title: Abandoning changes without deleting from history
body: <p>There is a commit that just didn't work, so I want to abandon it <em>without deleting it from history</em>.</p>
  
  <p>I have updated from an earlier revision and committed, thus creating a new head.</p>
  
  <hr>
  
  <p>I don't have branches, I don't want branches, I just want to simply go on with the new head exactly as it is, nothing fancy, no merge, no worries, just go on forgetting the previous one.</p>
  
  <p>I can't seem to find how to do that, and I'm starting to believe it can't be done. All I find is stuff about branches, or stuff about merging.</p>