title: What exactly is a "grafted" commit in a shallow clone?
body: <p>When doing a shallow clone in git (using the <code>--depth</code> option), the root commit is marked as <em>grafted</em>.</p>
  
  <p><img src="https://i.stack.imgur.com/dZlsX.png" alt="enter image description here"></p>
  
  <p>Googling didn't lead to any satisfacting documentation.</p>
  
  <p>It doesn't seem to have anything to do with <a href="https://git.wiki.kernel.org/index.php/GraftPoint" rel="noreferrer">git grafts</a>, which the similar terminology would imply.<br>
  Is it just a flag to signal that this commit actually has more parents and isn't the "real" root commit? Or is there something more special about it?</p>