bug#32555: 26.1; Async command buffer navigation bug

[Live System User]

Hi,

        After an `async-shell-command' finished, I tried to
        navigate its buffer with the arrow-keys and got the
        following:

Debugger entered--Lisp error: (wrong-type-argument processp nil)
  process-mark(nil)
  comint-after-pmark-p()
  (if (comint-after-pmark-p) (comint-previous-input 1) (previous-line 1))
  (lambda nil (interactive) (if (comint-after-pmark-p) (comint-previous-input 
1) (previous-line 1)))()
  funcall-interactively((lambda nil (interactive) (if (comint-after-pmark-p) 
(comint-previous-input 1) (previous-line 1))))
  call-interactively((lambda nil (interactive) (if (comint-after-pmark-p) 
(comint-previous-input 1) (previous-line 1))) nil nil)
  command-execute((lambda nil (interactive) (if (comint-after-pmark-p) 
(comint-previous-input 1) (previous-line 1))))


  Thanks.




In GNU Emacs 26.1 (build 3, x86_64-pc-linux-gnu, GTK+ Version 3.20.6)
 of 2018-06-26 built on localhost.localdomain
Windowing system distributor 'Fedora Project', version 11.0.11803000
Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
Making completion list...

Configured using:
 'configure 'CFLAGS=-DMAIL_USE_LOCKF -O0 -ggdb3 -pipe -Wall
 -Werror=format-security -fexceptions -fstack-protector-strong
 --param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic'
 LDFLAGS=-Wl,-z,relro
 --prefix=/tmp/emacs-26.1 --with-dbus
 --with-gif --with-jpeg --with-png --with-rsvg --with-lcms2 --with-tiff
 --with-xft --with-xpm --with-x-toolkit=gtk3 --with-gpm=yes
 --with-xwidgets --with-modules'

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

Important settings:
  value of $LANG: en_US.UTF-8
  value of $XMODIFIERS: @im=ibus
  locale-coding-system: utf-8-unix

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-mode: t
  global-eldoc-mode: t
  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
  line-number-mode: t
  transient-mark-mode: t

Load-path shadows:
None found.

Features:
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format-spec rfc822 mml easymenu mml-sec password-cache epa derived epg
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mail-parse rfc2231 mailabbrev gmm-utils mailheader sendmail rfc2047
rfc2045 ietf-drums mm-util mail-prsvr mail-utils elec-pair 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
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custom widget hashtable-print-readable backquote dbusbind inotify lcms2
dynamic-setting system-font-setting font-render-setting xwidget-internal
move-toolbar gtk x-toolkit x multi-tty make-network-process emacs)

Memory information:
((conses 16 96036 8641)
 (symbols 48 20390 1)
 (miscs 40 39 119)
 (strings 32 28829 1396)
 (string-bytes 1 764526)
 (vectors 16 14653)
 (vector-slots 8 497302 7330)
 (floats 8 49 304)
 (intervals 56 248 0)
 (buffers 992 12)
 (heap 1024 34169 1076))