If a field value is NULL its stored in the DB as "N;". When this is retrieved back from the DB the value returned is of type String with value "N;" instead of NULL.
Chnaging the condition in the set function to
if ($value === NULL OR ($this->null AND empty($value)) OR @unserialize($value)===NULL)
If a field value is NULL its stored in the DB as "N;". When this is retrieved back from the DB the value returned is of type String with value "N;" instead of NULL.
Chnaging the condition in the set function to
fixes the bug