ConfigurationConverter does not handle CompositeConfiguration correctly

ConfigurationConverter doesn't seem to respect the ordering of a composite configuration. I am having problems describing the behavior, but I thinks the following test case illustrates it best:

@Test
public void showBug() {
PropertiesConfiguration p = new PropertiesConfiguration();
p.addProperty("foo", "initial");
p.addProperty("bar", "${foo}");
p.addProperty("prefix.foo", "override");

CompositeConfiguration cfg = new CompositeConfiguration();
cfg.addConfiguration(p.subset("prefix"));
cfg.addConfiguration(p);

// this assertion passes as expected since the subset
// was added first to the composite configuration
Assert.assertEquals("override", cfg.getString("bar"));

// after converting to properties, this assertion fails and
// reports that the value is 'initial'
Properties properties = ConfigurationConverter.getProperties(cfg);
Assert.assertEquals("override", properties.getProperty("bar"));
}