bug#42316: 28.0.50; package.el has trouble reloading and activating GNU ELPA :core packages

[Stefan Kangas]

João Távora <joaotavora@gmail.com> writes:

> Stefan Monnier <monnier@iro.umontreal.ca> writes:
>
>>> 2. When you shut down that Emacs session, start it again, run
>>>    package-initialize, you _still_ don't have the new eldoc.el file
>>>    (1.2.0) loaded.  This is only for eldoc.el, flymake.el works
>>>    correctly in this use case.
>>
>> Yes, this is because it's preloaded in Emacs, so when package.el comes
>> to activate the package, the autoloads in `eldoc-autoloads.el` won't have any
>> effect because all its functions are already defined (since `eldoc.el`
>> is already loaded).
>>
>> This is not a really bug in package.el but arguably a missing feature,
>> indeed.  When `package-activate-all` is called, it should probably
>> reload all packages that were already loaded before (when the version
>> already loaded is different from the one that's just been activated).

Is this the same as Bug#40971?

> Sounds reasonable.  But can these changes ever reach Emacs 26.3?  How?
> Only by updating package.el itself, right?  Is that possible?

I guess if we make package.el into a :core package.  But then again we
will have the same bug on Emacs 26.3, so it will never be loaded...