Although the 'algorithm' component of the Authorization header is 
considered optional by RFC 2617, there are sites that do not 
function without providing algorithm notification.  Specifically, this 
problem is encounted with LiveJournal RSS feeds (where HTTP 
digest authentication can be used to view non-public livejournal 
entries).

This patch makes the algorithm flag always sent in the 
Authorization header.  The following test script demonstrates the 
problem for a LiveJournal RSS feed (username and password must 
be entered):

    import urllib2

    class PasswordMgr(object):
        def find_user_password(self, realm, authuri):
            return "someuser", "somepass"
        def add_password(self):
            pass

    rssURI = "http://livejournal.com/users/someuser/data/rss?
auth=digest"

    handler = urllib2.HTTPDigestAuthHandler(PasswordMgr())
    opener = urllib2.build_opener(handler)
    opener.open(rssURI)

With the attached patch, this works successfully.  Without it, it fails 
with an HTTP 401 error.