Exception: Warning: Trying to access array offset on value of type null

[r-martins]

Preconditions (*)

1. Trying to place an order as a new customer
2. OpenMage 20.10

Steps to reproduce (*)

1. Add product to cart and proceed to checkout
2. Create a new customer (instead of login)
3. Place order

Expected result (*)

1. Order to be placed with no issues

Actual result (*)

1. Alert saying something went wrong. The following is logged:

Exception: Warning: Trying to access array offset on value of type null in /var/www/html/app/code/core/Mage/Checkout/Model/Type/Onepage.php on line 733 in /var/www/html/app/code/core/Mage/Core/functions.php:207 Stack trace: #0 /var/www/html/app/code/core/Mage/Checkout/Model/Type/Onepage.php(733): mageCoreErrorHandler(2, 'Trying to acces...', '/var/www/html/a...', 733) #1 /var/www/html/app/code/core/Mage/Checkout/Model/Type/Onepage.php(811): Mage_Checkout_Model_Type_Onepage->_prepareNewCustomerQuote() #2 /var/www/html/app/code/core/Mage/Checkout/controllers/OnepageController.php(605): Mage_Checkout_Model_Type_Onepage->saveOrder() #3 /var/www/html/app/code/core/Mage/Core/Controller/Varien/Action.php(437): Mage_Checkout_OnepageController->saveOrderAction() #4 /var/www/html/app/code/core/Mage/Core/Controller/Varien/Router/Standard.php(262): Mage_Core_Controller_Varien_Action->dispatch('saveOrder') #5 /var/www/html/app/code/core/Mage/Core/Controller/Varien/Front.php(192): Mage_Core_Controller_Varien_Router_Standard->match(Object(Mage_Core_Controller_Request_Http)) #6 /var/www/html/app/code/core/Mage/Core/Model/App.php(381): Mage_Core_Controller_Varien_Front->dispatch() #7 /var/www/html/app/Mage.php(763): Mage_Core_Model_App->run(Array) #8 /var/www/html/index.php(93): Mage::run('', 'store')

Additional config that may be relevant:

378|default|0|admin/security/session_cookie_lifetime|50400|
758|default|0|web/default/cms_no_cookies|enable-cookies|
761|default|0|web/cookie/cookie_lifetime|50400|
762|default|0|web/cookie/cookie_path||
763|default|0|web/cookie/cookie_domain||
764|default|0|web/cookie/cookie_httponly|0|
765|default|0|web/cookie/cookie_samesite|None|
766|default|0|web/cookie/cookie_restriction|0|
772|default|0|web/browser_capabilities/cookies|1|


default|0|customer/address/street_lines|4
default|0|shipping/origin/street_line1|Rua Angelo Guerra
default|0|shipping/origin/street_line2|1

• PHP 8.0.30
• MariaDB 10.4.17