Revert "`belongs_to :touch` behavior now touches old association when...

Revert "`belongs_to :touch` behavior now touches old association when transitioning to new association" until a proper fix is found for #10197

activerecord/CHANGELOG.md

@@ -110,26 +110,6 @@
 
     *Neeraj Singh*
 
-*   `belongs_to :touch` behavior now touches old association when
-    transitioning to new association.
-
-        class Passenger < ActiveRecord::Base
-          belongs_to :car, touch: true
-        end
-
-        car_1 = Car.create
-        car_2 = Car.create
-
-        passenger = Passenger.create car: car_1
-
-        passenger.car = car_2
-        passenger.save
-
-    Previously only car_2 would be touched. Now both car_1 and car_2
-    will be touched.
-
-    *Adam Gamble*
-
 *   Extract and deprecate Firebird / Sqlserver / Oracle database tasks, because
     These tasks should be supported by 3rd-party adapter.
 

activerecord/lib/active_record/associations/builder/belongs_to.rb

@@ -67,19 +67,8 @@ def belongs_to_counter_cache_after_update_for_#{name}
     def add_touch_callbacks(reflection)
       mixin.class_eval <<-CODE, __FILE__, __LINE__ + 1
         def belongs_to_touch_after_save_or_destroy_for_#{name}
-          foreign_key_field = #{reflection.foreign_key.inspect}
-          old_foreign_id    = attribute_was(foreign_key_field)
-
-          if old_foreign_id
-            reflection_klass = #{reflection.klass}
-            old_record       = reflection_klass.find_by(reflection_klass.primary_key => old_foreign_id)
-
-            if old_record
-              old_record.touch #{options[:touch].inspect if options[:touch] != true}
-            end
-          end
-
           record = #{name}
+
           unless record.nil? || record.new_record?
             record.touch #{options[:touch].inspect if options[:touch] != true}
           end

activerecord/test/cases/timestamp_test.rb

@@ -176,32 +176,6 @@ def self.name; 'Toy'; end
     assert_not_equal time, owner.updated_at
   end
 
-  def test_changing_parent_of_a_record_touches_both_new_and_old_parent_record
-    klass = Class.new(ActiveRecord::Base) do
-      def self.name; 'Toy'; end
-      belongs_to :pet, touch: true
-    end
-
-    toy1 = klass.find(1)
-    old_pet = toy1.pet
-
-    toy2 = klass.find(2)
-    new_pet = toy2.pet
-    time = 3.days.ago.at_beginning_of_hour
-
-    old_pet.update_columns(updated_at: time)
-    new_pet.update_columns(updated_at: time)
-
-    toy1.pet = new_pet
-    toy1.save!
-
-    old_pet.reload
-    new_pet.reload
-
-    assert_not_equal time, new_pet.updated_at
-    assert_not_equal time, old_pet.updated_at
-  end
-
   def test_clearing_association_touches_the_old_record
     klass = Class.new(ActiveRecord::Base) do
       def self.name; 'Toy'; end