Fixed case where a missing meta_field value would error

Author: jerel

rest_framework_json_api/renderers.py

@@ -325,7 +325,7 @@ def extract_meta(serializer, resource):
             meta = getattr(serializer.child, 'Meta', None)
         else:
             meta = getattr(serializer, 'Meta', None)
-        meta_fields = getattr(meta, 'meta_fields', {})
+        meta_fields = getattr(meta, 'meta_fields', [])
         data = OrderedDict()
         for field_name in meta_fields:
             data.update({

rest_framework_json_api/serializers.py

@@ -148,10 +148,10 @@ def get_field_names(self, declared_fields, info):
         We override the parent to omit explicity defined meta fields (such
         as SerializerMethodFields) from the list of declared fields
         """
-        meta_fields = getattr(self.Meta, 'meta_fields', None)
+        meta_fields = getattr(self.Meta, 'meta_fields', [])
 
         declared = OrderedDict()
-        for field_name in declared_fields.keys():
+        for field_name in set(declared_fields.keys()):
             field = declared_fields[field_name]
             if field_name not in meta_fields:
                 declared[field_name] = field