// XXX: Relies on RUNE_xxx == BRANCH_xxx. See rune_type in enum.h.
static bool player_has_rune(branch_type branch)
{
    for (int i = 0; i < ENDOFPACK; i++)
        if (is_valid_item( you.inv[i] )
            && you.inv[i].base_type == OBJ_MISCELLANY
            && you.inv[i].sub_type == MISC_RUNE_OF_ZOT
            && you.inv[i].plus == branch)
        {
            return (true);
        }
    return (false);
}

            // The tomb is a laid out maze, it'd be a shame if the player
            // just teleports through any of it... so we only allow 
            // teleport once they have the rune.
            ret = false;
            for (int i = 0; i < ENDOFPACK; i++)
            {
                if (is_valid_item( you.inv[i] )
                    && you.inv[i].base_type == OBJ_MISCELLANY
                    && you.inv[i].sub_type == MISC_RUNE_OF_ZOT
                    && you.inv[i].plus == BRANCH_TOMB)
                {
                    ret = true;
                    break;
                }
            }

            ret = player_has_rune(you.where_are_you);

        case BRANCH_COCYTUS:
        case BRANCH_DIS:
        case BRANCH_TARTARUS:
        case BRANCH_GEHENNA:
            if (player_branch_depth() == branches[you.where_are_you].depth)
                ret = player_has_rune(you.where_are_you);
            break;