has_one :through supports :source_type. Fix up some tests. References #4756.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@9075 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

2 files changed, 8 insertions, 3 deletions

diff --git a/activerecord/lib/active_record/association_preload.rb b/activerecord/lib/active_record/association_preload.rb
index 0c31c85bb0..ad9b9d6488 100644
--- a/activerecord/lib/active_record/association_preload.rb
+++ b/activerecord/lib/active_record/association_preload.rb
@@ -165,8 +165,13 @@ module ActiveRecord
           through_records = []
           records.compact.each do |record|
             proxy = record.send(through_association)
-            through_records << proxy.target
-            proxy.reset
+
+            if proxy.respond_to?(:target)
+              through_records << proxy.target
+              proxy.reset
+            else # this is a has_one :through reflection
+              through_records << proxy if proxy
+            end
           end
           through_records = through_records.flatten
         else
diff --git a/activerecord/lib/active_record/associations.rb b/activerecord/lib/active_record/associations.rb
index aa68a42c44..068f2f9de2 100755
--- a/activerecord/lib/active_record/associations.rb
+++ b/activerecord/lib/active_record/associations.rb
@@ -1326,7 +1326,7 @@ module ActiveRecord
         
         def create_has_one_through_reflection(association_id, options)
           options.assert_valid_keys(
-            :class_name, :foreign_key, :remote, :conditions, :order, :include, :dependent, :counter_cache, :extend, :as, :through, :source
+            :class_name, :foreign_key, :remote, :conditions, :order, :include, :dependent, :counter_cache, :extend, :as, :through, :source, :source_type
           )
           create_reflection(:has_one, association_id, options, self)
         end