phpbb/phpbb3 — pull request #1688 by nickvergessen (2013-09-02 10:25:50+00:00)
Title: [ticket/11769-develop] Correctly supply the post author's username in posting.php - Develop

Only supply the username, when it is a guest posting and it was supplied.
otherwise post_data might hold data of the post we quote, in which case
username is the original poster, not the current one.

http://tracker.phpbb.com/browse/PHPBB3-11769