title: Using RestAPI to get linked changesets after branch merge
body: <p>For the sake of this question we have two branches in our team project; QA and Release. All changesets  have important info in description field which is a link to our helpdesk software in form of - RZ:issue_number; I'm trying to develop a console app which would get all issue numbers from all changesets that went into last team build. Build is based on Release branch. I have no issues getting this info from changesets directly checked in Release. But, QA gets merged into Release before build and those changesets have no description in Release branch. So, I planned to get linked changesets from merge action so I could read their description but I have not found a way how.</p>
  
  <pre><code>            var changes = buildKlijent.GetBuildChangesAsync("Argosy", build.Id).Result;
  
              foreach (var change in changes)
              {
                  string komentar = change.Message;
  
                  if (komentar.Contains("RZ:"))
                  {
                      int start = komentar.IndexOf("RZ:") + 3;
                      int end = komentar.LastIndexOf(';');
  
                      string[] sirovirzovi = komentar.Substring(start, end - start).Split(new char[] { ',', ';' });
                      foreach (string rz in sirovirzovi)
                      {
                          int id;
                          if (int.TryParse(rz, out id))
                              radniZadaci.Rows.Add(id);
                      }
                  }
                  else
                  {
                      var changeSet = sourceKlijent.GetChangesetAsync(int.Parse(change.Id.Substring(1))).Result;
                      //TO DO: Get linked changeset from QA branch
                  }
              }
  </code></pre>
  
  <p>So, my question boiles down to: Given a changeset ID and that changeset is created during a branch merge operation, how can I get linked changeset?</p>
  
  <p>We're using TFS2015 server for development.</p>