Don't redefine autosave association callbacks in nested attrs

These callbacks will already have been defined when the association was
built. The check against `reflection.autosave` happens at call time, not
at define time, so simply modifying the reflection is sufficient.

Fixes #18704

2 files changed, 2 insertions, 0 deletions

diff --git a/activerecord/test/models/ship.rb b/activerecord/test/models/ship.rb
index c2f6d492d8..312caef604 100644
--- a/activerecord/test/models/ship.rb
+++ b/activerecord/test/models/ship.rb
@@ -4,6 +4,7 @@ class Ship < ActiveRecord::Base
   belongs_to :pirate
   belongs_to :update_only_pirate, :class_name => 'Pirate'
   has_many :parts, :class_name => 'ShipPart'
+  has_many :treasures
 
   accepts_nested_attributes_for :parts, :allow_destroy => true
   accepts_nested_attributes_for :pirate, :allow_destroy => true, :reject_if => proc(&:empty?)
diff --git a/activerecord/test/models/treasure.rb b/activerecord/test/models/treasure.rb
index a69d3fd3df..ffc65466d5 100644
--- a/activerecord/test/models/treasure.rb
+++ b/activerecord/test/models/treasure.rb
@@ -1,6 +1,7 @@
 class Treasure < ActiveRecord::Base
   has_and_belongs_to_many :parrots
   belongs_to :looter, :polymorphic => true
+  belongs_to :ship
 
   has_many :price_estimates, :as => :estimate_of
   has_and_belongs_to_many :rich_people, join_table: 'peoples_treasures', validate: false