title: Eclipse --launcher.openFile does not open the file
body: <p>I have been trying to open a file from the command line in a running Eclipse session. Based on the <a href="http://help.eclipse.org/indigo/index.jsp?topic=%2Forg.eclipse.platform.doc.isv%2Freference%2Fmisc%2Fruntime-options.html" rel="nofollow">documentation</a>, I should be able to do</p>
  
  <pre><code>eclipse --launcher.openFile myfilename
  </code></pre>
  
  <p>However, when I do  this, there is a long pause, and then Eclipse tries to launch a new session. It gives me an error message that the workspace is not available, and then wants me to choose a new workspace.</p>
  
  <p>How do I open a file in the <em>currently running</em> Eclipse session, from the commandline?</p>