From 279406aa207584b22d27b4e8c5e5ecdef6c70ee9 Mon Sep 17 00:00:00 2001
From: David Redondo <qt@david-redondo.de>
Date: Tue, 16 Jul 2024 11:57:17 +0200
Subject: [PATCH] Client: Use std::unique_ptr to manage window decoration

There was a potential crash in the QWaylandWindow destructor. First it
deletes the window decoration (but does not unset the pointer!) and then
deletes the surface via reset(). This eventually triggers
QWaylandDisplay::handleKeyboardFocusChanged which will call
decoration->update().
Using std::unique_ptr makes it easier to manage and prevents such errors.

Change-Id: I52edcdab0d25c35dc656581fbb5c1c9b5ca481c4
Reviewed-by: Vlad Zahorodnii <vlad.zahorodnii@kde.org>
---
 src/plugins/platforms/wayland/qwaylandwindow.cpp | 12 +++++-------
 src/plugins/platforms/wayland/qwaylandwindow_p.h |  2 +-
 2 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/src/plugins/platforms/wayland/qwaylandwindow.cpp b/src/plugins/platforms/wayland/qwaylandwindow.cpp
index b9112d81ee1..581d353aaf0 100644
--- a/src/plugins/platforms/wayland/qwaylandwindow.cpp
+++ b/src/plugins/platforms/wayland/qwaylandwindow.cpp
@@ -72,7 +72,7 @@ QWaylandWindow::QWaylandWindow(QWindow *window, QWaylandDisplay *display)
 
 QWaylandWindow::~QWaylandWindow()
 {
-    delete mWindowDecoration;
+    mWindowDecoration.reset();
 
     if (mSurface)
         reset();
@@ -1064,8 +1064,7 @@ bool QWaylandWindow::createDecoration()
     if (decoration && !decorationPluginFailed) {
         if (!mWindowDecorationEnabled) {
             if (mWindowDecoration) {
-                delete mWindowDecoration;
-                mWindowDecoration = nullptr;
+                mWindowDecoration.reset();
             }
 
             QStringList decorations = QWaylandDecorationFactory::keys();
@@ -1104,8 +1103,7 @@ bool QWaylandWindow::createDecoration()
             if (targetKey.isEmpty())
                 targetKey = decorations.first(); // first come, first served.
 
-
-            mWindowDecoration = QWaylandDecorationFactory::create(targetKey, QStringList());
+            mWindowDecoration.reset(QWaylandDecorationFactory::create(targetKey, QStringList()));
             if (!mWindowDecoration) {
                 qWarning() << "Could not create decoration from factory! Running with no decorations.";
                 decorationPluginFailed = true;
@@ -1137,12 +1135,12 @@ bool QWaylandWindow::createDecoration()
         window()->requestUpdate();
     }
 
-    return mWindowDecoration;
+    return mWindowDecoration.get();
 }
 
 QWaylandAbstractDecoration *QWaylandWindow::decoration() const
 {
-    return mWindowDecorationEnabled ? mWindowDecoration : nullptr;
+    return mWindowDecorationEnabled ? mWindowDecoration.get() : nullptr;
 }
 
 static QWaylandWindow *closestShellSurfaceWindow(QWindow *window)
diff --git a/src/plugins/platforms/wayland/qwaylandwindow_p.h b/src/plugins/platforms/wayland/qwaylandwindow_p.h
index 38423f79b1a..c165125501b 100644
--- a/src/plugins/platforms/wayland/qwaylandwindow_p.h
+++ b/src/plugins/platforms/wayland/qwaylandwindow_p.h
@@ -270,7 +270,7 @@ protected:
     QWaylandSubSurface *mSubSurfaceWindow = nullptr;
     QList<QWaylandSubSurface *> mChildren;
 
-    QWaylandAbstractDecoration *mWindowDecoration = nullptr;
+    std::unique_ptr<QWaylandAbstractDecoration> mWindowDecoration;
     bool mWindowDecorationEnabled = false;
     bool mMouseEventsInContentArea = false;
     Qt::MouseButtons mMousePressedInContentArea = Qt::NoButton;