Order create API: Fix addon_to in simulated mode

PRETIXEU-275

src/pretix/api/serializers/order.py

@@ -416,6 +416,14 @@ class OrderSerializer(I18nAwareModelSerializer):
         return instance
 
 
+class SimulatedOrderPositionSerializer(OrderPositionSerializer):
+    addon_to = serializers.SlugRelatedField(read_only=True, slug_field='positionid')
+
+
+class SimulatedOrderSerializer(OrderSerializer):
+    positions = SimulatedOrderPositionSerializer(many=True, read_only=True)
+
+
 class PriceCalcSerializer(serializers.Serializer):
     item = serializers.PrimaryKeyRelatedField(queryset=Item.objects.none(), required=False, allow_null=True)
     variation = serializers.PrimaryKeyRelatedField(queryset=ItemVariation.objects.none(), required=False, allow_null=True)
@@ -963,7 +971,10 @@ class OrderCreateSerializer(I18nAwareModelSerializer):
                 else:
                     pos.order = order
                 if addon_to:
-                    pos.addon_to = pos_map[addon_to]
+                    if simulate:
+                        pos.addon_to = pos_map[addon_to]._wrapped
+                    else:
+                        pos.addon_to = pos_map[addon_to]
 
                 if pos.price is None:
                     price = get_price(

src/pretix/api/views/order.py

@@ -26,7 +26,7 @@ from pretix.api.serializers.order import (
     InvoiceSerializer, OrderCreateSerializer, OrderPaymentCreateSerializer,
     OrderPaymentSerializer, OrderPositionSerializer,
     OrderRefundCreateSerializer, OrderRefundSerializer, OrderSerializer,
-    PriceCalcSerializer,
+    PriceCalcSerializer, SimulatedOrderSerializer,
 )
 from pretix.base.i18n import language
 from pretix.base.models import (
@@ -488,10 +488,12 @@ class OrderViewSet(viewsets.ModelViewSet):
             self.perform_create(serializer)
             send_mail = serializer._send_mail
             order = serializer.instance
-            serializer = OrderSerializer(order, context=serializer.context)
             if not order.pk:
                 # Simulation
+                serializer = SimulatedOrderSerializer(order, context=serializer.context)
                 return Response(serializer.data, status=status.HTTP_201_CREATED)
+            else:
+                serializer = OrderSerializer(order, context=serializer.context)
 
             order.log_action(
                 'pretix.event.order.placed',

src/tests/api/test_orders.py

@@ -1664,6 +1664,58 @@ def test_order_create_simulate(token_client, organizer, event, item, quota, ques
     }
 
 
+@pytest.mark.django_db
+def test_order_create_positionids_addons_simulated(token_client, organizer, event, item, quota):
+    res = copy.deepcopy(ORDER_CREATE_PAYLOAD)
+    res['positions'] = [
+        {
+            "positionid": 1,
+            "item": item.pk,
+            "variation": None,
+            "price": "23.00",
+            "attendee_name_parts": {"full_name": "Peter"},
+            "attendee_email": None,
+            "addon_to": None,
+            "answers": [],
+            "subevent": None
+        },
+        {
+            "positionid": 2,
+            "item": item.pk,
+            "variation": None,
+            "price": "23.00",
+            "attendee_name_parts": {"full_name": "Peter"},
+            "attendee_email": None,
+            "addon_to": 1,
+            "answers": [],
+            "subevent": None
+        }
+    ]
+    res['simulate'] = True
+    resp = token_client.post(
+        '/api/v1/organizers/{}/events/{}/orders/'.format(
+            organizer.slug, event.slug
+        ), format='json', data=res
+    )
+    assert resp.status_code == 201
+    del resp.data['positions'][0]['secret']
+    del resp.data['positions'][1]['secret']
+    assert [dict(f) for f in resp.data['positions']] == [
+        {'id': 0, 'order': '', 'positionid': 1, 'item': 1, 'variation': None, 'price': '23.00',
+         'attendee_name': 'Peter', 'attendee_name_parts': {'full_name': 'Peter', '_scheme': 'full'}, 'company': None,
+         'street': None, 'zipcode': None, 'city': None, 'country': None, 'state': None, 'attendee_email': None,
+         'voucher': None, 'tax_rate': '0.00', 'tax_value': '0.00',
+         'addon_to': None, 'subevent': None, 'checkins': [], 'downloads': [], 'answers': [], 'tax_rule': None,
+         'pseudonymization_id': 'PREVIEW', 'seat': None, 'canceled': False},
+        {'id': 0, 'order': '', 'positionid': 2, 'item': 1, 'variation': None, 'price': '23.00',
+         'attendee_name': 'Peter', 'attendee_name_parts': {'full_name': 'Peter', '_scheme': 'full'}, 'company': None,
+         'street': None, 'zipcode': None, 'city': None, 'country': None, 'state': None, 'attendee_email': None,
+         'voucher': None, 'tax_rate': '0.00', 'tax_value': '0.00',
+         'addon_to': 1, 'subevent': None, 'checkins': [], 'downloads': [], 'answers': [], 'tax_rule': None,
+         'pseudonymization_id': 'PREVIEW', 'seat': None, 'canceled': False}
+    ]
+
+
 @pytest.mark.django_db
 def test_order_create_autocheckin(token_client, organizer, event, item, quota, question, clist_autocheckin):
     res = copy.deepcopy(ORDER_CREATE_PAYLOAD)