title: After a Git merge conflict, a lot of files I didn't touch become changes to be committed
body: <p>So I'm working in a branch, make some changes, and run <code>git merge master</code>. I get a merge conflict on one of the files I modified (which I know how to deal with), but for some reason, a bunch of files I did <em>not</em> touch (but which got updated in master) suddenly enter my list of "Changes to be committed".</p>
  
  <p>Why is this? And how do I fix this? I don't want any of these not-by-me changes to get committed.</p>