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;