EXWM does not respect EWMH recommended stacking order when switching workspaces

[toshokan]

The EWMH specification recommends the following stacking order (last stacked highest):

• windows of type _NET_WM_TYPE_DESKTOP
• windows having state _NET_WM_STATE_BELOW
• windows not belonging in any other layer
• windows of type _NET_WM_TYPE_DOCK (unless they have state _NET_WM_TYPE_BELOW) and windows having state _NET_WM_STATE_ABOVE
• focused windows having state _NET_WM_STATE_FULLSCREEN

I have a panel (occupying the top 16 pixels of my display) with the following X window properties:

WM_CLASS(STRING) = "bergamot", "bergamot"
_NET_WM_STRUT_PARTIAL(CARDINAL) = 0, 0, 16, 0, 0, 0, 0, 0, 0, 1366, 0, 0
_NET_WM_STATE(ATOM) = _NET_WM_STATE_BELOW
_NET_WM_WINDOW_TYPE(ATOM) = _NET_WM_WINDOW_TYPE_DOCK

If the application displaying this window is running and an EXWM-managed window goes fullscreen, that window is correctly stacked above the panel.

If I switch workspace away from the one with the fullscreen window and then back to it, the panel is now incorrectly stacked above the fullscreen application (leaving fullscreen and going fullscreen again re-stacks correctly)

[daviwil]

I've also been experiencing this issue, it requires me to kill my panel app when using another app full screen.

[medranocalvo]

Thank you for the detailed report.

This is a bug: the _NET_WM_TYPE_DOCK should maintain its stacking order after the fullscreen.

I could only have a quick look at this. The issue is around https://github.com/ch11ng/exwm/blob/571ca227e7857b5fd95f4f3211d471083d69ec32/exwm-layout.el#L133; we should probably invoke exwm-layout-set-fullscreen (which should be refactored) instead of just setting the geometry.

[toshokan]

@medranocalvo thanks for pointing me in that direction!

I did a quick test to see if calling exwm-layout-set-fullscreen in that body is sufficient to set the stacking order correctly and unfortunately it isn't, but it gives me an area to focus on while I keep investigating :)