Re: gnus-extra-headers

[Eric Abrahamsen <eric@ericabrahamsen.net>]

Colin Baxter <m43cap@yandex.com> writes:

> Hello,
>
> If emacs (tested with 27.2 and 28.0.50) is launched with -Q (or
> gnus-extra-headers has not been set explicitly by the user) then the
> variable gnus-extra-headers has the value:
>
> gnus-extra-headers is a variable defined in ‘gnus-sum.el’.
> Its value is
> (X-Diary-Time-Zone X-Diary-Dow X-Diary-Year X-Diary-Month X-Diary-Dom X-Diary-Hour X-Diary-Minute To Cc Keywords Gcc Newsgroups X-GM-LABELS)
> Original value was 
> (To Cc Keywords Gcc Newsgroups X-GM-LABELS)
>
>   You can customize this variable.
>
>
> This variable was introduced, or its default value was changed, in
> version 25.1 of Emacs.
>
> Documentation:
> Extra headers to parse.
>
> The X-Diary settings seem to come from nndiary.el, but there is nothing
> in the doc-string to indicate this.
>
> Is this a bug? Is not the "Original value" of gnus-extra-headers incorrect?

I don't think it's really a bug. If you don't use the nndiary backend,
those headers don't get added to `gnus-extra-headers', and it has its
"original value" as noted in *Help*. I don't think there's any contract
that says additional libraries can't manipulate the value of
customization options... is there?