#4 Cannot edit cascading protected page

[liangent]

def can(self, action):
level = self.protection.get(action, (action, ))[0]
if level == 'sysop': level = compatibility.protectright(self.site.version)

return level in self.site.rights

This piece of code has some bug. Even if I'm sysop it says I cannot edit a cascading protected page.