Re: [elpa] externals-release/org e2366ac283: * lisp/org-persist.el: Do not litter /tmp when native compiling

[Stefan Monnier <monnier@iro.umontreal.ca>]

> +(when (and org-persist--disable-when-emacs-Q
> +           ;; FIXME: This is relying on undocumented fact that
> +           ;; Emacs sets `user-init-file' to nil when loaded with
> +           ;; "-Q" argument.
> +           (not user-init-file))
> +  (setq org-persist-directory
> +        (make-temp-file "org-persist-" 'dir))
> +  ;; We don't need the temp directory to exist.
> +  ;; `org-persist-write-all' will refrain from creating and writing to the dir if
> +  ;; none exists yet.
> +  (delete-directory org-persist-directory))

Could we skip the "create dir" so we can skip the `delete-directory`
part as well?

Also, this smells like a security hole: after `delete-directory`, with
the /tmp setup as mode #o1777, some other user can come and create
a directory at that location, so that our `org-persist-directory` will
then point to their directory (where they may be able to read the
things we write) or they can replace it with a link to a directory of
our own tricking us into overwriting some of our own files.

IOW, I suggest we use something like

    (setq org-persist-directory "/non-existing")
or
    (setq org-persist-directory (make-temp-name "/non-existing"))

[ Not sure if there is a standard such name that's "guaranteed" not to
  exist.  ]


        Stefan