IPAddress Property does not typecast Resolv::IPv4 / Resolv::IPv6 objects

[postmodern]

If you create a Resolv::DNS object to query a specific nameserver, it will return Resolv::IPv4 / Resolv::IPv6 objects instead of Strings. The IPAddress Property does not typecast these objects.

[postmodern]

ArgumentError: +value+ must be nil or a String
    from /home/hal/.rvm/gems/ruby-1.9.2-p290/gems/dm-types-1.2.0/lib/dm-types/ip_address.rb:28:in `load'
    from /home/hal/.rvm/gems/ruby-1.9.2-p290/gems/dm-types-1.2.0/lib/dm-types/ip_address.rb:37:in `typecast_to_primitive'
    from /home/hal/.rvm/gems/ruby-1.9.2-p290/gems/dm-core-1.2.0/lib/dm-core/property.rb:686:in `typecast'
    from /home/hal/.rvm/gems/ruby-1.9.2-p290/gems/dm-core-1.2.0/lib/dm-core/property.rb:625:in `set'
    from /home/hal/.rvm/gems/ruby-1.9.2-p290/gems/dm-core-1.2.0/lib/dm-core/resource/persistence_state.rb:22:in `set'
    from /home/hal/.rvm/gems/ruby-1.9.2-p290/gems/dm-core-1.2.0/lib/dm-core/resource/persistence_state/transient.rb:14:in `set'
    from /home/hal/.rvm/gems/ruby-1.9.2-p290/gems/dm-core-1.2.0/lib/dm-core/model/property.rb:237:in `address='
    from /home/hal/.rvm/gems/ruby-1.9.2-p290/gems/dm-core-1.2.0/lib/dm-core/resource.rb:333:in `block in attributes='
    from /home/hal/.rvm/gems/ruby-1.9.2-p290/gems/dm-core-1.2.0/lib/dm-core/resource.rb:329:in `each'
    from /home/hal/.rvm/gems/ruby-1.9.2-p290/gems/dm-core-1.2.0/lib/dm-core/resource.rb:329:in `attributes='
    from /home/hal/.rvm/gems/ruby-1.9.2-p290/gems/dm-core-1.2.0/lib/dm-core/resource.rb:748:in `initialize'
    from /home/hal/.rvm/gems/ruby-1.9.2-p290/gems/dm-core-1.2.0/lib/dm-core/property/discriminator.rb:33:in `new'
    from /home/hal/.rvm/gems/ruby-1.9.2-p290/gems/dm-core-1.2.0/lib/dm-core/property/discriminator.rb:33:in `new'

[solnic]

@postmodern can you reproduce it on current master?

[postmodern]

Confirmed on master (ddf9682):

require 'dm-core'
require 'dm-types'
require 'resolv'

class Test
  include DataMapper::Resource

  property :id, Serial
  property :ip, IPAddress
end
DataMapper.finalize

ip = Resolv::DNS.new(:nameserver => '4.2.2.1').getaddress('www.google.com')
t = Test.new(:ip => ip)

ArgumentError: +value+ must be nil or a String
    from /home/hal/.rvm/gems/ruby-1.9.2-p290/bundler/gems/dm-types-ddf96829985c/lib/dm-types/ip_address.rb:21:in `load'
    from /home/hal/.rvm/gems/ruby-1.9.2-p290/bundler/gems/dm-types-ddf96829985c/lib/dm-types/ip_address.rb:30:in `typecast'
    from /home/hal/.rvm/gems/ruby-1.9.2-p290/bundler/gems/dm-core-d74ae6e8c4a3/lib/dm-core/property.rb:618:in `set'
    from /home/hal/.rvm/gems/ruby-1.9.2-p290/bundler/gems/dm-core-d74ae6e8c4a3/lib/dm-core/resource/persistence_state.rb:22:in `set'
    from /home/hal/.rvm/gems/ruby-1.9.2-p290/bundler/gems/dm-core-d74ae6e8c4a3/lib/dm-core/resource/persistence_state/transient.rb:14:in `set'
    from /home/hal/.rvm/gems/ruby-1.9.2-p290/bundler/gems/dm-core-d74ae6e8c4a3/lib/dm-core/model/property.rb:237:in `ip='
    from /home/hal/.rvm/gems/ruby-1.9.2-p290/bundler/gems/dm-core-d74ae6e8c4a3/lib/dm-core/resource.rb:333:in `block in attributes='
    from /home/hal/.rvm/gems/ruby-1.9.2-p290/bundler/gems/dm-core-d74ae6e8c4a3/lib/dm-core/resource.rb:329:in `each'
    from /home/hal/.rvm/gems/ruby-1.9.2-p290/bundler/gems/dm-core-d74ae6e8c4a3/lib/dm-core/resource.rb:329:in `attributes='
    from /home/hal/.rvm/gems/ruby-1.9.2-p290/bundler/gems/dm-core-d74ae6e8c4a3/lib/dm-core/resource.rb:748:in `initialize'
    from (irb):16:in `new'
    from (irb):16
    from /home/hal/.rvm/rubies/ruby-1.9.2-p290/bin/irb:16:in `'