bug#40589: ^L printed when resizing Emacs split window using ksh93

bug#40589: ^L printed when resizing Emacs split window using ksh93

[Nicholas Papadonis]

[-- Attachment #1: Type: text/plain, Size: 939 bytes --]

I have attached a screen shot of the issue.  The issue occurs when Emacs is in split window mode, X session and M-x shell is invoked.  The shell is ksh93.  I tried finding the Emacs bug tracker, however this is the only method I found to file a bug. This has been reproduced by others.

Screenshot of issue:
http://nickpapadonis.com/images-share/emacs-ksh-0.png <http://nickpapadonis.com/images-share/emacs-ksh-0.png>

PS2 is printed multiple times during the resize.  When entered is pressed after the resize, multiple ^L s are displayed.  I set PS2="" and the brackets are omitted, however ^L still remain after pressing enter.

Is this a known issue?  I have CC'd KSH list in case the problem is on the ksh93 side.

Thanks

Emacs 26.1 build 2.

1 [debian:~]$ echo $0
-ksh93
2 [debian:~]$ ksh93 --version
  version         sh (AT&T Research) 93u+ 2012-08-01
3 [debian:~]$ echo ${.sh.version}
Version AJM 93u+ 2012-08-01

[-- Attachment #2: Type: text/html, Size: 1665 bytes --]

bug#40589: ^L printed when resizing Emacs split window using ksh93

[Mike Kupfer]

Nicholas Papadonis wrote:

> PS2 is printed multiple times during the resize.  When entered is
> pressed after the resize, multiple ^L s are displayed.  I set PS2=""
> and the brackets are omitted, however ^L still remain after pressing
> enter.
> 
> Is this a known issue?

Yes.  Here's the text from the Emacs PROBLEMS file:

  *** In Shell buffers using ksh, resizing a window inserts random characters.
  
  The characters come from the PS2 prompt, but they are not followed by
  a newline, which messes up the next command you type.  This strange
  effect is caused by Emacs 25 and later telling the shell that its
  screen size changed.
  
  To work around the problem, customize the option
  'window-adjust-process-window-size-function' to "Do not adjust process
  window sizes" (Lisp value 'ignore').
  
regards,
mike

bug#40589: ^L printed when resizing Emacs split window using ksh93

[Lars Ingebrigtsen]

Mike Kupfer <mkupfer@alum.berkeley.edu> writes:

>> PS2 is printed multiple times during the resize.  When entered is
>> pressed after the resize, multiple ^L s are displayed.  I set PS2=""
>> and the brackets are omitted, however ^L still remain after pressing
>> enter.
>> 
>> Is this a known issue?
>
> Yes.  Here's the text from the Emacs PROBLEMS file:
>
>   *** In Shell buffers using ksh, resizing a window inserts random characters.

I tried to reproduce this in Emacs 26.1 (and 28), but I was unable to.
Do you have a recipe, starting from "emacs -Q", that displays the
problem?

I tried:

emacs -Q
(setq shell-file-name "/bin/ksh")
M-x shell

and then resizing the window, and nothing untoward happened.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

bug#40589: ^L printed when resizing Emacs split window using ksh93

[Mike Kupfer]

Lars Ingebrigtsen wrote:

> I tried to reproduce this in Emacs 26.1 (and 28), but I was unable to.
> Do you have a recipe, starting from "emacs -Q", that displays the
> problem?
> 
> I tried:
> 
> emacs -Q
> (setq shell-file-name "/bin/ksh")
> M-x shell
> 
> and then resizing the window, and nothing untoward happened.

Try

  emacs -Q
  M-x shell
  $ ksh
  C-x 2

On my Debian desktop (running Buster), that's enough to provoke
misbehavior, without even resizing.  Resizing just makes the issue more
apparent. :-) This is with Emacs 27.2 and Emacs 28 (15c57fc4cc); the
build information for Emacs 28 is below.  (The git changeset doesn't
match what I just wrote because my build includes a couple MH-E fixes
that I need to get reviewed before pushing to savannah.)

