bug#63757: 29.0.91 order of package paths changed: random old versions of packages in load-path

[Philip Kaludercic <philipk@posteo.net>]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Евгений Бойков <artscan@list.ru>
>> Date: Sun, 4 Jun 2023 15:37:31 +1000
>> Cc: Philip Kaludercic <philipk@posteo.net>, Eli Zaretskii <eliz@gnu.org>, 63757@debbugs.gnu.org
>> 
>> Excuse me for extra messages, I've already found a bug in the previous patch.
>> I need a review, especially with in-place operations.
>> 
>> move "Prefer VC packages" to `package-process-define-package`
>> drop `package-disabled-p` and "Prefer builtin packages" comment
>
> Thanks, but I'm not really comfortable with such non-trivial changes
> in package.el at this late stage of the pretest.
>
> Is this problem new in Emacs 29, or did it exist in Emacs 28 as well?
> If it is new, which change(s) caused the incorrect ordering of
> versions in Emacs 29?

It is new, and the simplest solution that should revert the issue could
be just to have `package-load-all-descriptors' sort the files when
loading descriptors.  I am not sure if the issue that Stefan raised,
with `sort' in `package--get-activatable-pkg' destructively modifying
`package-alist', but if anything that has been an issue before Emacs 29
as well.