Subject: Re: bug#24073: 24.5; outline-on-heading-p sees any invisible text property as outline invisible

From: Noam Postavsky <[email-masked]>
Date: Tue, 2 Aug 2016 10:31:24 -0400

On Tue, Aug 2, 2016 at 3:20 AM, Paul Rankin <[email-masked]> wrote:
> I've added the following into my major mode to patch outline until the
> bug is addressed...
>
>     (with-eval-after-load 'outline
>       (advice-add 'outline-invisible-p :filter-return
>                   (lambda (return) (eq return (or 'outline t)))
>                   '((name . "fountain-mode-patch")))
>       (dolist (fun '(outline-back-to-heading
>                      outline-on-heading-p
>                      outline-next-visible-heading))
>         (let ((source (find-function-noselect fun)))
>           (with-current-buffer (car source)
>             (goto-char (cdr source))
>             (eval (read (current-buffer))))))
>       (message "Function `outline-invisible-p' has been patched"))
>
> But I'm a bit concerned if users install Emacs without uncompiled Lisp
> source, will this result in an error that Emacs simply can't find the
> library outline?

Yes, perhaps you want to wrap the loop body in with-demoted-errors, or similar.