I see the post on bugzilla, but to be honest I don't know what is meant by 'Patch for trunk'. I see that there's a a bit of code that was added to SkinTemplate.php; does this code fix the external link problem?
Yes it does. I did it for the trunk version (development is done there). Backporting to 1.17 or a older version should be easy because the patch is not big at all.
But keep in mind that the patch was not accepted. Maybe we should wait a bit before discussing about backporting or other things.