tty: top-left part of the screen doesn't refresh after window switch

[nycko123]

platform

ArchLinux
kernels: 4.19.arch1-1 and custom manually built 4.19 from sources
tmux: 2.8
terminal: tty
shell: bash
outside tmux: printenv TERM = linux
inside tmux: printenv TERM = screen

new test user without any ENVIRONMENTS set

steps to reproduce

1. start tmux in tty (rich config or without any)
2. add a pane (vertical or horizontal)
3. add new window, switch to it and print anything in it (cat a file, journalctl -f, etc.)
4. switch back to window 0
5. pane 0 has a part of the output from window 1

logs

tmux -vv -Ltest -f/dev/null new
tmux-server-988.log

exceptions

• the issue does not exist on above kernels when using xserver terminal emulators
• the issue does not exist on kernels 4.18.16 and below (tty, xserver)

[nicm]

So if you change kernel version, the problem disappears? Sounds like a bug in their terminal implementation.

…

On Sat, 3 Nov 2018, 10:39 nycko123 ***@***.*** wrote: *platform* ArchLinux kernels: 4.19.arch1-1 and custom manually built 4.19 from sources tmux: 2.8 terminal: tty shell: bash outside tmux: printenv TERM = linux inside tmux: printenv TERM = screen new test user without any ENVIRONMENTS set *steps to reproduce* 1. start tmux in tty (rich config or without any) 2. add a pane (vertical or horizontal) 3. add new window, switch to it and print anything in it (cat a file, journalctl -f, etc.) 4. switch back to window 0 5. pane 0 has a part of the output from window 1 *logs* tmux -vv -Ltest -f/dev/null new tmux-server-988.log <https://github.com/tmux/tmux/files/2544874/tmux-server-988.log> *exceptions* - the issue does not exist on above kernels when using xserver terminal emulators - the issue does not exist on kernels 4.18.16 and below (tty, xserver) — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#1521>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AASkc7mYxKhjnfg8DNA4lhup3eRBWILCks5urXJXgaJpZM4YMvdk> .

[nycko123]

Yes, everything works great on kernels 4.18.16 and below.
Arch's kernel config of 4.19 doesn't differ from the 4.18.16 one, so maybe there was a change in the kernel upstream KMS method or in the way framebuffer works.
I have no knowledge or experience to check that.

I will try to add nomodeset to the kernel which should at least remove KMS as a source of this issue.

EDIT: adding nomodeset to kernel line doesn't fix the issue.
I have to add, that if i have i.e. two windows with only single pane (window 0 + pane 0 and window 1 pane 0), the refreshing after windows switching works OK. The problem exists if any of the windows has more than 1 pane open. The top left one doesn't refresh.

[nicm]

What do both of these show?

printf 'abcdefghi\033[6D\033[Kxyz\n'
printf 'abcdefghi\033[6D\033[1Kxyz\n'

[nycko123]

screen output

abcxyz
   xyzghi

redirecting output to file gives

abcxyz
abcxyzghi

inside the file

[nicm]

Seems fine. I don't know then, you will need to ask the kernel maintainers.

[nycko123]

Sure, will do. Thank you for your time.

[nycko123]

Please consider re-opening this issue. This bug is not Arch Linux specific. It happens on other distributions with kernel 4.19 too.

https://raw.githubusercontent.com/nycko123/ArchLinux/master/ss/tmux-bug/1.png
https://raw.githubusercontent.com/nycko123/ArchLinux/master/ss/tmux-bug/2.png
https://raw.githubusercontent.com/nycko123/ArchLinux/master/ss/tmux-bug/3.png

[nicm]

Right but it still seems like a kernel bug not a tmux bug, right?

[nycko123]

Seems like it, but I don't know. Could be a bug in kernel or tmux. I cannot do more than what i've already done to point it out being as much helpfull as i could to keep you aware of this issue.

[nicm]

There is nothing in the tmux logs that shows it sending anything incorrectly, it clears the existing content as expected, in the same way as every other terminal. And there is no way that would change purely based on kernel version. It seems very likely to be a terminal problem. Your best bet is to report it to the terminal maintainers.

If I could reproduce I could try to figure out what escape sequence it is handling incorrectly but there is no point in me faffing around to get a 4.19 kernel just for that.

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.