MeshUtils.CreatMesh iOS崩溃问题

Creator 3.x
#1

所有iOS设备必现
MeshUtils.CreatMesh 传入的primitives.IGeometry中如果顶点长度为0
mesh赋值给一个meshrender

必现崩溃

安卓小游戏均无此问题

加入长度检查后 不再崩溃
let geometries = this.regenerateMeshForHexs(hexagons);

    if (geometries) {

        if (this.mesh) this.mesh.destroy();

        if(geometries.positions.length > 0)

        {

            this.mesh = utils.MeshUtils.createMesh(geometries);

            this.meshRender.mesh = this.mesh;

            this.meshRender.enabled = true;

        }else{

            this.meshRender.mesh = null;

            this.meshRender.enabled = false;

        }

    }