I also see the problem on a Debian Bullseye test system, using the
bundled Emacs 27.1 (emacs-lucid build).

cheers,
mike

In GNU Emacs 28.0.50 (build 5, x86_64-pc-linux-gnu, X toolkit, cairo version 1.16.0, Xaw scroll bars)
 of 2021-06-06 built on alto
Repository revision: d933668e2d15cbb8e1fa367d97d2bff2559ff838
Repository branch: master-mdk
Windowing system distributor 'The X.Org Foundation', version 11.0.12004000
System Description: Debian GNU/Linux 10 (buster)

Configured using:
 'configure --prefix=/usr/new'

Configured features:
CAIRO FREETYPE GIF GLIB GMP GNUTLS GSETTINGS HARFBUZZ JPEG LIBSELINUX
LIBXML2 MODULES NOTIFY INOTIFY PDUMPER PNG SECCOMP SOUND THREADS TIFF
TOOLKIT_SCROLL_BARS X11 XDBE XIM XPM LUCID ZLIB

Important settings:
  value of $LC_TIME: C
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8-unix

Major mode: Shell

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
  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 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 help-mode
cl-loaddefs cl-lib shell pcomplete comint ansi-color ring 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 inotify
dynamic-setting system-font-setting font-render-setting cairo x-toolkit
x multi-tty make-network-process emacs)

Memory information:
((conses 16 56240 5854)
 (symbols 48 7118 1)
 (strings 32 21011 1185)
 (string-bytes 1 677693)
 (vectors 16 13412)
 (vector-slots 8 178144 7617)
 (floats 8 27 48)
 (intervals 56 416 0)
 (buffers 992 12))

bug#40589: ^L printed when resizing Emacs split window using ksh93

[Lars Ingebrigtsen]

[-- Attachment #1: Type: text/plain, Size: 277 bytes --]

Mike Kupfer <mkupfer@alum.berkeley.edu> writes:

> Try
>
>   emacs -Q
>   M-x shell
>   $ ksh
>   C-x 2
>
> On my Debian desktop (running Buster), that's enough to provoke
> misbehavior, without even resizing.

I'm also using Debian/bullseye, and it doesn't misbehave for me:


[-- Attachment #2: Type: image/png, Size: 89745 bytes --]

[-- Attachment #3: Type: text/plain, Size: 945 bytes --]



> In GNU Emacs 28.0.50 (build 5, x86_64-pc-linux-gnu, X toolkit, cairo version 1.16.0, Xaw scroll bars)
>  of 2021-06-06 built on alto
> Repository revision: d933668e2d15cbb8e1fa367d97d2bff2559ff838
> Repository branch: master-mdk
> Windowing system distributor 'The X.Org Foundation', version 11.0.12004000
> System Description: Debian GNU/Linux 10 (buster)

Here's my version:

In GNU Emacs 28.0.50 (build 6, x86_64-pc-linux-gnu, GTK+ Version 3.24.24, cairo version 1.16.0)
 of 2021-06-14 built on xo
Repository revision: 794ec934a76d0647a72b7be32e20dc5b95e5ec11
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12011000
System Description: Debian GNU/Linux 11 (bullseye)

Looks pretty similar...  but mine is with Gtk and yours is without?
(And of course a newer version of ksh etc, I guess.)

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

bug#40589: ^L printed when resizing Emacs split window using ksh93

[Lars Ingebrigtsen]

Lars Ingebrigtsen <larsi@gnus.org> writes:

>> On my Debian desktop (running Buster), that's enough to provoke
>> misbehavior, without even resizing.
>
> I'm also using Debian/bullseye, and it doesn't misbehave for me:

(Remove that "also".  :-))

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

bug#40589: ^L printed when resizing Emacs split window using ksh93

[Mike Kupfer]

[-- Attachment #1: Type: text/plain, Size: 424 bytes --]

Lars Ingebrigtsen wrote:

> Mike Kupfer <mkupfer@alum.berkeley.edu> writes:
> 
> > Try
> >
> >   emacs -Q
> >   M-x shell
> >   $ ksh
> >   C-x 2
> >
> > On my Debian desktop (running Buster), that's enough to provoke
> > misbehavior, without even resizing.
> 
> I'm also using Debian/bullseye, and it doesn't misbehave for me:

Hmm.  I replaced emacs-lucid with emacs-gtk on my bullseye system, and
I'm still seeing it.  


