7 files changed, 14 insertions, 5 deletions
diff --git a/activerecord/test/cases/associations/has_one_associations_test.rb b/activerecord/test/cases/associations/has_one_associations_test.rb
index 5a8afaf4d2..d46e7ad235 100644
--- a/activerecord/test/cases/associations/has_one_associations_test.rb
+++ b/activerecord/test/cases/associations/has_one_associations_test.rb
@@ -107,6 +107,14 @@ class HasOneAssociationsTest < ActiveRecord::TestCase
     assert_nil Account.find(old_account_id).firm_id
   end
 
+  def test_nullification_on_destroyed_association
+    developer = Developer.create!(name: "Someone")
+    ship = Ship.create!(name: "Planet Caravan", developer: developer)
+    ship.destroy
+    assert !ship.persisted?
+    assert !developer.persisted?
+  end
+
   def test_natural_assignment_to_nil_after_destroy
     firm = companies(:rails_core)
     old_account_id = firm.account.id
diff --git a/activerecord/test/cases/migration_test.rb b/activerecord/test/cases/migration_test.rb
index 782a7906cc..128a242495 100644
--- a/activerecord/test/cases/migration_test.rb
+++ b/activerecord/test/cases/migration_test.rb
@@ -132,13 +132,9 @@ class MigrationTest < ActiveRecord::TestCase
     Person.connection.drop_table :testings2, if_exists: true
   end
 
-  def connection
-    ActiveRecord::Base.connection
-  end
-
   def test_migration_instance_has_connection
     migration = Class.new(ActiveRecord::Migration).new
-    assert_equal connection, migration.connection
+    assert_equal ActiveRecord::Base.connection, migration.connection
   end
 
   def test_method_missing_delegates_to_connection
diff --git a/activerecord/test/cases/persistence_test.rb b/activerecord/test/cases/persistence_test.rb
index 42e7507631..cdf63957f4 100644
--- a/activerecord/test/cases/persistence_test.rb
+++ b/activerecord/test/cases/persistence_test.rb
@@ -17,6 +17,7 @@ require 'models/minivan'
 require 'models/owner'
 require 'models/person'
 require 'models/pet'
+require 'models/ship'
 require 'models/toy'
 require 'rexml/document'
 
diff --git a/activerecord/test/cases/readonly_test.rb b/activerecord/test/cases/readonly_test.rb
index 1c919f0b57..5f6eb41240 100644
--- a/activerecord/test/cases/readonly_test.rb
+++ b/activerecord/test/cases/readonly_test.rb
@@ -7,6 +7,7 @@ require 'models/computer'
 require 'models/project'
 require 'models/reader'
 require 'models/person'
+require 'models/ship'
 
 class ReadOnlyTest < ActiveRecord::TestCase
   fixtures :authors, :posts, :comments, :developers, :projects, :developers_projects, :people, :readers
diff --git a/activerecord/test/models/developer.rb b/activerecord/test/models/developer.rb
index d2a5a7fc49..8ac7a9df6a 100644
--- a/activerecord/test/models/developer.rb
+++ b/activerecord/test/models/developer.rb
@@ -50,6 +50,7 @@ class Developer < ActiveRecord::Base
   has_many :firms, :through => :contracts, :source => :firm
   has_many :comments, ->(developer) { where(body: "I'm #{developer.name}") }
   has_many :ratings, through: :comments
+  has_one :ship, dependent: :nullify
 
   scope :jamises, -> { where(:name => 'Jamis') }
 
diff --git a/activerecord/test/models/ship.rb b/activerecord/test/models/ship.rb
index 95172e4d3e..e333b964ab 100644
--- a/activerecord/test/models/ship.rb
+++ b/activerecord/test/models/ship.rb
@@ -3,6 +3,7 @@ class Ship < ActiveRecord::Base
 
   belongs_to :pirate
   belongs_to :update_only_pirate, :class_name => 'Pirate'
+  belongs_to :developer, dependent: :destroy
   has_many :parts, :class_name => 'ShipPart'
   has_many :treasures
 
diff --git a/activerecord/test/schema/schema.rb b/activerecord/test/schema/schema.rb
index 6f34115534..994ece9244 100644
--- a/activerecord/test/schema/schema.rb
+++ b/activerecord/test/schema/schema.rb
@@ -673,6 +673,7 @@ ActiveRecord::Schema.define do
   create_table :ships, force: true do |t|
     t.string :name
     t.integer :pirate_id
+    t.belongs_to :developer
     t.integer :update_only_pirate_id
     # Conventionally named column for counter_cache
     t.integer :treasures_count, default: 0