Unexpect error when use default function in expression of generated column

[Deardrops]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. What did you do?
   If possible, provide a recipe for reproducing the error.

create table t1(a int default 9, b int as (default(a)));
insert into t1 values(1, default);
select * from t1;

2. What did you expect to see?
   

3. What did you see instead?
   

4. What version of TiDB are you using (tidb-server -V or run select tidb_version(); on TiDB)?

Release Version: v4.0.0-alpha-341-g0df9bb7b8-dirty

[Deardrops]

Related PR: #8540

The issue is caused by the check in

tidb/planner/core/expression_rewriter.go

Lines 1508 to 1514 in 41ac571

	if colExpr.OrigTblName.O == "" {
	// column is evaluated by some expressions, for example:
	// `select default(c) from (select (a+1) as c from t) as t0`
	// in such case, a 'no default' error is returned
	er.err = table.ErrNoDefaultValue.GenWithStackByArgs(colExpr.ColName)
	return
	}

Same as sql statement select default(c) from (select (a+1) as c from t) as t0, When use default() function in expression of generated columns, its colExpr also has an empty field of OrigTblName.O.So the latter will throw an unexpected error.

Any suggessions for fixup this issue?
This Issue fixup in #12550