title: How to abandon an uncommitted hg merge?
body: <p>I'm new to collaborating with Mercurial. My situation:</p>
  
  <ul>
  <li>Another programmer changed rev 1 of a file to replace 4-space indents with 2-space indent. (I.e. changed every line.) Call that rev 2, pushed to the remote repo.</li>
  <li>I've committed substantive changes rev 1 with various code changes in my local workspace. Call that rev 3. </li>
  <li>I've <code>hg pull</code>ed and <code>hg merge</code>d without a clear idea of what was going on.</li>
  <li>The conflicts are myriad and not really substantive.</li>
  </ul>
  
  <p>So I really wish I'd changed my local repo to 2-space indents before merging; then the merge will be trivial (i'm supposing). But I can't seem to back up. I think I need to <code>hg update -r 3</code> but it says <code>abort: outstanding uncommitted merges</code>. </p>
  
  <p>How can I undo the merge, changes spacing in my local repo, and remerge?</p>