Subject: bug#39823: 26.3; update-directory-autoloads regression from Emacs 26 to Emacs 27

From: Noam Postavsky <[email-masked]>
Date: Sun, 19 Apr 2020 08:19:06 -0400

Maxim Cournoyer <[email-masked]> writes:

> (defun update-directory-autoloads (&rest dirs)
>
> I don't see how &key can be combined with &rest without potentially
> causing problems.

You can check if the first arg is a keyword like
:generated-autoload-file (which can't be a directory, since it's not a
string), and if it is, then handle the second arg specially.