Merged in feature/harmonize_branches_in_changesets (pull request #81)

Add branch to changeset collections

scm-core/src/main/java/sonia/scm/repository/ChangesetPagingResult.java

@@ -82,6 +82,22 @@ public class ChangesetPagingResult implements Iterable<Changeset>, Serializable
   {
     this.total = total;
     this.changesets = changesets;
+    this.branchName = null;
+  }
+
+  /**
+   * Constructs a new changeset paging result for a specific branch.
+   *
+   *
+   * @param total total number of changesets
+   * @param changesets current list of fetched changesets
+   * @param branchName branch name this result was created for
+   */
+  public ChangesetPagingResult(int total, List<Changeset> changesets, String branchName)
+  {
+    this.total = total;
+    this.changesets = changesets;
+    this.branchName = branchName;
   }
 
   //~--- methods --------------------------------------------------------------
@@ -158,6 +174,7 @@ public class ChangesetPagingResult implements Iterable<Changeset>, Serializable
     return MoreObjects.toStringHelper(this)
                   .add("changesets", changesets)
                   .add("total", total)
+                  .add("branch", branchName)
                   .toString();
     //J+
   }
@@ -186,37 +203,35 @@ public class ChangesetPagingResult implements Iterable<Changeset>, Serializable
     return total;
   }
 
-  //~--- set methods ----------------------------------------------------------
+  void setChangesets(List<Changeset> changesets)
-
-  /**
-   * Sets the current list of changesets.
-   *
-   *
-   * @param changesets current list of changesets
-   */
-  public void setChangesets(List<Changeset> changesets)
   {
     this.changesets = changesets;
   }
 
-  /**
+  void setTotal(int total)
-   * Sets the total number of changesets
-   *
-   *
-   * @param total total number of changesets
-   */
-  public void setTotal(int total)
   {
     this.total = total;
   }
 
+  void setBranchName(String branchName) {
+    this.branchName = branchName;
+  }
+
+  /**
+   * Returns the branch name this result was created for. This can either be an explicit branch ("give me all
+   * changesets for branch xyz") or an implicit one ("give me the changesets for the default").
+   */
+  public String getBranchName() {
+    return branchName;
+  }
+
   //~--- fields ---------------------------------------------------------------
 
-  /** current list of changesets */
   @XmlElement(name = "changeset")
   @XmlElementWrapper(name = "changesets")
   private List<Changeset> changesets;
 
-  /** total number of changesets */
   private int total;
+
+  private String branchName;
 }

scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/GitChangesetConverter.java

@@ -39,7 +39,6 @@ import com.google.common.collect.Lists;
 import com.google.common.collect.Multimap;
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.PersonIdent;
-import org.eclipse.jgit.lib.Ref;
 import org.eclipse.jgit.revwalk.RevCommit;
 import org.eclipse.jgit.revwalk.RevWalk;
 import org.eclipse.jgit.treewalk.TreeWalk;
@@ -51,8 +50,8 @@ import java.io.Closeable;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.List;
-import java.util.Set;
 
 //~--- JDK imports ------------------------------------------------------------
 
@@ -130,27 +129,9 @@ public class GitChangesetConverter implements Closeable
    *
    * @throws IOException
    */
-  public Changeset createChangeset(RevCommit commit) throws IOException
+  public Changeset createChangeset(RevCommit commit)
   {
-    List<String> branches = Lists.newArrayList();
+    return createChangeset(commit, Collections.emptyList());
-    Set<Ref> refs = repository.getAllRefsByPeeledObjectId().get(commit.getId());
-
-    if (Util.isNotEmpty(refs))
-    {
-
-      for (Ref ref : refs)
-      {
-        String branch = GitUtil.getBranch(ref);
-
-        if (branch != null)
-        {
-          branches.add(branch);
-        }
-      }
-
-    }
-
-    return createChangeset(commit, branches);
   }
 
