My mitigation to Wine bug 43030

line-helper.service

#How to setup:
#1. Have systemd and xdotool installed
#2. store the script (Line_helper.sh) as $HOME/.local/script/Line_helper.sh
#3. store this service file as $HOME/.config/systemd/user/line-helper.service
#4. chmod +x $HOME/.local/script/Line_helper.sh
#5. start line-helper.service before you start line

[Unit]
Description=Automatically minimize Line
After=graphical.target

[Service]
ExecStart=%h/.local/script/Line_helper.sh
Restart=always
RestartSec=30

[Install]
WantedBy=default.target

Line_helper.sh

#! /bin/sh

if [[ $(which xdotool) = "" ]]; then
        echo "xdotool is required to run this script."
        exit
fi

if [[ $(which xwininfo) = "" ]]; then
        echo "xwininfo is required to run this script."
        exit
fi

while true
do
    xwininfo -tree -root |
        grep 'has no name.*"line.*\.exe"' |
        awk '{ print $1 }' |
        xargs -rl xdotool windowclose
    sleep 10
done

What does the script do?
In order to mitigate https://bugs.winehq.org/show_bug.cgi?id=43030 I decided to create a script that minimizes Line windows when it loses focus.

con:

1. Another program needs to run in the background
2. Maximal delay of (1+execution overhead) seconds before window gets minimized.
   (timer can be adjusted to something like 0.5 to reduce delay)
3. User needs to create some sort of cron job that runs at startup
4. Sometimes Line window gets minimized as soon as it shows up... I believe that the chance of this happening multiple times in a row is very small.

When I was writing this script, I experimented with approach of

xdotool search --sync ...... behave %@ blur windowminimize

It only works well if (1) You run that script when main line window is open and (2) You don't close Line window, like minimize it to icon
As that approach don't register new line windows.

A example on how to start systemd service with Line. (I use Lutris to setup Line)

I use this script to kill LINE's borders:

xwininfo -tree -root |
   grep 'has no name.*"line.*\.exe"' |
   awk '{ print $1 }' |
   xargs -rl xdotool windowclose

That works very well without the need to minimize Line, thank you!

This would be another option, but it requires a modification of the wine sourcecode:
https://forum.winehq.org/viewtopic.php?t=41118