Q:

TFS2010 - Track Merges

Given a changeset c and given that c contains merge operations, I would like to get a list of all changesets that have been merged and resulted in c.
For example:

Changeset 1 contains some edits for some files.
Changeset 2 contains some edits for some other files.
Changeset 3 is a merge of changesets 1+2 to a parent branch.

Now I would like to get changesets 1+2 from asking changeset 3 which changeset merges it contained.
I want to do this using the TFS API. I came across the versionControlServer.TrackMerges method, however I do not understand what the ItemIdentifiers that the method expects should be. Unfortunately, I cannot find an example of how to use this method. Also I'm not sure if that is really the correct one.

A:

Okay, it took me really long, but I think I found out how to do this. This is the Code that will find all the "parent" changesets:
/// <summary>
/// Gets the changesets which have resulted in the given changeset due
/// to a merge operation.
/// </summary>
/// <param name="changeset">The changeset.</param>
/// <param name="versionControlServer">The version control server.</param>
/// <returns>
/// A list of all changesets that have resulted into the given changeset.
/// </returns>
public static List<Changeset> GetMergedChangesets(Changeset changeset, VersionControlServer versionControlServer)
{
    // remember the already covered changeset id's
    Dictionary<int, bool> alreadyCoveredChangesets = new Dictionary<int, bool>();

    // initialize list of parent changesets
    List<Changeset> parentChangesets = new List<Changeset>();

    // go through each change inside the changeset
    foreach(Change change in changeset.Changes)
    {
        // query for the items' history
        var queryResults = versionControlServer.QueryMergesExtended(
                                new ItemSpec(change.Item.ServerItem, RecursionType.Full),
                                new ChangesetVersionSpec(changeset.ChangesetId),
                                null,
                                null);

        // go through each changeset in the history
        foreach (var result in queryResults)
        {
            // only if the target-change is the given changeset, we have a hit
            if (result.TargetChangeset.ChangesetId == changeset.ChangesetId)
            {
                // if that hit has already been processed elsewhere, then just skip it
                if (!alreadyCoveredChangesets.ContainsKey(result.SourceChangeset.ChangesetId))
                {
                    // otherwise add it
                    alreadyCoveredChangesets.Add(result.SourceChangeset.ChangesetId, true);
                    parentChangesets.Add(versionControlServer.GetChangeset(result.SourceChangeset.ChangesetId));
                }
            }
        }
    }

    return parentChangesets;
}

Edit:
I just realized that there is a small "bug" in the above code, I used to write "VersionSpec.Latest" in the query, however: "new ChangesetVersionSpec(changeset.ChangesetId)" would be better, because then the changesets would also be tracked once the source branch has been deleted.

