title: Abort: cannot apply a patch over an already active patch
body: <p>I am using <a href="https://www.sourcetreeapp.com/" rel="nofollow noreferrer"><code>Source Tree</code></a> as a Mercurial client.</p>
  
  <p>I made changes and save them in <code>Shelve</code>. Now, I am unanble to <code>unshelve</code> them, get error:</p>
  
  <blockquote>
    <p>abort: cannot apply a patch over an already active patch</p>
  </blockquote>
  
  <p>What can I do now? How can I get my changes from shelve?</p>
  
  <hr>
  
  <p>Command to unshelve: <code>hg unshelve -y ui.merge=internal:merge edit-request-20160511</code></p>
  
  <hr>
  
  <p>I've discard all pending changes, but it doesn't help</p>