From b33821736008580ad9b13c005a06d498d4eb1d9a Mon Sep 17 00:00:00 2001
From: Christian Ehrlicher <ch.ehrlicher@gmx.de>
Date: Thu, 5 Dec 2024 21:20:18 +0100
Subject: [PATCH] QWidget: Don't offset the clip region for windows using
 effects

When a top-level widget has a graphic effect applied,
QWidgetPrivate::clipToEffectiveMask() must not use the parent widget for
the mask calculation as this prevents the loop below from bailing out in
the first loop (w->isWindow()) and might mess up the clip region when
there is a widget with a mask in the parent chain.

Pick-to: 6.8
Fixes: QTBUG-131893
Change-Id: I5d5777e730bee309db21ad5eb65387d19321ee6c
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
(cherry picked from commit 49f462b7f873ecba6bb205697338a4f1eef6d307)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
---
 src/widgets/kernel/qwidget.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/widgets/kernel/qwidget.cpp b/src/widgets/kernel/qwidget.cpp
index 54808e9f136..47a801b7251 100644
--- a/src/widgets/kernel/qwidget.cpp
+++ b/src/widgets/kernel/qwidget.cpp
@@ -2123,7 +2123,7 @@ void QWidgetPrivate::clipToEffectiveMask(QRegion &region) const
     QPoint offset;
 
 #if QT_CONFIG(graphicseffect)
-    if (graphicsEffect) {
+    if (graphicsEffect && !w->isWindow()) {
         w = q->parentWidget();
         offset -= data.crect.topLeft();
     }