title: How to fix whitespace before pull request?
body: <p>Sometimes my pull request looks HUGE because of indentation or whitespace changes. For example, if I work on a file with 2-space indentation and then my editor automatically converts it to 4-space, it will appear that nearly the entire file is changed.</p>
  
  <p>How can I revert <strong>only the whitespace</strong> in a file before sending someone a pull request?</p>
  
  <p>Note, I did see <a href="https://stackoverflow.com/questions/4449834/commit-without-whitespace-changes-on-github">this answer</a> but it's about ignoring changed whitespace <em>after</em> it's on GitHub. I'm looking for how to <em>revert</em> the whitespace <em>before</em> the commit.</p>