From 35a3184ea3cbfcb0a66a49b466f9f6793c466d10 Mon Sep 17 00:00:00 2001
From: Vlad Zahorodnii <vlad.zahorodnii@kde.org>
Date: Mon, 20 Jun 2022 11:57:19 +0300
Subject: [PATCH] Fix computation of effective opaque region of SurfaceItemX11

The value of _NET_WM_OPAQUE_REGION can be out of sync with the geometry
of the window. The NETWM spec suggests to compute the effective opaque
region by taking intersection of _NET_WM_OPAQUE_REGION and the bounding
region set by the shape extension.

SurfaceItemX11::opaque() got broken after refactoring opaque region
handling in wayland surfaces so SurfaceInterface::opaque() always
returns a sane value, the computation of effective opaque region is done
in SurfaceInterface at commit time.

BUG: 455617
---
 src/surfaceitem_x11.cpp | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/surfaceitem_x11.cpp b/src/surfaceitem_x11.cpp
index 075c9eea2a..6c5e106856 100644
--- a/src/surfaceitem_x11.cpp
+++ b/src/surfaceitem_x11.cpp
@@ -139,7 +139,11 @@ QRegion SurfaceItemX11::shape() const
 
 QRegion SurfaceItemX11::opaque() const
 {
-    return window()->opaqueRegion();
+    if (!window()->hasAlpha()) {
+        return shape();
+    } else {
+        return window()->opaqueRegion() & shape();
+    }
 }
 
 SurfacePixmap *SurfaceItemX11::createPixmap()