Hello,

I have a problem with Nokogiri::HTML::Element#line, it always returns
zero(0):

html = Nokogiri::HTML(<<eohtml)
<html>
  <head>
    <title>test test</title>
  </head>
  <body>
    Hello, world!
  </body>
</html>
eohtml

html.xpath("/html/head/title")[0].line # 0
html.xpath("/html/body")[0].line # 0

if I replace Nokogiri::HTML with Nokogiri::XML, all going to be
perfect.

Nokogiri::HTML::Element extends Nokogiri::XML::Node, so, #line should
return the line of the HTML node, isn't it?