Is this error expected ?

Hi,

i have an 

"ERROR:  UNION types "char" and text cannot be matched CASE WHEN indisprimary THEN"

error from 

https://github.com/yiisoft/yii/blob/e7c298343bf1f76186d443b62ff853d2d36e19f0/framework/db/schema/pgsql/CPgsqlSchema.php#L233

I read release notes, but can't find any related change,

It works for PostgreSQL 14.5 but fails with PostgreSQL 15.0, a test sample below.

Is this error expected ?

Thanks,

create table tbla
(    a "char"
);

create table tblb
(    b char(1)
);

insert into tbla values ('a');
insert into tbla values ('b');

insert into tblb values ('c');
insert into tblb values ('d');

-- works with 14.5 fails on 15.0

select a from tbla
union all
select
case when true then    'p'
else    'u'
end from tblb;