[Bug]: Tmux horizontal split panel messed up when using Zsh

[pseudoparenchymatous]

Problem description

Tmux is bugging with the colors
https://imgur.com/a/3JirVAx

What steps will reproduce the bug?

Run tmux with certain colorschemes

What is the expected behavior?

Display the shell/terminal color similar non-tmux

System information

termux-info:

Termux Variables:
TERMUX_APK_RELEASE=GITHUB
TERMUX_APP_PACKAGE_MANAGER=apt
TERMUX_APP_PID=3914
TERMUX_IS_DEBUGGABLE_BUILD=1
TERMUX_MAIN_PACKAGE_FORMAT=debian
TERMUX_VERSION=0.118.0
Packages CPU architecture:
aarch64
Subscribed repositories:
# sources.list
deb https://packages-cf.termux.dev/apt/termux-main stable main
Updatable packages:
All packages up to date
termux-tools version:
1.31.0
Android version:
11
Kernel build information:
Linux localhost 4.14.190-perf-gceaf914a4ae1-dirty #2 SMP PREEMPT Wed Feb 16 22:34:35 WIB 2022 aarch64 Android
Device manufacturer:
Xiaomi
Device model:
Redmi Note 8

[agnostic-apollo]

Check if termux/termux-app#3036 (comment) is the issue.

[pseudoparenchymatous]

Check if termux/termux-app#3036 (comment) is the issue.

I tried disabling the per app dark mode but it's still the same. Apparently this bug only happens if I make a pane to the right (horizontal split).

[sylirre]

Looks like more a shell prompt formatting issue.

Can't reproduce the issue.

[pseudoparenchymatous]

Looks like more a shell prompt formatting issue.

Can't reproduce the issue.

How does yours look like if you do this (try light themes)?

Screenrecorder-2022-10-27-04-36-38-477.mp4

[sylirre]

As I said, no issues in Tmux:

tmux_record_01.mp4

---

Try different shell like bash or dash via chsh (make sure no fancy prompts there) and try using tmux again.

[pseudoparenchymatous]

You're right, zsh is breaking this (even running zsh -f). Should I change this to zsh bug instead of tmux?

[sylirre]

I can confirm that terminal gets messed up when zsh is being launched in Tmux horizontal split panel. This happens regardless of screen size.

This can be a Tmux bug as well.

[xtkoba]

I don't really get the point of this issue. Couldn't it be that this is poking a bug of Termux app? In other words, is this reproducible with other terminals, e.g. xfce4-terminal in X11 environment, or any terminal in GNU/Linux environment which Termux is SSHed from?

[sylirre]

Can reproduce only in Termux. If connect from laptop to Termux over SSH and try to perform steps to reproduce, everything is fine.

However for some reason issue is partial for me as happens only with light themes. Previously it was reproducible on dark themes too.

[pseudoparenchymatous]

In the meantime, I stopped using Tmux and instead now using Zellij. Splits are too useful for me. Also, fish shell can reproduce the bug for me when executing clear command in a vertical split.

[GR3YH4TT3R93]

Have you tried adding the following to your tmux config?

set-option -ga terminal-overrides ",xterm-256color:Tc"