Fixed field type of CachedTicket.order

src/pretix/base/migrations/0013_auto_20150916_0941.py

@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import models, migrations
+import versions.models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('pretixbase', '0012_remove_order_tickets'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='cachedticket',
+            name='order',
+            field=versions.models.VersionedForeignKey(to='pretixbase.Order'),
+        ),
+    ]

src/pretix/base/models.py

@@ -1704,7 +1704,7 @@ class Order(Versionable):
 
 
 class CachedTicket(models.Model):
-    order = models.ForeignKey(Order, on_delete=models.CASCADE)
+    order = VersionedForeignKey(Order, on_delete=models.CASCADE)
     cachedfile = models.ForeignKey(CachedFile, on_delete=models.CASCADE)
     provider = models.CharField(max_length=255)