Wayland: resolve session lock client crashes on sleep, unlock, and output changes

changelog/next.md

@@ -4,3 +4,4 @@
 - Fixed WlSessionLockSurface.visible crashing if accessed before backing surface creation.
 - Fixed mpris players returning `rate` for `minRate` and `maxRate`.
 - Fixed missing/wrong change signals on various properties.
+- Fixed session lock crashes on sleep, wake, DPMS, and unlocking.

src/wayland/session_lock.cpp

@@ -56,9 +56,12 @@ void WlSessionLock::updateSurfaces(bool show, WlSessionLock* old) {
 	auto screens = QGuiApplication::screens();
 
 	screens.removeIf([](QScreen* screen) {
-		if (dynamic_cast<QtWaylandClient::QWaylandScreen*>(screen->handle()) == nullptr) {
+		auto* waylandScreen = dynamic_cast<QtWaylandClient::QWaylandScreen*>(screen->handle());
+		if (waylandScreen == nullptr || waylandScreen->isPlaceholder()
+		    || waylandScreen->output() == nullptr)
+		{
 			qDebug() << "Not creating lock surface for screen" << screen
-			         << "as it is not backed by a wayland screen.";
+			         << "as it is not backed by a valid wayland output.";
 
 			return true;
 		}
@@ -207,6 +210,7 @@ WlSessionLockSurface::WlSessionLockSurface(QObject* parent)
 
 WlSessionLockSurface::~WlSessionLockSurface() {
 	if (this->window != nullptr) {
+		this->window->destroy();
 		this->window->deleteLater();
 	}
 }

src/wayland/session_lock/surface.cpp

@@ -38,6 +38,7 @@ QSWaylandSessionLockSurface::QSWaylandSessionLockSurface(QtWaylandClient::QWayla
 }
 
 QSWaylandSessionLockSurface::~QSWaylandSessionLockSurface() {
+	if (this->object() == nullptr) return;
 	if (this->ext != nullptr) this->ext->surface = nullptr;
 	this->destroy();
 }