bug#42823: 27.1; gnus-unplugged: nnimap (gmail) folder names having spaces not appearing

[ozhap@vollbio.de]

1. Gmail IMAP should be accessible. Keep credentials in .authinfo.gpg.
   No Gnus files or directories (News, .newsrc*, Mail) present.
2. emacs -Q
3. Run:

(setq gnus-select-method
      '(nnimap "gmail"
	       (nnimap-address "imap.gmail.com")
	       (nnimap-server-port 993)
	       (nnimap-stream ssl)))

4. M-x gnus
5. ^ (Server list)
6. Go to 'gmail' and: J a (agentize)
7. q (back to Group buffer)
8. g (refresh)
9. q (quit Gnus)
10. Go offline.
11. M-x gnus-unplugged

'Sent mail' is missing. (The space character seems to be the problem
as it also happens to 'All mail', if set up). Works properly in 26.3.


In GNU Emacs 27.1 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.20)
 of 2020-08-11 built on Compu
Repository revision: 86d8d76aa36037184db0b2897c434cdaab1a9ae8
Repository branch: HEAD
Windowing system distributor 'The X.Org Foundation', version 11.0.12008000
System Description: Ubuntu 20.04.1 LTS

Recent messages:
Saving /home/abc/.newsrc.eld...
Saving file /home/abc/.newsrc.eld...
Wrote /home/abc/.newsrc.eld
Saving /home/abc/.newsrc.eld...done
<XF86RFKill> is undefined
Reading /home/abc/.newsrc.eld...
Checking new news...
Reading active file from gmail via nnimap...done
Reading active file via nndraft...done
Checking new news...done

Configured using:
 'configure --prefix=/home/abc/emacs'

Configured features:
XPM JPEG TIFF GIF PNG RSVG SOUND GPM DBUS GSETTINGS GLIB NOTIFY INOTIFY
ACL LIBSELINUX GNUTLS LIBXML2 FREETYPE HARFBUZZ M17N_FLT LIBOTF XFT ZLIB
TOOLKIT_SCROLL_BARS GTK3 X11 XDBE XIM MODULES THREADS LIBSYSTEMD PDUMPER
LCMS2 GMP

Important settings:
  value of $LANG: en_IN
  locale-coding-system: iso-latin-1-unix

Major mode: Group

Minor modes in effect:
  cursor-sensor-mode: t
  gnus-undo-mode: t
  tooltip-mode: t
  global-eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  buffer-read-only: t
  line-number-mode: t
  transient-mark-mode: t

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug sendmail nnagent nnml cursor-sensor
nndraft nnmh nnfolder utf-7 epa-file gnutls network-stream nsm
gnus-agent gnus-srvr gnus-score score-mode nnvirtual gnus-msg gnus-art
mm-uu mml2015 mm-view mml-smime smime dig nntp gnus-cache gnus-sum url
url-proxy url-privacy url-expand url-methods url-history mailcap shr
url-cookie url-domsuf url-util url-parse auth-source cl-seq eieio
eieio-core cl-macs eieio-loaddefs json map url-vars svg xml dom
browse-url gnus-group gnus-undo gnus-start gnus-cloud nnimap nnmail
mail-source utf7 netrc nnoo parse-time iso8601 gnus-spec gnus-int
gnus-range message rmc puny format-spec rfc822 mml easymenu mml-sec
password-cache epa derived epg epg-config mm-decode mm-bodies mm-encode
mail-parse rfc2231 mailabbrev gmm-utils mailheader gnus-win gnus
nnheader gnus-util rmail rmail-loaddefs rfc2047 rfc2045 ietf-drums
text-property-search time-date subr-x seq byte-opt gv bytecomp
byte-compile cconv mail-utils mm-util mail-prsvr wid-edit cl-loaddefs
cl-lib dired dired-loaddefs tooltip eldoc electric uniquify ediff-hook
vc-hooks lisp-float-type mwheel term/x-win x-win term/common-win x-dnd
tool-bar dnd fontset image regexp-opt fringe tabulated-list replace
newcomment text-mode elisp-mode lisp-mode prog-mode register page
tab-bar menu-bar rfn-eshadow isearch timer select scroll-bar mouse
jit-lock font-lock syntax facemenu font-core term/tty-colors frame
minibuffer cl-generic cham georgian utf-8-lang misc-lang vietnamese
tibetan thai tai-viet lao korean japanese eucjp-ms cp51932 hebrew greek
romanian slovak czech european ethiopic indian cyrillic chinese
composite charscript charprop case-table epa-hook jka-cmpr-hook help
simple abbrev obarray cl-preloaded nadvice loaddefs button faces
cus-face macroexp files text-properties overlay sha1 md5 base64 format
env code-pages mule custom widget hashtable-print-readable backquote
threads dbusbind inotify lcms2 dynamic-setting system-font-setting
font-render-setting move-toolbar gtk x-toolkit x multi-tty
make-network-process emacs)

Memory information:
((conses 16 142608 15208)
 (symbols 48 14296 1)
 (strings 32 41121 2403)
 (string-bytes 1 1407412)
 (vectors 16 21744)
 (vector-slots 8 291245 17836)
 (floats 8 196 23)
 (intervals 56 701 373)
 (buffers 1000 19))