title: git: shortest command to fetch upstream branch of specific tracking branch?
body: <p>Given a properly configured local, remote-tracking branch <code>example</code>, what is the shortest way to fetch <code>example</code>'s remote counterpart specifically?</p>
  
  <p>I could use a bare <code>git fetch origin</code> to fetch <em>all</em> branches, the counterpart included, but this would cause a large additional amount of data to be downloaded, which I'd like to avoid.</p>
  
  <p>If the counterpart shares the name <code>example</code>, I could run <code>git fetch origin example:</code>, but that name similarity is not guaranteed.</p>
  
  <p>I could just <em>find out</em> the name of the counterpart, say, <code>counterpart</code>, as per <a href="https://stackoverflow.com/questions/171550/">this question</a>, and run <code>git fetch origin counterpart:</code>. But, that's two commands, which may or may not be the shortest.</p>
  
  <p>So, given these restrictions, what is the shortest way to accomplish this?</p>