From 43a9add5fec388c9f06363b624768dae3b669a02 Mon Sep 17 00:00:00 2001
From: Xaver Hugl <xaver.hugl@gmail.com>
Date: Fri, 3 Mar 2023 14:56:00 +0100
Subject: [PATCH] windowitem: properly handle sub-subsurfaces

The damage of the whole subsurface tree needs to be considered, not just the
topmost subsurfaces of a window.

BUG: 466747
---
 src/scene/windowitem.cpp | 18 ++++++++++++------
 src/scene/windowitem.h   |  1 +
 2 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/src/scene/windowitem.cpp b/src/scene/windowitem.cpp
index f11b641fa9..28373bb5b0 100644
--- a/src/scene/windowitem.cpp
+++ b/src/scene/windowitem.cpp
@@ -176,6 +176,17 @@ void WindowItem::updatePosition()
     setPosition(m_window->pos());
 }
 
+void WindowItem::addSurfaceItemDamageConnects(Item *item)
+{
+    auto surfaceItem = static_cast<SurfaceItem *>(item);
+    connect(surfaceItem, &SurfaceItem::damaged, this, &WindowItem::markDamaged);
+    connect(surfaceItem, &SurfaceItem::childAdded, this, &WindowItem::addSurfaceItemDamageConnects);
+    const auto childItems = item->childItems();
+    for (const auto &child : childItems) {
+        addSurfaceItemDamageConnects(child);
+    }
+}
+
 void WindowItem::updateSurfaceItem(SurfaceItem *surfaceItem)
 {
     m_surfaceItem.reset(surfaceItem);
@@ -184,12 +195,7 @@ void WindowItem::updateSurfaceItem(SurfaceItem *surfaceItem)
         connect(m_window, &Window::shadeChanged, this, &WindowItem::updateSurfaceVisibility);
         connect(m_window, &Window::bufferGeometryChanged, this, &WindowItem::updateSurfacePosition);
         connect(m_window, &Window::frameGeometryChanged, this, &WindowItem::updateSurfacePosition);
-
-        connect(surfaceItem, &SurfaceItem::damaged, this, &WindowItem::markDamaged);
-        connect(surfaceItem, &SurfaceItem::childAdded, this, [this](Item *item) {
-            auto surfaceItem = static_cast<SurfaceItem *>(item);
-            connect(surfaceItem, &SurfaceItem::damaged, this, &WindowItem::markDamaged);
-        });
+        addSurfaceItemDamageConnects(surfaceItem);
 
         updateSurfacePosition();
         updateSurfaceVisibility();
diff --git a/src/scene/windowitem.h b/src/scene/windowitem.h
index 9beaa7807f..329388a33d 100644
--- a/src/scene/windowitem.h
+++ b/src/scene/windowitem.h
@@ -65,6 +65,7 @@ private Q_SLOTS:
     void updatePosition();
     void updateOpacity();
     void updateStackingOrder();
+    void addSurfaceItemDamageConnects(Item *item);
 
 private:
     bool computeVisibility() const;