From e11ee4a4277cf21729f4504ab31cbb3f280c3832 Mon Sep 17 00:00:00 2001
From: Raphael Michel <mail@raphaelmichel.de>
Date: Tue, 18 Dec 2018 09:56:58 +0100
Subject: [PATCH] Do not allow to delete vouchers assigned to canceled orders

---
 src/pretix/base/models/vouchers.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/pretix/base/models/vouchers.py b/src/pretix/base/models/vouchers.py
index 314ccb1234..61104be6e5 100644
--- a/src/pretix/base/models/vouchers.py
+++ b/src/pretix/base/models/vouchers.py
@@ -182,7 +182,7 @@ class Voucher(LoggedModel):
         return self.code
 
     def allow_delete(self):
-        return self.redeemed == 0
+        return self.redeemed == 0 and not self.orderposition_set.exists()
 
     def clean(self):
         Voucher.clean_item_properties(