Html wrongly encoded fetched by Nokogiri - ruby

Question

I use Nokogiri to parse an html. I need both the content and image tags in the page, so I use inner_html instead of content method. But the value returned by content is encoded correct, while wrongly encoded by inner_html. One note, the page is in Chinese and not use UTF-8 encoding.
Here is my code:
# encoding: utf-8
require 'rubygems'
require 'nokogiri'
require 'open-uri'
require 'iconv'
doc = Nokogiri::HTML.parse(open("http://www.sfzt.org/advise/view.asp?id=536"), nil, 'gb18030')
doc.css('td.font_info').each do |link|
# output, correct but not i expect: 目前市面上影响比
puts link.content
# output, wrong and not i expect: <img ....></img>Ŀǰ??????Ӱ??Ƚϴ?Ľ????
# I expect: <img ....></img>目前市面上影响比
puts link.inner_html
end

Answer 1

That is written on the 'Encoding' section on README: http://nokogiri.org/
Strings are always stored as UTF-8 internally. Methods that return
text values will always return UTF-8 encoded strings. Methods that
return XML (like to_xml, to_html and inner_html) will return a string
encoded like the source document.
So, you should convert inner_html string manually if you want to get it as UTF-8 string:
puts link.inner_html.encode('utf-8') # for 1.9.x

Answer 2

I think content strips out tags well, however the inner_html method nodes does not do this very well or at all.
"I think you can end up with some pretty weird states if you change the inner_html (which contain tags) while you are traversing. In other words, if you are traversing a node tree, you shouldn’t do anything that could add or remove nodes."
Try this:
doc.css('td.font_info').each do |link|
puts link.content
some_stuff = link.inner_html
link.children = Nokogiri::HTML.fragment(some_stuff, 'utf-8')
end