Steps to reproduce the issue

Easy reproduction of this behaviour can be achieved by opening the Weblinks component in de Administrator, create a new Weblink (or edit an existing Weblink) and add #sometag to the end of the url in the URL field. For instance: http://www.google.nl/index.php#anchor

Expected result

The expected result would be a Weblink with the # part still in tact. Like with the google example the url would remain: http://www.google.nl/index.php#anchor

Actual result

Instead of the expected result, the url get's "sanitized" and looses the # element. In the example of the google url it results in http://www.google.nl/index.php where everything after the # is removed.

System information (as much as possible)

• Joomla 3.3.4 Stable [ Ember ] 23-September-2014 14:00 GMT
  Joomla Platform 13.1.0 Stable [ Curiosity ] 24-Apr-2013 00:00 GMT
  Ubuntu 14.04
  PHP 5.5.9
  Apache 2.4.7

• Joomla 3.3.4 Stable [ Ember ] 23-September-2014 14:00 GMT
  Joomla Platform 13.1.0 Stable [ Curiosity ] 24-Apr-2013 00:00 GMT
  Windows Server 2008
  PHP 5.3.15
  IIS7

Additional comments

To be clear, this is NOT an issue with the com_weblinks component since it is also something that happens with components we build ourselves from scratch.

It looks like the fragment part is not reassembled when JStringPunycode::urlToUTF8() or JStringPunycode::urlToPunycode() is executed. In both methods the scheme, port, path and query are put back in the $newuri variable that is returned but the fragment part is left out.

A possible fix would be to add the following three lines to the end of both methods:

if (!empty($parsed['fragment']))
{
$newuri .= '#' . $parsed['fragment'];
}