Added snippet that shows that #1235 is resolved

1235.rb

@@ -0,0 +1,41 @@
+require 'dm-core'
+require 'dm-migrations'
+
+DataMapper::Logger.new($stdout, :debug)
+DataMapper.setup(:default, 'sqlite3::memory')
+
+class Activity
+  include DataMapper::Resource
+  property :id,   Serial
+  property :name, String
+  has n, :activity_fields
+  after :save do
+    self.activity_fields.create :name => 'default field'
+  end
+end
+
+class ActivityField
+  include DataMapper::Resource
+  property :id,          Serial
+  property :name,        String
+  property :activity_id, Integer
+  belongs_to :activity
+end
+
+
+DataMapper.auto_migrate!
+
+Activity.create :name => 'AAA'
+
+__END__
+
+ree-1.8.7-2010.01 mungo:dm-snippets snusnu$ bundle exec ruby 1235.rb 
+ ~ (0.000045) SELECT sqlite_version(*)
+ ~ (0.045876) DROP TABLE IF EXISTS "activities"
+ ~ (0.000021) PRAGMA table_info("activities")
+ ~ (0.002323) CREATE TABLE "activities" ("id" INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, "name" VARCHAR(50))
+ ~ (0.002498) DROP TABLE IF EXISTS "activity_fields"
+ ~ (0.000021) PRAGMA table_info("activity_fields")
+ ~ (0.002648) CREATE TABLE "activity_fields" ("id" INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, "name" VARCHAR(50), "activity_id" INTEGER)
+ ~ (0.003030) INSERT INTO "activities" ("name") VALUES ('AAA')
+ ~ (0.001995) INSERT INTO "activity_fields" ("name", "activity_id") VALUES ('default field', 1)