'Fix href attributes for genindex pages.'

def fix_genindex(self, tree):

    for (key, columns) in tree:
        for (entryname, (links, subitems, key_)) in columns:
            for (i, (ismain, link)) in enumerate(links):
                m = self.refuri_re.match(link)
                if m:
                    links[i] = (ismain, self.fix_fragment(m.group(1), m.group(2)))
            for (subentryname, subentrylinks) in subitems:
                for (i, (ismain, link)) in enumerate(subentrylinks):
                    m = self.refuri_re.match(link)
                    if m:
                        subentrylinks[i] = (ismain, self.fix_fragment(m.group(1), m.group(2)))
