Location: search.php
Before //
$sql = "SELECT $sql_select
Parameters: $sql_select, $sql_from, $sql_where
Explanation: Allow extensions to get additional topic data when viewing search results as topics by modifying the $sql_select, $sql_from, $sql_where parameters just before they are put into the final $sql variable for querying.
For example, Topic Preview MOD does this, it adds the first_post_text by modifying the $sql_select and $sql_from variables.