title: git: Why doesn't git diff show any differences?
body: <p>If I run 'git status' on my repo it gives:</p>
  
  <pre><code># On branch master
  # Changes to be committed:
  #   (use "git reset HEAD &lt;file&gt;..." to unstage)
  #
  #   modified: myfile
  </code></pre>
  
  <p>However, if I do a 'git diff myfile' it shows no differences. Is this because I have made a change and removed it so it is back to the original?</p>
  
  <p>Should I run 'git checkout myfile' to clear it?</p>