[-- Attachment #2: screenshot --]
[-- Type: image/png, Size: 109984 bytes --]

[-- Attachment #3: Type: text/plain, Size: 2011 bytes --]


Maybe there's some difference in our environment variables?

  debtest$ printenv
  _=*4625*/usr/bin/printenv
  CLUTTER_BACKEND=x11
  COLUMNS=80
  CPU=x86_64
  DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1000/bus
  DESKTOP_SESSION=mate
  DISPLAY=:0
  DMAKE_OUTPUT_MODE=TXT2
  EDITOR=emacsclient
  GDMSESSION=mate
  GIT_PAGER=
  GPG_AGENT_INFO=/run/user/1000/gnupg/S.gpg-agent:0:1
  GS_OPTIONS=-sPAPERSIZE=letter
  GTK_MODULES=xapp-gtk3-module:gail:atk-bridge:canberra-gtk-module
  GTK_OVERLAY_SCROLLING=0
  HGRCPATH=/home/kupfer/.hgrc:/home/kupfer/.hg.d
  HOME=/home/kupfer
  HOST=debtest
  IGNOREEOF=4
  INSIDE_EMACS=27.1,comint
  LANG=en_US.UTF-8
  LC_TIME=C
  LOGNAME=kupfer
  MAILCHECK=60
  MANPATH=/home/kupfer/man:/usr/local/man:/usr/local/nmh/share/man:/usr/share/man:/usr/X11R6/man
  MATE_DESKTOP_SESSION_ID=this-is-deprecated
  MDK_PROFILE_DONE=Mon Jun 14 07:26:07 PDT 2021
  OS=Linux
  PATH=/sbin:/usr/sbin:/home/kupfer/bin:/home/kupfer/bin/x86_64:/usr/local/bin:/usr/bin/mh:/usr/bin:/bin:/usr/X11R6/bin
  PS1=debtest$ 
  PWD=/home/kupfer
  QT_ACCESSIBILITY=1
  QT_AUTO_SCREEN_SCALE_FACTOR=0
  QT_SCALE_FACTOR=1
  SESSION_MANAGER=local/debtest:@/tmp/.ICE-unix/999,unix/debtest:/tmp/.ICE-unix/999
  SHELL=/bin/bash
  SHLVL=2
  SSH_AGENT_PID=1136
  SSH_AUTH_SOCK=/run/user/1000/keyring/ssh
  TERM=dumb
  TERMCAP=
  USER=kupfer
  XAUTHORITY=/home/kupfer/.Xauthority
  XDG_CURRENT_DESKTOP=MATE
  XDG_DATA_DIRS=/usr/share/mate:/usr/local/share/:/usr/share/
  XDG_GREETER_DATA_DIR=/var/lib/lightdm/data/kupfer
  XDG_RUNTIME_DIR=/run/user/1000
  XDG_SEAT=seat0
  XDG_SEAT_PATH=/org/freedesktop/DisplayManager/Seat0
  XDG_SESSION_CLASS=user
  XDG_SESSION_DESKTOP=mate
  XDG_SESSION_ID=3
  XDG_SESSION_PATH=/org/freedesktop/DisplayManager/Session0
  XDG_SESSION_TYPE=x11
  XDG_VTNR=7
  A__z="*MAILCHECK="*SHLVL
  debtest$ 

I tried unsetting IGNOREEOF; that didn't make a difference.  And
changing SHELL to /usr/bin/ksh didn't make a difference.  Maybe there's
something about EDITOR, TERM, or TERMCAP?

mike

bug#40589: ^L printed when resizing Emacs split window using ksh93

[Lars Ingebrigtsen]

Mike Kupfer <mkupfer@alum.berkeley.edu> writes:

> Maybe there's some difference in our environment variables?

