diff --git a/mysql-test/suite/federated/federatedx.result b/mysql-test/suite/federated/federatedx.result
index c93ff1493d9..7dfcfd9f359 100644
--- a/mysql-test/suite/federated/federatedx.result
+++ b/mysql-test/suite/federated/federatedx.result
@@ -2157,6 +2157,12 @@ DROP TABLE federated.t1;
 End of 5.1 tests
 SET @@GLOBAL.CONCURRENT_INSERT= @OLD_MASTER_CONCURRENT_INSERT;
 SET @@GLOBAL.CONCURRENT_INSERT= @OLD_SLAVE_CONCURRENT_INSERT;
+#
+# MDEV-9346 - The federatedx and spider engine make mysqld crash when
+#             they are configured withtout username
+#
+CREATE TABLE t1 (a INT) ENGINE=FEDERATED CONNECTION='mysql://@127.0.0.1:SLAVE_PORT/federated/t1';
+ERROR HY000: Can't create federated table. Foreign data src error:  database: 'federated'  username: ''  hostname: '127.0.0.1'
 DROP TABLE IF EXISTS federated.t1;
 DROP DATABASE IF EXISTS federated;
 DROP TABLE IF EXISTS federated.t1;
diff --git a/mysql-test/suite/federated/federatedx.test b/mysql-test/suite/federated/federatedx.test
index 818cc2c1681..5e405dd8d09 100644
--- a/mysql-test/suite/federated/federatedx.test
+++ b/mysql-test/suite/federated/federatedx.test
@@ -2000,4 +2000,13 @@ SET @@GLOBAL.CONCURRENT_INSERT= @OLD_SLAVE_CONCURRENT_INSERT;
 
 connection default;
 
+--echo #
+--echo # MDEV-9346 - The federatedx and spider engine make mysqld crash when
+--echo #             they are configured withtout username
+--echo #
+connection master;
+--replace_result $SLAVE_MYPORT SLAVE_PORT
+--error ER_CANT_CREATE_FEDERATED_TABLE
+eval CREATE TABLE t1 (a INT) ENGINE=FEDERATED CONNECTION='mysql://@127.0.0.1:$SLAVE_MYPORT/federated/t1';
+
 source include/federated_cleanup.inc;
diff --git a/sql/client_settings.h b/sql/client_settings.h
index 1397c1f1e23..f2ad1797b8e 100644
--- a/sql/client_settings.h
+++ b/sql/client_settings.h
@@ -37,7 +37,7 @@
                              CLIENT_PLUGIN_AUTH_LENENC_CLIENT_DATA | \
                              CLIENT_CONNECT_ATTRS)
 
-#define read_user_name(A) {strmov(A,"");}
+#define read_user_name(A) A[0]= 0
 #undef _CUSTOMCONFIG_
 
 #define mysql_server_init(a,b,c) mysql_client_plugin_init()