phpbb/phpbb3 — pull request #1354 by dhruvgoel92 (2013-04-20 13:55:28+00:00)
Title: [ticket/11437] add an extra condition

When search returns no results there is no need to go inside the if
statement. Since $result_count becomes zero, $start becomes negative
which leads to failed assertion.
http://tracker.phpbb.com/browse/PHPBB3-11437

PHPBB3-11437