bug#29309: 25.2; Gnus: please make message-from-style 'angles the only option

[Michael Stapelberg]

Package: emacs,gnus

Currently, the custom option message-from-style can be one of:

'parens, resulting in e.g. “stapelberg@debian.org (Michael Stapelberg)”

'angles, resulting in e.g. “Michael Stapelberg <stapelberg@debian.org>”

However, https://tools.ietf.org/html/rfc2822#section-3.4 (from 2001)
states:

>    Note: Some legacy implementations used the simple form where the
>    addr-spec appears without the angle brackets, but included the name
>    of the recipient in parentheses as a comment following the addr-spec.
>    Since the meaning of the information in a comment is unspecified,
>    implementations SHOULD use the full name-addr form of the mailbox,
>    instead of the legacy form, to specify the display name associated
>    with a mailbox.  Also, because some legacy implementations interpret
>    the comment, comments generally SHOULD NOT be used in address fields
>    to avoid confusing such implementations.

Let us please make Gnus a better citizen by following the RFC’s
recommendation and removing the legacy form.

Thanks,

-- 
Best regards,
Michael