Fix helpful--autoloaded-p in Emacs 29.0.50

[rhaps0dy]

I don't know how (or whether to) add this change, since it likely breaks helpful for anyone not using the latest Emacs. What to do?

help-fns--autoloaded-p

The function help-fns--autoloaded-p now only takes 1 argument, so describe-function errors out; as described in doomemacs/doomemacs#6097 . The change was made on 2022-01-31.

helpful--skip-advice

Also fixed helpful--skip-advice. The advice info is now appended to the
documentation, so the test helpful--docstring-advice would fail.

That is, the docstring from (documentation #'test-foo-advised t) now reads:

"Docstring here too.

This function has :around advice: ‘ad-Advice-test-foo-advised’.

(fn)"

[baracunatana]

I don't know how (or whether to) add this change, since it likely breaks helpful for anyone not using the latest Emacs. What to do?

Maybe a simple (when (equal emacs-version "20.0.50) ...?

[tpeacock19]

I would suggest using the following that has worked for me:

(defun helpful--autoloaded-p (sym buf)
  "Return non-nil if function SYM is autoloaded."
  (-when-let (file-name (buffer-file-name buf))
    (setq file-name (s-chop-suffix ".gz" file-name))
    (if (boundp 'read-symbol-positions-list)
        (help-fns--autoloaded-p sym file-name)
      (help-fns--autoloaded-p sym))))

Additionally, with the changes from my PR
Wilfred/elisp-refs#36 there is no need to edit
helpful--skip-advice

[rhaps0dy]

Thank you very much @tpeacock19 ! Your fix does solve helpful--skip-advice.

In the end I've gone with the advice of Stefan in StackOverflow and just tried to call the old function first.

[tpeacock19]

I'm still learning about lisp and programming in general. So may I ask why you prefer to call the function?

[Wilfred]

Thanks for the PR :)

[rhaps0dy]

@tpeacock19 I think checking whether read-symbol-positions-list is a proxy for what we actually care about, which is the number of arguments to help-fns--autoloaded-p. So I'd rather check directly for the latter. Maybe a user defined read-symbol-positions-list in their config but help-fns--autoloaded-p still takes two arguments, in which case checking for read-symbol-positions-list would be the wrong thing to do.