Print a dummy section in order not to interference

with /etc/my.cnf and ~/.my.cnf [client] section.

mysql-test/t/mysqldump.test

@@ -766,10 +766,10 @@ DROP TABLE t1, t2;
 # Bugs #9136, #12917: problems with --defaults-extra-file option
 #
 
---exec echo "[client]" > $MYSQL_TEST_DIR/var/tmp/tmp.cnf
+--exec echo "[mysqltest1]" > $MYSQL_TEST_DIR/var/tmp/tmp.cnf
 --exec echo "port=1234" >> $MYSQL_TEST_DIR/var/tmp/tmp.cnf
---exec $MYSQL_MY_PRINT_DEFAULTS -c $MYSQL_TEST_DIR/var/tmp/tmp.cnf client
---exec $MYSQL_MY_PRINT_DEFAULTS -e $MYSQL_TEST_DIR/var/tmp/tmp.cnf client
+--exec $MYSQL_MY_PRINT_DEFAULTS -c $MYSQL_TEST_DIR/var/tmp/tmp.cnf mysqltest1
+--exec $MYSQL_MY_PRINT_DEFAULTS -e $MYSQL_TEST_DIR/var/tmp/tmp.cnf mysqltest1
 --exec rm $MYSQL_TEST_DIR/var/tmp/tmp.cnf
 
 #