From 4bc74d6831253b545a65bf74d2714af3603f17cf Mon Sep 17 00:00:00 2001
From: Vlad Zahorodnii <vlad.zahorodnii@kde.org>
Date: Tue, 13 Aug 2024 22:26:43 +0300
Subject: [PATCH] scene: Ignore xwayland window shape

The shape region is used to clip the window contents. But, in practice,
it's used by a few applications. The most notable is xeyes.

The APIs that the shape region requires are manageable, but it would be
much preferred if we had a much simpler design.

In terms of the shape region support on Wayland, it's not widely
supported across all wayland compositors, to my knowledge, only two
support it, some compositors even want to disable XSHAPE extension at all.

This change makes the Xwayland windows ignore the shape region to see if
any real world applications are affected by it. If not, then we could
safely simplify the scene bits later.

The Xorg session is unaffected by this change.
---
 src/scene/surfaceitem_wayland.cpp | 19 ++-----------------
 src/scene/surfaceitem_wayland.h   |  1 -
 2 files changed, 2 insertions(+), 18 deletions(-)

diff --git a/src/scene/surfaceitem_wayland.cpp b/src/scene/surfaceitem_wayland.cpp
index 4a307565c0..a4d012f774 100644
--- a/src/scene/surfaceitem_wayland.cpp
+++ b/src/scene/surfaceitem_wayland.cpp
@@ -252,30 +252,15 @@ SurfaceItemXwayland::SurfaceItemXwayland(X11Window *window, Item *parent)
     : SurfaceItemWayland(window->surface(), parent)
     , m_window(window)
 {
-    connect(window, &X11Window::shapeChanged, this, &SurfaceItemXwayland::discardQuads);
-}
-
-QList<QRectF> SurfaceItemXwayland::shape() const
-{
-    QList<QRectF> shape = m_window->shapeRegion();
-    for (QRectF &shapePart : shape) {
-        shapePart = shapePart.intersected(rect());
-    }
-    return shape;
 }
 
 QRegion SurfaceItemXwayland::opaque() const
 {
-    QRegion shapeRegion;
-    for (const QRectF &shapePart : shape()) {
-        shapeRegion += shapePart.toRect();
-    }
     if (!m_window->hasAlpha()) {
-        return shapeRegion;
+        return rect().toRect();
     } else {
-        return m_window->opaqueRegion() & shapeRegion;
+        return m_window->opaqueRegion() & rect().toRect();
     }
-    return QRegion();
 }
 #endif
 } // namespace KWin
diff --git a/src/scene/surfaceitem_wayland.h b/src/scene/surfaceitem_wayland.h
index f769284172..991cd168c3 100644
--- a/src/scene/surfaceitem_wayland.h
+++ b/src/scene/surfaceitem_wayland.h
@@ -95,7 +95,6 @@ public:
     explicit SurfaceItemXwayland(X11Window *window, Item *parent = nullptr);
 
     QRegion opaque() const override;
-    QList<QRectF> shape() const override;
 
 private:
     X11Window *m_window;