Offset refunds: Catch exceptions in the right place

src/pretix/base/models/orders.py

@@ -1213,6 +1213,7 @@ class OrderPayment(models.Model):
         """
         return self.order.event.get_payment_providers(cached=True).get(self.provider)
 
+    @transaction.atomic()
     def _mark_paid(self, force, count_waitinglist, user, auth, ignore_date=False, overpaid=False):
         from pretix.base.signals import order_paid
         can_be_paid = self.order._can_be_paid(count_waitinglist=count_waitinglist, ignore_date=ignore_date, force=force)
@@ -1281,7 +1282,7 @@ class OrderPayment(models.Model):
             'provider': self.provider,
         }, user=user, auth=auth)
 
-        if self.order.status == Order.STATUS_PAID:
+        if self.order.status in (Order.STATUS_PAID, Order.STATUS_CANCELED):
             return
 
         payment_sum = self.order.payments.filter(

src/pretix/base/payment.py

@@ -871,7 +871,10 @@ class OffsettingProvider(BasePaymentProvider):
             provider='offsetting',
             info=json.dumps({'orders': [refund.order.code]})
         )
-        p.confirm(ignore_date=True)
+        try:
+            p.confirm(ignore_date=True)
+        except Quota.QuotaExceededException:
+            pass
 
     @property
     def settings_form_fields(self) -> dict: