qt5-qtdeclarative/0009-V4-Do-not-call-dtor-of-an-object-we-continue-to-use.patch

From b964ba12bf118afbbf42cd9e4e7b4903ad107060 Mon Sep 17 00:00:00 2001
From: Ulf Hermann <ulf.hermann@qt.io>
Date: Thu, 3 Feb 2022 10:02:06 +0100
Subject: [PATCH 09/21] V4: Do not call dtor of an object we continue to use

After destroyObject(), the QObjectWrapper is still alive. We might use
its heap object again. Furthermore, the Heap::QObjectWrapper dtor does
not actually do anything defined. What we want to do here is clear the
QObject pointer because we've just gotten rid of the QObject. There is a
method for that: Heap::QObjectWrapper::destroy().

Finally, the internalClass must never ever be nullptr. Assert on that
rather than checking it.

Pick-to: 5.15 6.2 6.3
Task-number: QTBUG-100431
Change-Id: I794a295c182b2ed4ba80673f58d6143c861b7391
Reviewed-by: Andrei Golubev <andrei.golubev@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
(cherry picked from commit 6c197319f34b8098d034f1543eb5feb9d7be54c3)
---
 src/qml/jsruntime/qv4qobjectwrapper.cpp | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/qml/jsruntime/qv4qobjectwrapper.cpp b/src/qml/jsruntime/qv4qobjectwrapper.cpp
index e57cdd8278..94613598af 100644
--- a/src/qml/jsruntime/qv4qobjectwrapper.cpp
+++ b/src/qml/jsruntime/qv4qobjectwrapper.cpp
@@ -1145,8 +1145,7 @@ void Heap::QObjectWrapper::markObjects(Heap::Base *that, QV4::MarkStack *markSta
 void QObjectWrapper::destroyObject(bool lastCall)
 {
     Heap::QObjectWrapper *h = d();
-    if (!h->internalClass)
-        return; // destroyObject already got called
+    Q_ASSERT(h->internalClass);
 
     if (h->object()) {
         QQmlData *ddata = QQmlData::get(h->object(), false);
@@ -1176,7 +1175,7 @@ void QObjectWrapper::destroyObject(bool lastCall)
         }
     }
 
-    h->~Data();
+    h->destroy();
 }
 
 
-- 
2.39.0