bug#46332: Eshell color control characters not displayed correctly

[Morgan Smith <Morgan.J.Smith@outlook.com>]

Hi Lars,

Thanks for all the hard work you do! I read your blog :)


I can't seem to be able to not reproduce this. Meaning no matter what I
do the bug shows up. Maybe it's a compile flag issue? I'm using guix to
build emacs so I'm wondering if you're willing to install guix (just the
package manager, not the operating system) to check if that's the issue.

Using this command I'm able to recreate the bug. This command boots up a
container, creates a user for the container, and exposes pretty much
nothing except the current working directory (so do this in a git
repository to check). I expose /tmp too because X11 seems to want it but
you might not have to.

guix environment --preserve='^DISPLAY$' --expose=/tmp
--with-commit=emacs-next=817a49748f0cd7f746ce1895d7c31c086289a91e
--with-git-url=emacs-next=/home/USERNAME/src/emacs --user=testyboi -C
--ad-hoc emacs-next git -- emacs -Q

Then M-x eshell
Then type: git log --color

Around 300 lines later, the control characters start being printed
verbatim. The amount of time until it happens seems to vary sometimes,
but it always seems to happen eventually.


If you don't want to install guix, I'll include the bug report stuff here:


In GNU Emacs 28.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version
3.24.24, cairo version 1.16.0)
Windowing system distributor 'The X.Org Foundation', version 11.0.12010000
Configured using:
 'configure
 CONFIG_SHELL=/gnu/store/pwcp239kjf7lnj5i4lkdzcfcxwcfyk72-bash-minimal-5.0.16/bin/bash
 SHELL=/gnu/store/pwcp239kjf7lnj5i4lkdzcfcxwcfyk72-bash-minimal-5.0.16/bin/bash
 --prefix=/gnu/store/s0gxsqli2jx89sdj5xli8l44i7g49slr-emacs-next-git.817a497
 --enable-fast-install --with-modules --with-cairo
 --disable-build-details'

Configured features:
ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GSETTINGS HARFBUZZ JPEG JSON
LIBOTF LIBSELINUX LIBXML2 M17N_FLT MODULES NOTIFY INOTIFY PDUMPER PNG
RSVG SOUND THREADS TIFF TOOLKIT_SCROLL_BARS X11 XDBE XIM XPM GTK3 ZLIB

Important settings:
  value of $EMACSLOADPATH:
/gnu/store/1wbb10gwhahy7gmh8n9csza1cl2mipwy-profile/share/emacs/site-lisp:/gnu/store/1wbb10gwhahy7gmh8n9csza1cl2mipwy-profile/share/emacs/28.0.50/lisp
  locale-coding-system: nil

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
  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:
(shadow sort mail-extr emacsbug message rmc puny dired dired-loaddefs
rfc822 mml mml-sec epa derived epg epg-config gnus-util rmail
rmail-loaddefs auth-source 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 cl-seq em-unix em-term
term disp-table easymenu shell ehelp em-script em-prompt em-ls
cl-loaddefs cl-lib em-hist em-pred em-glob em-dirs esh-var em-cmpl
pcomplete comint ansi-color ring em-basic em-banner em-alias esh-mode
eshell esh-cmd esh-ext esh-opt esh-proc esh-io esh-arg esh-module
esh-groups esh-util 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 timer
select scroll-bar mouse jit-lock font-lock syntax facemenu 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
dynamic-setting system-font-setting font-render-setting cairo
move-toolbar gtk x-toolkit x multi-tty make-network-process emacs)

Memory information:
((conses 16 69622 6268)
 (symbols 48 8356 1)
 (strings 32 24845 1877)
 (string-bytes 1 835448)
 (vectors 16 14757)
 (vector-slots 8 195777 13108)
 (floats 8 27 32)
 (intervals 56 641 0)
 (buffers 984 12))