SQL Parser Error: cannot resolve column reference with nested group_concat

[zhangysh1995]

Bug Report

Preview:

mysql> select group_concat(c order by (select group_concat(c order by a) from t2  where a=t1.a)) from t1;
ERROR 1105 (HY000): Can't find column Column#7 in schema Column: [test.t1.c] Unique key: []

1. Minimal reproduce step (Required)

drop table if exists t1, t2;
create table t1 (a int, c int); 
insert into t1 values (1, 1), (1, 2), (2, 3), (2, 4); 
create table t2 (a int, c int); 
insert into t2 values (1, 1), (1, 2), (2, 3), (2, 4); 
select group_concat(c order by (select group_concat(c order by a) from t2 where a=t1.a)) from t1; 

2. What did you expect to see? (Required)

It should execute without error and produce result similar to the following:

-- there are many possible orders regrading the final result
mysql> select group_concat(c order by (select group_concat(c order by a) from t2 where a=t1.a)) from t1;
+-----------------------------------------------------------------------------------+
| group_concat(c order by (select group_concat(c order by a) from t2 where a=t1.a)) |
+-----------------------------------------------------------------------------------+
| 2,1,4,3                                                                           |
+-----------------------------------------------------------------------------------+
1 row in set (0.00 sec)

3. What did you see instead (Required)

The parser cannot resolve the column name and produces meaningless error message to the user.

4. Affected version (Required)

Master branch

commit 6fa2badf388445f8f91e72b0aad0c217b7fcfb83 (HEAD -> master, origin/master, origin/HEAD)
Author: cfzjywxk <lsswxr@163.com>
Date:   Wed Jun 24 17:43:10 2020 +0800

5. Root Cause Analysis

[lhy1024]

/label component/parser

[yudongusa]

@fzhedu is there any update of this issue?