title: SVN export throws "project/subfolder/ is not a working copy" for non-existing "subfolder"
body: <p>I am trying to export the working copy of an SVN project to some other folder. When I do svn export I get :</p>
  
  <pre><code>'D:\project\trunk\subfolder' is not a working copy. 
  </code></pre>
  
  <p>I read that this might happen when <strong>subfolder</strong> does not have a .svn directory (so it is not being tracked by SVN). However in this case the <strong>subfolder</strong> directory does not exist. I imagine it is being tracked in some SVN metadata where I must remove the reference, but do not know where to look for it. </p>
  
  <p>Anyone knows how to fix this so that I can do the clean svn export?</p>