queries with spaces in :contains argument return incorrect results

[hagabaka]

When a query uses :contains(text), and the text contains a space, the result is incorrect. For example:

require 'open-uri'
page = open('http://code.whytheluckystiff.net/hpricot/') {|f| Hpricot(f)}
(page / 'h2:contains(Tougher)').length
#=> 1 (correct)
(page / 'h2:contains(The Tougher)').length
#=> 12 (incorrect)
(page / 'h2').length 
#=> 6 (notice the previous result is more than the total number of h2's)