Re: .dir-locals.el in AUCTeX tree

[Gustavo Barros]

Hi Tassilo,

On Wed, 30 Dec 2020 at 02:52, Tassilo Horn <tsdh@gnu.org> wrote:

> Gustavo Barros <gusbrs.2016@gmail.com> writes:
>
> Hi Gustavo,
>
> > And it may generate some inconveniences.  As an example, in my case,
> > precisely because I want to ensure I won't fat finger the packages in
> > the elpa/ directory, I use a .dir-locals there to open any package
> > source files read-only.  But, if AUCTeX distributes its own
> > .dir-locals, it overrides any other ones found up in the tree.
>
> Out of curiosity: if you have ~/.emacs.d/elpa/.dir-locals.el and there
> is an additional ~/.emacs.d/elpa/auctex-13.0.1/.dir-locals.el, 
> shouldn't
> the settings of *both* apply in non-conflicting cases?  (I'm not sure
> after reading the docs and too lazy to test myself.)

I'm no expert in directory local variables, but that's not what I 
understand from the docs (admittedly thin in this issue), and also not 
my experience.

As far as I understand, Emacs searches for `.dir-locals.el' moving up 
the tree, but once it finds one, it looks no further.

What the Elisp manual says about it is:

"If some of the subdirectories have their own ‘.dir-locals.el’ files, 
Emacs uses the settings from the deepest file it finds starting from the 
file’s directory and moving up the directory tree."

Regardless of interpretation there, on the testing side, what I can tell 
you is that I have the following in ~/.emacs.d/elpa/.dir-locals.el:

#+begin_src emacs-lisp
((nil . ((magit-diff-refine-hunk . nil)
        ;; adapted from https://emacs.stackexchange.com/a/3681
        (eval . (when buffer-file-name
                  (setq-local view-no-disable-on-exit t)
                  ;; to trigger view-mode 'view-read-only t' is 
                  required
                  (read-only-mode 1))))))
#+end_src

And, if ~/.emacs.d/elpa/auctex-13.0.1/.dir-locals.el is present, files 
from ~/.emacs.d/elpa/auctex-13.0.1/ are not visited in `read-only-mode'.

I can also tell that from 48 packages in my ~/.emacs.d/elpa/ directory, 
only ess sends a `.dir-locals.el' with the package.


> > That's to say: would you please consider including `.dir-locals.el' 
> > to
> > `.elpaignore'?
>
> Considered, accepted, applied, and pushed.  Will be in 13.0.2 but is 
> not
> important enough to make a release just with this change.
>
> Bye,
> Tassilo

Thank you very much. And agreed, this is minor, when it comes it will be 
welcome, but there is no hush at all.

Best,
Gustavo.