From edeb72a3e25d0caf65450275212eb39061c2a4a3 Mon Sep 17 00:00:00 2001
From: helmutm <helmutm@fd906abe-77d9-0310-91a1-e0d9ade77398>
Date: Mon, 6 Jul 2009 16:18:24 +0000
Subject: [PATCH] accept None value for list

git-svn-id: svn://svn.cy55.de/Zope3/src/cybertools/trunk@3445 fd906abe-77d9-0310-91a1-e0d9ade77398
---
 composer/schema/field.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/composer/schema/field.py b/composer/schema/field.py
index c80e7ae..2afd887 100644
--- a/composer/schema/field.py
+++ b/composer/schema/field.py
@@ -303,6 +303,8 @@ class ListFieldInstance(FieldInstance):
     def marshall(self, value):
         if isinstance(value, basestring):
             return value
+        if value is None:
+            return u''
         return u'\n'.join(self.valueFieldInstance.marshall(v) for v in value)
         #return [self.valueFieldInstance.marshall(v) for v in value]