title: Git pull aborts itself, local file changes will be overwritten by merge
body: <p>I have changed a file that my friend is working at the same time. I did some changes and now I want to push it but it says I should pull first. When I <code>git pull</code>, it says: </p>
  
  <blockquote>
    <p>error: Your local changes to the following files would be overwritten by merge: Please, commit your changes or stash them before you can merge.<br>
       Aborting</p>
  </blockquote>
  
  <p>How can I merge the file? If I do it would the file from my friend completely change?  I am sure he has added some stuff and I have added my stuff. How will our changes be handled?</p>