Fixes :limit => 0 for enumerated columns in rails 3

gistfile1.rb

# Fixes :limit => 0 on enumerated columns, now you can test!
module ActiveRecord
  module ConnectionAdapters
    class Column
      def extract_limit_with_enum(sql_type)
        sql_type.scan(/enum/i)? 255 : extract_limit_without_enum(sql_type)
      end
      alias_method_chain :extract_limit, :enum
    end
  end
end