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.

3 files changed, 23 insertions, 3 deletions

diff --git a/activerecord/lib/active_record/association_relation.rb b/activerecord/lib/active_record/association_relation.rb
index 403667fb70..4c538ef2bd 100644
--- a/activerecord/lib/active_record/association_relation.rb
+++ b/activerecord/lib/active_record/association_relation.rb
@@ -31,9 +31,9 @@ module ActiveRecord
     private
 
       def exec_queries
-        super do |r|
-          @association.set_inverse_instance r
-          yield r if block_given?
+        super do |record|
+          @association.set_inverse_instance_from_queries(record)
+          yield record if block_given?
         end
       end
   end
diff --git a/activerecord/lib/active_record/associations/association.rb b/activerecord/lib/active_record/associations/association.rb
index 44596f4424..e4433356e2 100644
--- a/activerecord/lib/active_record/associations/association.rb
+++ b/activerecord/lib/active_record/associations/association.rb
@@ -103,6 +103,13 @@ module ActiveRecord
         record
       end
 
+      def set_inverse_instance_from_queries(record)
+        if inverse = inverse_association_for(record)
+          inverse.inversed_from_queries(owner)
+        end
+        record
+      end
+
       # Remove the inverse association, if possible
       def remove_inverse_instance(record)
         if inverse = inverse_association_for(record)
@@ -114,6 +121,7 @@ module ActiveRecord
         self.target = record
         @inversed = !!record
       end
+      alias :inversed_from_queries :inversed_from
 
       # Returns the class of the target. belongs_to polymorphic overrides this to look at the
       # polymorphic_type field on the owner.
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