   /**
@@ -165,7 +146,6 @@ public class GitChangesetConverter implements Closeable
    * @throws IOException
    */
   public Changeset createChangeset(RevCommit commit, String branch)
-    throws IOException
   {
     return createChangeset(commit, Lists.newArrayList(branch));
   }
@@ -183,7 +163,6 @@ public class GitChangesetConverter implements Closeable
    * @throws IOException
    */
   public Changeset createChangeset(RevCommit commit, List<String> branches)
-    throws IOException
   {
     String id = commit.getId().name();
     List<String> parentList = null;

scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/GitUtil.java

@@ -63,8 +63,11 @@ import javax.servlet.http.HttpServletRequest;
 import java.io.File;
 import java.io.IOException;
 import java.util.Map;
+import java.util.Optional;
 import java.util.concurrent.TimeUnit;
 
+import static java.util.Optional.of;
+
 //~--- JDK imports ------------------------------------------------------------
 
 /**
@@ -345,12 +348,11 @@ public final class GitUtil
    *
    * @throws IOException
    */
-  public static ObjectId getBranchId(org.eclipse.jgit.lib.Repository repo,
+  public static Ref getBranchId(org.eclipse.jgit.lib.Repository repo,
     String branchName)
     throws IOException
   {
-    ObjectId branchId = null;
+    Ref ref = null;
-
     if (!branchName.startsWith(REF_HEAD))
     {
       branchName = PREFIX_HEADS.concat(branchName);
@@ -360,24 +362,19 @@ public final class GitUtil
 
     try
     {
-      Ref ref = repo.findRef(branchName);
+      ref = repo.findRef(branchName);
 
-      if (ref != null)
+      if (ref == null)
-      {
-        branchId = ref.getObjectId();
-      }
-      else if (logger.isWarnEnabled())
       {
         logger.warn("could not find branch for {}", branchName);
       }
-
     }
     catch (IOException ex)
     {
       logger.warn("error occured during resolve of branch id", ex);
     }
 
-    return branchId;
+    return ref;
   }
 
   /**
@@ -499,68 +496,48 @@ public final class GitUtil
     return ref;
   }
 
-  /**
+  public static ObjectId getRepositoryHead(org.eclipse.jgit.lib.Repository repo) {
-   * Method description
+    return getRepositoryHeadRef(repo).map(Ref::getObjectId).orElse(null);
-   *
-   *
-   * @param repo
-   *
-   * @return
-   *
-   * @throws IOException
-   */
-  public static ObjectId getRepositoryHead(org.eclipse.jgit.lib.Repository repo)
-    throws IOException
-  {
-    ObjectId id = null;
-    String head = null;
-    Map<String, Ref> refs = repo.getAllRefs();
-
-    for (Map.Entry<String, Ref> e : refs.entrySet())
-    {
-      String key = e.getKey();
-
-      if (REF_HEAD.equals(key))
-      {
-        head = REF_HEAD;
-        id = e.getValue().getObjectId();
-
-        break;
-      }
-      else if (key.startsWith(REF_HEAD_PREFIX))
-      {
-        id = e.getValue().getObjectId();
-        head = key.substring(REF_HEAD_PREFIX.length());
-
-        if (REF_MASTER.equals(head))
-        {
-          break;
-        }
-      }
   }
 
-    if (id == null)
+  public static Optional<Ref> getRepositoryHeadRef(org.eclipse.jgit.lib.Repository repo) {
-    {
+    Optional<Ref> foundRef = findMostAppropriateHead(repo.getAllRefs());
-      id = repo.resolve(Constants.HEAD);
+
+    if (foundRef.isPresent()) {
+      if (logger.isDebugEnabled()) {
+        logger.debug("use {}:{} as repository head for directory {}",
+          foundRef.map(GitUtil::getBranch).orElse(null),
+          foundRef.map(Ref::getObjectId).map(ObjectId::name).orElse(null),
+          repo.getDirectory());
+      }
+    } else {
+      logger.warn("could not find repository head in directory {}", repo.getDirectory());
     }
 
