title: Why git pull origin master creates a merge commit
body: <p>My remote colleague always creates dummy merge commits with no practical reason - they contain the very same code which was already pushed to the repo since he last time pulled.
  I want to prevent that but can't really figure out how he does it - he says that the only thing he does is <code>git pull origin master</code> and for some reason it pulls down remote code as his own. Any ideas how that could be happening? I think I'll go and <code>tmate</code> to his terminal to check myself.</p>