[REG: 6.4→6.5] First evaluation of nullish coalescing and optional chaining

It seems  that in QML the first time that an expression with nullish coalescing and/or optional chaining is evaluated, this evaluation fails.

Example:

Take the following QT example: https://doc.qt.io/qt-6/qtquick-models-stringlistmodel-example.html

If I change the delegate by adding a

property var test

and by modifying the text content as follows

Text { text: parent.test ?? parent.modelData }

the first three items in the list are displayed correctly with the value contained in modelData, while the last one is empty and in console I have the following error:

qrc:/qt/qml/stringlistmodel/view.qml:17:16: Unable to assign [undefined] to QString

Similarly, if I change the text this way

Text { text: parent.test?.prop ?? parent.modelData }

again the first three items in the list are displayed correctly with the value contained in modelData, while the last one is empty and in console I have the following error:

qrc:/qt/qml/stringlistmodel/view.qml:17: TypeError: Cannot read property 'prop' of undefined

I would expect that the error would be logged either for every delegate item (i.e. it is a programming error) or for none, but not just for one element, and the same applies for the displayed values.

The same changes work as expected with Qt 6.2.3 and 6.4.2