title: Git diff doesn't work after git stash pop
body: <p>After <code>git stash pop</code>, there were some conflicts, things like:</p>
  
  <pre><code>&lt;&lt;&lt;&lt;&lt;&lt;&lt; Updated upstream
  int foo = 5;
  =======
  int foo = 6;
  &gt;&gt;&gt;&gt;&gt;&gt;&gt; Stashed changes
  </code></pre>
  
  <p>I resolved them in the code, but now I can't preview my changes before committing them. All I get is this, and I know there are changes:</p>
  
  <pre><code>diff --cc mainwindow.cpp
  index 24dc025,2c44ad8..0000000
  --- a/mainwindow.cpp
  +++ b/mainwindow.cpp
  </code></pre>
  
  <p>How do I force git diff to compare my current source to the last commit?</p>