setting TextEdit.textDocument.source moves the cursor to the end

import QtQuick
// import QtQuick.Controls

Window {
    id: window
    width: 1024
    height: 600
    visible: true
    title: edit.textDocument.source

    Flickable {
        id: flick

        anchors.fill: parent
        contentWidth: edit.contentWidth
        contentHeight: edit.contentHeight
        clip: true

        function ensureVisible(r)
        {
            if (contentX >= r.x)
                contentX = r.x;
            else if (contentX+width <= r.x+r.width)
                contentX = r.x+r.width-width;
            if (contentY >= r.y)
                contentY = r.y;
            else if (contentY+height <= r.y+r.height)
                contentY = r.y+r.height-height;
        }

        TextEdit {
            id: edit
            width: flick.width
            focus: true
            wrapMode: TextEdit.Wrap
            onCursorRectangleChanged: flick.ensureVisible(cursorRectangle)
            textFormat: Qt.RichText
        }
    }

    Component.onCompleted: edit.textDocument.source = "sth.html"

    // Component.onCompleted: {
    //     var request = new XMLHttpRequest()
    //     request.open('GET', 'sth.html')
    //     request.onreadystatechange = function(event) {
    //         if (request.readyState === XMLHttpRequest.DONE)
    //             edit.text = request.responseText
    //     }
    //     request.send()
    // }
}

1   QQuickTextControlPrivate::_q_updateCursorPosChanged qquicktextcontrol.cpp       435  
2   QQuickTextControl::qt_static_metacall               moc_qquicktextcontrol_p.cpp 310  
3   QQuickTextControl::qt_metacall                      moc_qquicktextcontrol_p.cpp 459  
4   QMetaObject::metacall                               qmetaobject.cpp             337  
5   doActivate<false>                                   qobject.cpp                 4070 
6   QMetaObject::activate                               qobject.cpp                 4104 
7   QTextDocument::cursorPositionChanged                moc_qtextdocument.cpp       516  
8   QTextDocumentPrivate::finishEdit                    qtextdocument_p.cpp         1213 
9   QTextDocumentPrivate::endEditBlock                  qtextdocument_p.cpp         1171 
10  QTextDocument::setHtml                              qtextdocument.cpp           1300 
11  QQuickTextDocumentPrivate::load                     qquicktextdocument.cpp      158  
12  QQuickTextDocument::setSource                       qquicktextdocument.cpp      108