bug#14559: 24.3.50; accept-process-output hang

[Chep <ptit.chep@gmail.com>]

accept-process-output hangs sometimes. It always happens with erc (decrypting
password file with gpg), sometimes with ampc and ispell.

create a ~/.authinfo.gpg encrypted file (I think you can write what you want in
this file)
 
start emacs -Q
M-x toggle-debug-on-quit
M-x erc
RET RET RET (default values)
*emacs hangs after displaying "Decrypting /home/chep/.authinfo.gpg...done" *
C-g

Backtrace:
Debugger entered--Lisp error: (quit)
  accept-process-output(#<process epg> 1)
  epg-wait-for-completion((epg-context . [OpenPGP nil nil nil nil nil nil (epa-file-passphrase-callback-function . "/home/chep/.authinfo.gpg") (epa-progress-callback-function . "Decrypting /home/chep/.authinfo.gpg") nil nil #<process epg> "/tmp/epg-output10821MWw" ((decryption-okay . t) (encrypted-to ("6A2BCF610629F4AC" 1 0))) decrypt nil]))
  epg-decrypt-file((epg-context . [OpenPGP nil nil nil nil nil nil (epa-file-passphrase-callback-function . "/home/chep/.authinfo.gpg") (epa-progress-callback-function . "Decrypting /home/chep/.authinfo.gpg") nil nil #<process epg> "/tmp/epg-output10821MWw" ((decryption-okay . t) (encrypted-to ("6A2BCF610629F4AC" 1 0))) decrypt nil]) "/home/chep/.authinfo.gpg" nil)
  #[0 "\302\303\301\300\304#\240\207" ["/home/chep/.authinfo.gpg" (epg-context . [OpenPGP nil nil nil nil nil nil (epa-file-passphrase-callback-function . "/home/chep/.authinfo.gpg") (epa-progress-callback-function . "Decrypting /home/chep/.authinfo.gpg") nil nil #<process epg> "/tmp/epg-output10821MWw" ((decryption-okay . t) (encrypted-to ("6A2BCF610629F4AC" 1 0))) decrypt nil]) (nil) epg-decrypt-file nil] 5 "\n\n(fn)"]()
  funcall(#[0 "\302\303\301\300\304#\240\207" ["/home/chep/.authinfo.gpg" (epg-context . [OpenPGP nil nil nil nil nil nil (epa-file-passphrase-callback-function . "/home/chep/.authinfo.gpg") (epa-progress-callback-function . "Decrypting /home/chep/.authinfo.gpg") nil nil #<process epg> "/tmp/epg-output10821MWw" ((decryption-okay . t) (encrypted-to ("6A2BCF610629F4AC" 1 0))) decrypt nil]) (nil) epg-decrypt-file nil] 5 "\n\n(fn)"])
  epa-file-insert-file-contents("/home/chep/.authinfo.gpg" nil nil nil nil)
  apply(epa-file-insert-file-contents ("/home/chep/.authinfo.gpg" nil nil nil nil))
  epa-file-handler(insert-file-contents "/home/chep/.authinfo.gpg" nil nil nil nil)
  insert-file-contents("~/.authinfo.gpg")
  auth-source-netrc-parse(:max 1 :require (:secret) :delete nil :file "~/.authinfo.gpg" :host "irc.freenode.net" :user "chep" :port 6667)
  auth-source-netrc-search(:backend [object auth-source-backend "~/.authinfo.gpg" netrc "~/.authinfo.gpg" t t t nil auth-source-netrc-create auth-source-netrc-search] :type netrc :require (:secret) :create nil :delete nil :host "irc.freenode.net" :max 1 :user "chep" :port 6667 :require (:secret))
  apply(auth-source-netrc-search :backend [object auth-source-backend "~/.authinfo.gpg" netrc "~/.authinfo.gpg" t t t nil auth-source-netrc-create auth-source-netrc-search] :type netrc :require (:secret) :create nil :delete nil (:host "irc.freenode.net" :max 1 :user "chep" :port 6667 :require (:secret)))
  auth-source-search-backends(([object auth-source-backend "~/.authinfo" netrc "~/.authinfo" t t t nil auth-source-netrc-create auth-source-netrc-search] [object auth-source-backend "~/.authinfo.gpg" netrc "~/.authinfo.gpg" t t t nil auth-source-netrc-create auth-source-netrc-search] [object auth-source-backend "~/.netrc" netrc "~/.netrc" t t t nil auth-source-netrc-create auth-source-netrc-search]) (:host "irc.freenode.net" :max 1 :user "chep" :port 6667 :require (:secret)) 1 nil nil (:secret))
  auth-source-search(:host "irc.freenode.net" :max 1 :user "chep" :port 6667 :require (:secret))
  erc-open("irc.freenode.net" 6667 "chep" "unknown" t nil)
  erc(:server "irc.freenode.net" :port 6667 :nick "chep" :password nil)
  call-interactively(erc record nil)
  command-execute(erc record)
  execute-extended-command(nil "erc")







