undefined method `name' for nil:NilClass

Problem

undefined method `name' for nil:NilClass

env: mri ruby 1.9.2-head, rails 3.0.7, libruby-mysql2

Occurred while uploading file and storing into binary field

Decision: none
Lets take a look into call hierarchy. This is start from 

activesupport (3.0.7) lib/active_support/whiny_nil.rb:48:in `method_missing'

raised by NoMethodError

    def method_missing(method, *args, &block)
      if klass = METHOD_CLASS_MAP[method]
        raise_nil_warning_for klass, method, caller
      else
        super
      end
    end