title: Git - working on wrong branch - how to copy changes to existing topic branch
body: <p>I've been working on a project, but unfortunately, I <em>forgot</em> to switch to my branch, and as such have been working on master</p>
  
  <p>How can I copy the work (3 files) I've done here from master, to my branch (called, for example <em>branch123</em>) without comitting to master?</p>