legendFilter 无法复原 x 轴的数据 #5506

• 问题：LegendFilter 之后 x 轴会多一个 undefined
• 版本：5.1.0

import { Chart } from '@antv/g2';

const chart = new Chart({
  container: 'container',
  autoFit: true,
});

chart.options({
  type: 'view',
  data: [
    { month: 'Jan', city: 'Tokyo', temperature: 7 },
    { month: 'Jan', city: 'London', temperature: 3.9 },
    { month: 'Feb', city: 'Tokyo', temperature: 6.9 },
    { month: 'Feb', city: 'London', temperature: 4.2 },
    { month: 'Mar', city: 'Tokyo', temperature: 9.5 },
    { month: 'Mar', city: 'London', temperature: 5.7 },
    { month: 'Apr', city: 'Tokyo', temperature: 14.5 },
    { month: 'Apr', city: 'London', temperature: 8.5 },
    { month: 'May', city: 'Tokyo', temperature: 18.4 },
    { month: 'May', city: 'London', temperature: 11.9 },
    { month: 'Jun', city: 'Tokyo', temperature: 21.5 },
    { month: 'Jun', city: 'London', temperature: 15.2 },
    { month: 'Jul', city: 'Tokyo', temperature: 25.2 },
    { month: 'Jul', city: 'London', temperature: 17 },
    { month: 'Aug', city: 'Tokyo', temperature: 26.5 },
    { month: 'Aug', city: 'London', temperature: 16.6 },
    { month: 'Sep', city: 'Tokyo', temperature: 23.3 },
    { month: 'Sep', city: 'London', temperature: 14.2 },
    { month: 'Oct', city: 'Tokyo', temperature: 18.3 },
    { month: 'Oct', city: 'London', temperature: 10.3 },
    { month: 'Nov', city: 'Tokyo', temperature: 13.9 },
    { month: 'Nov', city: 'London', temperature: 6.6 },
    { month: 'Dec', city: 'Tokyo', temperature: 9.6 },
    { month: 'Dec', city: 'London', temperature: 4.8 },
  ],
  encode: {
    x: 'month',
    y: 'temperature',
    color: 'city',
  },
  children: [
    { type: 'line' },
    { type: 'point', style: { shape: 'point' } },
    {
      type: 'text',
      data: ['Jul', 17],
      encode: {
        text: '当前点London温度最高',
        color: 'London', // 加上 color encode
      },
      style: { fill: '#000' },
    },
  ],
});

chart.render();