Re: void variable

[Richard Stallman]

       The manual should direct people to autoload variables used by
       autoloaded functions, if programs might want to bind them.

    It is not just the variables _used_ by the autoloaded function.  In
    the concrete bug, `dired-rename-file' does not use
    `dired-backup-overwrite', at least not directly.

Point noted.  However, it surely uses that variable indirectly, or
people would not have written code to bind that variable around that
call.