ZF-2409: Empty driver options are not ignored
When driver options passed to the Zend_Db::factory() method is an empty string it is not ignored but instead type casted to an array containing an empty string at index 0 which cause PDO to disabled autocommit.
The problem lies in the line 191 of the Zend_Db_Adapter_Abstract class.
The line is
and should be changed to