🐛 [#3924] Update payment status also if 'wait_for_payment_to_register…

…=True'

The problem was:
If the registration happens after payment, the status of the payment was never changed from 'completed' to 'registered'. The 'finalise_completion' task filters for payments with 'registered' status to decide whether the retry flag should be turned on. This resulted in the retry flag being True even though the payment has been registered.

Backport-of: #3935

src/openforms/registrations/tasks.py

@@ -11,6 +11,7 @@
 from openforms.celery import app
 from openforms.config.models import GlobalConfiguration
 from openforms.logging import logevent
+from openforms.payments.constants import PaymentStatus
 from openforms.submissions.constants import PostSubmissionEvents, RegistrationStatuses
 from openforms.submissions.models import Submission
 from openforms.submissions.public_references import set_submission_reference
@@ -278,5 +279,8 @@ def register_submission(submission_id: int, event: PostSubmissionEvents) -> None
         submission,
     )
 
+    if config.wait_for_payment_to_register and event.on_payment_complete:
+        submission.payments.update(status=PaymentStatus.registered)
+
     submission.save_registration_status(RegistrationStatuses.success, result or {})
     logevent.registration_success(submission, plugin)

src/openforms/submissions/tests/test_post_submission_event.py

@@ -1,7 +1,8 @@
+from decimal import Decimal
 from unittest.mock import patch
 
 from django.core import mail
-from django.test import TestCase, override_settings
+from django.test import TestCase, override_settings, tag
 from django.utils.translation import gettext_lazy as _
 
 from privates.test import temp_private_root
@@ -982,6 +983,39 @@ def test_cosign_not_required_but_filled_in_does_not_proceed_with_registration(se
         self.assertTrue(submission.confirmation_email_sent)
         self.assertEqual(submission.auth_info.value, "111222333")
 
+    @tag("gh-3924")
+    def test_payment_complete_does_not_set_retry_flag(self):
+        submission = SubmissionFactory.create(
+            form__payment_backend="demo",
+            form__product__price=Decimal("11.35"),
+            form__registration_backend="email",
+            form__registration_backend_options={"to_emails": ["[email protected]"]},
+            form__name="Pretty Form",
+            with_public_registration_reference=True,
+            with_completed_payment=True,
+        )
+
+        with (
+            patch(
+                "openforms.registrations.contrib.email.plugin.EmailRegistration.register_submission"
+            ),
+            patch(
+                "openforms.registrations.contrib.email.plugin.EmailRegistration.update_payment_status"
+            ),
+            patch(
+                "openforms.registrations.tasks.GlobalConfiguration.get_solo",
+                return_value=GlobalConfiguration(wait_for_payment_to_register=True),
+            ),
+        ):
+            with self.captureOnCommitCallbacks(execute=True):
+                on_post_submission_event(
+                    submission.id, PostSubmissionEvents.on_payment_complete
+                )
+
+            submission.refresh_from_db()
+
+            self.assertFalse(submission.needs_on_completion_retry)
+
 
 @temp_private_root()
 @override_settings(CELERY_TASK_ALWAYS_EAGER=True)