Wrong default name for changed signal handlers when property starts with underscore

When I add a property whose name starts with an underscore (e.g. _foo) to a QML file and try to add a signal handler for its changed signal, then the signal handler name suggested by Qt Creator's code completer has the wrong capitalization. In this case it would suggested "onfooChanged" whereas the correct name is "on_FooChanged".

The following file gives no errors in the editor in Qt Creator:

import QtQuick 2.2
import QtQuick.Window 2.1

Window {
    visible: true
    width: 360
    height: 360

    property real __foo: 0.0
    on__fooChanged: console.debug("test")

}

However, when run it will give the following error: Cannot assign to non-existent property "on__fooChanged"

The following code runs fine with QML:

import QtQuick 2.2
import QtQuick.Window 2.1

Window {
    visible: true
    width: 360
    height: 360

    property real __foo: 0.0
    on__FooChanged: console.debug("test")

}

But in Qt Creator it gives a red underline for "on__FooChanged" with the error "Invalid property name (M16)".