2 files changed, 25 insertions, 0 deletions
diff --git a/activerecord/test/cases/autosave_association_test.rb b/activerecord/test/cases/autosave_association_test.rb
index fa618735d7..db3a58eba9 100644
--- a/activerecord/test/cases/autosave_association_test.rb
+++ b/activerecord/test/cases/autosave_association_test.rb
@@ -14,6 +14,7 @@ require "models/line_item"
 require "models/order"
 require "models/parrot"
 require "models/pirate"
+require "models/project"
 require "models/ship"
 require "models/ship_part"
 require "models/tag"
@@ -1787,3 +1788,21 @@ class TestAutosaveAssociationOnAHasManyAssociationWithInverse < ActiveRecord::Te
     assert_equal 1, comment.post_comments_count
   end
 end
+
+class TestAutosaveAssociationOnAHasManyAssociationDefinedInSubclassWithAcceptsNestedAttributes < ActiveRecord::TestCase
+  def test_should_update_children_when_asssociation_redefined_in_subclass
+    agency = Agency.create!(name: "Agency")
+    valid_project = Project.create!(firm: agency, name: "Initial")
+    agency.update!(
+      "projects_attributes" => {
+        "0" => {
+          "name" => "Updated",
+          "id" => valid_project.id
+        }
+      }
+    )
+    valid_project.reload
+
+    assert_equal "Updated", valid_project.name
+  end
+end
diff --git a/activerecord/test/models/company.rb b/activerecord/test/models/company.rb
index 485b35d58b..838f515aad 100644
--- a/activerecord/test/models/company.rb
+++ b/activerecord/test/models/company.rb
@@ -122,6 +122,12 @@ class RestrictedWithErrorFirm < Company
   has_many :companies, -> { order("id") }, foreign_key: "client_of", dependent: :restrict_with_error
 end
 
+class Agency < Firm
+  has_many :projects, foreign_key: :firm_id
+
+  accepts_nested_attributes_for :projects
+end
+
 class Client < Company
   belongs_to :firm, foreign_key: "client_of"
   belongs_to :firm_with_basic_id, class_name: "Firm", foreign_key: "firm_id"