Order import: Respect sales channel when validating seats (#4707)

src/pretix/base/modelimport_orders.py

@@ -585,7 +585,7 @@ class SeatColumn(ImportColumn):
                 raise ValidationError(_('Multiple matching seats were found.'))
             except Seat.DoesNotExist:
                 raise ValidationError(_('No matching seat was found.'))
-            if not value.is_available() or value in self._cached:
+            if not value.is_available(sales_channel=previous_values.get('sales_channel')) or value in self._cached:
                 raise ValidationError(
                     _('The seat you selected has already been taken. Please select a different seat.'))
             self._cached.add(value)
@@ -754,11 +754,11 @@ def get_order_import_columns(event):
         AttendeeState(event),
         Price(event),
         Secret(event),
+        Saleschannel(event),
         SeatColumn(event),
         ValidFrom(event),
         ValidUntil(event),
         Locale(event),
-        Saleschannel(event),
         CheckinAttentionColumn(event),
         CheckinTextColumn(event),
         Expires(event),

src/pretix/base/services/modelimport.py

@@ -118,7 +118,7 @@ def import_orders(event: Event, fileid: str, settings: dict, locale: str, user,
                     c.assign(record.get(c.identifier), order, position, order._address)
 
                 if position.seat is not None:
-                    lock_seats.append(position.seat)
+                    lock_seats.append((order.sales_channel, position.seat))
             except (ValidationError, ImportError) as e:
                 raise DataImportError(
                     _('Invalid data in row {row}: {message}').format(row=i, message=str(e))
@@ -128,9 +128,9 @@ def import_orders(event: Event, fileid: str, settings: dict, locale: str, user,
             with transaction.atomic():
                 # We don't support vouchers, quotas, or memberships here, so we only need to lock if seats are in use
                 if lock_seats:
-                    lock_objects(lock_seats, shared_lock_objects=[event])
-                    for s in lock_seats:
-                        if not s.is_available():
+                    lock_objects([s for c, s in lock_seats], shared_lock_objects=[event])
+                    for c, s in lock_seats:
+                        if not s.is_available(sales_channel=c):
                             raise DataImportError(_('The seat you selected has already been taken. Please select a different seat.'))
 
                 save_transactions = []