In GNU Emacs 24.3.50.1 (x86_64-pc-linux-gnu, GTK+ Version 3.4.2)
 of 2013-05-24 on gkar, modified by Debian
 (emacs-snapshot package, version 2:20130520-1~bpo70+1)
Windowing system distributor `The X.Org Foundation', version 11.0.11204000
System Description:	Debian GNU/Linux testing (jessie)

Configured using:
 `configure --build x86_64-linux-gnu --host x86_64-linux-gnu --prefix=/usr
 --sharedstatedir=/var/lib --libexecdir=/usr/lib --localstatedir=/var
 --infodir=/usr/share/info --mandir=/usr/share/man --with-pop=yes
 --enable-locallisppath=/etc/emacs-snapshot:/etc/emacs:/usr/local/share/emacs/24.3.50/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/24.3.50/site-lisp:/usr/share/emacs/site-lisp
 --without-compress-info --with-crt-dir=/usr/lib/x86_64-linux-gnu/ --with-x=yes
 --with-x-toolkit=gtk3 --with-imagemagick=yes CFLAGS='-DDEBIAN
 -DSITELOAD_PURESIZE_EXTRA=5000 -g -O2' CPPFLAGS='-D_FORTIFY_SOURCE=2'
 LDFLAGS='-g -Wl,--as-needed -znocombreloc''

Important settings:
  value of $LANG: fr_FR.utf8
  locale-coding-system: utf-8-unix
  default enable-multibyte-characters: t

Major mode: Lisp Interaction

Minor modes in effect:
  diff-auto-refine-mode: t
  show-paren-mode: t
  erc-smiley-mode: t
  shell-dirtrack-mode: t
  global-auto-complete-mode: t
  auto-complete-mode: t
  virtual-desktops-mode: t
  display-time-mode: t
  tooltip-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
  column-number-mode: t
  line-number-mode: t
  transient-mark-mode: t
  hs-minor-mode: t

Recent input:
M-x e m a <tab> b u <tab> <backspace> <backspace> <M-backspace> 
r e p o <tab> r <tab> b <tab> <return>

Recent messages:
Loading battery...done
Loading time...done
Battery status not available
Appointment reminders enabled (no diary file found)
Loading /home/chep/.emacs.d/config.erc.el (source)...done
Loading /home/chep/.emacs.d/config.wl.el (source)...done
Starting Emacs daemon.
Restarting server
When done with this frame, type C-x 5 0
Making completion list...

