QQmlObjectCreator: fix member func call with this == nullptr

The test example is based on
qtvirtualkeyboard/src/virtualkeyboard/content/components/PopupList.qml

Luckily ((QQmlPropertyCache *)nullptr) -> property(-1)
is ended without access to this, so this was not caught before.
But this is UB, plus I can not run Qt and my application compiled with
-fsanitizer=X, because of it crashed after the first member function
call with nullptr as this

Fixes: QTBUG-85605
Change-Id: If6a71fde9a14cc4f73139dfa0e6ee3005453104d
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/qml/qml/qqmlobjectcreator.cpp b/src/qml/qml/qqmlobjectcreator.cpp
index 1142618e2d..5fa0eb281e 100644
--- a/src/qml/qml/qqmlobjectcreator.cpp
+++ b/src/qml/qml/qqmlobjectcreator.cpp
@@ -1589,7 +1589,7 @@ bool QQmlObjectCreator::populateInstance(int index, QObject *instance, QObject *
         if (!target)
             continue;
         QQmlData *targetDData = QQmlData::get(target, /*create*/false);
-        if (!targetDData)
+        if (targetDData == nullptr || targetDData->propertyCache == nullptr)
             continue;
         int coreIndex = QQmlPropertyIndex::fromEncoded(alias->encodedMetaPropertyIndex).coreIndex();
         QQmlPropertyData *const targetProperty = targetDData->propertyCache->property(coreIndex);