Merge pull request #5334 from courtland/master

Fix deleting from a HABTM join table upon destroying an object of a model with optimistic locking enabled.

activerecord/lib/active_record/locking/optimistic.rb

@@ -104,6 +104,8 @@ def update(attribute_names = @attributes.keys) #:nodoc:
         def destroy #:nodoc:
           return super unless locking_enabled?
 
+          destroy_associations
+
           if persisted?
             table = self.class.arel_table
             lock_col = self.class.locking_column

activerecord/test/cases/locking_test.rb

@@ -22,7 +22,7 @@ class ReadonlyFirstNamePerson < Person
 end
 
 class OptimisticLockingTest < ActiveRecord::TestCase
-  fixtures :people, :legacy_things, :references, :string_key_objects
+  fixtures :people, :legacy_things, :references, :string_key_objects, :peoples_treasures
 
   def test_non_integer_lock_existing
     s1 = StringKeyObject.find("record1")
@@ -239,6 +239,16 @@ def test_polymorphic_destroy_with_dependencies_and_lock_version
     end
     assert car.destroyed?
   end
+
+  def test_removing_has_and_belongs_to_many_associations_upon_destroy
+    p = RichPerson.create!
+    p.treasures.create!
+    assert !p.treasures.empty?
+    p.destroy
+    assert p.treasures.empty?
+    assert RichPerson.connection.select_all("SELECT * FROM peoples_treasures WHERE rich_person_id = 1").empty?
+  end
+
 end
 
 class OptimisticLockingWithSchemaChangeTest < ActiveRecord::TestCase

activerecord/test/fixtures/peoples_treasures.yml

@@ -0,0 +1,3 @@
+michael_diamond:
+  rich_person_id: <%= ActiveRecord::Fixtures.identify(:michael) %>
+  treasure_id: <%= ActiveRecord::Fixtures.identify(:diamond) %>

activerecord/test/models/person.rb

@@ -85,3 +85,9 @@ class TightPerson < ActiveRecord::Base
 end
 
 class TightDescendant < TightPerson; end
+
+class RichPerson < ActiveRecord::Base
+  self.table_name = 'people'
+
+  has_and_belongs_to_many :treasures, :join_table => 'peoples_treasures'
+end

activerecord/test/schema/schema.rb

@@ -469,6 +469,11 @@ def create_table(*args, &block)
     t.references :best_friend_of
     t.timestamps
   end
+
+  create_table :peoples_treasures, :id => false, :force => true do |t|
+    t.column :rich_person_id, :integer
+    t.column :treasure_id, :integer
+  end
 
   create_table :pets, :primary_key => :pet_id ,:force => true do |t|
     t.string :name