wayland/toplevel: null check window passed to Toplevel::setRectangle

Fixes Toplevel::unsetRectangle, which passes a null.

changelog/next.md

@@ -13,3 +13,4 @@
 - Fixed `qs kill` not waiting for the process to exit.
 - Fixed IPC calls from children of a crashed and relaunched process crashing.
 - Fixed JsonAdapter crashing when deserializing new objects into an array.
+- Fixed `Toplevel.unsetRectangle` crashing when calle.

src/wayland/toplevel/qml.cpp

@@ -98,7 +98,7 @@ void Toplevel::setRectangle(QObject* window, QRect rect) {
 	}
 
 	this->rectangle = rect;
-	this->handle->setRectangle(proxyWindow->backingWindow(), rect);
+	this->handle->setRectangle(proxyWindow ? proxyWindow->backingWindow() : nullptr, rect);
 }
 
 void Toplevel::unsetRectangle() { this->setRectangle(nullptr, QRect()); }

src/wayland/toplevel/wlr_toplevel.cpp

@@ -121,8 +121,11 @@ void ToplevelHandle::setRectangle(QWindow* window, QRect rect) {
 			}
 		}
 
-		QObject::disconnect(this->rectWindow, nullptr, this, nullptr);
-		this->rectWindow = nullptr;
+		if (this->rectWindow) {
+			QObject::disconnect(this->rectWindow, nullptr, this, nullptr);
+			this->rectWindow = nullptr;
+		}
+
 		return;
 	}