kanshi exits when undocking laptop from two external monitors

[MayeulC]

Hello and thank you for this project.

I have a Dell laptop and a WD-15 USB-C dock. It seems that kanshi unexpectedly exits when I run it, plug the dock (with two additional monitors connected), then unplug it:

% kanshi
applying profile 'laptop-only'
applying profile output 'Unknown 0x63ED 0x00000000' on connected head 'eDP-1'
running commands for configuration 'laptop-only'
configuration for profile 'laptop-only' applied

# Output Stable, now I plug the dock

applying profile 'INL-homestation2'
applying profile output 'Dell Inc. DELL P2219H F64FYS2' on connected head 'DP-3'
applying profile output 'Unknown 0x63ED 0x00000000' on connected head 'eDP-1'
applying profile 'INL-homestation2'
applying profile output 'Dell Inc. DELL P2219H F64FYS2' on connected head 'DP-3'
applying profile output 'Unknown 0x63ED 0x00000000' on connected head 'eDP-1'
applying profile 'double-inl'
applying profile output 'Dell Inc. DELL P2419HC 4832JQ2' on connected head 'DP-4'
applying profile output 'Dell Inc. DELL P2219H F64FYS2' on connected head 'DP-3'
applying profile output 'Unknown 0x63ED 0x00000000' on connected head 'eDP-1'
applying profile 'double-inl'
applying profile output 'Dell Inc. DELL P2419HC 4832JQ2' on connected head 'DP-4'
applying profile output 'Dell Inc. DELL P2219H F64FYS2' on connected head 'DP-3'
applying profile output 'Unknown 0x63ED 0x00000000' on connected head 'eDP-1'
configuration for profile 'INL-homestation2' cancelled, retrying
configuration for profile 'INL-homestation2' cancelled, retrying
configuration for profile 'double-inl' cancelled, retrying
applying profile 'double-inl'
applying profile output 'Dell Inc. DELL P2419HC 4832JQ2' on connected head 'DP-4'
applying profile output 'Dell Inc. DELL P2219H F64FYS2' on connected head 'DP-3'
applying profile output 'Unknown 0x63ED 0x00000000' on connected head 'eDP-1'
running commands for configuration 'double-inl'
configuration for profile 'double-inl' applied
running commands for configuration 'double-inl'
configuration for profile 'double-inl' applied

# Outputs Stable, now I unplug the dock

applying profile 'INL-homestation1'
applying profile output 'Dell Inc. DELL P2419HC 4832JQ2' on connected head 'DP-4'
applying profile output 'Unknown 0x63ED 0x00000000' on connected head 'eDP-1'
applying profile 'laptop-only'
applying profile output 'Unknown 0x63ED 0x00000000' on connected head 'eDP-1'
wl_display@1: error 1: invalid arguments for [email protected]_head
% echo $?
0

The above always happens when unplugging the laptop from the dock, regardless of when kanshi was launched (before or after docking).

Obviously kanshi becomes a whole less useful if it exits like this. The only suspicious thing I notice is the transient activation of the "INL-homestation1" and 2, which consists of one of the two external monitors. It might be a race condition when one of those disappear, kanshi tries to set the other up according to a profile, but it's already gone? It doesn't happen when only one external monitor is connected, which suggest it is related.

Reproductibility is extremelly good FWIW, it happens every time, with the exact same lines.

Here are the relevant lines in the kanshi config:

## Work profiles
profile laptop-only {
	output "Unknown 0x63ED 0x00000000" mode 1920x1080 position 0,0 enable
}

profile INL-workstation {
	output "Dell Inc. DELL E2218HN 33G587CKC67I" mode 1920x1080 position 0,0
	output "Unknown 0x63ED 0x00000000" mode 1920x1080 position 1920,360
}

profile INL-homestation1 {
	output "Unknown 0x63ED 0x00000000" mode 1920x1080 position 0,0
	output "Dell Inc. DELL P2419HC 4832JQ2" mode 1920x1080 position 1920,0
}

profile INL-homestation2 {
	output "Dell Inc. DELL P2219H F64FYS2" mode 1920x1080 position 0,0
	output "Unknown 0x63ED 0x00000000" mode 1920x1080 position 1920,0
}

profile double-inl {
	output "Dell Inc. DELL P2419HC 4832JQ2" position 0,0 mode 1920x1080 transform 90
	output "Dell Inc. DELL P2219H F64FYS2" position 1080,416
	output "Unknown 0x63ED 0x00000000" disable
}

[emersion]

Duplicate of #99

[MayeulC]

You beat me to it by 3 minutes, sorry about that.