Redirect and Error Issues During Checkout with Stripe

[RobinTheHood]

See: https://www.modified-shop.org/forum/index.php?topic=34167.msg403225#msg403225

Problem: When using the Stripe module during checkout, users experience errors when clicking the back button in their browser or on the Stripe page.

Steps to Reproduce:

1. Install the Stripe module.
2. Follow the described setup steps.
3. Proceed to checkout and be redirected to the Stripe payment page.
4. Click the back button in the browser or on the Stripe page.

Observed Behavior:

• Clicking the back button in the browser redirects to checkout_confirmation but displays an error.
• Clicking the back button on the Stripe page redirects to checkout_payment.
• In both cases, the order is created in the shop's backend (as shown in the provided screenshots).

Findings:

• The issue might be related to the requirement for confirming the terms and conditions (AGB).
• When AGB confirmation is required, the error can be reproduced.
• In the test environment where AGB confirmation was not required, no errors were initially found.

Suggested Fix:

• Investigate and resolve the issue related to AGB confirmation causing errors during the back navigation.