Re: Protect Org export from auto-formatting hooks

[Nicolas Goaziou <mail@nicolasgoaziou.fr>]

Hello,

David Lukeš <dafydd.lukes@gmail.com> writes:

> So I think Org should try to protect the export buffer from these
> shenanigans as much as possible. The best way I can think of to achieve
> that is to keep the export buffer in fundamental mode. This should
> prevent all the mode-related code from running, potentially even making
> the export speedier.
>
> After some experimenting, the way I finally got this to work was by
> locally overriding the `set-auto-mode’ function:
>
> ┌────
> │ diff --git a/lisp/ox.el b/lisp/ox.el
> │ index 2a3edaa50..d5a77c26e 100644
> │ --- a/lisp/ox.el
> │ +++ b/lisp/ox.el
> │ @@ -6462,14 +6462,16 @@ or FILE."
> │       ',ext-plist)))
> │         (with-temp-buffer
> │   (insert output)
> │ - (let ((coding-system-for-write ',encoding))
> │ + (cl-letf ((coding-system-for-write ',encoding)
> │ +   ((symbol-function 'set-auto-mode) #'ignore))
> │     (write-file ,file)))
> │         (or (ignore-errors (funcall ',post-process ,file)) ,file)))
> │          (let ((output (org-export-as
> │                         backend subtreep visible-only body-only
> ext-plist)))
> │            (with-temp-buffer
> │              (insert output)
> │ -            (let ((coding-system-for-write encoding))
> │ +            (cl-letf ((coding-system-for-write encoding)
> │ +                      ((symbol-function 'set-auto-mode) #'ignore))
> │        (write-file file)))
> │            (when (and (org-export--copy-to-kill-ring-p) (org-string-nw-p
> output))
> │              (org-kill-new output))
> └────
>
> What are your thoughts? Is this desirable? In my mind, yes: even if
> someone has configured auto-formatting manually, they might still not
> realize it’s getting run in a hidden buffer they never get to see. After
> all, this is an implementation detail – if Emacs had a built-in function
> to write a string to a file, I presume that would get used instead?
>
> (In a way, I was lucky that I encountered quite noticeable issues with
> mangled characters. With the recent version of tidy, which only messes
> up whitespace, I might not have noticed at all.)
>
> And if such protection is desirable, is this the best way to do it? Or
> can you come up with a better approach?

What about using `write-region' instead of `write-file' and not touching
`set-auto-mode' function? Could you test it? Note the arguments are
different, the equivalent to (write-file file) would be (write-region
nil nil file).

Regards,
-- 
Nicolas Goaziou