Fix `AssociationRelation` not to set inverse instance key just like before

Since #31575, `set_inverse_instance` replaces the foreign key by the
current owner immediately to make it happen when a record is added to
collection association.

But `set_inverse_instance` is not only called when a record is added,
but also when a record is loaded from queries. And also, that loaded
records are not always associated records for some reason (using `or`,
`unscope`, `rewhere`, etc).

It is hard to distinguish whether or not we should invoke
`set_inverse_instance`, but at least we should avoid the undesired
side-effect which was brought from #31575.

Fixes #34108.

1 files changed, 12 insertions, 0 deletions

diff --git a/activerecord/test/cases/associations/has_many_associations_test.rb b/activerecord/test/cases/associations/has_many_associations_test.rb
index 036df1c31e..45e2aadaf4 100644
--- a/activerecord/test/cases/associations/has_many_associations_test.rb
+++ b/activerecord/test/cases/associations/has_many_associations_test.rb
@@ -2356,6 +2356,18 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
     assert_equal [accounts(:signals37)], firm.accounts.open
   end
 
+  def test_association_with_or_doesnt_set_inverse_instance_key
+    firm = companies(:first_firm)
+    accounts = firm.accounts.or(Account.where(firm_id: nil)).order(:id)
+    assert_equal [firm.id, nil], accounts.map(&:firm_id)
+  end
+
+  def test_association_with_rewhere_doesnt_inverse_instance_key
+    firm = companies(:first_firm)
+    accounts = firm.accounts.rewhere(firm_id: [firm.id, nil]).order(:id)
+    assert_equal [firm.id, nil], accounts.map(&:firm_id)
+  end
+
   test "first_or_initialize adds the record to the association" do
     firm = Firm.create! name: "omg"
     client = firm.clients_of_firm.first_or_initialize