saveToFile() does not accept url with protocol

FileDialog {
    folder: shortcuts.documents
    selectExisting: false
    onAccepted: {
        content.grabToImage(function(result){
            if (!result.saveToFile(fileUrl)){
              console.error('Unknown error');
            }
        });
    }
}

FileDialog {
    folder: shortcuts.documents
    selectExisting: false
    onAccepted: {
        var urlNoProtocol = (fileUrl+"").replace('file://','');
        content.grabToImage(function(result){
            if (!result.saveToFile(fileNoProtocol)){
              console.error('Unknown error saving',fileNoProtocol);
            }
        });
    }
}