bug#47432: 28.0.50; Dired using ! or & on file should fail without command supplied

[Jean Louis]

In Dired, when using ! or & on a file, it should file if there is no
command supplied.

This is what happens if I use ! on file ~/.asoundrc but without
supplying command, just pressing RET:

/bin/bash: line 1: .asoundrc: command not found

But it should not, if command is not supplied in:
(dired-do-shell-command COMMAND &optional ARG FILE-LIST) -- then it
shall rather silently fail or tell "Command not entered" or nothing to
do.

Same for (dired-do-async-shell-command COMMAND &optional ARG FILE-LIST)





In GNU Emacs 28.0.50 (build 2, x86_64-pc-linux-gnu, X toolkit, cairo version 
1.17.4, Xaw scroll bars)
 of 2021-03-22 built on protected.rcdrun.com
Repository revision: cb5d1fe1aa9f280d60fcb33b58fc83ace3d95081
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12010000
Configured using:
 'configure --with-x-toolkit=lucid'

Configured features:
ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GPM GSETTINGS HARFBUZZ JPEG
JSON LCMS2 LIBOTF LIBSYSTEMD LIBXML2 M17N_FLT MODULES NOTIFY INOTIFY
PDUMPER PNG RSVG SOUND THREADS TIFF TOOLKIT_SCROLL_BARS X11 XDBE XIM XPM
LUCID ZLIB

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

Major mode: Dired by name

Minor modes in effect:
  shell-dirtrack-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

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message rmc puny rfc822 mml mml-sec epa
derived epg epg-config gnus-util rmail rmail-loaddefs auth-source cl-seq
eieio eieio-core cl-macs eieio-loaddefs password-cache json map
text-property-search time-date subr-x seq byte-opt gv bytecomp
byte-compile cconv mm-decode mm-bodies mm-encode mail-parse rfc2231
mailabbrev gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums
mm-util mail-prsvr mail-utils shell pcomplete comint ansi-color ring
dired-aux cl-loaddefs cl-lib dired dired-loaddefs iso-transl 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 tab-bar menu-bar rfn-eshadow isearch
easymenu timer select scroll-bar mouse jit-lock font-lock syntax
font-core term/tty-colors frame minibuffer 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
cl-preloaded nadvice button loaddefs faces cus-face macroexp files
window 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
cairo x-toolkit x multi-tty make-network-process emacs)

Memory information:
((conses 16 69609 8322)
 (symbols 48 7679 0)
 (strings 32 22446 2230)
 (string-bytes 1 727018)
 (vectors 16 14870)
 (vector-slots 8 197548 10923)
 (floats 8 23 36)
 (intervals 56 2480 0)
 (buffers 992 13))

-- 
Thanks,
Jean Louis
⎔ λ 🄯 𝍄 𝌡 𝌚