property alias causes crash in 5.9.1

[Surka]

When calling createObject() on the component with property alias, crash happens.

The code snipet is as follows.
[main.qml]
import QtQuick 2.7
import QtQuick.Controls 2.0
import QtQuick.Layouts 1.3

ApplicationWindow {
visible: true
width: 640
height: 480
title: qsTr("Hello World")

Item {
    id: root
    anchors.fill: parent

    Foo {
        id: foo
    }

    Timer {
        id: timer

        running: true
        repeat: true
        interval: 1000

        onTriggered: {
            foo.createObject(root, {"foo": 0.5, "foo2": 2, "foo3": true})
        }
    }
}

}

[Foo.qml]
Component {
Item {
property alias foo: bar.opacity
property alias foo2: bar.scale
property alias foo3: bar.visible

    id: foo

    x: 100
    y: 100
    width: 100
    height: 100

    Rectangle {
        id: bar
        anchors.fill: parent
        color: "green"
    }
}

}

[Surka]

Failed to attach screenshot.

The assert dialog shows
"properties.count == propertyIndexCache.count()" in file qml\qqmlpropertycache.cpp, line 1188.

[m.kuncevicius]

@Surka Hi. Property alias and the Item id has the same name foo - it can't be the same. I also don't think that Rectangle has property scale.

[Surka]

@m-kuncevicius Yes, that's my typo. But it is irrelavant to the crash. The issue here is Qt reporting its internal assertion. btw, scale is property of Item.