-    if (logger.isDebugEnabled())
+    return foundRef;
-    {
-      if ((head != null) && (id != null))
-      {
-        logger.debug("use {}:{} as repository head", head, id.name());
-      }
-      else if (id != null)
-      {
-        logger.debug("use {} as repository head", id.name());
-      }
-      else
-      {
-        logger.warn("could not find repository head");
-      }
   }
 
-    return id;
+  private static Optional<Ref> findMostAppropriateHead(Map<String, Ref> refs) {
+    Ref refHead = refs.get(REF_HEAD);
+    if (refHead != null && refHead.isSymbolic() && isBranch(refHead.getTarget().getName())) {
+      return of(refHead.getTarget());
+    }
+
+    Ref master = refs.get(REF_HEAD_PREFIX + REF_MASTER);
+    if (master != null) {
+      return of(master);
+    }
+
+    Ref develop = refs.get(REF_HEAD_PREFIX + "develop");
+    if (develop != null) {
+      return of(develop);
+    }
+
+    return refs.entrySet()
+      .stream()
+      .filter(e -> e.getKey().startsWith(REF_HEAD_PREFIX))
+      .map(Map.Entry::getValue)
+      .findFirst();
   }
 
   /**

scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/spi/AbstractGitCommand.java

@@ -34,19 +34,20 @@ package sonia.scm.repository.spi;
 
 //~--- non-JDK imports --------------------------------------------------------
 
-import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Strings;
-import org.eclipse.jgit.lib.Repository;
-
-//~--- JDK imports ------------------------------------------------------------
-
-import java.io.IOException;
 import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.Ref;
+import org.eclipse.jgit.lib.Repository;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import sonia.scm.repository.GitConstants;
 import sonia.scm.repository.GitUtil;
 
+import java.io.IOException;
+import java.util.Optional;
+
+//~--- JDK imports ------------------------------------------------------------
+
 /**
  *
  * @author Sebastian Sdorra
@@ -98,26 +99,28 @@ public class AbstractGitCommand
     return commit;
   }
 
-  protected ObjectId getBranchOrDefault(Repository gitRepository, String requestedBranch) throws IOException {
+  protected ObjectId getDefaultBranch(Repository gitRepository) throws IOException {
-    ObjectId head;
+    Ref ref = getBranchOrDefault(gitRepository, null);
-    if ( Strings.isNullOrEmpty(requestedBranch) ) {
+    if (ref == null) {
-      head = getDefaultBranch(gitRepository);
+      return null;
     } else {
-      head = GitUtil.getBranchId(gitRepository, requestedBranch);
+      return ref.getObjectId();
     }
-    return head;
   }
 
-  protected ObjectId getDefaultBranch(Repository gitRepository) throws IOException {
+  protected Ref getBranchOrDefault(Repository gitRepository, String requestedBranch) throws IOException {
-    ObjectId head;
+    if ( Strings.isNullOrEmpty(requestedBranch) ) {
       String defaultBranchName = repository.getProperty(GitConstants.PROPERTY_DEFAULT_BRANCH);
       if (!Strings.isNullOrEmpty(defaultBranchName)) {
-      head = GitUtil.getBranchId(gitRepository, defaultBranchName);
+        return GitUtil.getBranchId(gitRepository, defaultBranchName);
       } else {
         logger.trace("no default branch configured, use repository head as default");
-      head = GitUtil.getRepositoryHead(gitRepository);
+        Optional<Ref> repositoryHeadRef = GitUtil.getRepositoryHeadRef(gitRepository);
+        return repositoryHeadRef.orElse(null);
+      }
+    } else {
+      return GitUtil.getBranchId(gitRepository, requestedBranch);
     }
-    return head;
   }
 
