REG 5.9.1->5.9.2: TextInput ignores validator

//// 5.6.3 - works fine
//import QtQuick 2.6
//import Qt.labs.controls 1.0

//// 5.7.1 - works fine
//import QtQuick 2.7
//import QtQuick.Controls 2.0

//// 5.8.0 - works fine
//import QtQuick 2.8
//import QtQuick.Controls 2.1

//// 5.9.0 - works fine
//import QtQuick 2.9
//import QtQuick.Controls 2.2

//// 5.9.1 - works fine
//import QtQuick 2.9
//import QtQuick.Controls 2.2

//// 5.9.2 - validator ignored, able to input "33", "f2", " 9"
//import QtQuick 2.9
//import QtQuick.Controls 2.2

// 5.10 Beta 4 - validator ignored, able to input "33", "f2", " 9"
import QtQuick 2.10
import QtQuick.Controls 2.3

ApplicationWindow {
    title: "validator ignored with input mask"
    width: 350; height: 90
    visible: true

    TextInput {
        id: input
        anchors.fill: parent
        horizontalAlignment: TextInput.AlignHCenter; verticalAlignment: TextInput.AlignVCenter

        text: "+1"
        inputMask: "X9;_"
        validator: RegExpValidator { regExp: /[+-][0-9]/ }
    }
}