title: Replace branch completely with another branch
body: <p>I have 3 branches: <code>development</code>, <code>qa</code>, and <code>staging</code>. I have almost the same code in both <code>development</code> and <code>qa</code>, so making a pr from <code>development</code> to <code>qa</code> doesn't yield too many changes (and or conflicts).</p>
  <p>But now I have a move all the stuff from <code>qa</code> to <code>staging</code>. And <code>qa</code> code is practically completely different and new from <code>staging</code>, so what's the best option? I searched and found this <a href="https://stackoverflow.com/a/4624383/9664">other answer</a>:</p>
  <pre><code>git checkout qa
  git merge -s ours staging
  git checkout staging
  git merge qa
  </code></pre>
  <p>Is this a good idea for my case? Thanks in advance!</p>
  <p>EDIT: I don't want to lose all the commits from staging branch.</p>