Optimizer trace: multi-component range is not printed correctly

create table t2 (kp1 int, kp2 int, key(kp1, kp2));

insert into t2 values (1,1),(1,5),(5,1),(5,5);

set optimizer_trace=1;

select * from t2 force index(kp1) where (kp1=2 and kp2 >=4);

select * from information_schema.optimizer_trace;

      "range_scan_alternatives": [

        {

          "index": "kp1",

          "ranges": ["(2,3) <= (kp1,kp2)"],

          "rowid_ordered": false,

          "using_mrr": false,

          "index_only": false,

          "rows": 10,  

          "cost": 58.75,

          "chosen": true

        }

      ],