bug#23181: 25.1.50; rmail renders text left to right when it shouldn't

[ams@gnu.org (Alfred M. Szmidt)]

When I get a message that is detected as written in Arabic, it renders
left to right.  But any messages subsequent I read -- even if pure
7-bit ASCII, will continue to render left to right.  E.g (note the
screwed up punctuation):

                              X-Spam-Status: No, score=-0.2 required=5.0 tests=BAYES_50,RP_MATCHES_RCVD
                                                                       autolearn=disabled version=3.3.2
                                                                       <From: Werner Koch <wk@gnupg.org
                                                         To: gnupg-announce@gnupg.org, info-gnu@gnu.org
                                                                         Subject: GnuPG 2.0.29 released
                                                                            Organisation: g10 Code GmbH
                                                                Mail-Followup-To: gnupg-users@gnupg.org
                                                                  Date: Thu, 31 Mar 2016 13:12:40 +0200
                         "==Content-Type: multipart/mixed; boundary="===============8795560078139731226


                                                                              [1:multipart/signed Hide]


                                                                                  [1/1:text/plain Hide]

                                                                                                 !Hello

                                  We are pleased to announce the availability of a new stable GnuPG-2.0
                                  release: Version 2.0.30.  This is a maintenance release which fixes a
                                                                                        .couple of bugs

                                 The GNU Privacy Guard (GnuPG) is a complete and free implementation of
                                   .the OpenPGP standard as defined by RFC-4880 and better known as PGP



In GNU Emacs 25.1.50.1 (x86_64-unknown-linux-gnu, GTK+ Version 3.18.8)
 of 2016-03-02 built on berylium
Repository revision: 7d69780681bd68a052a3b2ee814675b78d4a5063
Windowing system distributor 'The X.Org Foundation', version 11.0.11801000
Configured features:
XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND GPM DBUS GCONF GSETTINGS
NOTIFY ACL GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB
TOOLKIT_SCROLL_BARS GTK3 X11

Important settings:
  value of $LANG: C
  locale-coding-system: nil

Major mode: RMAIL

Minor modes in effect:
  shell-dirtrack-mode: t
  rcirc-track-minor-mode: t
  diff-auto-refine-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
  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:
Showing message 3748...done
Showing message 3749...done
Showing message 3750...done
Showing message 3751...done
Showing message 4344...done
Showing message 4474...done
Mark set [2 times]
Saved text until "tps://www.gnu.org/help/evaluation.html.
"
Making completion list...

Load-path shadows:
~/loaddefs hides /home/ams/emacs/lisp/loaddefs

Features:
(shadow emacsbug python js json info scheme idlwave idlwave-help
idlw-help cl-indent diary-lib diary-loaddefs rot13 warnings nroff-mode
asm-mode novice bookmark iso-transl cal-move debug goto-addr map view
ps-mode tramp-cmds thai-util thai-word ruler-mode hl-line hexl
eieio-opt speedbar sb-image ezimage dframe help-fns ibuf-ext ibuffer
ibuffer-loaddefs smerge-mode face-remap rmailedit macros timezone sort
parse-time fortran cus-edit url-http url-gw url-cache url-auth eww
mm-url gnus nnheader wid-edit url-queue url url-proxy url-privacy
url-expand url-methods url-history url-cookie url-domsuf mailcap
rng-xsd xsd-regexp rng-cmpct rng-nxml rng-valid rng-loc rng-uri
rng-parse nxml-parse rng-match rng-dt rng-util rng-pttrn nxml-ns
nxml-mode nxml-outln nxml-rap sgml-mode nxml-util nxml-enc xmltok
verilog-mode tar-mode org-element org-rmail org-mhe org-irc org-info
org-gnus org-docview doc-view 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 sh-script executable mule-diag ispell diff cc-mode
cc-fonts cc-guess cc-menus cc-cmds cc-styles cc-align cc-engine
cc-vars cc-defs two-column battery tabify imenu man ediff-ptch
ediff-merg ediff-wind ediff-diff ediff-mult ediff-help ediff-init
ediff-util ediff vc-bzr vc-src vc-sccs vc-svn vc-cvs vc-rcs vc-dir
ewoc ruby-mode smie log-view wdired tramp-cache tramp-sh tramp
tramp-compat tramp-loaddefs trampver ucs-normalize conf-mode dabbrev
make-mode pcmpl-gnu log-edit pcvs-util add-log ansible-doc rx
yaml-mode grep vc vc-dispatcher markdown-mode pcmpl-unix shell
dired-aux network-stream puny nsm starttls tls gnutls rect
character-fold misearch multi-isearch cus-start cus-load quail
rmailout qp rmailsum url-util url-parse auth-source url-vars shr-color
color shr svg xml seq dom subr-x rmailmm message dired dired-loaddefs
format-spec rfc822 mml mml-sec password-cache epa epg epg-config
gnus-util mm-decode mm-bodies mm-encode mailabbrev gmm-utils
mailheader mail-parse rfc2231 rmail rmail-loaddefs em-unix em-term
term ehelp em-script em-prompt em-ls em-hist em-pred em-glob em-dirs
em-cmpl em-basic em-banner em-alias pcomplete esh-var esh-io esh-cmd
esh-opt esh-ext esh-proc esh-arg esh-groups eshell esh-module esh-mode
esh-util repeat server rcirc mail-queue sendmail rfc2047 rfc2045
ietf-drums mm-util mail-prsvr mail-utils slime-fancy
slime-trace-dialog slime-fontifying-fu slime-package-fu
slime-references slime-compiler-notes-tree slime-scratch
slime-presentations advice bridge slime-mdot-fu
slime-enclosing-context slime-fuzzy slime-fancy-trace
slime-fancy-inspector slime-c-p-c slime-editing-commands slime-autodoc
slime-repl elp slime-parse slime derived edmacro kmacro gud apropos
compile etags xref cl-seq project eieio byte-opt bytecomp byte-compile
cl-extra help-mode cconv eieio-core eieio-loaddefs arc-mode
archive-mode noutline outline pp comint ansi-color ring hyperspec
thingatpt browse-url slime-autoloads cl-macs vc-git diff-mode easymenu
easy-mmode time-date autoload lisp-mnt cl gv cl-loaddefs pcase cl-lib
disp-table mule-util tooltip eldoc electric uniquify ediff-hook
vc-hooks lisp-float-type mwheel term/x-win x-win term/common-win x-dnd
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 term/tty-colors 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 obarray 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 dbusbind inotify dynamic-setting
system-font-setting font-render-setting move-toolbar gtk x-toolkit x
multi-tty make-network-process emacs)

Memory information:
((conses 16 1214639 992995)
 (symbols 48 80544 49)
 (miscs 40 51587 29422)
 (strings 32 199545 102612)
 (string-bytes 1 6450580)
 (vectors 16 91883)
 (vector-slots 8 2413156 93103)
 (floats 8 821 2444)
 (intervals 56 129137 27576)
 (buffers 976 185)
 (heap 1024 309626 475483))