title: Pull request indicates every file has changed but no changes in each file
body: <p>My Pull request indicates that I have 7188 changed files, with no actual changes in almost all of these.  My actual changes were to around 10 files.</p>
  
  <p>How did I get into this weird git state, and how do I get out?  </p>
  
  <p><a href="https://i.stack.imgur.com/RJ2LF.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/RJ2LF.png" alt="enter image description here"></a></p>