Nothing really stood out for me...  here's my printenv:

larsi@xo:~/src/emacs/trunk$ ksh
$ printenv
_=*1390660*/usr/bin/printenv
COLORTERM=truecolor
COLUMNS=79
DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1000/bus
DESKTOP_SESSION=gnome
DISPLAY=:1
GDMSESSION=gnome
GDM_LANG=en_US.UTF-8
GNOME_DESKTOP_SESSION_ID=this-is-deprecated
GNOME_TERMINAL_SCREEN=/org/gnome/Terminal/screen/804db694_e57a_4a44_9e7f_a011b0c330ef
GNOME_TERMINAL_SERVICE=:1.79
GPG_AGENT_INFO=/run/user/1000/gnupg/S.gpg-agent:0:1
GTK_MODULES=gail:atk-bridge
HOME=/home/larsi
IM_CONFIG_PHASE=1
INSIDE_EMACS=27.1,comint
LANG=en_US.UTF-8
LANGUAGE=en_US:en
LD_LIBRARY_PATH=/usr/local/lib:/usr/local/lib:
LESSCLOSE=/usr/bin/lesspipe %s %s
LESSOPEN=| /usr/bin/lesspipe %s
LOGNAME=larsi
LS_COLORS=
OLDPWD=/home/larsi
PATH=/home/larsi/src/auto-scale:/home/larsi/src/auto-scale:/home/larsi/bin:/usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games
PWD=/home/larsi/src/emacs/trunk
QT_ACCESSIBILITY=1
QT_IM_MODULE=ibus
SESSION_MANAGER=local/xo:@/tmp/.ICE-unix/10782,unix/xo:/tmp/.ICE-unix/10782
SHELL=/bin/bash
SHLVL=3
SSH_AGENT_PID=10740
SSH_AUTH_SOCK=/run/user/1000/keyring/ssh
TERM=dumb
TERMCAP=
USER=larsi
USERNAME=larsi
VTE_VERSION=6203
WINDOWPATH=2
XAUTHORITY=/run/user/1000/gdm/Xauthority
XDG_CURRENT_DESKTOP=GNOME
XDG_DATA_DIRS=/usr/share/gnome:/usr/local/share/:/usr/share/
XDG_MENU_PREFIX=gnome-
XDG_RUNTIME_DIR=/run/user/1000
XDG_SESSION_CLASS=user
XDG_SESSION_DESKTOP=gnome
XDG_SESSION_TYPE=x11
XMODIFIERS=@im=ibus
A__z="*SHLVL
$ 

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

bug#40589: ^L printed when resizing Emacs split window using ksh93

[Mike Kupfer]

Lars Ingebrigtsen wrote:

> Mike Kupfer <mkupfer@alum.berkeley.edu> writes:
> 
> > Maybe there's some difference in our environment variables?
> 
> Nothing really stood out for me...  here's my printenv:

I noticed that EDITOR is not set for you.  But unsetting it didn't make
a difference for me.

I'm afraid I won't have time today to look at this further, and probably
not tomorrow, either.  But I might have some time on Thursday.

cheers,
mike

bug#40589: ^L printed when resizing Emacs split window using ksh93

[Andreas Schwab]

This has nothing to do with Emacs.  You can reproduce that in any
terminal if you disable echo.

$ stty -echo; ksh

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510  2552 DF73 E780 A9DA AEC1
"And now for something completely different."

bug#40589: ^L printed when resizing Emacs split window using ksh93

[Mike Kupfer]

Andreas Schwab wrote:

> This has nothing to do with Emacs.  You can reproduce that in any
> terminal if you disable echo.
> 
> $ stty -echo; ksh

I'm not sure I follow.  Do you mean run that command and then resize the
terminal emulator?  That doesn't reproduce the problem for me, using
mate-terminal, xfce4-terminal, or xterm.

regards,
mike

bug#40589: ^L printed when resizing Emacs split window using ksh93

[Andreas Schwab]

Make sure the emacs (or vi) option is enabled.

