[Tefra]

Here is a different version which seems to be working better without breaking the original html tags at least. The process is based on this highlight function.

PHP Code:

function terms_build_relation($message, $intermid = 0)
{
    global $db;

    $words         = array();
    $keywords     = $db->escape_string(strip_tags($message));
    $sql         = $db->query_read("SELECT term_id, term_title FROM ".VBSED_PREFIX."terms WHERE MATCH(term_title) AGAINST('$keywords') ".iif($intermid, "AND term_id <> $intermid", '')." AND term_active = 1");            
    while($sim     = $db->fetch_array($sql)) {    $words[$sim['term_id']] = $sim['term_title']; }
    $message = str_replace('\"', '"', $message);
    $pattern = '#(?!<.*?)(%s)(?![^<>]*?>)#i';
    foreach ($words AS $key => $word)
    {
        $word         =     '\b' . preg_quote($word) . '\b';
        $replace     =     '<em><a href="'.VBSED_TERMS_URL.'item='.$key.'">\1</a></em>';
        $search     =     sprintf($pattern, $word);
        $message     =     preg_replace($search, $replace, $message, 1);
    }
    return $message;    
}