bug#35233: 27.0.50; Error in gnus-group-describe-all-groups

[Basil L. Contovounesios]

The recent move to hash-tables[1] introduced the following regression:

0. HOME=$(mktemp -d) emacs -Q
1. (setq gnus-select-method '(nntp "news.gwene.org")) C-j
2. M-x gnus RET s M-d
   Wrong number of arguments: #<subr sort>, 1

Passing string-lessp to sort further leads to the following:

3. Steps 0-2 as above.
   Wrong type argument: vectorp, #s(hash-table ...)

Replacing (intern group gnus-description-hashtb) with just group, and
repeating steps 0-2 as above, reveals that
gnus-group-describe-all-groups inserts the group name twice, rather than
the group name followed by its description.  This regression predates
the move to hash-tables[2].

[1: c1b63af445]: Change Gnus hash tables into real hash tables
  2019-03-22 10:23:30 -0700
  
https://git.savannah.gnu.org/cgit/emacs.git/commit/?id=c1b63af4458e92bad33da0def2b15c206656e2fa

[2: 3982245371]: Sort groups before inserting them into the group buffer
  2016-02-13 18:45:11 +1100
  
https://git.savannah.gnu.org/cgit/emacs.git/commit/?id=3982245371c0b8e17b4d96d16ed4b1d87c0ffc25

Patch fixing these to follow.

-- 
Basil

Gnus v5.13
In GNU Emacs 27.0.50 (build 9, x86_64-pc-linux-gnu, X toolkit, Xaw3d scroll 
bars)
 of 2019-04-11 built on thunk
Repository revision: 0627a8d7bc6ffa29d7a503fd36e760778ecb9fa1
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12003000
System Description: Debian GNU/Linux buster/sid