title: How to revert a Mercurial hg pull?
body: <p>If you do an <code>hg pull</code> and then an <code>hg update</code> (or an <code>hg merge</code>), is there a way to back this out?  Ie: revert your repository to the state prior to doing the <code>hg pull</code>? </p>
  
  <p>I believe you can do <code>hg update -r n</code> where you would specify the changeset prior to the pull as <code>n</code>.  Though I'm guessing this will still leave the changesets in your repository but this isn't really what we want.  ??  </p>