title: Make a git branch equal to master again
body: <p><em>Short version</em></p>
  
  <p>What is the easiest way to make a branch equal to <code>master</code> again, discarding any differences?
  Up until now, I simply used <code>git branch -D wip</code>, followed by <code>git checkout -b wip</code>, but that seems a bit silly. </p>
  
  <p><em>Motivation</em></p>
  
  <p>I often have a <code>wip</code> branch alongside my <code>master</code> branch, for 'work in progress'. Sometimes the work on such a branch gets 'left behind' and when I rediscover it, I find I no longer want it. This rediscovery often happens when I want to use the branch to store a new set of 'work in progress' and I find I simply want to discard any differences with <code>master</code>, so the new 'work in progress' fits on top. Figuring out the differences is not worth the trouble: the solution described above works fine for me. Any better solutions to address this use case?</p>