mysqltest crashes on an attempt to send a query when no connection is active

[Elena Stepanova]

#2 0x00000000004275a9 in signal_handler (sig=11) at /home/elenst/maria-5.5/client/mysqltest.cc:8571
#3 <signal handler called>
#4 0x0000000000434a40 in mysql_send_query (mysql=0x0, query=0x193b790 "SELECT 1", length=8) at /home/elenst/maria-5.5/sql-common/client.c:3920
#5 0x0000000000434b23 in mysql_real_query (mysql=0x0, query=0x193b790 "SELECT 1", length=8) at /home/elenst/maria-5.5/sql-common/client.c:3931
#6 0x00000000004161c2 in wrap_mysql_real_query (mysql=0x0, stmt_str=0x193b790 "SELECT 1", length=8) at /home/elenst/maria-5.5/client/../tests/nonblock-wrappers.h:175
#7 0x000000000041acf9 in var_query_set (var=0x193b670, query=0x193ae01 "SELECT 1`", query_end=0x7fff53b35da0) at /home/elenst/maria-5.5/client/mysqltest.cc:2519
#8 0x000000000041b9c2 in eval_expr (v=0x193b670, p=0x193ae00 "`SELECT 1`", p_end=0x7fff53b35da0, open_end=false, do_eval=true) at /home/elenst/maria-5.5/client/mysqltest.cc:2821
#9 0x000000000041a79c in var_set (var_name=0x193ad85 "a = `SELECT 1`", var_name_end=0x193ad86 " = `SELECT 1`", var_val=0x193ae00 "`SELECT 1`", var_val_end=0x193ae0a "") at /home/elenst/maria-5.5/client/mysqltest.cc:2381
#10 0x000000000041f71e in do_let (command=0x193ac30) at /home/elenst/maria-5.5/client/mysqltest.cc:4763
#11 0x0000000000428667 in main (argc=11, argv=0x7fff53b36228) at /home/elenst/maria-5.5/client/mysqltest.cc:9006

bzr version-info
revision-id: <email address hidden>
date: 2012-05-03 16:00:41 +0300
build-date: 2012-05-03 23:09:38 +0400
revno: 3392

Also reproducible on MariaDB 5.1, 5.2, 5.3. No crash on MySQL 5.5 or MySQL trunk.

# Test case
# Run either from MTR or as
# mysqltest --socket=<your_socket> -uroot < t.test

connect (con1,localhost,root,,);
disconnect con1;
# Just to wait till it is disconnected
--sleep 2
let $a = `SELECT 1`;
connection default;

# End of test case