   //~--- fields ---------------------------------------------------------------

scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/spi/GitLogCommand.java

@@ -39,6 +39,7 @@ import com.google.common.base.Strings;
 import com.google.common.collect.Lists;
 import org.eclipse.jgit.errors.MissingObjectException;
 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;
@@ -170,8 +171,8 @@ public class GitLogCommand extends AbstractGitCommand implements LogCommand
     GitChangesetConverter converter = null;
     RevWalk revWalk = null;
 
-    try (org.eclipse.jgit.lib.Repository gr = open()) {
+    try (org.eclipse.jgit.lib.Repository repository = open()) {
-      if (!gr.getAllRefs().isEmpty()) {
+      if (!repository.getAllRefs().isEmpty()) {
         int counter = 0;
         int start = request.getPagingStart();
 
@@ -188,18 +189,18 @@ public class GitLogCommand extends AbstractGitCommand implements LogCommand
         ObjectId startId = null;
 
         if (!Strings.isNullOrEmpty(request.getStartChangeset())) {
-          startId = gr.resolve(request.getStartChangeset());
+          startId = repository.resolve(request.getStartChangeset());
         }
 
         ObjectId endId = null;
 
         if (!Strings.isNullOrEmpty(request.getEndChangeset())) {
-          endId = gr.resolve(request.getEndChangeset());
+          endId = repository.resolve(request.getEndChangeset());
         }
 
-        revWalk = new RevWalk(gr);
+        revWalk = new RevWalk(repository);
 
-        converter = new GitChangesetConverter(gr, revWalk);
+        converter = new GitChangesetConverter(repository, revWalk);
 
         if (!Strings.isNullOrEmpty(request.getPath())) {
           revWalk.setTreeFilter(
@@ -207,13 +208,13 @@ public class GitLogCommand extends AbstractGitCommand implements LogCommand
               PathFilter.create(request.getPath()), TreeFilter.ANY_DIFF));
         }
 
-        ObjectId head = getBranchOrDefault(gr, request.getBranch());
+        Ref branch = getBranchOrDefault(repository,request.getBranch());
 
-        if (head != null) {
+        if (branch != null) {
           if (startId != null) {
             revWalk.markStart(revWalk.lookupCommit(startId));
           } else {
-            revWalk.markStart(revWalk.lookupCommit(head));
+            revWalk.markStart(revWalk.lookupCommit(branch.getObjectId()));
           }
 
           Iterator<RevCommit> iterator = revWalk.iterator();
@@ -234,10 +235,14 @@ public class GitLogCommand extends AbstractGitCommand implements LogCommand
           }
         }
 
+        if (branch != null) {
+          changesets = new ChangesetPagingResult(counter, changesetList, GitUtil.getBranch(branch.getName()));
+        } else {
           changesets = new ChangesetPagingResult(counter, changesetList);
+        }
       } else if (logger.isWarnEnabled()) {
         logger.warn("the repository {} seems to be empty",
-          repository.getName());
+          this.repository.getName());
 
         changesets = new ChangesetPagingResult(0, Collections.EMPTY_LIST);
       }

scm-plugins/scm-git-plugin/src/test/java/sonia/scm/repository/spi/GitLogCommandTest.java

@@ -1,3 +1,4 @@
+
 /**
  * Copyright (c) 2010, Sebastian Sdorra
  * All rights reserved.
@@ -33,14 +34,17 @@
 
 package sonia.scm.repository.spi;
 
-//~--- non-JDK imports --------------------------------------------------------
+import com.google.common.io.Files;
-
 import org.junit.Test;
 import sonia.scm.repository.Changeset;
 import sonia.scm.repository.ChangesetPagingResult;
 import sonia.scm.repository.GitConstants;
 import sonia.scm.repository.Modifications;
 
+import java.io.File;
+import java.io.IOException;
+
+import static java.nio.charset.Charset.defaultCharset;
 import static org.hamcrest.Matchers.contains;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
@@ -48,8 +52,6 @@ import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertThat;
 import static org.junit.Assert.assertTrue;
 
