Alias properties incorrectly allow duplicating property names

Look at the following code:

import QtQuick 2.6

Item {
    property alias currentText: myText.text
    readonly property string currentText: myText.text
    //readonly property string currentText: myText.text

    Text {
        id: myText
        text: "hello"
    }
}

Note that it defines currentText twice. Once as an alias, once as a property. Notice that it runs without error, which already seems very questionable/wrong.

Then uncomment the second declaration, and notice that it does correctly error in that case:

test.qml:6 Duplicate property name