c# - Code formatting with XHtmlTextWriter and Control instance

Question

XHtmlTextWriter takes second parameter tabString. I set it to HtmlTextWriter.DefaultTabString

When we use xhtmlTextWriter.WriteLine(), it indents the code.

But if we use control.RenderControl(xhtmlTextWriter), it performs only one indentation for the root element.

public string Rendering(Control baseControl)
{

    using (StringWriter stringWriter = new StringWriter())
    using (XhtmlTextWriter htmlWriter = new XhtmlTextWriter(stringWriter,
                                                     HtmlTextWriter.DefaultTabString))
    {
        baseControl.RenderControl(htmlWriter);

        return stringWriter.ToString();
    }
}

It seems like Control.RenderControl() is recursively aggregating child nodes in a temporary string and then with a single WriteLine(), its writing to XHtmlTextWriter.

Ideally, its suppose to call WriteLine() for each node, to respect HtmlTextWriter's second parameter.

Due to this glitch, after rendering (un-indented) markup to string, I need to pass the string to XPathDocument, and create XPathNavigator then convert back to string, which does the desired formatting.

public string Rendering(Control baseControl)
{
    using (StringWriter stringWriter = new StringWriter())
    using (XhtmlTextWriter htmlWriter = new XhtmlTextWriter(stringWriter,
                                                     HtmlTextWriter.DefaultTabString))
    {
        baseControl.RenderControl(htmlWriter);

        return UnwantedFormatting(stringWriter.ToString());
    }
}

private string UnwantedFormatting(string markup)
{
    StringReader sr = new StringReader(markup);
    XPathDocument doc;
    using (XmlReader xr = XmlReader.Create(sr,
                       new XmlReaderSettings()
                       {
                           ConformanceLevel = ConformanceLevel.Fragment
                           // for multiple roots
                        }))
    {
        doc = new XPathDocument(xr);
    }

    return doc.CreateNavigator().InnerXml.ToString();
}

Is there a better way to render control to string with indentation without this undesired extra formatting step?