Don't save through records twice

If the through record gets created in an `after_create` hook that is
defined before the association is defined (therefore after its
`after_create` hook) get saved twice. This ensures that the through
records are created only once, regardless of the order of the hooks.

1 files changed, 2 insertions, 3 deletions

diff --git a/activerecord/lib/active_record/autosave_association.rb b/activerecord/lib/active_record/autosave_association.rb
index b3c3e26c9f..dd92e29199 100644
--- a/activerecord/lib/active_record/autosave_association.rb
+++ b/activerecord/lib/active_record/autosave_association.rb
@@ -184,9 +184,7 @@ module ActiveRecord
             before_save :before_save_collection_association
 
             define_non_cyclic_method(save_method) { save_collection_association(reflection) }
-            # Doesn't use after_save as that would save associations added in after_create/after_update twice
-            after_create save_method
-            after_update save_method
+            after_save save_method
           elsif reflection.has_one?
             define_method(save_method) { save_has_one_association(reflection) } unless method_defined?(save_method)
             # Configures two callbacks instead of a single after_save so that
@@ -364,6 +362,7 @@ module ActiveRecord
 
               raise ActiveRecord::Rollback unless saved
             end
+            @new_record_before_save = false
           end
 
           # reconstruct the scope now that we know the owner's id