QQmlValueTypeWrapper: readReferenceValue in virtualGetOwnProperty

Otherwise we may end up with a nullptr gadget.

Fixes: QTBUG-104803
Change-Id: Ia0c3741fdf0214f0c3d4b352006442747f635f5c
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
(cherry picked from commit 0e48d9d9387aeb39c8289f61f75d9c6fcd6c753f)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

1 files changed, 21 insertions, 4 deletions

diff --git a/src/qml/qml/qqmlvaluetypewrapper.cpp b/src/qml/qml/qqmlvaluetypewrapper.cpp
index c2bbd7f498..2cba0375e7 100644
--- a/src/qml/qml/qqmlvaluetypewrapper.cpp
+++ b/src/qml/qml/qqmlvaluetypewrapper.cpp
@@ -281,10 +281,27 @@ PropertyAttributes QQmlValueTypeWrapper::virtualGetOwnProperty(const Managed *m,
 {
     if (id.isString()) {
         const QQmlValueTypeWrapper *r = static_cast<const QQmlValueTypeWrapper *>(m);
-        QQmlPropertyData result = r->dataForPropertyKey(id);
-        if (p && result.isValid())
-            p->value = getGadgetProperty(r->engine(), r->d(), result.propType(), result.coreIndex(), result.isFunction(), result.isEnum());
-        return result.isValid() ? Attr_Data : Attr_Invalid;
+        Q_ASSERT(r);
+
+        const QQmlPropertyData result = r->dataForPropertyKey(id);
+        if (!result.isValid())
+            return Attr_Invalid; // Property doesn't exist. Object shouldn't meddle with it.
+
+        if (!p)
+            return Attr_Data; // Property exists, but we're not interested in the value
+
+        const QQmlValueTypeReference *ref = r->as<const QQmlValueTypeReference>();
+        if (!ref || ref->readReferenceValue()) {
+            // Property exists, and we can retrieve it
+            p->value = getGadgetProperty(
+                        r->engine(), r->d(), result.propType(), result.coreIndex(),
+                        result.isFunction(), result.isEnum());
+        } else {
+            // Property exists, but we can't retrieve it. Make it undefined.
+            p->value = Encode::undefined();
+        }
+
+        return Attr_Data;
     }
 
     return QV4::Object::virtualGetOwnProperty(m, id, p);