BUG #19410: Cannot ser client_encoding

The following bug has been logged on the website:

Bug reference:      19410
Logged by:          Guest-615695028
Email address:      615695028@qq.com
PostgreSQL version: 18.1
Operating system:   Microsoft Windows [版本 10.0.26200.7840]
Description:

PS C:\> psql -U postgres
Password for user postgres:

psql (18.1)
Type "help" for help.

postgres=# SHOW client_encoding;
 client_encoding
-----------------
 GBK
(1 row)


postgres=# SET client_encoding='UTF8';
SET
postgres=# SHOW client_encoding;
 client_encoding
-----------------
 UTF8
(1 row)


postgres=# \q
PS C:\> psql -U postgres
Password for user postgres:

psql (18.1)
Type "help" for help.

postgres=# SHOW client_encoding;
 client_encoding
-----------------
 GBK
(1 row)


postgres=#