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510  2552 DF73 E780 A9DA AEC1
"And now for something completely different."

bug#40589: ^L printed when resizing Emacs split window using ksh93

[Mike Kupfer]

Andreas Schwab wrote:

> Make sure the emacs (or vi) option is enabled.

Ah, right, I had EDITOR set to a wrapper script.

Yes, I can now reproduce the problem with just ksh and a terminal
emulator, without Emacs.

mike

bug#40589: ^L printed when resizing Emacs split window using ksh93

[Lars Ingebrigtsen]

Mike Kupfer <mkupfer@alum.berkeley.edu> writes:

>> Make sure the emacs (or vi) option is enabled.
>
> Ah, right, I had EDITOR set to a wrapper script.
>
> Yes, I can now reproduce the problem with just ksh and a terminal
> emulator, without Emacs.

What are the steps to reproduce this, then?

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

bug#40589: ^L printed when resizing Emacs split window using ksh93

[Mike Kupfer]

[-- Attachment #1: Type: text/plain, Size: 669 bytes --]

Lars Ingebrigtsen wrote:

> Mike Kupfer <mkupfer@alum.berkeley.edu> writes:
> 
> >> Make sure the emacs (or vi) option is enabled.
> >
> > Ah, right, I had EDITOR set to a wrapper script.
> >
> > Yes, I can now reproduce the problem with just ksh and a terminal
> > emulator, without Emacs.
> 
> What are the steps to reproduce this, then?

1. $ export EDITOR=emacs; stty -echo; ksh
2. resize the terminal emulator (either vertically or horizontally)

In the screenshot, the first "not found" came from pressing RET after a
vertical resize.  The second "not found" came from typing "date RET"
after a horizontal resize.  The ">" characters appear during the
resizing.


[-- Attachment #2: screenshot --]
[-- Type: image/png, Size: 23608 bytes --]

[-- Attachment #3: Type: text/plain, Size: 14 bytes --]


cheers,
mike

bug#40589: ^L printed when resizing Emacs split window using ksh93

[Lars Ingebrigtsen]

Mike Kupfer <mkupfer@alum.berkeley.edu> writes:

>> What are the steps to reproduce this, then?
>
> 1. $ export EDITOR=emacs; stty -echo; ksh
> 2. resize the terminal emulator (either vertically or horizontally)

Ah, right -- I can reproduce this, too (on Debian/bullseye).

> In the screenshot, the first "not found" came from pressing RET after a
> vertical resize.  The second "not found" came from typing "date RET"
> after a horizontal resize.  The ">" characters appear during the
> resizing.

Yup.

Is this something we can do something about on the Emacs side, or is it
just a ksh bug/feature?

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

bug#40589: ^L printed when resizing Emacs split window using ksh93

[Mike Kupfer]

Lars Ingebrigtsen wrote:

> Is this something we can do something about on the Emacs side, or is it
> just a ksh bug/feature?

Well, there's the workaround listed in etc/PROBLEMS:

    To work around the problem, customize the option
    'window-adjust-process-window-size-function' to "Do not adjust process
    window sizes" (Lisp value 'ignore').

Beyond that, I don't know.

mike

bug#40589: ^L printed when resizing Emacs split window using ksh93

[Andreas Schwab]

On Jun 19 2021, Lars Ingebrigtsen wrote:

> Is this something we can do something about on the Emacs side, or is it
> just a ksh bug/feature?

It's a ksh bug.

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510  2552 DF73 E780 A9DA AEC1
"And now for something completely different."

bug#40589: ^L printed when resizing Emacs split window using ksh93

[Lars Ingebrigtsen]

Andreas Schwab <schwab@linux-m68k.org> writes:

> On Jun 19 2021, Lars Ingebrigtsen wrote:
>
>> Is this something we can do something about on the Emacs side, or is it
>> just a ksh bug/feature?
>
> It's a ksh bug.

Thanks.  I'm closing this in the Emacs bug tracker, then, and it should
be reported to the ksh maintainers instead.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no