-//~--- JDK imports ------------------------------------------------------------
-
 /**
  * Unit tests for {@link GitLogCommand}.
  *
@@ -72,6 +74,8 @@ public class GitLogCommandTest extends AbstractGitCommandTestBase
     assertEquals("86a6645eceefe8b9a247db5eb16e3d89a7e6e6d1", result.getChangesets().get(1).getId());
     assertEquals("592d797cd36432e591416e8b2b98154f4f163411", result.getChangesets().get(2).getId());
     assertEquals("435df2f061add3589cb326cc64be9b9c3897ceca", result.getChangesets().get(3).getId());
+    assertEquals("master", result.getBranchName());
+    assertTrue(result.getChangesets().stream().allMatch(r -> r.getBranches().isEmpty()));
 
     // set default branch and fetch again
     repository.setProperty(GitConstants.PROPERTY_DEFAULT_BRANCH, "test-branch");
@@ -79,10 +83,12 @@ public class GitLogCommandTest extends AbstractGitCommandTestBase
     result = createCommand().getChangesets(new LogCommandRequest());
 
     assertNotNull(result);
+    assertEquals("test-branch", result.getBranchName());
     assertEquals(3, result.getTotal());
     assertEquals("3f76a12f08a6ba0dc988c68b7f0b2cd190efc3c4", result.getChangesets().get(0).getId());
     assertEquals("592d797cd36432e591416e8b2b98154f4f163411", result.getChangesets().get(1).getId());
     assertEquals("435df2f061add3589cb326cc64be9b9c3897ceca", result.getChangesets().get(2).getId());
+    assertTrue(result.getChangesets().stream().allMatch(r -> r.getBranches().isEmpty()));
   }
 
   @Test
@@ -210,6 +216,32 @@ public class GitLogCommandTest extends AbstractGitCommandTestBase
     assertEquals("435df2f061add3589cb326cc64be9b9c3897ceca", c2.getId());
   }
 
+  @Test
+  public void shouldFindDefaultBranchFromHEAD() throws Exception {
+    setRepositoryHeadReference("ref: refs/heads/test-branch");
+
+    ChangesetPagingResult changesets = createCommand().getChangesets(new LogCommandRequest());
+
+    assertEquals("test-branch", changesets.getBranchName());
+  }
+
+  @Test
+  public void shouldFindMasterBranchWhenHEADisNoRef() throws Exception {
+    setRepositoryHeadReference("592d797cd36432e591416e8b2b98154f4f163411");
+
+    ChangesetPagingResult changesets = createCommand().getChangesets(new LogCommandRequest());
+
+    assertEquals("master", changesets.getBranchName());
+  }
+
+  private void setRepositoryHeadReference(String s) throws IOException {
+    Files.write(s, repositoryHeadReferenceFile(), defaultCharset());
+  }
+
+  private File repositoryHeadReferenceFile() {
+    return new File(repositoryDirectory, "HEAD");
+  }
+
   private GitLogCommand createCommand()
   {
     return new GitLogCommand(createContext(), repository);

scm-plugins/scm-hg-plugin/src/main/java/sonia/scm/repository/spi/HgLogCommand.java

@@ -132,7 +132,11 @@ public class HgLogCommand extends AbstractCommand implements LogCommand
         List<Changeset> changesets = on(repository).rev(start + ":"
                                        + end).execute();
 
+        if (request.getBranch() == null) {
           result = new ChangesetPagingResult(total, changesets);
+        } else {
+          result = new ChangesetPagingResult(total, changesets, request.getBranch());
+        }
       }
       else
       {

scm-plugins/scm-hg-plugin/src/main/java/sonia/scm/repository/spi/javahg/AbstractChangesetCommand.java

