[BUG] [P1] NPE crash in CardReaderPaymentAPIDrivenPageActivity on next checkout after transaction cancelled on reader while app backgrounded

[paulneesham-autocab]

Dependency Versions

• SumUp SDK: 7.0.0 (com.sumup:merchant-sdk)
• Kotlin: 2.4.0
• Android Gradle Plugin: 9.2.1
• Gradle: 9.5.1

Steps to reproduce

1. Start checkout → SDK payment screen opens, reader waits for card
2. Press Home/Back on phone (app moves to background)
3. Cancel the transaction on the reader
4. Return to the app
5. Start a new checkout → crash (NPE in CardReaderPaymentAPIDrivenPageActivity.onResume)

Video / Screenshot

N/A — crash log above; happy to provide a screen recording of the repro steps if helpful.

Other Information

• The sticky-event mechanism is visible in the stack trace: EventBus.checkPostStickyEventToSubscription → the subscriber is invoked immediately upon register() in onResume(), before any state for the new checkout exists.
• Possibly related to [BUG] Random Crash on android 15 #264, which shows the same NPE signature (CardReaderPaymentFlowState.addScreens on null) via a different trigger — in our case it is 100% reproducible with the steps above: background the app mid-transaction, cancel on the reader, then start a new checkout.

[paulneesham-autocab]

7.1.0 fixes this already my mistake.