1 files changed, 17 insertions, 0 deletions
diff --git a/activerecord/test/cases/nested_attributes_test.rb b/activerecord/test/cases/nested_attributes_test.rb
index 8bc42b8890..198cd6f341 100644
--- a/activerecord/test/cases/nested_attributes_test.rb
+++ b/activerecord/test/cases/nested_attributes_test.rb
@@ -1037,4 +1037,21 @@ class TestHasManyAutosaveAssociationWhichItselfHasAutosaveAssociations < ActiveR
     ShipPart.create!(:ship => @ship, :name => "Stern")
     assert_no_queries { @ship.valid? }
   end
+
+  test "circular references do not perform unnecessary queries" do
+    ship = Ship.new(name: "The Black Rock")
+    part = ship.parts.build(name: "Stern")
+    ship.treasures.build(looter: part)
+
+    assert_queries 3 do
+      ship.save!
+    end
+  end
+
+  test "nested singular associations are validated" do
+    part = ShipPart.new(name: "Stern", ship_attributes: { name: nil })
+
+    assert_not part.valid?
+    assert_equal ["Ship name can't be blank"], part.errors.full_messages
+  end
 end