When not overwriting unsaved updates in nested attributes, allow already-saved...

When not overwriting unsaved updates in nested attributes, allow already-saved records to be refreshed.
Signed-off-by: NJosé Valim <jose.valim@gmail.com>

activerecord/lib/active_record/associations/association_collection.rb

@@ -349,7 +349,11 @@ def load_target
             begin
               if !loaded?
                 if @target.is_a?(Array) && @target.any?
-                  @target = find_target.map { |f| i = @target.index(f); i ? @target.delete_at(i) : f } + @target
+                  @target = find_target.map do |f|
+                    i = @target.index(f)
+                    t = @target.delete_at(i) if i
+                    (t && t.changed?) ? t : f
+                  end + @target
                 else
                   @target = find_target
                 end

activerecord/test/cases/nested_attributes_test.rb

@@ -468,15 +468,22 @@ def test_should_not_load_association_when_updating_existing_records
   def test_should_not_overwrite_unsaved_updates_when_loading_association
     @pirate.reload
     @pirate.send(association_setter, [{ :id => @child_1.id, :name => 'Grace OMalley' }])
-    @pirate.send(@association_name).send(:load_target)
-    assert_equal 'Grace OMalley', @pirate.send(@association_name).target.find { |r| r.id == @child_1.id }.name
+    assert_equal 'Grace OMalley', @pirate.send(@association_name).send(:load_target).find { |r| r.id == @child_1.id }.name
   end
 
   def test_should_preserve_order_when_not_overwriting_unsaved_updates
     @pirate.reload
     @pirate.send(association_setter, [{ :id => @child_1.id, :name => 'Grace OMalley' }])
-    @pirate.send(@association_name).send(:load_target)
-    assert_equal @pirate.send(@association_name).target.first.id, @child_1.id
+    assert_equal @child_1.id, @pirate.send(@association_name).send(:load_target).first.id
+  end
+
+  def test_should_refresh_saved_records_when_not_overwriting_unsaved_updates
+    @pirate.reload
+    record = @pirate.class.reflect_on_association(@association_name).klass.new(:name => 'Grace OMalley')
+    @pirate.send(@association_name) << record
+    record.save!
+    @pirate.send(@association_name).last.update_attributes!(:name => 'Polly')
+    assert_equal 'Polly', @pirate.send(@association_name).send(:load_target).last.name
   end
 
   def test_should_take_a_hash_with_composite_id_keys_and_assign_the_attributes_to_the_associated_models