title: How to undo merge of master branch?
body: <p>I'm new Github so please forgive what may seem like an obvious question.  I have an <code>Experimentation</code> branch which is 24 commits ahead of the <code>master</code> branch.</p>
  <p>Following this tutorial, I merged the <code>master</code> branch with the <code>Experimentation</code> branch like so:</p>
  <pre><code>git checkout master
  git merge Experimentation
  </code></pre>
  <p>(There were no merge conflicts.)</p>
  <p>But then I realized that merging the two branches would not keep the commit history of the <code>Experimentation</code> branch and what I really wanted was to do a rebase (in order to keep the commit history of the <code>Experimentation</code> branch).</p>
  <p>So my question is: <strong>how do I undo the merge of the <code>master</code> branch?</strong></p>
  <p>I've already tried:</p>
  <pre><code>$ git branch
        Experimentation
      * master
        pod-attempt
  
  $ git merge --abort
        fatal: There is no merge to abort (MERGE_HEAD missing).
  </code></pre>
  <p>The &quot;fatal&quot; message confused me b/c I thought I <em>did</em> merge the <code>master</code> branch.</p>