API: Check-in response code for canceled

src/pretix/api/views/checkin.py

@@ -281,6 +281,7 @@ class CheckinListPositionViewSet(viewsets.ReadOnlyModelViewSet):
                 nonce=nonce,
                 datetime=dt,
                 questions_supported=self.request.data.get('questions_supported', True),
+                canceled_supported=self.request.data.get('canceled_supported', False),
                 user=self.request.user,
                 auth=self.request.auth,
             )

src/pretix/base/services/checkin.py

@@ -60,7 +60,7 @@ def _save_answers(op, answers, given_answers):
 @transaction.atomic
 def perform_checkin(op: OrderPosition, clist: CheckinList, given_answers: dict, force=False,
                     ignore_unpaid=False, nonce=None, datetime=None, questions_supported=True,
-                    user=None, auth=None):
+                    user=None, auth=None, canceled_supported=False):
     """
     Create a checkin for this particular order position and check-in list. Fails with CheckInError if the check in is
     not valid at this time.
@@ -90,10 +90,10 @@ def perform_checkin(op: OrderPosition, clist: CheckinList, given_answers: dict,
         'answers'
     ).get(pk=op.pk)
 
-    if op.canceled:
+    if op.canceled or op.order.status not in (Order.STATUS_PAID, Order.STATUS_PENDING):
         raise CheckInError(
             _('This order position has been canceled.'),
-            'unpaid'
+            'canceled' if canceled_supported else 'unpaid'
         )
 
     answers = {a.question: a for a in op.answers.all()}

src/tests/api/test_checkin.py

@@ -586,6 +586,23 @@ def test_forced_multiple(token_client, organizer, clist, event, order):
 def test_require_paid(token_client, organizer, clist, event, order):
     with scopes_disabled():
         p = order.positions.first()
+
+    order.status = Order.STATUS_CANCELED
+    order.save()
+    resp = token_client.post('/api/v1/organizers/{}/events/{}/checkinlists/{}/positions/{}/redeem/'.format(
+        organizer.slug, event.slug, clist.pk, p.pk
+    ), {}, format='json')
+    assert resp.status_code == 400
+    assert resp.data['status'] == 'error'
+    assert resp.data['reason'] == 'unpaid'
+
+    resp = token_client.post('/api/v1/organizers/{}/events/{}/checkinlists/{}/positions/{}/redeem/'.format(
+        organizer.slug, event.slug, clist.pk, p.pk
+    ), {'canceled_supported': True}, format='json')
+    assert resp.status_code == 400
+    assert resp.data['status'] == 'error'
+    assert resp.data['reason'] == 'canceled'
+
     order.status = Order.STATUS_PENDING
     order.save()
     resp = token_client.post('/api/v1/organizers/{}/events/{}/checkinlists/{}/positions/{}/redeem/'.format(