Remove some irregularities in 8abfbba9

src/pretix/base/migrations/0104_auto_20181114_1526.py

@@ -8,8 +8,7 @@ from django.db import migrations, models
 
 def change_refunded_to_canceled(apps, schema_editor):
     Order = apps.get_model('pretixbase', 'Order')
-    Order.objects.filter(status='r').update(status='c', total=0)
+    Order.objects.filter(status='r').update(status='c')
-    Order.objects.filter(status='c').update(total=0)
 
 
 class Migration(migrations.Migration):

src/pretix/base/models/orders.py

@@ -421,7 +421,7 @@ class Order(LockModel, LoggedModel):
         return (
             self.status == Order.STATUS_PENDING
             or (self.status == Order.STATUS_PAID and self.total == Decimal('0.00'))
-        ) and self.event.settings.cancel_allow_user and cancelable
+        ) and self.event.settings.cancel_allow_user and cancelable and self.positions.exists()
 
     @property
     def is_expired_by_time(self):

src/pretix/base/services/orders.py

@@ -1173,7 +1173,7 @@ class OrderChangeManager:
         return payment_sum - refund_sum
 
     def _recalculate_total_and_payment_fee(self):
-        total = sum([p.price for p in self.order.positions.all() if not p.canceled]) + sum([f.value for f in self.order.fees.all()])
+        total = sum([p.price for p in self.order.positions.all()]) + sum([f.value for f in self.order.fees.all()])
         payment_fee = Decimal('0.00')
         if self.open_payment:
             current_fee = Decimal('0.00')