bug#19304: 25.0.50; vc-dir hangs forever

[Sam Steingold]

When I do C-x v d ~ RET (C-x v d runs the command vc-dir), I get the
buffer and the message "running hg status -mardui -C . in background"
and the *vc-dir* buffer never actually becomes usable.

This behavior started relatively recently (within the last couple of
weeks).

My home directory is under hg and many subtrees are ignored:

--8<---------------cut here---------------start------------->8---
$ time hg status -mardui -C . | cut -f1 -d' ' | sort | uniq -c | sort -n'
   1 A
   5 M
  19 ?
185661 I

real    0m11.587s
user    0m10.745s
sys     0m1.103s
--8<---------------cut here---------------end--------------->8---

as you see, the hg command completes fast but emacs, apparently, chokes
on the 180k ignored files.

In GNU Emacs 25.0.50.9 (x86_64-apple-darwin14.0.0, NS appkit-1343.16 Version 
10.10.1 (Build 14B25))
 of 2014-12-08 on sds-MacBook-Pro.local
Repository revision: 7fb8fc35ebf980ed299ce9dfd1694fa0f1ea169b
Windowing system distributor `Apple', version 10.3.1343
Configured using:
 `configure --with-ns'

Configured features:
IMAGEMAGICK ACL GNUTLS LIBXML2 ZLIB

Important settings:
  value of $LANG: C
  locale-coding-system: utf-8-unix

Major mode: Shell

Minor modes in effect:
  diff-auto-refine-mode: t
  rcirc-track-minor-mode: t
  which-function-mode: t
  url-handler-mode: t
  show-paren-mode: t
  desktop-save-mode: t
  shell-dirtrack-mode: t
  tooltip-mode: t
  global-eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-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
  column-number-mode: t
  line-number-mode: t

Recent messages:
Spell-checking region using aspell with default dictionary...
Exited spell-checking
Sending...
Mark set [2 times]
Sending via mail...
Type "q" in help window to delete it.
Sending email 
Sending email done
gnutls.c: [0] (Emacs) fatal error: The TLS connection was non-properly 
terminated.
Sending...done
next-line: End of buffer [3 times]

Load-path shadows:
None found.

Features:
(help-mode gnutls smtpmail ispell cl-indent pp shadow sort bbdb-message
mailalias cookie1 mail-extr gnus-msg gnus-art mm-uu mml2015 mm-view
mml-smime smime dig mailcap gnus-sum gnus-group gnus-undo gnus-start
gnus-cloud nnimap nnmail mail-source utf7 netrc nnoo parse-time
gnus-spec gnus-int gnus-range gnus-win skeleton emacsbug message rfc822
mml mml-sec mm-decode mm-bodies mm-encode mail-parse rfc2231 gmm-utils
mailheader sendmail rfc2047 rfc2045 ietf-drums vc-bzr vc-src vc-sccs
vc-svn vc-cvs vc-rcs disp-table network-stream nsm starttls tls
time-stamp ediff-merg ediff-wind ediff-diff ediff-mult ediff-help
ediff-init ediff-util ediff misearch multi-isearch tramp-cache mule-util
tramp-sh tramp tramp-compat tramp-loaddefs trampver remember
bug-reference add-log sh-script smie dired-aux python json pig-mode
vc-hg make-mode view noutline outline vc-git diff-mode easy-mmode vc-dir
ewoc vc vc-dispatcher package epg-config dired midnight warnings gnus
gnus-ems nnheader mail-utils wid-edit bbdb-mua bbdb-com crm mailabbrev
bbdb-loaddefs bbdb bbdb-site timezone rcirc server which-func imenu
url-handlers url-parse auth-source cl-macs eieio byte-opt bytecomp
byte-compile cl-extra cconv eieio-core gnus-util mm-util mail-prsvr
password-cache url-vars paren help-at-pt desktop frameset cus-start
cus-load ido ess-toolbar ess-mouse mouseme thingatpt browse-url ess-menu
ess-swv ess-noweb ess-noweb-font-lock-mode ess-bugs-l essd-els ess-sas-d
ess-sas-l ess-sas-a shell pcomplete ess-sta-d ess-sta-l cc-vars cc-defs
make-regexp ess-sp6-d ess-sp3-d ess-julia ess-r-d compile ess-tracebug
format-spec ess-roxy advice help-fns hideshow ess-help ess-developer
ess-r-args ess-s-l ess ess-inf comint ansi-color ring ess-mode
ess-noweb-mode ess-utils ess-custom executable easymenu ess-compat
ess-site cl gv cl-loaddefs cl-lib time-date tooltip eldoc electric
uniquify ediff-hook vc-hooks lisp-float-type mwheel ns-win tool-bar dnd
fontset image regexp-opt fringe tabulated-list newcomment elisp-mode
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
cocoa ns multi-tty emacs)

Memory information:
((conses 16 2340516 126226)
 (symbols 48 65311 0)
 (miscs 40 101868 767)
 (strings 32 286040 38685)
 (string-bytes 1 13454818)
 (vectors 16 148643)
 (vector-slots 8 1800520 46530)
 (floats 8 612 1030)
 (intervals 56 578435 12684)
 (buffers 976 60))

-- 
Sam Steingold (http://sds.podval.org/) on darwin Ns 10.3.1343
http://www.childpsy.net/ http://americancensorship.org
http://mideasttruth.com http://honestreporting.com http://iris.org.il
People hear what they want to hear and discard the rest.