title: How do you fix a bad merge, and replay your good commits onto a fixed merge?
body: <p>I accidentally committed an unwanted file (<code>filename.orig</code> while resolving a merge) to my repository several commits ago, without me noticing it until now. I want to completely delete the file from the repository history. </p>
  
  <p>Is it possible to rewrite the change history such that <code>filename.orig</code> was never added to the repository in the first place?</p>