4 files changed, 58 insertions, 0 deletions
diff --git a/activerecord/test/cases/autosave_association_test.rb b/activerecord/test/cases/autosave_association_test.rb
index 676b29ed7c..6b69b96e21 100644
--- a/activerecord/test/cases/autosave_association_test.rb
+++ b/activerecord/test/cases/autosave_association_test.rb
@@ -67,6 +67,14 @@ class TestAutosaveAssociationsInGeneral < ActiveRecord::TestCase
     assert_no_difference_when_adding_callbacks_twice_for Pirate, :parrots
   end
 
+  def test_cyclic_autosaves_do_not_add_multiple_validations
+    ship = ShipWithoutNestedAttributes.new
+    ship.prisoners.build
+
+    assert_not ship.valid?
+    assert_equal 1, ship.errors[:name].length
+  end
+
   private
 
   def assert_no_difference_when_adding_callbacks_twice_for(model, association_name)
diff --git a/activerecord/test/cases/nested_attributes_test.rb b/activerecord/test/cases/nested_attributes_test.rb
index d72225f3d3..b8a0401fe3 100644
--- a/activerecord/test/cases/nested_attributes_test.rb
+++ b/activerecord/test/cases/nested_attributes_test.rb
@@ -1064,4 +1064,39 @@ class TestHasManyAutosaveAssociationWhichItselfHasAutosaveAssociations < ActiveR
     assert_not part.valid?
     assert_equal ["Ship name can't be blank"], part.errors.full_messages
   end
+
+  class ProtectedParameters
+    def initialize(hash)
+      @hash = hash
+    end
+
+    def permitted?
+      true
+    end
+
+    def [](key)
+      @hash[key]
+    end
+
+    def to_h
+      @hash
+    end
+  end
+
+  test "strong params style objects can be assigned for singular associations" do
+    params = { name: "Stern", ship_attributes:
+               ProtectedParameters.new(name: "The Black Rock") }
+    part = ShipPart.new(params)
+
+    assert_equal "Stern", part.name
+    assert_equal "The Black Rock", part.ship.name
+  end
+
+  test "strong params style objects can be assigned for collection associations" do
+    params = { trinkets_attributes: ProtectedParameters.new("0" => ProtectedParameters.new(name: "Necklace"), "1" => ProtectedParameters.new(name: "Spoon")) }
+    part = ShipPart.new(params)
+
+    assert_equal "Necklace", part.trinkets[0].name
+    assert_equal "Spoon", part.trinkets[1].name
+  end
 end
diff --git a/activerecord/test/models/ship.rb b/activerecord/test/models/ship.rb
index 312caef604..fcc533380b 100644
--- a/activerecord/test/models/ship.rb
+++ b/activerecord/test/models/ship.rb
@@ -19,6 +19,17 @@ class Ship < ActiveRecord::Base
   end
 end
 
+class ShipWithoutNestedAttributes < ActiveRecord::Base
+  self.table_name = "ships"
+  has_many :prisoners, inverse_of: :ship, foreign_key: :ship_id
+
+  validates :name, presence: true
+end
+
+class Prisoner < ActiveRecord::Base
+  belongs_to :ship, autosave: true, class_name: "ShipWithoutNestedAttributes", inverse_of: :prisoners
+end
+
 class FamousShip < ActiveRecord::Base
   self.table_name = 'ships'
   belongs_to :famous_pirate
diff --git a/activerecord/test/schema/schema.rb b/activerecord/test/schema/schema.rb
index 6872b49ad9..2fc806f181 100644
--- a/activerecord/test/schema/schema.rb
+++ b/activerecord/test/schema/schema.rb
@@ -678,6 +678,10 @@ ActiveRecord::Schema.define do
     t.datetime :updated_at
   end
 
+  create_table :prisoners, force: true do |t|
+    t.belongs_to :ship
+  end
+
   create_table :speedometers, force: true, id: false do |t|
     t.string :speedometer_id
     t.string :name