Mechanize problem with proxies

[Dani Pardo]

Hi, I'm using Mechanize-0.8.4 to pass some traffic through a custom
proxy. This proxy requires basic authentication.
If I request www.google.com, I will get redirected to google.co.uk or
whatever. The problem is that if the request is https, and if the
proxy server sends a redirect (302) to the client, mechanize will
fail:

c:/ruby/lib/ruby/1.8/net/http.rb:2106:in `error!': 302 "Moved
Temporarily" (Net::HTTPRetriableError)
from c:/ruby/lib/ruby/1.8/net/http.rb:2115:in `value'
from c:/ruby/lib/ruby/1.8/net/http.rb:588:in `connect'
from c:/ruby/lib/ruby/1.8/net/http.rb:557:in `do_start'
from c:/ruby/lib/ruby/1.8/net/http.rb:552:in `start'
from c:/ruby/lib/ruby/gems/1.8/gems/mechanize-0.8.4/lib/www/mechanize.rb:450:in
`fetch_page'
from c:/ruby/lib/ruby/gems/1.8/gems/mechanize-0.8.4/lib/www/mechanize.rb:221:in
`get'

Instead of giving this error, I would expect mechanize to follow the
redirect, as it normally does without using a proxy.

Any hint appreciated, thanks!