1 files changed, 19 insertions, 5 deletions
diff --git a/activerecord/lib/active_record/associations/has_many_through_association.rb b/activerecord/lib/active_record/associations/has_many_through_association.rb
index 3d3d53c677..573e29ca31 100644
--- a/activerecord/lib/active_record/associations/has_many_through_association.rb
+++ b/activerecord/lib/active_record/associations/has_many_through_association.rb
@@ -40,6 +40,21 @@ module ActiveRecord
       end
 
       protected
+        def through_reflection
+          unless @through_reflection ||= @owner.class.reflections[@reflection.options[:through]]
+            raise ActiveRecordError, "Could not find the association '#{@reflection.options[:through]}' in model #{@reflection.klass}"
+          end
+          @through_reflection
+        end
+
+        def source_reflection
+          @source_reflection_name ||= @reflection.name.to_s.singularize.to_sym
+          unless @source_reflection ||= through_reflection.klass.reflect_on_association(@source_reflection_name)
+            raise ActiveRecordError, "Could not find the source association '#{@source_reflection_name}' in model #{@through_reflection.klass}"
+          end
+          @source_reflection
+        end
+
         def method_missing(method, *args, &block)
           if @target.respond_to?(method) || (!@reflection.klass.respond_to?(method) && Class.respond_to?(method))
             super
@@ -61,12 +76,8 @@ module ActiveRecord
         end
 
         def construct_conditions
-          unless through_reflection = @owner.class.reflections[@reflection.options[:through]]
-            raise ActiveRecordError, "Could not find the association '#{@reflection.options[:through]}' in model #{@reflection.klass}"
-          end
-          
           # Get the actual primary key of the belongs_to association that the reflection is going through
-          source_primary_key = through_reflection.klass.reflect_on_association(@reflection.name.to_s.singularize.to_sym).primary_key_name
+          source_primary_key = source_reflection.primary_key_name
           
           if through_reflection.options[:as]
             conditions = 
@@ -119,6 +130,9 @@ module ActiveRecord
           end
         end
         
+        def sql_conditions
+          @conditions ||= interpolate_sql(@reflection.active_record.send(:sanitize_sql, through_reflection.options[:conditions])) if through_reflection.options[:conditions]
+        end
     end
   end
 end