Searching search results from "any terms" produces incorrect results

How to reproduce:

Go to the demo: http://www.try-phpbb.com/30x/search.php

Set the following options:

• Search for any terms
• Topic titles only
• Display as topics

Search for "phpBB3 test": http://www.try-phpbb.com/30x/search.php?st=0&sk=t&sd=d&sr=topics&keywords=phpBB3+test&terms=any&sf=titleonly

In the results, search for "phpBB3". In this example, this should not change the results, but the board will state "No posts were found because the word test is not contained in any post."