set sql_mode="";
#
# MDEV-4594 - CREATE SERVER crashes embedded
#
CREATE SERVER s1 FOREIGN DATA WRAPPER mysql OPTIONS(HOST 'localhost');
SELECT * FROM mysql.servers;
Server_name	Host	Db	Username	Password	Port	Socket	Wrapper	Owner
s1	localhost				3306		mysql	
DROP SERVER s1;
CREATE SERVER s1 FOREIGN DATA WRAPPER foo OPTIONS(USER 'bar');
SELECT * FROM mysql.servers;
Server_name	Host	Db	Username	Password	Port	Socket	Wrapper	Owner
s1			bar		0		foo	
DROP SERVER s1;
CREATE SERVER s1 FOREIGN DATA WRAPPER mysql OPTIONS(USER 'bar');
ERROR HY000: Can't create federated table. Foreign data src error:  either HOST or SOCKET must be set
CREATE SERVER s1 FOREIGN DATA WRAPPER mysql OPTIONS(HOST 'bar');
SELECT * FROM mysql.servers;
Server_name	Host	Db	Username	Password	Port	Socket	Wrapper	Owner
s1	bar				3306		mysql	
DROP SERVER s1;
CREATE SERVER s1 FOREIGN DATA WRAPPER mysql OPTIONS(SOCKET 'bar');
SELECT * FROM mysql.servers;
Server_name	Host	Db	Username	Password	Port	Socket	Wrapper	Owner
s1					3306	bar	mysql	
DROP SERVER s1;
CREATE SERVER s1 FOREIGN DATA WRAPPER mysql OPTIONS(SOCKET '/tmp/1234567890_1234567890_1234567890_1234567890_1234567890_1234567890.sock');
SELECT Socket FROM mysql.servers where Server_name = 's1';
Socket
/tmp/1234567890_1234567890_1234567890_1234567890_1234567890_1234567890.sock
DROP SERVER s1;
#
# MDEV-33783 CREATE SERVER segfaults on wrong mysql.servers
#
create server s1 foreign data wrapper foo options(user 'a');
alter server s1 options(host 'server.example.org');
rename table mysql.servers to mysql.servers_save;
create table mysql.servers (x int);
alter server s1 options(host 'server.example.org');
ERROR HY000: The foreign server name you are trying to reference does not exist. Data source error:  s1
create server s2 foreign data wrapper foo options(user 'a');
ERROR HY000: Can't read record in system table
drop table mysql.servers;
rename table mysql.servers_save to mysql.servers;
drop server s1;
#
# MDEV-35641 foreign server "disappears" after ALTERing the servers system table to use innodb and FLUSH PRIVILEGES
#
CREATE SERVER s1 FOREIGN DATA WRAPPER mysql OPTIONS (HOST '127.0.0.1');
ALTER TABLE mysql.servers ENGINE=innodb;
FLUSH PRIVILEGES;
drop server s1;