setContains to ListBranchCommand (branch --contains)

To correspond to the behavior of "git branch", also return HEAD in case
it is detached.

Bug: 425678
Change-Id: Ie615731434d70b99bd18c7a02e832c0a2c3ceef3
Signed-off-by: Robin Stocker <robin@nibor.org>

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

@@ -196,6 +196,20 @@ public class BranchCommandTest extends RepositoryTestCase {
 		git.branchList().setListMode(ListMode.ALL).call();
 	}
 
+	@Test
+	public void testListBranchesWithContains() throws Exception {
+		git.branchCreate().setName("foo").setStartPoint(secondCommit).call();
+
+		List<Ref> refs = git.branchList().call();
+		assertEquals(2, refs.size());
+
+		List<Ref> refsContainingSecond = git.branchList()
+				.setContains(secondCommit.name()).call();
+		assertEquals(1, refsContainingSecond.size());
+		// master is on initial commit, so it should not be returned
+		assertEquals("refs/heads/foo", refsContainingSecond.get(0).getName());
+	}
+
 	@Test
 	public void testCreateFromCommit() throws Exception {
 		Ref branch = git.branchCreate().setName("FromInitial").setStartPoint(

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

@@ -1,6 +1,7 @@
 /*
  * Copyright (C) 2010, Mathias Kinzler <mathias.kinzler@sap.com>
  * Copyright (C) 2010, Chris Aniszczyk <caniszczyk@gmail.com>
+ * Copyright (C) 2014, Robin Stocker <robin@nibor.org>
  * and other copyright owners as documented in the project's IP log.
  *
  * This program and the accompanying materials are made available
@@ -44,21 +45,30 @@
 package org.eclipse.jgit.api;
 
 import java.io.IOException;
+import java.text.MessageFormat;
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.Comparator;
-import java.util.HashMap;
 import java.util.List;
-import java.util.Map;
 
 import org.eclipse.jgit.api.errors.GitAPIException;
 import org.eclipse.jgit.api.errors.JGitInternalException;
+import org.eclipse.jgit.api.errors.RefNotFoundException;
+import org.eclipse.jgit.internal.JGitText;
 import org.eclipse.jgit.lib.Constants;
+import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.Ref;
 import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.revwalk.RevCommit;
+import org.eclipse.jgit.revwalk.RevWalk;
+import org.eclipse.jgit.revwalk.RevWalkUtils;
 
 /**
  * Used to obtain a list of branches.
+ * <p>
+ * In case HEAD is detached (it points directly to a commit), it is also
+ * returned in the results.
  *
  * @see <a
  *      href="http://www.kernel.org/pub/software/scm/git/docs/git-branch.html"
@@ -67,6 +77,8 @@ import org.eclipse.jgit.lib.Repository;
 public class ListBranchCommand extends GitCommand<List<Ref>> {
 	private ListMode listMode;
 
+	private String containsCommitish;
+
 	/**
 	 * The modes available for listing branches (corresponding to the -r and -a
 	 * options)
@@ -91,23 +103,28 @@ public class ListBranchCommand extends GitCommand<List<Ref>> {
 
 	public List<Ref> call() throws GitAPIException {
 		checkCallable();
-		Map<String, Ref> refList;
+		List<Ref> resultRefs;
 		try {
+			Collection<Ref> refs = new ArrayList<Ref>();
+
+			// Also return HEAD if it's detached
+			Ref head = repo.getRef(Constants.HEAD);
+			if (head != null && head.getLeaf().getName().equals(Constants.HEAD))
+				refs.add(head);
+
 			if (listMode == null) {
-				refList = repo.getRefDatabase().getRefs(Constants.R_HEADS);
+				refs.addAll(getRefs(Constants.R_HEADS));
 			} else if (listMode == ListMode.REMOTE) {
-				refList = repo.getRefDatabase().getRefs(Constants.R_REMOTES);
+				refs.addAll(getRefs(Constants.R_REMOTES));
 			} else {
-				refList = new HashMap<String,Ref>(repo.getRefDatabase().getRefs(
-						Constants.R_HEADS));
-				refList.putAll(repo.getRefDatabase().getRefs(
-						Constants.R_REMOTES));
+				refs.addAll(getRefs(Constants.R_HEADS));
+				refs.addAll(getRefs(Constants.R_REMOTES));
 			}
+			resultRefs = new ArrayList<Ref>(filterRefs(refs));
 		} catch (IOException e) {
 			throw new JGitInternalException(e.getMessage(), e);
 		}
-		List<Ref> resultRefs = new ArrayList<Ref>();
-		resultRefs.addAll(refList.values());
+
 		Collections.sort(resultRefs, new Comparator<Ref>() {
 			public int compare(Ref o1, Ref o2) {
 				return o1.getName().compareTo(o2.getName());
@@ -117,6 +134,26 @@ public class ListBranchCommand extends GitCommand<List<Ref>> {
 		return resultRefs;
 	}
 
+	private Collection<Ref> filterRefs(Collection<Ref> refs)
+			throws RefNotFoundException, IOException {
+		if (containsCommitish == null)
+			return refs;
+
+		RevWalk walk = new RevWalk(repo);
+		try {
+			ObjectId resolved = repo.resolve(containsCommitish);
+			if (resolved == null)
+				throw new RefNotFoundException(MessageFormat.format(
+						JGitText.get().refNotResolved, containsCommitish));
+
+			RevCommit containsCommit = walk.parseCommit(resolved);
+			return RevWalkUtils.findBranchesReachableFrom(containsCommit, walk,
+					refs);
+		} finally {
+			walk.release();
+		}
+	}
+
 	/**
 	 * @param listMode
 	 *            optional: corresponds to the -r/-a options; by default, only
@@ -128,4 +165,23 @@ public class ListBranchCommand extends GitCommand<List<Ref>> {
 		this.listMode = listMode;
 		return this;
 	}
+
+	/**
+	 * If this is set, only the branches that contain the specified commit-ish
+	 * as an ancestor are returned.
+	 *
+	 * @param containsCommitish
+	 *            a commit ID or ref name
+	 * @return this instance
+	 * @since 3.3
+	 */
+	public ListBranchCommand setContains(String containsCommitish) {
+		checkCallable();
+		this.containsCommitish = containsCommitish;
+		return this;
+	}
+
+	private Collection<Ref> getRefs(String prefix) throws IOException {
+		return repo.getRefDatabase().getRefs(prefix).values();
+	}
 }