title: Why does git svn dcommit lose the history of merge commits for local branches?
body: <p>I have a local git repository created with <code>git svn clone</code>.  I make a local branch, make some changes, switch back to master, <code>git svn rebase</code> and if it's all good, I merge my branch back into master.  Then the tree looks something like this:</p>
  
  <p><a href="http://img.skitch.com/20090108-cjguu3hcci9x2k17mcftamw8f1.jpg">alt text http://img.skitch.com/20090108-cjguu3hcci9x2k17mcftamw8f1.jpg</a></p>
  
  <p>Sometimes, later when I <code>git svn rebase</code> again and get some remote changes, it loses the fact that a_branch was merged into the mainline and the tree looks like this:</p>
  
  <p><a href="http://img.skitch.com/20090108-kn3bn1qgi5ijw8ja5ijkd75pa3.jpg">alt text http://img.skitch.com/20090108-kn3bn1qgi5ijw8ja5ijkd75pa3.jpg</a></p>
  
  <p>Why is that?  Can I stop it?  Is there an easy way to tell that a branch was merged, or should I delete my branches when I'm done so I don't forget what has and hasn't been merged?</p>