Destroying records via nested attributes works independent of reject_if:

- When a :_destroy truthiness is provided in the attributes hash, the
  record should get destroyed regardless of the result of the proc or
    method supplied to :reject_if. (If :allow_destroy is true)

[#6006 state:committed]
Signed-off-by: NSantiago Pastorino <santiago@wyeworks.com>

activerecord/lib/active_record/nested_attributes.rb

@@ -452,6 +452,7 @@ def reject_new_record?(association_name, attributes)
     end
 
     def call_reject_if(association_name, attributes)
+      return false if has_destroy_flag?(attributes)
       case callback = self.nested_attributes_options[association_name][:reject_if]
       when Symbol
         method(callback).arity == 0 ? send(callback) : send(callback, attributes)

activerecord/test/cases/nested_attributes_test.rb

@@ -131,6 +131,14 @@ def test_reject_if_with_a_proc_which_returns_true_always_for_has_many
     assert_equal 'photography', interest.reload.topic
   end
 
+  def test_destroy_works_independent_of_reject_if
+    Man.accepts_nested_attributes_for :interests, :reject_if => proc {|attributes| true }, :allow_destroy => true
+    man = Man.create(:name => "Jon")
+    interest = man.interests.create(:topic => 'the ladies')
+    man.update_attributes({:interests_attributes => { :_destroy => "1", :id => interest.id } })
+    assert man.reload.interests.empty?
+  end
+
   def test_has_many_association_updating_a_single_record
     Man.accepts_nested_attributes_for(:interests)
     man = Man.create(:name => 'John')