Correctly ignore `mark_for_destruction` without `autosave`

As per the docs, `mark_for_destruction` should do nothing if `autosave`
is not set to true. We normally persist associations on a record no
matter what if the record is a new record, but we were always skipping
records which were `marked_for_destruction?`.

Fixes #20882

1 files changed, 7 insertions, 0 deletions

diff --git a/activerecord/test/cases/autosave_association_test.rb b/activerecord/test/cases/autosave_association_test.rb
index 6b69b96e21..37ec3f1106 100644
--- a/activerecord/test/cases/autosave_association_test.rb
+++ b/activerecord/test/cases/autosave_association_test.rb
@@ -1154,6 +1154,13 @@ class TestAutosaveAssociationOnAHasOneAssociation < ActiveRecord::TestCase
   def test_should_not_load_the_associated_model
     assert_queries(1) { @pirate.catchphrase = 'Arr'; @pirate.save! }
   end
+
+  def test_mark_for_destruction_is_ignored_without_autosave_true
+    ship = ShipWithoutNestedAttributes.new(name: "The Black Flag")
+    ship.parts.build.mark_for_destruction
+
+    assert_not ship.valid?
+  end
 end
 
 class TestAutosaveAssociationOnAHasOneThroughAssociation < ActiveRecord::TestCase