# Pre-1.9 versions of Ruby have a bug with marshaling Time instances, where utc instances are
# unmarshalled in the local zone, instead of utc. We're layering behavior on the _dump and _load
# methods so that utc instances can be flagged on dump, and coerced back to utc on load.
if !Marshal.load(Marshal.dump(Time.now.utc)).utc?
  class Time
    class << self
      alias_method :_load_without_utc_flag, :_load
      def _load(marshaled_time)
        time = _load_without_utc_flag(marshaled_time)
        time.instance_eval do
          if defined?(@marshal_with_utc_coercion)
            val = remove_instance_variable("@marshal_with_utc_coercion")
          end
          val ? utc : self
        end
      end
    end

    alias_method :_dump_without_utc_flag, :_dump
    def _dump(*args)
      obj = dup
      obj.instance_variable_set('@marshal_with_utc_coercion', utc?)
      obj._dump_without_utc_flag(*args)
    end
  end
end

# Ruby 1.9.2 adds utc_offset and zone to Time, but marshaling only
# preserves utc_offset. Preserve zone also, even though it may not
# work in some edge cases.
if Time.local(2010).zone != Marshal.load(Marshal.dump(Time.local(2010))).zone
  class Time
    class << self
      alias_method :_load_without_zone, :_load
      def _load(marshaled_time)
        time = _load_without_zone(marshaled_time)
        time.instance_eval do
          if zone = defined?(@_zone) && remove_instance_variable('@_zone')
            ary = to_a
            ary[-1] = zone
            utc? ? Time.utc(*ary) : Time.local(*ary)
          else
            self
          end
        end
      end
    end

    alias_method :_dump_without_zone, :_dump
    def _dump(*args)
      obj = dup
      obj.instance_variable_set('@_zone', zone)
      obj._dump_without_zone(*args)
    end
  end
end