From 73e8321255d9f0e70529a58c10dbaf4790a9a659 Mon Sep 17 00:00:00 2001
From: David Edmundson <davidedmundson@kde.org>
Date: Tue, 6 Mar 2018 10:56:23 +0000
Subject: [PATCH 28/29] Rebuild property cache in QObjectWrapper::getProperty
 if deleted

QQmlData is shared between engines, but the relevant QObjectWrapper is
not.

Since 749a7212e903d8e8c6f256edb1836b9449cc7fe1 when a QObjectWrapper is
deleted it resets the shared QQmlData propertyCache.

ab5d4c78224c9ec79165e8890e5f8b8e838e0709 fixed this situation for
bindings, however we would still hit effectively the same crash in the
same situation if a function is evaluated before a binding.

Change-Id: I20cd91cd8e31fd0176d542822c67e81a790599ba
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>
---
 src/qml/jsruntime/qv4qobjectwrapper.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/qml/jsruntime/qv4qobjectwrapper.cpp b/src/qml/jsruntime/qv4qobjectwrapper.cpp
index 5ebd385cf..c1bbe2a33 100644
--- a/src/qml/jsruntime/qv4qobjectwrapper.cpp
+++ b/src/qml/jsruntime/qv4qobjectwrapper.cpp
@@ -335,6 +335,11 @@ ReturnedValue QObjectWrapper::getProperty(ExecutionEngine *engine, QObject *obje
     if (!ddata)
         return QV4::Encode::undefined();
 
+    if (Q_UNLIKELY(!ddata->propertyCache)) {
+        ddata->propertyCache = QQmlEnginePrivate::get(engine)->cache(object->metaObject());
+        ddata->propertyCache->addref();
+    }
+
     QQmlPropertyCache *cache = ddata->propertyCache;
     Q_ASSERT(cache);
     QQmlPropertyData *property = cache->property(propertyIndex);
-- 
2.14.3