Possible regression in 1.9 -> 1.10: Node order incorrect in .focus tree attribute

[Lcchy]

• Sway Version:
  1.10

Hi, I recently came across an odd behavior of the swaymsg -t get_tree output tree, since 1.10.

The focus array attribute of nodes does not guarantee the order of nodes anymore, it does not seem to be updated when moving a window between containers.

I have created a minimal reproduction.
The idea is to create 2 containers (i.e. windows with a split) and move a third window between them.
After the move, the focus array of the containers does not get updated.
See the output of bug.sh.

I also ran a git bisect and found the cause to be 5e18ed3

Reverting this commit solves the issue for me but I am not sure of other consequences it has.

Minimal reproduction:

# sway.conf
exec ./layout.sh

#layout.sh
#!/usr/bin/env bash

foot &
foot &
sleep 0.5

swaymsg focus left
swaymsg splith
swaymsg focus right
swaymsg splith

foot bash -c "sleep 2; ./bug.sh; bash" &

# bug.sh
#!/usr/bin/env bash

swaymsg focus left
swaymsg "move left"

gp=$(swaymsg -t get_tree | jq -r '.. | select(.id? == 4) | "\(.id) \(.focus)"')
echo "Container id, Focus array ${gp}"
echo "This order is incorrect"

echo "Switching to workspace 2 and back to 1 - in order to update order. This shouldn't have any effect on the focus array."
swaymsg 'workspace number 1; workspace number 2; workspace number 1'

gp=$(swaymsg -t get_tree | jq -r '.. | select(.id? == 4) | "\(.id) \(.focus)"')
echo "Container id, Focus array ${gp}"
echo "It does! Now the order is correct"

[emersion]

cc @rpigott