title: Merged a Pull request merged multiple branches at once
body: <p>Yesterday I merged 1 pull request of a branch done by another developer that I am replacing while he is vacation into Master, the code changes in this branch was code reviewed and tested thoroughly. </p>
  
  <p>All of the sudden he CI reported so many errors, totally unrelated to the changes done in that branch that merged in that pull request, so we assumed it was something else (lately we have been having issues with our CI, because is a plan to reorganize the CI).</p>
  
  <p>This morning I got yelled by two different developers demanding an explanation on why I merged their branches when they are not done.</p>
  
  <p>I have no idea how this is possible. In one Pull Request you merge different branches to the one that generated the Pull Request?</p>
  
  <p>Can someone explain if this is possible, why and how.....  </p>