WaylandWindow: Don't move windows to null output when the size is empty

Do not decide on the output when the window is empty, contains won't
report empty rects. We'll be sending leave events unnecessarily.
Make sure we don't pass unexisting outputs.

Signed-off-by: Victoria Fischer <victoria.fischer@mbition.io>

src/waylandwindow.cpp

@@ -151,8 +151,13 @@ void WaylandWindow::updateClientOutputs()
     if (isDeleted()) {
         return;
     }
-    surface()->setOutputs(waylandServer()->display()->outputsIntersecting(frameGeometry().toAlignedRect()),
-                          waylandServer()->display()->largestIntersectingOutput(frameGeometry().toAlignedRect()));
+    const auto rect = frameGeometry().toAlignedRect();
+    if (rect.isEmpty()) {
+        return;
+    }
+
+    surface()->setOutputs(waylandServer()->display()->outputsIntersecting(rect),
+                          waylandServer()->display()->largestIntersectingOutput(rect));
 }
 
 void WaylandWindow::updateIcon()