gistfile1.diff

diff --git a/lib/dm-core/query.rb b/lib/dm-core/query.rb
index 434d8ce..fb48204 100644
--- a/lib/dm-core/query.rb
+++ b/lib/dm-core/query.rb
@@ -1440,8 +1440,8 @@ module DataMapper
       {
         :child_key              => keys,
         :parent_key             => keys,
-        :child_repository_name  => repository,
-        :parent_repository_name => repository,
+        :child_repository_name  => repository.name,
+        :parent_repository_name => repository.name,
       }
     end

repositories_killa.rb

require 'pp'
require 'do_sqlite3'
require 'dm-core'

DataMapper.setup(:default, 'sqlite3:///tmp/bs.db')

class Infestation
  include DataMapper::Resource
  property :id, Serial

  belongs_to :sheep
  belongs_to :flea
end

class Sheep
  include DataMapper::Resource
  
  property :id, Serial
  property :name, String, :lazy => false

  has n, :infestations
  has n, :fleas, :through => :infestations
end

class Flea
  include DataMapper::Resource

  property :id, Serial
  property :name, String, :lazy => false

  has n, :infestations
  has n, :sheeps, :through => :infestations
end

DataMapper.auto_migrate!
DataObjects::Sqlite3.logger = DataObjects::Logger.new(STDOUT, 0)

# now for the interesting stuff
s = Sheep.create(:name => 'Shaun')
s.fleas.new(:name => 'Fred')
s.fleas.new(:name => 'Frank')
s.save or raise "argh?"

@s = Sheep.first

puts "==========================="
puts "Flea.repositories is normal"
pp Flea.repositories
puts "@properties before we break it"
pp Flea.instance_variable_get("@properties")

puts "This screws up @properties on Flea"
(@s.fleas(:name => "Fred") - @s.fleas(:name => "Frank")).to_a

puts "This should not have the Repository as a key"
pp Flea.instance_variable_get("@properties")
puts "And accessing repositories will raise"
Flea.repositories # This raises