[fw-db] Undefined variable in Zend_Db_Select

I´m using Zend_Db_Select in a way that I´m getting this undefined variable notice:

( ! ) Notice: Undefined variable: lastFromCorrelationName in /data/html/vilagenet.com.br/library/Zend/Db/Select.php on line 828

To reproduce this notice:

$adapter = Vilage_Db_Table::getDefaultAdapter();
$select = $adapter->select()
    ->from('sometable', 'id');

$select2 = $adapter->select()
    ->from(null, 'COUNT(*) FROM (' . $select->__toString() . ') AS count');

$result = $adapter->fetchCol($select2);

The variable $lastFromCorrelationName is declared in Zend_Db_Select on line 798, inside an if statement, but is used outside it, on line 828.