When the URL has characters like äöå and other non ISO-8859-1 characters, the insert throws an exception.
PDOException: in dblog_watchdog() (line 154 of C:\inetpub\wwwroot\Hevospiste\modules\dblog\dblog.module).
This can be solved by urlencoding the line before entering it to the database.
Working code:
function dblog_watchdog(array $log_entry) {
Database::getConnection('default', 'default')->insert('watchdog')
->fields(array('uid' => $log_entry['uid'],'type' => substr($log_entry['type'], 0, 64),'message' => $log_entry['message'],'variables' => serialize($log_entry['variables']),'severity' => $log_entry['severity'],'link' => substr($log_entry['link'], 0, 255),'location' => urlencode($log_entry['request_uri']),'referer' => $log_entry['referer'],'hostname' => substr($log_entry['ip'], 0, 128),'timestamp' => $log_entry['timestamp'],
))
->execute();
}