message: fix(sector): set `arc` as 0 if `startAngle` equals `endAngle`, skip the normalization.
  fix apache/echarts#14074. sector blink issue when zero data exists.
diff: @@ -126,10 +126,17 @@ export function buildPath(ctx: CanvasRenderingContext2D | PathProxy, shape: {
  const startAngle = shape.startAngle;
  const endAngle = shape.endAngle;
  - // FIXME: whether normalizing angles is required?
  + // PENDING: whether normalizing angles is required?
  + let arc: number;
  + // FIXME: there may be a precision issue in `normalizeArcAngles`
  + if (startAngle === endAngle) {
  + arc = 0;
  + }
  + else {
  const tmpAngles = [startAngle, endAngle];
  normalizeArcAngles(tmpAngles, !clockwise);
  - const arc = mathAbs(tmpAngles[0] - tmpAngles[1]);
  + arc = mathAbs(tmpAngles[0] - tmpAngles[1]);
  + }
  const x = shape.cx;
  const y = shape.cy;
  