Zend Session fatal error in get array copy

If you call getArrayCopy on a zend session container after calling exchangeArray you get:

Fatal error: Call to a member function getArrayCopy() on a non-object in vendor/zendframework/zendframework/library/Zend/Session/AbstractContainer.php on line 614

This is one of several potential fixes. 

Another would be to have the exchangeArray method ensure that an ArrayObject is always created and assigned to storage.