title: git-subtree pull complications
body: <p>We have been trying to get <a href="https://github.com/apenwarr/git-subtree" rel="noreferrer">git-subtree</a> working on a project (with git version 1.7.9.4) and have run into a bit of a complication. Someone else previous added the subtree with this command some months ago: </p>
  
  <pre><code>git subtree add --prefix=foo git@example.com:foo.git master
  </code></pre>
  
  <p>Now there have been substantive changes to <code>foo</code> and we'd like to merge in those changes, ideally squashing them in. None of the files have been modified since they were imported. </p>
  
  <p>I've tried three things to try and merge in the changes.</p>
  
  <p>First:</p>
  
  <pre><code>git subtree pull --squash -P foo git@example.com:foo.git master
  </code></pre>
  
  <p>Which throws the exception: <code>Can't squash-merge: 'foo' was never added.</code></p>
  
  <p>Second:</p>
  
  <pre><code>git subtree pull -P foo git@example.com:foo.git master
  </code></pre>
  
  <p>This works (sort of), but has the issue of pulling in all of the commits and has conflicts with the files that have been modified. </p>
  
  <p>Finally, I tried this:</p>
  
  <pre><code>git pull --squash -s subtree git@example.com:foo.git  master
  </code></pre>
  
  <p>This gives me the desired result, with the output <code>Automatic merge went well; stopped before committing as requested</code> and all of the files showing up as modified (with the correct content).</p>
  
  <p>Ideally I'd like to continue using first <code>git-subtree</code> version and get an output close to the last version.  If we have to use the last version consistently going forward, we will, but I am a little confused as to why the last one doesn't produce merge conflicts while the middle one does.</p>
  
  <p>Any help is appreciated.</p>