Subject: bug#59650: 29.0.50; Eshell: Non-idempotent behavior of undefined commands

From: Milan Zimmermann <[email-masked]>
Date: Mon, 28 Nov 2022 03:33:00 -0500

I am reporting this realizing, this non-idempotent behavior will likely
not be considered a bug.

However, in a scripting language, when one would want to use scripts not
attended, it is disturbing (at least, to me).

Try any command that does not exist, four (4) times. The first three
times, we get "Command not found". The fourth time, we are prompted for
an alias. This is not desirable. If anything, why not ask the first time?

========================
~/tmp $ 1
1: command not found
~/tmp $ 1
1: command not found
~/tmp $ 1
1: command not found
~/tmp $ 1 ### Prompt: Define alias for "1"
========================

Is there a way to change this, to never ask for an alias? I
apologize if I missed some customization, I did look quite a bit.

Addendum:
=================================
I also offer this slant on the issue:

~/tmp $ if ${> 3 1} {echo "FIRST"} {echo "SECOND"}
FIRST
~/tmp $ if ${> 3 1} {echo "FIRST"} {echo "SECOND"}
FIRST
~/tmp $ if ${> 3 1} {echo "FIRST"} {echo "SECOND"}
FIRST
~/tmp $ if ${> 3 1} {echo "FIRST"} {echo "SECOND"} ###  Prompt: Define
alias for "nil"

This actually shows a bug in the conditionals. I assume the test returns
nil which for some reason is, on the 4th attempt to considered a
command?

Maybe it is confused because of this behavior:

~/tmp $ if ${< 3 1} {echo "FIRST"} {echo "SECOND"}
Eshell does not support input redirection

and same here:

~/tmp $ if {< 3 1} {echo "FIRST"} {echo "SECOND"}
Eshell does not support input redirection

I assume all this should be reported as a separate bug?

Thanks
Milan

In GNU Emacs 29.0.50 (build 1, x86_64-suse-linux-gnu, GTK+ Version
3.24.34, cairo version 1.17.6)
System Description: openSUSE Tumbleweed

Configured using:
 'configure --host=x86_64-suse-linux-gnu --build=x86_64-suse-linux-gnu
 --program-prefix= --disable-dependency-tracking --prefix=/usr
 --exec-prefix=/usr --bindir=/usr/bin --sbindir=/usr/sbin
 --sysconfdir=/etc --datadir=/usr/share --includedir=/usr/include
 --libdir=/usr/lib64 --libexecdir=/usr/libexec --localstatedir=/var
 --sharedstatedir=/var/lib --mandir=/usr/share/man
 --infodir=/usr/share/info --disable-build-details --without-pop
 --with-mailutils --without-hesiod --with-gameuser=:games
 --with-kerberos --with-kerberos5 --with-file-notification=inotify
 --with-modules --enable-autodepend --prefix=/usr
 --mandir=/usr/share/man --infodir=/usr/share/info --datadir=/usr/share
 --localstatedir=/var --sharedstatedir=/var/lib
 --libexecdir=/usr/libexec --with-file-notification=yes
 --enable-locallisppath=/usr/share/emacs/29.0.50/site-lisp:/usr/share/emacs/site-lisp
 --without-x --with-json --without-xim --with-sound --with-xpm
 --with-jpeg --with-tiff --with-gif --with-png --with-rsvg --with-dbus
 --without-xft --without-gpm --with-pgtk --without-native-compilation
 --with-toolkit-scroll-bars --with-libotf --with-m17n-flt --with-cairo
 --without-xwidgets --with-dumping=pdumper 'CFLAGS=-O2 -Wall
 -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=3 -fstack-protector-strong
 -funwind-tables -fasynchronous-unwind-tables -fstack-clash-protection
 -Werror=return-type -flto=auto -D_GNU_SOURCE
 -DGDK_DISABLE_DEPRECATION_WARNINGS -DGLIB_DISABLE_DEPRECATION_WARNINGS'
 LDFLAGS=-flto=auto'

Configured features:
ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GSETTINGS HARFBUZZ JPEG JSON
LCMS2 LIBOTF LIBSELINUX LIBSYSTEMD LIBXML2 MODULES NOTIFY INOTIFY
PDUMPER PGTK PNG RSVG SECCOMP SOUND SQLITE3 THREADS TIFF
TOOLKIT_SCROLL_BARS WEBP XIM GTK3 ZLIB

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

Major mode: Eshell

Minor modes in effect:
  shell-dirtrack-mode: t
  eshell-prompt-mode: t
  eshell-hist-mode: t
  eshell-pred-mode: t
  eshell-cmpl-mode: t
  eshell-proc-mode: t
  eshell-arg-mode: t
  tooltip-mode: t
  global-eldoc-mode: t
  show-paren-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
  line-number-mode: t
  indent-tabs-mode: t
  transient-mark-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message mailcap yank-media puny dired
dired-loaddefs rfc822 mml mml-sec password-cache epa derived epg rfc6068
epg-config gnus-util text-property-search mm-decode mm-bodies mm-encode
mail-parse rfc2231 mailabbrev gmm-utils mailheader sendmail rfc2047
rfc2045 ietf-drums mm-util mail-prsvr mail-utils time-date cl-seq
em-unix em-term term disp-table shell subr-x ehelp em-script em-prompt
em-ls em-hist em-pred em-glob em-extpipe em-cmpl em-dirs esh-var
pcomplete comint ansi-osc ansi-color ring em-basic em-banner em-alias
esh-mode eshell esh-cmd generator esh-ext esh-opt esh-proc esh-io
esh-arg esh-module esh-groups esh-util cus-edit pp cus-start cus-load
icons wid-edit cl-loaddefs cl-lib files-x rmc iso-transl tooltip cconv
eldoc paren electric uniquify ediff-hook vc-hooks lisp-float-type
elisp-mode mwheel term/pgtk-win pgtk-win term/common-win pgtk-dnd
tool-bar dnd fontset image regexp-opt fringe tabulated-list replace
newcomment text-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 nadvice seq
simple cl-generic indonesian philippine 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 emoji-zwj charscript charprop case-table
epa-hook jka-cmpr-hook help abbrev obarray oclosure cl-preloaded button
loaddefs theme-loaddefs faces cus-face macroexp files window
text-properties overlay sha1 md5 base64 format env code-pages mule
custom widget keymap hashtable-print-readable backquote threads dbusbind
inotify dynamic-setting system-font-setting font-render-setting cairo
gtk pgtk lcms2 multi-tty make-network-process emacs)

Memory information:
((conses 16 77472 8445)
 (symbols 48 8768 0)
 (strings 32 24219 1387)
 (string-bytes 1 726949)
 (vectors 16 14928)
 (vector-slots 8 203659 15195)
 (floats 8 34 36)
 (intervals 56 345 0)
 (buffers 984 11))