FabioBatSilva/doctrine2 — comment on commit 561da321a41779f449f9c449cc8f14075c161f51
File: lib/Doctrine/ORM/Query/ResultSetMapping.php line 303
By guilhermeblanco:

You can prevent the BC break if you do:

$this->typeMappings[$columnName] = $type ?: 'string';