@@ -216,10 +216,7 @@ public abstract class AbstractChangesetCommand extends AbstractCommand
 
     String branch = in.textUpTo('\n');
 
-    if (!BRANCH_DEFAULT.equals(branch))
-    {
     changeset.getBranches().add(branch);
-    }
 
     String p1 = readId(in, changeset, PROPERTY_PARENT1_REVISION);
 

scm-plugins/scm-hg-plugin/src/test/java/sonia/scm/repository/spi/HgLogCommandTest.java

@@ -88,6 +88,21 @@ public class HgLogCommandTest extends AbstractHgCommandTestBase
       result.getChangesets().get(2).getId());
   }
 
+  @Test
+  public void testGetDefaultBranchInfo() {
+    LogCommandRequest request = new LogCommandRequest();
+
+    request.setPath("a.txt");
+
+    ChangesetPagingResult result = createComamnd().getChangesets(request);
+
+    assertNotNull(result);
+    assertEquals(1,
+      result.getChangesets().get(0).getBranches().size());
+    assertEquals("default",
+      result.getChangesets().get(0).getBranches().get(0));
+  }
+
   @Test
   public void testGetAllWithLimit() {
     LogCommandRequest request = new LogCommandRequest();

scm-webapp/src/main/java/sonia/scm/api/v2/resources/BranchChangesetCollectionToDtoMapper.java

@@ -12,12 +12,12 @@ public class BranchChangesetCollectionToDtoMapper extends ChangesetCollectionToD
 
   @Inject
   public BranchChangesetCollectionToDtoMapper(ChangesetToChangesetDtoMapper changesetToChangesetDtoMapper, ResourceLinks resourceLinks) {
-    super(changesetToChangesetDtoMapper);
+    super(changesetToChangesetDtoMapper, resourceLinks);
     this.resourceLinks = resourceLinks;
   }
 
   public CollectionDto map(int pageNumber, int pageSize, PageResult<Changeset> pageResult, Repository repository, String branch) {
-    return this.map(pageNumber, pageSize, pageResult, repository, () -> createSelfLink(repository, branch));
+    return this.map(pageNumber, pageSize, pageResult, repository, () -> createSelfLink(repository, branch), branch);
   }
 
   private String createSelfLink(Repository repository, String branch) {

scm-webapp/src/main/java/sonia/scm/api/v2/resources/BranchReferenceDto.java

@@ -0,0 +1,19 @@
+package sonia.scm.api.v2.resources;
+
+import de.otto.edison.hal.HalRepresentation;
+import de.otto.edison.hal.Links;
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+@NoArgsConstructor @AllArgsConstructor @Getter @Setter
+public class BranchReferenceDto extends HalRepresentation {
+  private String name;
+
+  @Override
+  @SuppressWarnings("squid:S1185") // We want to have this method available in this package
+  protected HalRepresentation add(Links links) {
+    return super.add(links);
+  }
+}

scm-webapp/src/main/java/sonia/scm/api/v2/resources/ChangesetCollectionToDtoMapper.java

@@ -12,10 +12,13 @@ public class ChangesetCollectionToDtoMapper extends ChangesetCollectionToDtoMapp
 
   @Inject
   public ChangesetCollectionToDtoMapper(ChangesetToChangesetDtoMapper changesetToChangesetDtoMapper, ResourceLinks resourceLinks) {
-    super(changesetToChangesetDtoMapper);
+    super(changesetToChangesetDtoMapper, resourceLinks);
     this.resourceLinks = resourceLinks;
   }
 
+  public CollectionDto map(int pageNumber, int pageSize, PageResult<Changeset> pageResult, Repository repository, String branchName) {
+    return super.map(pageNumber, pageSize, pageResult, repository, () -> createSelfLink(repository), branchName);
+  }
   public CollectionDto map(int pageNumber, int pageSize, PageResult<Changeset> pageResult, Repository repository) {
     return super.map(pageNumber, pageSize, pageResult, repository, () -> createSelfLink(repository));
   }

scm-webapp/src/main/java/sonia/scm/api/v2/resources/ChangesetCollectionToDtoMapperBase.java

