title: Point branch to new commit
body: <p><em>(This question is the opposite of <a href="https://stackoverflow.com/questions/1628563/git-move-recent-commit-to-a-new-branch">this one</a>)</em></p>
  
  <p>How can I go from this</p>
  
  <pre><code>dev            C - D
               /
  master A - B 
  </code></pre>
  
  <p>to this?</p>
  
  <pre><code>dev                D
                   /
  master A - B - C 
  </code></pre>
  
  <p>I know I'm going to kick myself when I see the answer, but for the moment I'm a bit stuck...</p>