bug#18529: 24.4.50; gnus-asynchronous and long waits

[Tom Tromey]

I have gnus-asynchronous to t.

When I start reading a group -- I tried just now with
gmane.emacs.bugs -- I can read a single article just fine.
Then if I try to open the next article (say by typing "n"),
Emacs just pauses, saying:

    Waiting for async article...

I've waited several minutes before without it working.

If I C-g the wait, then try to read the chosen article again, it works.

At first I thought this was some issue with the network.
However, if I set gnus-asynchronous to nil, then everything works fine.




In GNU Emacs 24.4.50.9 (x86_64-unknown-linux-gnu, GTK+ Version 3.10.9)
 of 2014-09-21 on bapiya
Repository revision: 117912 eggert@cs.ucla.edu-20140921224924-sd071p5m85o5v0n5
Windowing system distributor `Fedora Project', version 11.0.11404000
Configured using:
 `configure --prefix=/home/tromey/Emacs/install'

Configured features:
XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND GPM DBUS GCONF GSETTINGS
NOTIFY LIBSELINUX GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB

Important settings:
  value of $LANG: en_US.UTF-8
  value of $XMODIFIERS: @im=none
  locale-coding-system: utf-8-unix

Major mode: Summary

Minor modes in effect:
  shell-dirtrack-mode: t
  diff-auto-refine-mode: t
  which-function-mode: t
  global-auto-revert-mode: t
  desktop-save-mode: t
  erc-services-mode: t
  erc-list-mode: t
  erc-menu-mode: t
  erc-autojoin-mode: t
  erc-ring-mode: t
  erc-networks-mode: t
  erc-pcomplete-mode: t
  erc-track-mode: t
  erc-match-mode: t
  erc-button-mode: t
  erc-fill-mode: t
  erc-stamp-mode: t
  erc-netsplit-mode: t
  erc-irccontrols-mode: t
  erc-noncommands-mode: t
  erc-move-to-prompt-mode: t
  erc-readonly-mode: t
  savehist-mode: t
  tooltip-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  buffer-read-only: t
  column-number-mode: t
  line-number-mode: t

Recent input:
d q SPC SPC SPC > q n n n n SPC c SPC n n SPC SPC SPC 
> < > q n n C-l SPC SPC 2 K i SPC SPC C-x o C-x o n 
SPC <return> <return> SPC SPC SPC n SPC > C-z n C-x 
b * M e s <tab> <return> C-z n n SPC n k q = SPC C-u 
<return> <return> <return> <return> <return> n SPC 
SPC C-z n C-c b C-z n n SPC n SPC n SPC n = d d d d 
d d d d SPC SPC n SPC SPC q M-g M-g M-g p SPC c SPC 
C-u C-p n SPC SPC SPC SPC SPC SPC = q n SPC c SPC C-u 
C-n p SPC d SPC SPC q p SPC 2 7 <return> C-u d d SPC 
n SPC SPC = C-u d d d d d M-x g n u s - a s <tab> C-g 
C-g C-z n C-h i d m g n u s <return> C-s a s y n c 
C-a m <return> q C-x b 8 s c r <tab> C-a C-k * s c 
r <tab> <return> g n u s - a s y n c ESC TAB <M-backspace> 
a s M-x f l s y C-t p e l - <backspace> l - m o e <return> 
<backspace> d e <return> ESC TAB ESC TAB h ESC TAB 
C-j C-p C-p ( s e t f SPC C-e SPC n i l ) C-j C-z n 
SPC n n = C-u C-n SPC Q y p M-g p SPC 2 7 <return> 
C-u d d SPC n n n n = M-x g n <M-backspace> r e p o 
r t - e m <tab> <return>

Recent messages:
fnord
 
Waiting for async article...
Quit [3 times]
Composing main Info directory...done
Mark saved where search started
Corrections: sync sync arsenic assn assoc aspic Eysenck Sang sang sank Sung 
Synge
Flyspell mode disabled
Making completion list...
Discard changes to this group and exit? (y or n) y

Load-path shadows:
/home/tromey/.emacs.d/elpa/css-mode-1.0/css-mode hides 
/home/tromey/Emacs/install/share/emacs/24.4.50/lisp/textmodes/css-mode
/home/tromey/.emacs.d/elpa/bubbles-0.5/bubbles hides 
/home/tromey/Emacs/install/share/emacs/24.4.50/lisp/play/bubbles

