set_value html_escape twice

I just found what was going wrong using the debug mode !
The form_prep method has a fallback case when the field has already been prepped.
This case was preventing my values to be double encoded !
Now there is no more strange case like that (because it's not safe at all).

PHP Code:

// we've already prepped a field with this name
// @todo need to figure out a way to namespace this so
// that we know the *exact* field and not just one with
// the same name
if (isset($prepped_fields[$field_name]))
{
return $str;
} 


So as you say either I change the framework's files which is bad. Either I change my 146 usage of set_value() ... I prefer not to panic people changing all the versioned files ...