when you are trying to create a folder user.foo&-bar and you are an admin the server dump core !
having track this down it seems that in function "is_an_imap_admin", in this case the "auth_newstate" return a NULL which we are trying to free at the end in "auth_freestate" !!! may be it's normal we can't create such a folder but I think it's a bug we deny this by coredumping !!! cheers valery