Features:
(shadow mail-hist emacsbug diff dired-aux idutils derived gdb-shell
cl-macs shell disass copyright misearch multi-isearch dabbrev eieio-opt
speedbar sb-image ezimage dframe help-mode shr qp gnus-fun gnus-html
browse-url xml url-cache mm-url url url-proxy url-privacy url-expand
url-methods url-history url-cookie url-domsuf url-util url-parse
url-vars bbdb-gui bbdb-hooks sort smiley gnus-cite flow-fill mm-archive
gnus-bcklg gnus-async gnus-ml disp-table gnus-topic nndraft nnmh
nnfolder utf-7 bbdb-gnus bbdb-snarf mail-extr bbdb-com warnings cl gv
gnutls network-stream starttls gnus-agent gnus-srvr gnus-score
score-mode nnvirtual gnus-msg nntp gnus-cache gnus-registry registry
eieio-base gnus-art mm-uu mml2015 epg-config mm-view mml-smime smime dig
mailcap gnus-sum gnus-group gnus-undo smtpmail sendmail gnus-start
gnus-cloud nnimap nnmail mail-source tls utf7 netrc nnoo parse-time
gnus-spec gnus-int gnus-range gnus-win gnus gnus-ems nnheader mule-util
smerge-mode message rfc822 mml mml-sec mm-decode mm-bodies mm-encode
mail-parse rfc2231 rfc2047 rfc2045 ietf-drums mailabbrev mail-utils
gmm-utils mailheader diff-mode autoconf autoconf-mode tcl goto-addr
add-log make-mode js bug-reference vc-arch vc-mtn vc-sccs vc-svn vc-cvs
vc-rcs sgml-mode vc-hg python json vc-bzr cc-mode cc-fonts cc-guess
cc-menus cc-cmds org-element org-rmail org-mhe org-irc org-info org-gnus
org-docview doc-view jka-compr image-mode dired org-bibtex bibtex
org-bbdb org-w3m org org-macro org-footnote org-pcomplete org-list
org-faces org-entities noutline outline easy-mmode org-version
ob-emacs-lisp ob ob-tangle org-src ob-ref ob-lob ob-table ob-keys ob-exp
ob-comint ob-core ob-eval org-compat org-macs org-loaddefs vc-git
flyspell ispell eldoc diminish projectile edmacro kmacro pkg-info
find-func lisp-mnt epl grep compile dash s appt diary-lib diary-loaddefs
cal-menu calendar cal-loaddefs which-func imenu minimap autorevert
filenotify desktop frameset cus-start cus-load status erc-services
erc-list erc-menu erc-join erc-ring erc-networks erc-pcomplete pcomplete
erc-track erc-match erc-button wid-edit cl-loaddefs cl-lib erc-fill
erc-stamp erc-netsplit erc-goodies erc erc-backend erc-compat
format-spec auth-source eieio byte-opt bytecomp byte-compile cconv
eieio-core gnus-util mm-util mail-prsvr password-cache thingatpt pp
advice help-fns vc-dir ewoc vc vc-dispatcher cc-styles cc-align
cc-engine cc-vars cc-defs bbdb timezone ange-ftp comint ansi-color ring
server savehist dwarf-mode-autoloads gdb-shell-autoloads
jabber-autoloads lisppaste-autoloads pydoc-info-autoloads info-look info
easymenu weblogger-autoloads package bbdb-autoloads time-date tooltip
electric uniquify ediff-hook vc-hooks lisp-float-type mwheel x-win x-dnd
tool-bar dnd fontset image regexp-opt fringe tabulated-list newcomment
lisp-mode prog-mode register page menu-bar rfn-eshadow timer select
scroll-bar 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 minibuffer 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 make-network-process
dbusbind gfilenotify dynamic-setting system-font-setting
font-render-setting move-toolbar gtk x-toolkit x multi-tty emacs)

Memory information:
((conses 16 957122 130534)
 (symbols 48 104082 0)
 (miscs 40 41575 3661)
 (strings 32 323566 49922)
 (string-bytes 1 7100816)
 (vectors 16 96353)
 (vector-slots 8 2170921 63900)
 (floats 8 398 1155)
 (intervals 56 31422 2624)
 (buffers 976 260)
 (heap 1024 140975 7970))

Tom