do_sqlite3 always return ASCII-8BIT string object on Ruby 1.9. (datamapper ticket #1120)

test-do_sqlite3-utf8-ruby1.9.rb

# coding: utf-8

# Ruby:         1.9.1p243 (2009-07-16 revision 24175) [i486-linux]
# dm-core:      'next' branch
# data_objects: 'next' branch

require 'dm-core'

class Foo
  include DataMapper::Resource
  property :id, Serial
  property :value, String
end

#DataMapper::Logger.new(STDOUT, :debug)
DataMapper.setup(:default, 'sqlite3::memory:')
DataMapper.auto_migrate!

Foo.create(:value => 'some UTF-8 string: 日本語')
p Foo.first.value.encoding.name
# => "ASCII-8BIT"
# This should be "UTF-8"!