Load-path shadows:
~/.emacs.d/site-lisp/magit-blame hides /usr/share/emacs/24.3.50/site-lisp/magit/magit-blame
/usr/share/emacs/24.3.50/site-lisp/debian-startup hides /usr/share/emacs/site-lisp/debian-startup
/usr/share/emacs/24.3.50/site-lisp/cscope/xcscope hides /usr/share/emacs/site-lisp/xcscope
/usr/share/emacs-snapshot/site-lisp/flim/md4 hides /usr/share/emacs/24.3.50/lisp/md4
/usr/share/emacs-snapshot/site-lisp/flim/hex-util hides /usr/share/emacs/24.3.50/lisp/hex-util
/usr/share/emacs-snapshot/site-lisp/flim/sasl-cram hides /usr/share/emacs/24.3.50/lisp/net/sasl-cram
/usr/share/emacs-snapshot/site-lisp/flim/sasl hides /usr/share/emacs/24.3.50/lisp/net/sasl
/usr/share/emacs-snapshot/site-lisp/flim/ntlm hides /usr/share/emacs/24.3.50/lisp/net/ntlm
/usr/share/emacs-snapshot/site-lisp/flim/sasl-ntlm hides /usr/share/emacs/24.3.50/lisp/net/sasl-ntlm
/usr/share/emacs-snapshot/site-lisp/flim/hmac-md5 hides /usr/share/emacs/24.3.50/lisp/net/hmac-md5
/usr/share/emacs-snapshot/site-lisp/flim/hmac-def hides /usr/share/emacs/24.3.50/lisp/net/hmac-def
/usr/share/emacs-snapshot/site-lisp/flim/sasl-digest hides /usr/share/emacs/24.3.50/lisp/net/sasl-digest
/usr/share/emacs-snapshot/site-lisp/wl/rfc2368 hides /usr/share/emacs/24.3.50/lisp/mail/rfc2368
/usr/share/emacs-snapshot/site-lisp/semi/pgg-pgp hides /usr/share/emacs/24.3.50/lisp/obsolete/pgg-pgp
/usr/share/emacs-snapshot/site-lisp/semi/pgg-pgp5 hides /usr/share/emacs/24.3.50/lisp/obsolete/pgg-pgp5
/usr/share/emacs-snapshot/site-lisp/semi/pgg-def hides /usr/share/emacs/24.3.50/lisp/obsolete/pgg-def
/usr/share/emacs-snapshot/site-lisp/semi/pgg-parse hides /usr/share/emacs/24.3.50/lisp/obsolete/pgg-parse
/usr/share/emacs-snapshot/site-lisp/semi/pgg-gpg hides /usr/share/emacs/24.3.50/lisp/obsolete/pgg-gpg
/usr/share/emacs-snapshot/site-lisp/semi/pgg hides /usr/share/emacs/24.3.50/lisp/obsolete/pgg

Features:
(shadow flyspell ispell wl-mime mime-edit pgg-parse pccl pccl-20 signature
mime-setup mail-mime-setup semi-setup mime-pgp pgg-def mime-image modb-standard
elmo-maildir wl-demo wl-news derived wl-address wl-thread wl-action wl-summary
ps-print ps-def lpr wl-refile wl-message elmo-mime mmelmo-buffer mmelmo-imap
mmimap mime-parse mmbuffer mmgeneric wl-highlight elmo-multi wl-folder wl wl-e21
wl-util elmo-flag wl-draft eword-encode wl-template wl-vars wl-version
epg-config elmo-net elmo-cache elmo-map elmo-dop elmo-localdir elmo elmo-signal
elmo-msgdb modb modb-generic modb-entity elmo-util utf7 elmo-date elmo-vars
elmo-version luna emacsbug message rfc822 mml mml-sec mm-decode mm-bodies
mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader sendmail rfc2047
rfc2045 ietf-drums mail-utils help-mode hideshow magit-blame magit-bisect
magit-key-mode magit diff-mode log-edit pcvs-util add-log php-mode cc-langs
speedbar sb-image ezimage dframe xcscope smart-tabs chep-tag-popup etags hideif
cc-mode cc-fonts cc-guess cc-menus cc-cmds cc-styles cc-align cc-engine cc-vars
cc-defs paren uniquify chep-strike chep-couleur chep-retourne chep-pastebin
google_search ifndef_fichier_h mime-play filename emu invisible inv-23 poem
poem-e20 poem-e20_3 mime-view mime-conf calist semi-def mime eword-decode mel
path-util mime-def mcharset mcs-20 mcs-e20 pces pces-e20 pces-20 broken pcustom
poe std11 alist pym static apel-ver product mime-w3m warnings advice help-fns
w3m browse-url doc-view jka-compr dired image-mode timezone w3m-hist w3m-fb
bookmark-w3m w3m-ems wid-edit w3m-ccl ccl w3m-favicon w3m-image w3m-proc
w3m-util erc-goodies erc erc-backend erc-compat format-spec thingatpt pp netrc
chep-notification readline-complete shell pcomplete comint ansi-color ring
auto-complete-config auto-complete edmacro kmacro cl-macs gv popup cl nadvice
cl-lib appt diary-lib diary-loaddefs cal-menu calendar cal-loaddefs ampc
easymenu avl-tree network-stream auth-source eieio byte-opt bytecomp
byte-compile cconv gnus-util time-date mm-util mail-prsvr password-cache
starttls tls chep-anchor easy-mmode virtual-desktops ido time battery cus-start
cus-load server w3m-load 50magit tooltip 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 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 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 inotify dynamic-setting system-font-setting
font-render-setting move-toolbar gtk x-toolkit x multi-tty emacs)