From 4e2e9ab78adf498405109603ce7d9f20d5f12abc Mon Sep 17 00:00:00 2001
From: Vlad Zahorodnii <vlad.zahorodnii@kde.org>
Date: Mon, 19 Dec 2022 18:15:00 +0000
Subject: [PATCH] wayland: Fix updating pixel data from translucent client
 buffers when using qpainter backend

We must set QPainter::CompositionMode_Source to overwrite the old
contents.
---
 .../scenes/qpainter/qpaintersurfacetexture_wayland.cpp           | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/platformsupport/scenes/qpainter/qpaintersurfacetexture_wayland.cpp b/src/platformsupport/scenes/qpainter/qpaintersurfacetexture_wayland.cpp
index a65f09da83..fd395353e8 100644
--- a/src/platformsupport/scenes/qpainter/qpaintersurfacetexture_wayland.cpp
+++ b/src/platformsupport/scenes/qpainter/qpaintersurfacetexture_wayland.cpp
@@ -43,6 +43,7 @@ void QPainterSurfaceTextureWayland::update(const QRegion &region)
     const QImage image = buffer->data();
     const QRegion dirtyRegion = mapRegion(m_pixmap->item()->surfaceToBufferMatrix(), region);
     QPainter painter(&m_image);
+    painter.setCompositionMode(QPainter::CompositionMode_Source);
 
     // The buffer data is copied as the buffer interface returns a QImage
     // which doesn't own the data of the underlying wl_shm_buffer object.