Error when running a shell script that outputs something and accesses session

[tobihille]

Preconditions (*)

1. OpenMage 20.2.0
2. Create a shell script that does an echo of something and then access the session (by accident)

Steps to reproduce (*)

1. See precondition 2.

Expected result (*)

1. Previous to PR Fixed PHP warnings when session backend exits before returning. #3109 everything worked

Actual result (*)

1. The shell script breaks

Additional Hint

To circumvent the issue something like Mage::getSingleton('customer/session') could be added to \Mage_Shell_Abstract::__construct.
By nature shell scripts are not time constraint so an additional call to the session should not be too bad, on the other hand it fixes a behavioural change that was probably not intended.