From e784556330c385ae73c39c009f62eb619af7a11f Mon Sep 17 00:00:00 2001
From: kaiyou <pierre@jaury.eu>
Date: Tue, 16 Oct 2018 20:47:38 +0200
Subject: [PATCH] Fix an edge case with old values containing None for coma
 separated lists

---
 core/admin/mailu/models.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/core/admin/mailu/models.py b/core/admin/mailu/models.py
index 6685fc60..63d0e4f9 100644
--- a/core/admin/mailu/models.py
+++ b/core/admin/mailu/models.py
@@ -64,7 +64,7 @@ class CommaSeparatedList(db.TypeDecorator):
         return ",".join(value)
 
     def process_result_value(self, value, dialect):
-        return filter(bool, value.split(","))
+        return filter(bool, value.split(",")) if value else []
 
 
 # Many-to-many association table for domain managers