bug#39545: 26.3; C-S-a gets translated to C-a in message-mode

[Kuba Orlik (sealcode.org)]

1. M-x message-mode
2. Enter some text
3. Press C-S-a

The point moves to the beggining of the line, but doesn't select the
text along the way, as C-S-a usually does


In GNU Emacs 26.3 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.10)
 of 2019-08-29 built on juergen
Windowing system distributor 'The X.Org Foundation', version 11.0.12007000
System Description:     Manjaro Linux

Recent messages:
Are you sure you want to execute 2 marks? (y or n) y
Are you sure you want to execute 1 mark? (y or n) y [2 times]
Are you sure you want to execute 2 marks? (y or n) y
Are you sure you want to execute 1 mark? (y or n) y
Template key: 
Invalid key ‘r’
Template key: 
Invalid key ‘e’
Template key: 
user-error: Abort
Quit
Configured using:
 'configure --prefix=/usr --sysconfdir=/etc --libexecdir=/usr/lib
 --localstatedir=/var --with-x-toolkit=gtk3 --with-xft --with-modules
 'CFLAGS=-march=x86-64 -mtune=generic -O2 -pipe -fno-plt'
 CPPFLAGS=-D_FORTIFY_SOURCE=2
 LDFLAGS=-Wl,-O1,--sort-common,--as-needed,-z,relro,-z,now'

Configured features:
XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND GPM DBUS GSETTINGS GLIB
NOTIFY ACL GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB
TOOLKIT_SCROLL_BARS GTK3 X11 XDBE XIM MODULES THREADS LIBSYSTEMD LCMS2

Important settings:
  value of $LC_MESSAGES: en_GB.UTF-8
  value of $LC_MONETARY: en_GB.UTF-8
  value of $LC_TIME: en_GB.UTF-8
  value of $LANG: en_GB.utf8
  value of $XMODIFIERS: @im=ibus
  locale-coding-system: utf-8-unix

Major mode: mu4e:view

Minor modes in effect:
  diff-auto-refine-mode: t
  override-global-mode: t
  delete-selection-mode: t
  global-edit-server-edit-mode: t
  projectile-mode: t
  my-override-mode: t
  show-paren-mode: t
  tooltip-mode: t
  global-eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-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

Load-path shadows:
None found.

Features:
(shadow emacsbug network-stream nsm starttls mailalias qp mail-extr sort
winner helm-buffers helm-occur helm-grep helm-regexp helm-utils
helm-help helm-types helm helm-source eieio-compat helm-multi-match
helm-lib async face-remap misearch multi-isearch xref project timezone
shr-color url-util shr svg xml dom bookmark pp tabify vc-git diff-mode
org-rmail org-mhe org-irc org-info org-gnus nnir org-docview org-bibtex
bibtex org-bbdb org-w3m org-capture cl org-mu4e org-element avl-tree
generator org org-macro org-footnote org-pcomplete pcomplete org-list
org-faces org-entities noutline outline 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 find-func mu4e desktop
frameset mu4e-speedbar speedbar sb-image ezimage dframe mu4e-main
mu4e-view cal-menu calendar cal-loaddefs browse-url 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 tls gnutls
utf7 netrc nnoo parse-time gnus-spec gnus-int gnus-range gnus-win gnus
nnheader wid-edit mu4e-headers mu4e-compose mu4e-context mu4e-draft
mu4e-actions ido rfc2368 smtpmail sendmail mu4e-mark mu4e-message
flow-fill mu4e-proc mu4e-utils doc-view jka-compr image-mode mu4e-lists
mu4e-vars message rmc puny dired dired-loaddefs format-spec rfc822 mml
mml-sec epa derived epg gnus-util rmail rmail-loaddefs mm-decode
mm-bodies mm-encode mail-parse rfc2231 rfc2047 rfc2045 mm-util
ietf-drums mail-prsvr mailabbrev mail-utils gmm-utils mailheader
mu4e-meta elec-pair time solarized-light-theme solarized-palettes
solarized solarized-faces color dash use-package use-package-ensure
use-package-delight use-package-diminish use-package-bind-key bind-key
cl-extra help-mode use-package-core delsel edit-server advice projectile
grep compile comint ansi-color ring ibuf-ext ibuffer ibuffer-loaddefs
thingatpt finder-inf rx info package easymenu epg-config url-handlers
url-parse auth-source cl-seq eieio eieio-core cl-macs eieio-loaddefs
password-cache url-vars seq byte-opt gv bytecomp byte-compile cconv
easy-mmode edmacro kmacro cl-loaddefs cl-lib paren hl-line time-date
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 replace newcomment
text-mode elisp-mode lisp-mode prog-mode register page menu-bar
rfn-eshadow isearch 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 composite charscript charprop
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 threads dbusbind
inotify lcms2 dynamic-setting system-font-setting font-render-setting
move-toolbar gtk x-toolkit x multi-tty make-network-process emacs)

Memory information:
((conses 16 482154 55142)
 (symbols 48 47900 1)
 (miscs 40 814 793)
 (strings 32 148961 6814)
 (string-bytes 1 4410463)
 (vectors 16 54773)
 (vector-slots 8 1655749 52308)
 (floats 8 619 360)
 (intervals 56 1530 1168)
 (buffers 992 28))