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

[Philip Kaludercic]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Philip Kaludercic <philipk@posteo.net>
>> Cc: artscan@list.ru,  monnier@iro.umontreal.ca,  63757@debbugs.gnu.org
>> Date: Sun, 04 Jun 2023 12:32:17 +0000
>> 
>> Eli Zaretskii <eliz@gnu.org> writes:
>> 
>> >> -      (dolist (pkg-dir (directory-files dir t "\\`[^.]" t))
>> >> +      (dolist (pkg-dir (directory-files dir t "\\`[^.]"))
>> >>          (when (file-directory-p pkg-dir)
>> >>            (package-load-descriptor pkg-dir))))))
>> >>  
>> >> (I attached the *vc-diff* buffer, but before sending the message I
>> >> invoked vc-diff again which modified the buffer contents.  Should have
>> >> just copied the diff manually...)
>> >
>> > Thanks, now it at least makes sense.
>> >
>> > But why does it matter whether the package directory names are sorted
>> > or not?  Is sorting package versions the same as sorting the names of
>> > their directories?
>> 
>> No, because directories are sorted by their names and by that metric,
>> "foo-10" is less than "foo-9".  But since package archives like MELPA
>> use ISO 8601-like release-dates as version numbers, the order "works".
>> If we disable sorting, the files returned in any order the operating
>> system might have arbitrary stored the directory entries in which might
>> even change depending on the file system.  So at the very least we can
>> argue that while sorting does not solve the issue, it provides a quick
>> hack to prevent sudden breakage from Emacs 28 to Emacs 29, due to users
>> relying on this kind of behaviour.  A proper solution, that takes
>> version numbers into account should be prepared on the master branch.
>
> OK, thanks.  Please install on emacs-29, and let's hope this doesn't
> cause new problems.

Done.  Should we close the issue then, or wait for more feedback?