crash when fetch url with invalid html

[ntop001]

eg: http://www.slideshare.net/hmason/strata-ny-sep-2011-big-data-short-urls-learning-in-realtime or http://cn.engadget.com/2011/10/08/thinkpad-tablet-china-preorder-price/

node readability use the jsdom to get a dom tree, but when processing invalid html, jsom crash , and readability followed.