bug#27391: 25.2.50; utf-8 coding cookie is not applied on some specific markdown file

[Vincent Belaïche]

================================================================================

I was editing some file written in Markdown. Here is the file :

https://framagit.org/latex-pourquoi-comment/lpc-articles/blob/795ecb9d4f7b8870486fe6557f01d2fe450c4461/CONTRIBUTING.md

My Emacs default configuration was to get files in latin-1. So I had
added some `coding: utf-8' cookie in this file. But it did not work, the
file was still read in latin-1 instead of utf8.

I made a test with one more cookie `eval: (message "Hello")', this one
worked, which means that the problem is not that cookies aren't read,
the problem is within the application of the coding scheme.

The only way for me to get the correct encoding is to place:

(modify-coding-system-alist 'file "\\.m\\(d\\|arkdown\\)\\'"
  'prefer-utf-8)

In my init file.

I made the trial with `emacs -q', and the problem is still there, which
shows that markdown-mode is not to blame. My first thought was that
markdown-mode was the culprit, see discussion here :
https://github.com/jrblevin/markdown-mode/issues/198

Jason Blevin is the author of markdown-mode, he noted that the presence
of the [ character has some impact. See:

https://github.com/jrblevin/markdown-mode/issues/198#issuecomment-308524696

I did not double check his analysis. To me this looks like some race
problem where the automatic encoding detection is applied after the
cookie and undoes it. Maybe some semaphore is missing, or something like
that.

   Vincent.

================================================================================


In GNU Emacs 25.2.50.1 (i686-pc-mingw32)
 of 2017-06-14 built on AIGLEROYAL
Repository revision: da62c1532e479bbac4ce242ee1d170df9c435591
Windowing system distributor 'Microsoft Corp.', version 10.0.14393
Configured using:
 'configure --prefix=c:/Nos_Programmes/GNU/Emacs --without-jpeg
 --without-tiff --without-gif --without-png 'CFLAGS= -Og -g3 -L
 C:/Programmes/installation/emacs-install/libXpm-3.5.8/src' 'CPPFLAGS=
 -DFOR_MSW=1 -I
 C:/Programmes/installation/emacs-install/libXpm-3.5.8/include -I
 C:/Programmes/installation/emacs-install/libXpm-3.5.8/src -L
 C:/Programmes/installation/emacs-install/libXpm-3.5.8/src''

Configured features:
XPM SOUND NOTIFY ACL TOOLKIT_SCROLL_BARS

Important settings:
  value of $LANG: FRA
  locale-coding-system: cp1252

Major mode: Dired by name

Minor modes in effect:
  diff-auto-refine-mode: t
  TeX-PDF-mode: t
  shell-dirtrack-mode: t
  recentf-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

Recent messages:
Mark set [2 times]
Mark saved where search started
Quit
scroll-up-command: End of buffer
Mark set
find-dired *Find* finished.
dired-get-file-for-visit: No file on this line [2 times]
Mark set
Quit
Making completion list...

Load-path shadows:
c:/Programmes/installation/cedet-install/cedet-git/lisp/speedbar/loaddefs hides 
c:/Nos_Programmes/GNU/Emacs/share/emacs/25.2.50/lisp/loaddefs
c:/Programmes/installation/cedet-install/cedet-git/lisp/speedbar/loaddefs hides 
c:/Programmes/installation/cedet-install/cedet-git/lisp/cedet/loaddefs

Features:
(shadow emacsbug find-dired calc-yank calc-mode calccomp calc-alg
calc-vec calc-aent calc-menu cal-move whitespace perl-mode log-edit
pcvs-util eieio-opt speedbar sb-image ezimage dframe vc-bzr vc-src
vc-sccs vc-svn vc-rcs vc-dir ewoc add-log org-element org-rmail org-mhe
org-irc org-info org-gnus org-docview doc-view subr-x jka-compr
image-mode org-bibtex bibtex org-bbdb org-w3m org org-macro org-footnote
org-pcomplete org-list org-faces org-entities org-version ob-emacs-lisp
ob ob-tangle ob-ref ob-lob ob-table ob-exp org-src ob-keys ob-comint
ob-core ob-eval org-compat org-macs org-loaddefs find-func cal-menu
calendar cal-loaddefs tex-info texinfo vc vc-dispatcher ediff-vers
thingatpt rect visual-basic-mode sh-script smie executable make-mode
misearch multi-isearch ediff-merg ediff-wind ediff-diff ediff-mult
ediff-help ediff-init ediff-util ediff vc-git diff-mode reftex-dcr
reftex reftex-vars preview prv-emacs noutline outline pcmpl-unix
latexenc tex-bar latex easy-mmode tex-style toolbar-x font-latex
plain-tex tex-buf tex advice tex-mode compile shell pcomplete comint
ansi-color ring bbdb-print info mailalias smtpmail sort ispell vc-cvs
hl-line balance eieio-compat calc-forms dired-aux mail-extr bbdb-message
sendmail gnus-async qp gnus-ml cursor-sensor nndraft nnmh nnfolder
bbdb-gnus bbdb-mua bbdb-com crm network-stream nsm auth-source eieio
eieio-core starttls gnus-agent gnus-srvr gnus-score score-mode nnvirtual
gnus-msg gnus-art mm-uu mml2015 mm-view mml-smime smime dig mailcap nntp
gnus-cache gnus-sum gnus-group gnus-undo gnus-start gnus-cloud nnimap
nnmail mail-source tls gnutls utf7 netrc nnoo parse-time gnus-spec
gnus-int gnus-range message dired-x dired format-spec rfc822 mml mml-sec
password-cache epg mm-decode mm-bodies mm-encode mail-parse rfc2231
rfc2047 rfc2045 ietf-drums mailabbrev gmm-utils mailheader gnus-win gnus
gnus-ems nnheader gnus-util mail-utils mm-util help-fns mail-prsvr
edmacro kmacro skeleton calc-misc calc-arith calc-ext calc calc-loaddefs
calc-macs tex-mik preview-latex tex-site auto-loads bbdb bbdb-site
timezone bbdb-loaddefs template w32utils cl-seq cl-macs cl recentf
tree-widget wid-edit load-path-to-cedet-svn finder-inf package
epg-config seq byte-opt gv bytecomp byte-compile cl-extra help-mode
easymenu cconv cl-loaddefs pcase cl-lib time-date mule-util tooltip
eldoc electric uniquify ediff-hook vc-hooks lisp-float-type mwheel
dos-w32 ls-lisp disp-table w32-win w32-vars term/common-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
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 charscript
case-table epa-hook jka-cmpr-hook help simple abbrev minibuffer
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 w32notify w32 multi-tty
make-network-process emacs)

Memory information:
((conses 8 899957 158092)
 (symbols 32 53590 0)
 (miscs 32 2257 2796)
 (strings 16 133750 20600)
 (string-bytes 1 5975277)
 (vectors 8 55330)
 (vector-slots 4 1716681 54830)
 (floats 8 651 494)
 (intervals 28 72632 8079)
 (buffers 516 78))

---
L'absence de virus dans ce courrier électronique a été vérifiée par le logiciel 
antivirus Avast.
https://www.avast.com/antivirus