When you return a dictionary from a handler and supply a fields attribute, the fields that get serialised are invalid.

You can duplicate this bug using the following code in the provided test case.

{{{

!python

class InvalidFieldBugHandler(BaseHandler): model = CircularA fields = ( 'link', )

namespace = 'invalid field bug'
references = 'invalid field bug'

def read(self, request, name):
    # Get the C object.
    circular_c = CircularC.objects.get(name=name)

    # Return a dictionary containing the circular_c model. If the bug
    # isn't patched then fields will be passed to serialise circular_c,
    # and the CircualrA object will be returned.
    return {'result': circular_c}

}}}

Here's the fix in resource.py around line 270. {{{

!python

emitter, ct = Emitter.get(em_format)

# This is a fix for an obscure bug that occurs when the following
# conditions are met:
#  * You have a handler that has a fields attribute.
#  * You override this handler's read function to return a dict.
#  * In that dict, you return a model.
# As you iterate over the new list, you will end up passing the
# wrong set of fields to the _model function. However, passing in
# the fields from this handler, as opposed to looking them up
# through the namespace is desirable because you may have a regex
# that purposefully matches this specific handler.
fields = None
if isinstance(result, (Model, QuerySet)):
    fields = handler.fields

if is_iterable(result) and hasattr(handler, 'list_fields'):
    fields = handler.list_fields

}}}