@@ -1,5 +1,6 @@
 package sonia.scm.api.v2.resources;
 
+import de.otto.edison.hal.Links;
 import sonia.scm.PageResult;
 import sonia.scm.repository.Changeset;
 import sonia.scm.repository.Repository;
@@ -10,14 +11,28 @@ import java.util.function.Supplier;
 class ChangesetCollectionToDtoMapperBase extends PagedCollectionToDtoMapper<Changeset, ChangesetDto> {
 
   private final ChangesetToChangesetDtoMapper changesetToChangesetDtoMapper;
+  private final ResourceLinks resourceLinks;
 
-  ChangesetCollectionToDtoMapperBase(ChangesetToChangesetDtoMapper changesetToChangesetDtoMapper) {
+  ChangesetCollectionToDtoMapperBase(ChangesetToChangesetDtoMapper changesetToChangesetDtoMapper, ResourceLinks resourceLinks) {
     super("changesets");
     this.changesetToChangesetDtoMapper = changesetToChangesetDtoMapper;
+    this.resourceLinks = resourceLinks;
   }
 
   CollectionDto map(int pageNumber, int pageSize, PageResult<Changeset> pageResult, Repository repository, Supplier<String> selfLinkSupplier) {
     return super.map(pageNumber, pageSize, pageResult, selfLinkSupplier.get(), Optional.empty(), changeset -> changesetToChangesetDtoMapper.map(changeset, repository));
   }
-}
 
+  CollectionDto map(int pageNumber, int pageSize, PageResult<Changeset> pageResult, Repository repository, Supplier<String> selfLinkSupplier, String branchName) {
+    CollectionDto collectionDto = this.map(pageNumber, pageSize, pageResult, repository, selfLinkSupplier);
+    collectionDto.withEmbedded("branch", createBranchReferenceDto(repository, branchName));
+    return collectionDto;
+  }
+
+  private BranchReferenceDto createBranchReferenceDto(Repository repository, String branchName) {
+    BranchReferenceDto branchReferenceDto = new BranchReferenceDto();
+    branchReferenceDto.setName(branchName);
+    branchReferenceDto.add(Links.linkingTo().self(resourceLinks.branch().self(repository.getNamespaceAndName(), branchName)).build());
+    return branchReferenceDto;
+  }
+}

scm-webapp/src/main/java/sonia/scm/api/v2/resources/ChangesetRootResource.java

@@ -65,7 +65,11 @@ public class ChangesetRootResource {
         .getChangesets();
       if (changesets != null && changesets.getChangesets() != null) {
         PageResult<Changeset> pageResult = new PageResult<>(changesets.getChangesets(), changesets.getTotal());
+        if (changesets.getBranchName() != null) {
+          return Response.ok(changesetCollectionToDtoMapper.map(page, pageSize, pageResult, repository, changesets.getBranchName())).build();
+        } else {
           return Response.ok(changesetCollectionToDtoMapper.map(page, pageSize, pageResult, repository)).build();
+        }
       } else {
         return Response.ok().build();
       }

scm-webapp/src/main/java/sonia/scm/api/v2/resources/CollectionDto.java

@@ -15,4 +15,9 @@ class CollectionDto extends HalRepresentation {
   CollectionDto(Links links, Embedded embedded) {
     super(links, embedded);
   }
+
+  @Override
+  protected HalRepresentation withEmbedded(String rel, HalRepresentation embeddedItem) {
+    return super.withEmbedded(rel, embeddedItem);
+  }
 }

scm-webapp/src/main/java/sonia/scm/api/v2/resources/FileHistoryCollectionToDtoMapper.java

@@ -13,7 +13,7 @@ public class FileHistoryCollectionToDtoMapper extends ChangesetCollectionToDtoMa
 
