树图重新载入数据时报错

[dongwenting]

One-line summary [问题简述]

需要重新载入数据，新的数据比原来的数据少，报错如下：

echarts.js中：

        data.diff(oldData)
            .add(function (newIdx) {
                if (symbolNeedsDraw$1(data, newIdx)) {
                    // create node and edge
                    updateNode(data, newIdx, null, group, seriesModel, seriesScope);
                }
            })
            .update(function (newIdx, oldIdx) {
                var symbolEl = oldData.getItemGraphicEl(oldIdx);
                if (!symbolNeedsDraw$1(data, newIdx)) {
                    symbolEl && removeNode(data, newIdx, symbolEl, group, seriesModel, seriesScope);
                    return;
                }
                // update  node and edge
                updateNode(data, newIdx, symbolEl, group, seriesModel, seriesScope);
            })
            .remove(function (oldIdx) {
                var symbolEl = oldData.getItemGraphicEl(oldIdx);
     //这里传入新的data和老的oldIdx
                removeNode(data, oldIdx, symbolEl, group, seriesModel, seriesScope);
            })
            .execute();

function removeNode(data, dataIndex, symbolEl, group, seriesModel, seriesScope) {
   //新的data数据少，返回的node等于undefined，因此getModel出错
    var node = data.tree.getNodeByDataIndex(dataIndex);
    var virtualRoot = data.tree.root;
    var itemModel = node.getModel();

Version & Environment [版本及环境]

• ECharts version [ master刚下的，3.8.4]: 建议在echarts.min.js上加版本
• Browser version [firefox 57.02，chrome 63.0]:
• OS Version [window 7专业版]:

Expected behaviour [期望结果]

ECharts option [ECharts配置项]

option = {

}

Other comments [其他信息]

[dongwenting]

找到解决办法了，先clear一下，再重载
myChart.clear();