title: PHP filter_var() - FILTER_VALIDATE_URL
body: <p>The <code>FILTER_VALIDATE_URL</code> filter seems to have some trouble validating non-ASCII URLs:</p>
  
  <pre><code>var_dump(filter_var('http://pt.wikipedia.org/wiki/', FILTER_VALIDATE_URL)); // http://pt.wikipedia.org/wiki/
  var_dump(filter_var('http://pt.wikipedia.org/wiki/Guimarães', FILTER_VALIDATE_URL)); // false
  </code></pre>
  
  <p>Why isn't the last URL correctly validated? And what are the possible workarounds? Running PHP 5.3.0.</p>
  
  <p>I'd also like to know where I can find the source code of the <code>FILTER_VALIDATE_URL</code> validation filter.</p>