title: A Ruby method for resolving relative paths while keeping absolute paths?
body: <p>I am working on writing a rake build scrip which will work cross platform ( Mac OSX, Linux , Windows ). The build script will be consumed by a  <a href="http://www.thoughtworks-studios.com/cruise-release-management" rel="nofollow noreferrer">CI server</a>.</p>
  
  <p>I want the logic of my script to be as follows:</p>
  
  <ol>
  <li>If the path is determined to be relative, make it absolute by making <em>output_path = FOO_HOME + user_supplied_relative_path</em></li>
  <li>If the path is determined to be absolute, take it as-is</li>
  </ol>
  
  <p>I'm currently using <em>Pathname.new(location).absolute?</em> but it's not working correctly on windows.</p>
  
  <p>What approach would you suggest for this?</p>