[#MDEV-12101] failed_auth_unixsocket may fail depending on OS user account name

replace_result mtr command may corrupt test output and trigger false test failure.

Confirmed with OS user account as short as just 'a' , then failure looks like below:

CURRENT_TEST: main.failed_auth_unixsocket

--- /home/a/servere/mysql-test/r/failed_auth_unixsocket.result	2017-02-20 14:48:22.920331503 +0100

+++ /home/a/servere/mysql-test/r/failed_auth_unixsocket.reject	2017-02-21 09:43:50.346668937 +0100

@@ -1,7 +1,7 @@

 update mysql.user set plugin='unix_socket';

 flush privileges;

-connect(localhost,USER,,test,MASTER_PORT,MASTER_SOCKET);

-ERROR HY000: Plugin 'unix_socket' is not loaded

+connect(locUSERlhost,USER,,test,MASTER_PORT,MASTER_SOCKET);

+ERROR HY000: Plugin 'unix_socket' is not loUSERded

 ERROR HY000: Plugin 'unix_socket' is not loaded

 install plugin unix_socket soname 'auth_socket.so';

 connect(localhost,USER,,test,MASTER_PORT,MASTER_SOCKET);

Please note that occurrences of 'a' in result message are replaced with 'USER' by this line in test body mysql-test/t/failed_auth_unixsocket.test :

[MDEV-12101] failed_auth_unixsocket may fail depending on OS user account name Created: 2017-02-21 Updated: 2021-01-26 Resolved: 2021-01-26
Status:	Closed
Project:	MariaDB Server
Component/s:	Tests
Affects Version/s:	None
Fix Version/s:	10.4.0