Client: Don't send fake SurfaceCreated/Destroyed events

QPlatformSurface relates to the platform window, not the wl_surface.
The events are already emitted by QPlatformWindow on create/destroy.

To preserve compatibility for a previous KDE version it was faked to
emit the events when the wl_surface is created/hidden to keep behavior.
This is no longer necessary, and it has caused multiple errors, the latest
being a crash when switching between sub-menus with the Sway compositor.

[ChangeLog][QPA plugin] QWaylandWindow no longer sends fake SurfaceCreated/Destroyed events.
Use expose events to be notified when a Wayland surface appears.

Task-number: QTBUG-76324
Fixes: QTBUG-81952
Pick-to: 5.15
Change-Id: I2f003bc9da85f032a0053677fd281152099fc9eb
Reviewed-by: Paul Olav Tvete <paul.tvete@qt.io>
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
Reviewed-by: David Edmundson <davidedmundson@kde.org>

1 files changed, 5 insertions, 2 deletions

diff --git a/examples/wayland/custom-extension/client-common/customextension.cpp b/examples/wayland/custom-extension/client-common/customextension.cpp
index aa0cb58a4..8b77c061a 100644
--- a/examples/wayland/custom-extension/client-common/customextension.cpp
+++ b/examples/wayland/custom-extension/client-common/customextension.cpp
@@ -81,8 +81,11 @@ QWindow *CustomExtension::windowForSurface(struct ::wl_surface *surface)
 
 bool CustomExtension::eventFilter(QObject *object, QEvent *event)
 {
-    if (event->type() == QEvent::PlatformSurface
-            && static_cast<QPlatformSurfaceEvent*>(event)->surfaceEventType() == QPlatformSurfaceEvent::SurfaceCreated) {
+    if (event->type() == QEvent::Expose) {
+        auto *exposeEvent = static_cast<QExposeEvent *>(event);
+        if (exposeEvent->region().isNull())
+            return false;
+
         QWindow *window = qobject_cast<QWindow*>(object);
         Q_ASSERT(window);
         window->removeEventFilter(this);