shell/element: Don't render decorations for dead windows

src/shell/element/mod.rs

@@ -606,6 +606,10 @@ impl CosmicMapped {
         CosmicMappedRenderElement<R>: RenderElement<R>,
         C: From<CosmicMappedRenderElement<R>>,
     {
+        if !self.element.alive() {
+            return None;
+        }
+
         match &self.element {
             CosmicMappedInternal::Stack(s) => s
                 .shadow_render_element::<R, CosmicMappedRenderElement<R>>(

src/shell/element/stack.rs

@@ -730,6 +730,13 @@ impl CosmicStack {
         R::TextureId: Send + Clone + 'static,
         C: From<CosmicStackRenderElement<R>>,
     {
+        if !self
+            .0
+            .with_program(|p| p.override_alive.load(Ordering::Acquire))
+        {
+            return Vec::new();
+        }
+
         let geometry = self
             .0
             .with_program(|p| p.windows.lock().unwrap()[p.active.load(Ordering::SeqCst)].geometry())

src/shell/element/window.rs

@@ -509,7 +509,7 @@ impl CosmicWindow {
             elements.push(elem);
         }
 
-        elements.extend(self.0.with_program(|p| {
+        let window_elements = self.0.with_program(|p| {
             p.window
                 .render_elements::<R, WaylandSurfaceRenderElement<R>>(
                     renderer,
@@ -518,8 +518,12 @@ impl CosmicWindow {
                     alpha,
                     scanout_override,
                 )
-                .into_iter()
+        });
-                .map(|elem| {
+        if window_elements.is_empty() {
+            return Vec::new();
+        }
+
+        elements.extend(window_elements.into_iter().map(|elem| {
             if has_ssd {
                 radii[1] = 0;
                 radii[3] = 0;
@@ -534,7 +538,6 @@ impl CosmicWindow {
             } else {
                 CosmicWindowRenderElement::Window(elem)
             }
-                })
         }));
 
         if has_ssd {