Erronious error: "no contextual parsing on unlinked nodes" for top-level node

[bananastalktome]

Issue when parsing top-level node in document fragments with nokogiri 1.4.2:
(gist at http://gist.github.com/413419)

$ irb 
>> a = "<br><p>Hey</p>"
=> "<br><p>Hey</p>"
>> b = Nokogiri::HTML.fragment a
=> #<Nokogiri::HTML::DocumentFragment:0x455e318 name="#document-fragment" children=[#<Nokogiri::XML::Element:0x455e14a name="br">, #<Nokogiri::XML::Element:0x455e12e name="p" children=[#<Nokogiri::XML::Text:0x455dba8 "Hey">]>]>
>> b.inner_html
=> "<br><p>Hey</p>"
>> b.inner_html = ""
RuntimeError: no contextual parsing on unlinked nodes
        from /local/lib/ruby/gems/1.9.1/gems/nokogiri-1.4.2/lib/nokogiri/xml/node.rb:443:in `in_context'
        from /local/lib/ruby/gems/1.9.1/gems/nokogiri-1.4.2/lib/nokogiri/xml/node.rb:443:in `parse'
        from /local/lib/ruby/gems/1.9.1/gems/nokogiri-1.4.2/lib/nokogiri/html/document_fragment.rb:16:in `initialize'
        from /local/lib/ruby/gems/1.9.1/gems/nokogiri-1.4.2/lib/nokogiri/xml/node.rb:424:in `new'
        from /local/lib/ruby/gems/1.9.1/gems/nokogiri-1.4.2/lib/nokogiri/xml/node.rb:424:in `fragment'
        from /local/lib/ruby/gems/1.9.1/gems/nokogiri-1.4.2/lib/nokogiri/xml/node.rb:776:in `coerce'
        from /local/lib/ruby/gems/1.9.1/gems/nokogiri-1.4.2/lib/nokogiri/xml/node.rb:313:in `inner_html='
        from (irb):6
        from /local/bin/irb:12:in `<main>'

[tenderlove]

This should be fixed here: 67a41b5

Thanks for reporting the error!