title: Mercurial Getting out of a bad merge
body: <p>I just merged branch A into B, and for some reason the merge did not go well. I want to revert B back to where it was before the merge and try again like it never happened before. I was thinking of just doing </p>
  
  <pre><code>hg clone myrepo newrepo -r A -r 12345
  </code></pre>
  
  <p>where 12345 is the revision number before B's bad merge commit</p>
  
  <p>I think this works, but I have a lot of other branches (most of which are closed using commit --close-branch) and this puts those branches back to an inactive state. </p>
  
  <p>Is there a way to clone everything except revision 123456 or something? (where 123456 is the bad commit on B)</p>