Romain Courteaud
authored
None may not be always considered as a NULL value of property, so it's better to take a default NULL value from _null. Value is considered a NULL if inside _null. git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@13562 20353a03-c40f-0410-a6d1-a30d3c3de9de