   @Inject
   public FileHistoryCollectionToDtoMapper(ChangesetToChangesetDtoMapper changesetToChangesetDtoMapper, ResourceLinks resourceLinks) {
-    super(changesetToChangesetDtoMapper);
+    super(changesetToChangesetDtoMapper, resourceLinks);
     this.resourceLinks = resourceLinks;
   }
 

scm-webapp/src/test/java/sonia/scm/api/v2/resources/ChangesetCollectionToDtoMapperTest.java

@@ -0,0 +1,61 @@
+package sonia.scm.api.v2.resources;
+
+import org.assertj.core.api.Assertions;
+import org.junit.Test;
+import sonia.scm.PageResult;
+import sonia.scm.repository.Changeset;
+import sonia.scm.repository.Repository;
+
+import java.net.URI;
+
+import static java.util.Arrays.asList;
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+public class ChangesetCollectionToDtoMapperTest {
+
+  public static final Repository REPOSITORY = new Repository("", "git", "space", "name");
+  public static final Changeset CHANGESET = new Changeset();
+  private final ChangesetToChangesetDtoMapper changesetToChangesetDtoMapper = mock(ChangesetToChangesetDtoMapper.class);
+
+  private final ChangesetCollectionToDtoMapper changesetCollectionToDtoMapper = new ChangesetCollectionToDtoMapper(changesetToChangesetDtoMapper, ResourceLinksMock.createMock(URI.create("/")));
+
+  @Test
+  public void shouldMapCollectionEntries() {
+    ChangesetDto expectedChangesetDto = new ChangesetDto();
+    when(changesetToChangesetDtoMapper.map(CHANGESET, REPOSITORY)).thenReturn(expectedChangesetDto);
+
+    CollectionDto collectionDto = changesetCollectionToDtoMapper.map(0, 1, new PageResult<>(asList(CHANGESET), 1), REPOSITORY);
+
+    assertThat(collectionDto.getEmbedded().hasItem("changesets")).isTrue();
+    assertThat(collectionDto.getEmbedded().getItemsBy("changesets")).containsExactly(expectedChangesetDto);
+    assertThat(collectionDto.getEmbedded().hasItem("branch")).isFalse();
+  }
+
+  @Test
+  public void shouldNotEmbedBranchIfNotSpecified() {
+    ChangesetDto expectedChangesetDto = new ChangesetDto();
+    when(changesetToChangesetDtoMapper.map(CHANGESET, REPOSITORY)).thenReturn(expectedChangesetDto);
+
+    CollectionDto collectionDto = changesetCollectionToDtoMapper.map(0, 1, new PageResult<>(asList(CHANGESET), 1), REPOSITORY);
+
+    assertThat(collectionDto.getEmbedded().hasItem("branch")).isFalse();
+  }
+
+  @Test
+  public void shouldEmbedBranchIfSpecified() {
+    ChangesetDto expectedChangesetDto = new ChangesetDto();
+    when(changesetToChangesetDtoMapper.map(CHANGESET, REPOSITORY)).thenReturn(expectedChangesetDto);
+
+    CollectionDto collectionDto = changesetCollectionToDtoMapper.map(0, 1, new PageResult<>(asList(CHANGESET), 1), REPOSITORY, "someBranch");
+
+    assertThat(collectionDto.getEmbedded().hasItem("branch")).isTrue();
+    assertThat(collectionDto.getEmbedded().getItemsBy("branch"))
+      .hasSize(1)
+      .first().matches(b -> b.getLinks().getLinkBy("self").isPresent())
+      .extracting(b -> b.getLinks().getLinkBy("self").get().getHref()).first().isEqualTo("/v2/repositories/space/name/branches/someBranch");
+    assertThat(collectionDto.getEmbedded().getItemsBy("branch"))
+      .first().extracting("name").first().isEqualTo("someBranch");
+  }
+}