From 99bc133540c197f1cb6d38209c75a18d2100746e Mon Sep 17 00:00:00 2001
From: Raphael Michel <michel@rami.io>
Date: Wed, 21 Apr 2021 12:56:28 +0200
Subject: [PATCH] Check-in list editor: Allow to delete last rule

---
 src/pretix/base/models/checkin.py   | 5 +++++
 src/pretix/control/forms/checkin.py | 2 +-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/pretix/base/models/checkin.py b/src/pretix/base/models/checkin.py
index 0f29743b47..8248671fc6 100644
--- a/src/pretix/base/models/checkin.py
+++ b/src/pretix/base/models/checkin.py
@@ -225,6 +225,11 @@ class CheckinList(LoggedModel):
         for v in values:
             cls.validate_rules(v, seen_nonbool=seen_nonbool or operator not in ('or', 'and'), depth=depth + 1)
 
+        if operator in ('or', 'and') and depth == 0 and not values:
+            return {}
+
+        return rules
+
 
 class Checkin(models.Model):
     """
diff --git a/src/pretix/control/forms/checkin.py b/src/pretix/control/forms/checkin.py
index 65427ae4a9..4cd0a1e6d4 100644
--- a/src/pretix/control/forms/checkin.py
+++ b/src/pretix/control/forms/checkin.py
@@ -128,7 +128,7 @@ class CheckinListForm(forms.ModelForm):
 
     def clean(self):
         d = super().clean()
-        CheckinList.validate_rules(d.get('rules'))
+        d['rules'] = CheckinList.validate_rules(d.get('rules'))
         return d