really_destroy! and has_one associations

lib/paranoia.rb

@@ -154,10 +154,14 @@ class ActiveRecord::Base
       if dependent_reflections.any?
         dependent_reflections.each do |name, _|
           associated_records = self.send(name)
-          # Paranoid models will have this method, non-paranoid models will not
-          associated_records = associated_records.with_deleted if associated_records.respond_to?(:with_deleted)
-          associated_records.each(&:really_destroy!)
-          self.send(name).reload
+          # has_one association can return nil
+          if associated_records && associated_records.respond_to?(:with_deleted)
+            # Paranoid models will have this method, non-paranoid models will not
+            associated_records.with_deleted.each(&:really_destroy!)
+            self.send(name).reload
+          elsif associated_records && !associated_records.respond_to?(:each) # single record
+            associated_records.really_destroy!
+          end
         end
       end
       touch_paranoia_column if ActiveRecord::VERSION::STRING >= "4.1"

test/paranoia_test.rb

@@ -435,6 +435,21 @@ class ParanoiaTest < test_framework
     
     assert hasOne.reload.deleted_at.nil?
   end
+  
+  # covers #131
+  def test_has_one_really_destroy_with_nil
+    model = ParanoidModelWithHasOne.create
+    model.really_destroy!
+    
+    refute ParanoidModelWithBelong.unscoped.exists?(model.id)
+  end
+  
+  def test_has_one_really_destroy_with_record
+    model = ParanoidModelWithHasOne.create { |record| record.build_paranoid_model_with_belong }
+    model.really_destroy!
+    
+    refute ParanoidModelWithBelong.unscoped.exists?(model.id)
+  end
 
   def test_observers_notified
     a = ParanoidModelWithObservers.create