System.Xml.XPath.XPathNavigator.CompareSiblings C# (CSharp) Method

        private XmlNodeOrder CompareSiblings(XPathNavigator n1, XPathNavigator n2)
        {
            int cmp = 0;

#if DEBUG
            Debug.Assert(!n1.IsSamePosition(n2));
            XPathNavigator p1 = n1.Clone(), p2 = n2.Clone();
            Debug.Assert(p1.MoveToParent() && p2.MoveToParent() && p1.IsSamePosition(p2));
#endif
            switch (n1.NodeType)
            {
                case XPathNodeType.Namespace:
                    break;
                case XPathNodeType.Attribute:
                    cmp += 1;
                    break;
                default:
                    cmp += 2;
                    break;
            }
            switch (n2.NodeType)
            {
                case XPathNodeType.Namespace:
                    if (cmp == 0)
                    {
                        while (n1.MoveToNextNamespace())
                        {
                            if (n1.IsSamePosition(n2))
                            {
                                return XmlNodeOrder.Before;
                            }
                        }
                    }
                    break;
                case XPathNodeType.Attribute:
                    cmp -= 1;
                    if (cmp == 0)
                    {
                        while (n1.MoveToNextAttribute())
                        {
                            if (n1.IsSamePosition(n2))
                            {
                                return XmlNodeOrder.Before;
                            }
                        }
                    }
                    break;
                default:
                    cmp -= 2;
                    if (cmp == 0)
                    {
                        while (n1.MoveToNext())
                        {
                            if (n1.IsSamePosition(n2))
                            {
                                return XmlNodeOrder.Before;
                            }
                        }
                    }
                    break;
            }
            return cmp < 0 ? XmlNodeOrder.Before : XmlNodeOrder.After;
        }