title: Why has POST git-receive-pack (x bytes) doubled in size between pushes to two different repositories?
body: <p>Using Sourcetree with BitBucket, I push to two repositories (different teams are working on them and the two instances should be kept separate) and I noticed that the push to the second repository (which I do immediately after the push to the first repository has completed) results in a <code>POST git-receive-pack (x bytes)</code> that is doubled in size.</p>
  
  <p>For those of you wondering why the filesize is so huge: it is an R environment consisting of several <code>data.frame</code> and <code>list</code> objects.</p>
  
  <p>This is what I get:</p>
  
  <p><code>Push to first repository: POST git-receive-pack (65432783 bytes)</code></p>
  
  <p><code>Push to second repository: POST git-receive-pack (130865566 bytes)</code></p>
  
  <p>Why is this happening?  How can I avoid it?</p>