bug#46917: 28.0.50; error when unloading feature after loading elp

[Mauro Aranda <maurooaranda@gmail.com>]

Lars Ingebrigtsen <larsi@gnus.org> writes:

> Mauro Aranda <maurooaranda@gmail.com> writes:
>
>>> Starting from emacs -Q, do:
>>>
>>> 1. In the *scratch* buffer, type and evaluate (in any order):
>>> (require 'autoarg) ; Whatever feature.
>>> (require 'elp)
>>>
>>> 2. Type and evaluate
>>> (unload-feature 'autoarg)
>>>
>>> 3. Emacs signals an error:
>>> "Unsupported qualifiers in function loadhist-unload-element:
>>> (:before :extra \"elp\")"
>>>
>>
>> Looks like the problem is the order of the qualifiers; the attached
>> patch should fix it.
>
> [...]
>
>> * lisp/emacs-lisp/elp.el (loadhist-unload-element): The :extra
>> qualifier is expected to come before the other qualifiers, so do
>> that.  (Bug#46917)
>
> I had a quick look at the documentation -- this limitation doesn't seem
> to be stated anywhere?

It's hard to take a long look, since the documentation about :extra is
scarce ;-)

> Perhaps it should be, or perhaps the restriction should be lifted?

I don't really have an opinion.  My guess is that expecting :extra to
come first just makes the code simpler.