Datamapper DataMapper

To reproduce:

class M < DataMapper::Base
  property :name, :string, :nullable => true
end

The problems is nullable autovalidation lambda function will return nil when nullable != false

From lib/datamaper/property.rb

  # NOTE: :length may also be used in place of :size 
    AUTO_VALIDATIONS = {
      :nullable => lambda { |k,v| "validates_presence_of :#{k}" if v == false },
      :size => lambda { |k,v| "validates_length_of :#{k}, " + (v.is_a?(Range) ? ":minimum => #{v.first}, :maximum => #{v.last}" : ":maximum => #{v}") },
      :format => lambda { |k, v| "validates_format_of :#{k}, :with => #{v.inspect}" }
    }