[mutter] wayland/window: Ignore state changes for popups

[Robert Mader <rmader src gnome org>]

commit fa74da0039b848e3beaff5d0da44e6d3f2c46dc9
Author: Jonas Ådahl <jadahl gmail com>
Date:   Thu Mar 12 19:34:03 2020 +0100

    wayland/window: Ignore state changes for popups
    
    We send configure events for state changes e.g. for `appears-focused`,
    etc. What we don't want to do is to do this for popup windows, as in
    Wayland don't care about this state.
    
    When the focus mode was configured to "sloppy focus" we'd get
    `appears-focused` state changes for the popup window only by moving the
    mouse cursor around, and while a popup may care about focus, it does not
    care about related appearance, as there is no such state in xdg_popup.
    
    What these state changes instead resulted in was absolute window
    configuration events, intended for toplevel (xdg_toplevel) windows. In
    the end this caused the popup to be positioned aginst at (0, 0) of the
    parent window, as the assumptions when the configuration of the popup
    was acknowledged is that it had received a relative position window
    configuration.
    
    Fix this by simply ignoring any state changes of the window if it is a
    popup, meaning we won't send any configuration events intended for
    toplevels for state changes. Currently we don't have any way to know
    this other than checking whether it has a placement rule. Cleaning up
    MetaWindow creation is left to be dealt with another day.
    
    Fixes: https://gitlab.gnome.org/GNOME/mutter/issues/1103
    
    https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1122

 src/wayland/meta-window-wayland.c | 4 ++++
 1 file changed, 4 insertions(+)
---
diff --git a/src/wayland/meta-window-wayland.c b/src/wayland/meta-window-wayland.c
index 86cdbf86e..b6b949e36 100644
--- a/src/wayland/meta-window-wayland.c
+++ b/src/wayland/meta-window-wayland.c
@@ -634,6 +634,10 @@ appears_focused_changed (GObject    *object,
                          gpointer    user_data)
 {
   MetaWindow *window = META_WINDOW (object);
+
+  if (window->placement.rule)
+    return;
+
   surface_state_changed (window);
 }