bug#51173: 28.0.60; gnus-article-describe-key doesn't work

[Juri Linkov <juri@linkov.net>]

>> The following example program returns `sh-case' on Emacs 27 and
>> olders, however to make it work on Emacs 28 and 29 the third
>> line has to be uncommented.  So does `describe-key' case.
>>
>> (with-temp-buffer
>>   (sh-mode)
>>   ;;(set-window-buffer nil (current-buffer))
>>   (describe-key-briefly "\C-c\C-c"))
>>
>> I don't know when/why those commands were changed to require the
>> buffer (where the keymap is) to be visited in the selected window,
>> but now `gnus-article-describe-key\(-briefly\)?' doesn't work
>> because of this.  A patch to gnus-art.el is attached, though the
>> one that should be fixed might be help.el.
>
> I think this sounds like a bug in describe-key*, so perhaps it should be
> fixed there?  Looking at the history, I'm not at all sure what caused
> this regression, but perhaps it's:
>
> commit 9d4af3e6bdfac374f6c9591566c010e6a1514751
> Author:     Stefan Monnier <monnier@iro.umontreal.ca>
> AuthorDate: Tue Jan 30 11:57:40 2018 -0500
>
> I've added Stefan to the CCs.

I think this is mea culpa - commit 2d1564103e.
It was changed to handle context menu clicks
in the displayed window.