bug#6638: gnus hangs on connection to IMAP account on Windows

[Christoph]

I am using Emacs 23.2.1 with the included gnus 5.13 on Windows 7 and I 
am trying to connect to a Gmail account via IMAP/SSL. gnus hangs at some 
point while connecting to the IMAP folder and C-g is needed to abort.

I have installed gnutls-cli v2.8.6 from http://josefsson.org/gnutls4win/ 
and added the bin/ directory to path and exec-path, but also tried the 
latest version v2.10.0 with the same result.

Relevant parts of .gnu.el:

(setq starttls-use-gnutls t
      starttls-gnutls-program "gnutls-cli"
      starttls-extra-arguments nil)

(setq imap-ssl-program "gnutls-cli --port %p %s")

(setq gnus-select-method
      '(nnimap "gmail"
               (nnimap-address "imap.gmail.com")
               (nnimap-stream ssl)
               (nnimap-server-port 993)
               (nnimap-authinfo-file "~/.emacs.d/.authinfo")))

(setq send-mail-function 'smtpmail-send-it
      message-send-mail-function 'smtpmail-send-it
      smtpmail-starttls-credentials '(("smtp.gmail.com" 587 nil nil))
      smtpmail-auth-credentials "~/.emacs.d/.authinfo"
      smtpmail-default-smtp-server "smtp.gmail.com"
      smtpmail-smtp-server "smtp.gmail.com"
      smtpmail-smtp-service 587
      smtpmail-debug-info t)


Relevant information from *Message* buffer:

imap: Connecting to imap.gmail.com...
imap: Opening SSL connection with `gnutls-cli --port %p %s'...done
Waiting for response from imap.gmail.com...done
Parsing authinfo file `~/.emacs.d/.authinfo'.
imap: Authenticating to `imap.gmail.com' using `login'...
imap: Plaintext authentication...
imap: Login successful...
imap: Authenticating to `imap.gmail.com' using `login'...done
Quit trying to open server nnimap+gmail
Unable to open server nnimap+gmail, go offline? (y or n)
Please answer y or n.  Unable to open server nnimap+gmail, go offline? 
(y or n)
nnimap (gmail) open error: ''.  Continue? (y or n)
Couldn't open server on gmail


Emacs bug report info:

In GNU Emacs 23.2.1 (i386-mingw-nt6.1.7600)
 of 2010-05-08 on G41R2F1
Windowing system distributor `Microsoft Corp.', version 6.1.7600
configured using `configure --with-gcc (3.4) --no-opt --cflags 
-Ic:/xpm/include'

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: ENU
  value of $XMODIFIERS: nil
  locale-coding-system: cp1252
  default enable-multibyte-characters: t

Major mode: Fundamental

Minor modes in effect:
  ido-everywhere: t
  yas/global-mode: t
  yas/minor-mode: t
  global-auto-revert-mode: t
  delete-selection-mode: t
  tooltip-mode: t
  mouse-wheel-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  column-number-mode: t
  line-number-mode: t

Recent input:
C-x C-f <backspace> w i n d o <backspace> <backspace>
<backspace> <backspace> <backspace> g n u s <return>
M-> C-x RET e v a l - b u f f e r <return> C-x RET
g n u s <return> <down-mouse-1> n n <down-mouse-1>
<mouse-1> <help-echo> C-x o <up> <up> <up> <up> <up>
<up> <up> <up> <up> <up> <up> <up> <up> <up> <up> <up>
<up> <up> <up> <up> <up> <up> <up> <up> <up> <up> <up>
<down> <down> <down> <down> <down> <down> <down> <down>
<down> <down> <down> <down> <down> <down> <down> <down>
<down> <down> <up> <up> <up> <up> <left> <left> <left>
<left> C-SPC C-SPC C-n C-n C-n C-n C-n C-n C-n C-n
C-n C-n C-n C-n C-n M-w <help-echo> <help-echo> <down-mouse-1>
<mouse-1> C-x 1 C-x k <return> C-x RET r e p o r t
- b u <tab> <return>

Recent messages:
Quit trying to open server nnimap+gmail
Unable to open server nnimap+gmail, go offline? (y or n)
Please answer y or n.  Unable to open server nnimap+gmail, go offline? 
(y or n)
nnimap (gmail) open error: ''.  Continue? (y or n)
Couldn't open server on gmail
Quit
Mark set
Mark activated
Saved text from "imap: Connecting to imap.gmail.com...
im"

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug auth-source nnimap imap gnus-agent
gnus-srvr gnus-score score-mode nnvirtual gnus-msg gnus-art mm-uu
mml2015 pgg pgg-parse pgg-def epg-config mm-view smime dig nntp
gnus-cache gnus-sum nnoo gnus-group gnus-undo nnmail mail-source
format-spec gnus-start gnus-spec gnus-int gnus-range message ecomplete
rfc822 mml mml-sec password-cache mm-decode mm-bodies mm-encode mailcap
mail-parse rfc2231 rfc2047 rfc2045 qp ietf-drums mailabbrev gmm-utils
mailheader canlock sha1 hex-util hashcash gnus-win gnus gnus-ems
nnheader gnus-util netrc time-date mail-utils mm-util mail-prsvr vc-hg
server re-builder ack-emacs ibuffer nav nav-tags python-21 python
nav-bufs xcscope anything-config semantic/util-modes semantic/util
semantic semantic/tag semantic/lex semantic/fw eieio byte-opt bytecomp
byte-compile mode-local cedet imenu bookmark pp ffap dired rx thingatpt
anything woman man cc-mode cc-fonts cc-menus cc-cmds cc-styles cc-align
cc-engine cc-vars cc-defs grep-o-matic grep compile comint
browse-kill-ring+ browse-kill-ring second-sel ido yasnippet
dropdown-list derived easy-mmode assoc etags-table etags ring remember
zenburn color-theme edmacro kmacro wid-edit cl cl-19 sendmail regexp-opt
reporter easymenu uniquify advice help-fns advice-preload autorevert
delsel tooltip ediff-hook vc-hooks lisp-float-type mwheel dos-w32
disp-table ls-lisp w32-win w32-vars tool-bar dnd fontset image fringe
lisp-mode register page menu-bar rfn-eshadow timer select scroll-bar
mldrag mouse jit-lock font-lock syntax facemenu font-core frame cham
georgian utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao
korean japanese hebrew greek romanian slovak czech european ethiopic
indian cyrillic chinese case-table epa-hook jka-cmpr-hook help simple
abbrev loaddefs button minibuffer faces cus-face files text-properties
overlay md5 base64 format env code-pages mule custom widget
hashtable-print-readable backquote make-network-process multi-tty emacs)