mysqltest memory leak on invalid replace_regex

[Laurynas Biveinis]

With LeakSanitizer-enabled AddressSanitizer build,

main.mysqltest w2 [ fail ]
        Test ended at 2016-05-23 07:10:28

CURRENT_TEST: main.mysqltest
sh: 1: illegal_command: not found
mysqltest: At line 2050: command "echo "--replace_regex a" | $MYSQL_TEST 2>&1" failed with wrong error: 23

which caused by

mysqltest: At line 1: Error parsing replace_regex "a"

=================================================================
==23684==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 3072 byte(s) in 1 object(s) allocated from:
    #0 0x7fdf8de5a54a in malloc (/usr/lib/x86_64-linux-gnu/libasan.so.2+0x9854a)
    #1 0x48fc49 in my_malloc /home/laurynas/mysql-server/mysys/my_malloc.c:38
    #2 0x49146d in init_dynamic_array2 /home/laurynas/mysql-server/mysys/array.c:70
    #3 0x413b35 in init_replace_regex(char*) /home/laurynas/mysql-server/client/mysqltest.cc:9388
    #4 0x414c57 in do_get_replace_regex(st_command*) /home/laurynas/mysql-server/client/mysqltest.cc:9539
    #5 0x426117 in main /home/laurynas/mysql-server/client/mysqltest.cc:8837
    #6 0x7fdf8d0d582f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2082f)

SUMMARY: AddressSanitizer: 3072 byte(s) leaked in 1 allocation(s).

[Laurynas Biveinis (laurynas-biveinis)]

https://github.com/percona/percona-server/pull/579, https://github.com/percona/percona-server/pull/580, https://github.com/percona/percona-server/pull/581

[Shahriyar Rzayev (rzayev-sehriyar)]

Percona now uses JIRA for bug reports so this bug report is migrated to: https://jira.percona.com/browse/PS-3453