title: Pull updates with git after cloned with --depth 1
body: <p>This morning I made a shallow clone of the Linux sources</p>
  
  <pre><code>git clone --depth 1 https://github.com/torvalds/linux.git
  </code></pre>
  
  <p>which resulted in a <code>linux</code> folder of 851Mb.</p>
  
  <p>Now I would like to pull the latest changes, but</p>
  
  <pre><code>git pull
  </code></pre>
  
  <p>starts a seemly huge download. After 60Mb I'm at 3% which extrapolates to 2Gb. However, the 5 commits since my clone change only a bunch of lines.</p>
  
  <p>Am I doing something wrong? What are the 2Gb that <code>git</code> tries to download?</p>