Package: joe
Version: 4.6-1+b1
Severity: important
Hi,
as of recently, if I start screen (or tmux, doesn't seem to matter) on a Linux
host, then use lxc-attach to enter a running LXC container, and start joe
inside that container, the terminal behaves in a hard to describe, but
completely broken way, making the editor essentially unusable.
Some examples:
1. Subsequent lines appear concatenated and then broken at an off-by-one
location. A file that contains
<<<
#
# foo
>>>
would be rendered as
<<<
# [... spaces up to the end of the terminal line ... ] #
foo
>>>
CTRL-R has no apparent effect. Enabling syntax highlighting seems to make it
worse (mangling more lines), but not always.
2. When typing, the cursor keeps jumping back to column 2 or 3, and the typed
characters are hidden, as if they were off-screen to the left. Pressing CTRL-R
fixes this problem temporarily. After pressing CTRL-R, pressing END (but not
^E) repeatedly moves the cursor to somewhere around colum 40, but the column
display in the upper right corner displays the correct position even after the
first END press (or ^E press).
3. Similar to #2, but happens especially when editing a new file, or an empty
line: instead of echoing the typed characters, either spaces echo, or the
cursor stays at the leftmost position.
If you can suggest a way for me to record what I see on the screen and the keys
I press concurrently, I suppose I can produce a "movie" of the breakage.
Other editors are unaffected (I tried vim, mcedit and nano).
I can't reproduce the problem without screen or tmux (ssh host, lxc-attach
container, joe works).
I can't reproduce the problem if I start the container's joe binary by
chrooting into the container's filesystem from the host.
I can't reproduce the problem if I ssh into the container instead of entering
it via lxc-attach, not even if I subsequently start screen inside the container
and joe inside screen.
I experimented with downgrading screen, ncurses, and joe itself, but either I
wasn't systematic enough or it really didn't help.
I experimented with using different terminal applications to ssh into the LXC
host (xterm, konsole), and it seemed to make no difference.
I *can* reproduce the problem by starting screen(1) locally, then ssh'ing into
the LXC host, using lxc-attach, then starting joe inside the container.
screen(1) sets my TERM to screen.xterm-256color. Setting TERM to just "screen"
apparently fixes problem #1 but not the others.
In tmux (whether started locally or on the LXC host doesn't matter), which sets
TERM to "screen-256color", breakage #1 is less pronounced and slightly
different: some lines are just visually missing their first character, but it's
not rendered at the end of the previous line. The other two problems are just
as in screen(1).
If I start tmux locally, then ssh into the LXC host and start screen there,
TERM is set to just "screen" but after lxc-attach, problem #1 is present again.
As a demonstration, I opened a 150x47 terminal, reproduced problem #1, and used
the X clipboard to copy and paste the contents of the window (with
/etc/login.defs opened in joe) into this message below, disabling automatic
line breaks:
--- 8< ---
IW /etc/login.defs
Row 45 Col 1
Enable display of unknown usernames when login failures are recorded.
#
# WARNING:
Unknown usernames may become world readable.
# See #290803 and #298773 for details about how this could become a security
# concern
LOG_UNKFAIL_ENAB no
#
# Enable
logging of successful logins
#
LOG_OK_LOGINS no
#
# Enable
"syslog" logging of su activity - in addition to sulog file logging.
# SYSLOG_SG_ENAB does the same for newgrp and sg.
#
SYSLOG_SU_ENAB yes
SYSLOG_SG_ENAB yes
#
# If
defined, all su activity is logged to this file.
#
#SULOG_FILE /var/log/sulog
#
# If
defined, file which maps tty line to TERM environment parameter.
# Each line of the file is in a format something like "vt100 tty01".
#
#TTYTYPE_FILE /etc/ttytype
#
# If
defined, login failures will be logged here in a utmp format
# last, when invoked as lastb, will read /var/log/btmp, so...
#
FTMP_FILE
/var/log/btmp
#
# If
defined, the command name to display when running "su -". For
# example, if this is defined as "su" then a "ps" will display the
# command is "-su". If not defined, then "ps" would display the
# name of the shell actually being run, e.g. something like "-sh".
#
SU_NAME
su
--- >8 ---
I don't know how much this helps, but it's the best I could do. (I made no
edits in login.defs, just scrolled around a bit.)
All experiments were carried out on reasonably recent sid boxes (a few weeks
old at most, some up to date as of Sunday), hosts and containers alike.
I'm afraid I have no idea how to even begin troubleshooting this further.
András
-- System Information:
Debian Release: bookworm/sid
Architecture: amd64 (x86_64)
Foreign Architectures: i386
Locale: LANG=en_US.UTF-8, LC_CTYPE=hu_HU.UTF-8 (charmap=UTF-8),
LANGUAGE=en_US.UTF-8
Shell: /bin/sh linked to /bin/dash
Init: runit (via /run/runit.stopit)
LSM: AppArmor: enabled
Versions of packages joe depends on:
ii libc6 2.33-7
ii libncurses6 6.3+20220423-2
ii libtinfo6 6.3+20220423-2
joe recommends no packages.
joe suggests no packages.
-- no debconf information
--
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