Chart Gets Break If It has Only One Date on X Axis On Hiding Series

Chart Gets Break If It has Only One Date on X Axis On Hiding Series

HTML

<script src="http://code.highcharts.com/master/highstock.js"></script>
 
<div id="container" style="min-width: 500px"></div>

JavaScript

$(function() {
     var chart, yAxis = [], seriesOptions = [], seriesCnt=0, top =0, yAxisCnt=0,
                topPadding = 10, dates = [1350239400000], 
                visibleSeriesMap = new Object();
                 Highcharts.setOptions({
                    global: {
                        useUTC: false
                    }
                }); 
               
                Highcharts.Series.prototype.toggleConnected = function(series) {
                    var visibility = !this.visible,
                    connectedSeries = series.options.connectedSeries,
                    seriesId = series.options.id,
                    len = connectedSeries ? connectedSeries.length : 0,
                    i = 0,
                    serie;
                    
                    for (; i < len; i++) {
                        serie = this.chart.get(connectedSeries[i]);
                        serie.setVisible(visibility, false);
                        visibleSeriesMap[serie.options.id] = visibility;
                        serie.checkbox.checked = visibility;
                    }
                    
                    this.setVisible(!visibility);
                    visibleSeriesMap[seriesId] = visibility;
                    chart.destroy();
                    defineSeries();      
                    this.checkbox.checked = visibility;
                }
                
                visibleSeriesMap['line']  =  true;
                visibleSeriesMap['line0']  =  true;
                visibleSeriesMap['dataLabel']  =  true;
                visibleSeriesMap['dataLabel']  =  true;
                
                function getSeriesGroup(name, length, visible) {
                    var seriesIdArray = [];
                    for(var i=0;i < length;i++){
                        seriesIdArray.push(name.toLowerCase() + i);
                    }
                    var series = {
                        id  : name.toLowerCase(),
                        name:...