bug#35383: 27.0.50; Complete process of decoding Gnus group names

[Katsumi Yamaoka]

> On 04/23/19 17:12 PM, Katsumi Yamaoka wrote:
>> Though I'm not quite sure
>> yet, the new and the old newsrc.eld files (containing non-ASCII
>> nnml and nnrss groups) seem to be compatible with the new and
>> the old Gnus mutually.

Not mutually but one-way from old Gnus[1] to new Gnus[2] is ok.
To activate the groups of the non-ASCII names for the old Gnus,
I realized I needed to convert those group names to that of

(prin1-to-string (encode-coding-string "Group Name" 'utf-8))

one by one in the .newsrc.eld file before starting the old Gnus.
No other tweak is necessary to switch back to the old Gnus, and
nothing to be done to switch to the new Gnus again.  I verified
it with only nnml and nnrss groups as I tried Gnus of the latest
git master today for the first time in about a month.

[1] currently that of the master and the emacs-26 branches
[2] currentlt that of the scratch/gnus-decoded branch

;; I can switch them by adding site-lisp/gnus (new) to load-path.

Regards,