inlineformset delete on empty revisited

[nbv4]

http://pastebin.com/f40a3bde9

I found this little snippet on this group and am trying to get it to
work on my model, but no luck. I'm using the code pretty much as-is
except for two small changes, which are noted by a code comment. I can
create new instances of my model using this formset, bit I can't edit
existing instances (I haven't gotten to testing whether "deleting by
blanking" works yet). When I try to formset.save(), I get this error:

'RouteBaseForm' object has no attribute 'cleaned_data'

which is thrown on line 57 on that snippet. For some reason
cleaned_data isn't being defined. Anyone care to take a stab at
figuring out whats wrong? I don't know enough about the internals of
django to get to the bottom of this...

[patrickk]

maybe this helps (well ... it probably doesn´t help, but it maybe
clarifies):
http://code.djangoproject.com/ticket/10828

regards,
patrick