push parent up to the superclass

We always want a linked list back to the root node.

3 files changed, 11 insertions, 7 deletions

diff --git a/activerecord/lib/active_record/associations/join_dependency/join_association.rb b/activerecord/lib/active_record/associations/join_dependency/join_association.rb
index f6a04ef9f1..e2ac892e71 100644
--- a/activerecord/lib/active_record/associations/join_dependency/join_association.rb
+++ b/activerecord/lib/active_record/associations/join_dependency/join_association.rb
@@ -9,10 +9,6 @@ module ActiveRecord
         # The reflection of the association represented
         attr_reader :reflection
 
-        # A JoinBase instance representing the active record we are joining onto.
-        # (So in Author.has_many :posts, the Author would be that base record.)
-        attr_reader :parent
-
         # What type of join will be generated, either Arel::InnerJoin (default) or Arel::OuterJoin
         attr_accessor :join_type
 
@@ -25,11 +21,10 @@ module ActiveRecord
         delegate :options, :through_reflection, :source_reflection, :chain, :to => :reflection
 
         def initialize(reflection, index, parent, join_type, alias_tracker)
-          super(reflection.klass)
+          super(reflection.klass, parent)
 
           @reflection      = reflection
           @alias_tracker   = alias_tracker
-          @parent          = parent
           @join_type       = join_type
           @aliased_prefix  = "t#{ index }"
           @tables          = construct_tables.reverse
diff --git a/activerecord/lib/active_record/associations/join_dependency/join_base.rb b/activerecord/lib/active_record/associations/join_dependency/join_base.rb
index c689d06594..c90ae80e4a 100644
--- a/activerecord/lib/active_record/associations/join_dependency/join_base.rb
+++ b/activerecord/lib/active_record/associations/join_dependency/join_base.rb
@@ -4,6 +4,10 @@ module ActiveRecord
   module Associations
     class JoinDependency # :nodoc:
       class JoinBase < JoinPart # :nodoc:
+        def initialize(klass)
+          super(klass, nil)
+        end
+
         def ==(other)
           other.class == self.class &&
             other.base_klass == base_klass
diff --git a/activerecord/lib/active_record/associations/join_dependency/join_part.rb b/activerecord/lib/active_record/associations/join_dependency/join_part.rb
index e27beb3b6f..3e9bdbfbab 100644
--- a/activerecord/lib/active_record/associations/join_dependency/join_part.rb
+++ b/activerecord/lib/active_record/associations/join_dependency/join_part.rb
@@ -10,6 +10,10 @@ module ActiveRecord
       class JoinPart # :nodoc:
         include Enumerable
 
+        # A JoinBase instance representing the active record we are joining onto.
+        # (So in Author.has_many :posts, the Author would be that base record.)
+        attr_reader :parent
+
         # The Active Record class which this join part is associated 'about'; for a JoinBase
         # this is the actual base model, for a JoinAssociation this is the target model of the
         # association.
@@ -17,8 +21,9 @@ module ActiveRecord
 
         delegate :table_name, :column_names, :primary_key, :arel_engine, :to => :base_klass
 
-        def initialize(base_klass)
+        def initialize(base_klass, parent)
           @base_klass = base_klass
+          @parent = parent
           @cached_record = {}
           @column_names_with_alias = nil
           @children = []