From b773f21b54463ed45ba78eb6f54f9b083742d6ef Mon Sep 17 00:00:00 2001
From: helmutm <helmutm@fd906abe-77d9-0310-91a1-e0d9ade77398>
Date: Thu, 29 Jan 2009 07:46:45 +0000
Subject: [PATCH] bug fix: handle missing value (None) on list field

git-svn-id: svn://svn.cy55.de/Zope3/src/cybertools/trunk@3189 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 8958fe4..92ef69a 100644
--- a/composer/schema/field.py
+++ b/composer/schema/field.py
@@ -306,6 +306,8 @@ class ListFieldInstance(FieldInstance):
         #return [self.valueFieldInstance.marshall(v) for v in value]
 
     def display(self, value):
+        if not value:
+            return u''
         if isinstance(value, basestring):
             return value
         return u' | '.join(self.valueFieldInstance.display(v) for v in value)