diff --git a/mysql-test/r/federated_server.result b/mysql-test/r/federated_server.result
index 0905aabb075..32717b4f0e3 100644
--- a/mysql-test/r/federated_server.result
+++ b/mysql-test/r/federated_server.result
@@ -253,6 +253,14 @@ drop user guest_usage@localhost;
 drop user guest_select@localhost;
 drop table federated.t1;
 drop server 's1';
+create server 's1' foreign data wrapper 'mysql' options (port 3306);
+alter server 's1' options
+(host 'localhost', database '', user '',
+password '', socket '', owner '', port 3306);
+alter server 's1' options
+(host 'localhost', database 'database1', user '',
+password '', socket '', owner '', port 3306);
+drop server 's1';
 # End of 5.1 tests
 use test;
 create procedure p1 ()
@@ -262,7 +270,7 @@ DECLARE e INT DEFAULT 0;
 DECLARE i INT;
 DECLARE CONTINUE HANDLER FOR SQLEXCEPTION SET e = e + 1;
 SET i = sleep(5);
-WHILE v < 20000 do
+WHILE v < 10000 do
 CREATE SERVER s
 FOREIGN DATA WRAPPER mysql
 OPTIONS (USER 'Remote', HOST '192.168.1.106', DATABASE 'test');
diff --git a/mysql-test/t/federated_server.test b/mysql-test/t/federated_server.test
index 87b67720104..444285ac045 100644
--- a/mysql-test/t/federated_server.test
+++ b/mysql-test/t/federated_server.test
@@ -2,7 +2,7 @@
 # if federated can utilise the servers table
 # should work with embedded server after mysqltest is fixed
 -- source include/not_embedded.inc
--- source include/federated.inc;
+-- source include/federated.inc
 -- source include/big_test.inc
 
 connection slave;
@@ -282,6 +282,18 @@ drop user guest_select@localhost;
 drop table federated.t1;
 drop server 's1';
 
+#
+# Bug#30671 - ALTER SERVER causes the server to crash
+#
+create server 's1' foreign data wrapper 'mysql' options (port 3306);
+alter server 's1' options
+  (host 'localhost', database '', user '',
+  password '', socket '', owner '', port 3306);
+# The next statement would crash unpatched server
+alter server 's1' options
+  (host 'localhost', database 'database1', user '',
+  password '', socket '', owner '', port 3306);
+drop server 's1';
 
 --echo # End of 5.1 tests
 
diff --git a/sql/sql_servers.cc b/sql/sql_servers.cc
index a780c561ffe..543884fdfa6 100644
--- a/sql/sql_servers.cc
+++ b/sql/sql_servers.cc
@@ -289,7 +289,7 @@ get_server_from_table_to_cache(TABLE *table)
 {
   /* alloc a server struct */
   char *ptr;
-  char *blank= (char*)"";
+  char * const blank= (char*)"";
   FOREIGN_SERVER *server= (FOREIGN_SERVER *)alloc_root(&mem,
                                                        sizeof(FOREIGN_SERVER));
   DBUG_ENTER("get_server_from_table_to_cache");
@@ -312,7 +312,7 @@ get_server_from_table_to_cache(TABLE *table)
   server->port= server->sport ? atoi(server->sport) : 0;
 
   ptr= get_field(&mem, table->field[6]);
-  server->socket= ptr && strlen(ptr) ? ptr : NULL;
+  server->socket= ptr && strlen(ptr) ? ptr : blank;
   ptr= get_field(&mem, table->field[7]);
   server->scheme= ptr ? ptr : blank;
   ptr= get_field(&mem, table->field[8]);