Fix preloading association with scope including joins

1 files changed, 10 insertions, 3 deletions

diff --git a/activerecord/lib/active_record/associations/preloader/through_association.rb b/activerecord/lib/active_record/associations/preloader/through_association.rb
index 34587fd3f5..0999746cd5 100644
--- a/activerecord/lib/active_record/associations/preloader/through_association.rb
+++ b/activerecord/lib/active_record/associations/preloader/through_association.rb
@@ -79,17 +79,24 @@ module ActiveRecord
 
           def through_scope
             scope = through_reflection.klass.unscoped
+            values = reflection_scope.values
 
             if options[:source_type]
               scope.where! reflection.foreign_type => options[:source_type]
             else
               unless reflection_scope.where_clause.empty?
-                scope.includes_values = Array(reflection_scope.values[:includes] || options[:source])
+                scope.includes_values = Array(values[:includes] || options[:source])
                 scope.where_clause = reflection_scope.where_clause
+                if joins = values[:joins]
+                  scope.joins!(source_reflection.name => joins)
+                end
+                if left_outer_joins = values[:left_outer_joins]
+                  scope.left_outer_joins!(source_reflection.name => left_outer_joins)
+                end
               end
 
-              scope.references! reflection_scope.values[:references]
-              if scope.eager_loading? && order_values = reflection_scope.values[:order]
+              scope.references! values[:references]
+              if scope.eager_loading? && order_values = values[:order]
                 scope = scope.order(order_values)
               end
             end