Test rpl.rpl_show_slave_running may crash debug build

[Laurynas Biveinis]

On 5.5 trunk:

rpl.rpl_show_slave_running 'mix' w3 [ fail ]
        Test ended at 2016-11-23 13:09:13

CURRENT_TEST: rpl.rpl_show_slave_running
mysqltest: In included file "./include/rpl_end.inc":
included from ./include/rpl_end.inc at line 71:
At line 70: query 'let $_tmp= query_get_value(SHOW SLAVE STATUS, Master_Host, 1)' failed: 2013: Lost connection to MySQL server during query
...
Program terminated with signal SIGSEGV, Segmentation fault.
#0 0xb7756b2e in __pthread_kill (threadid=2873174848, signo=signo@entry=11) at ../nptl/sysdeps/unix/sysv/linux/pthread_kill.c:61
61 ../nptl/sysdeps/unix/sysv/linux/pthread_kill.c: No such file or directory.
#0 0xb7756b2e in __pthread_kill (threadid=2873174848, signo=signo@entry=11) at ../nptl/sysdeps/unix/sysv/linux/pthread_kill.c:61
#1 0x08478e87 in my_write_core (sig=11) at /mnt/workspace/percona-server-5.5-trunk/BUILD_TYPE/debug/Host/debian-jessie-32bit/mysys/stacktrace.c:433
#2 0x0831b53b in handle_fatal_signal (sig=11) at /mnt/workspace/percona-server-5.5-trunk/BUILD_TYPE/debug/Host/debian-jessie-32bit/sql/signal_handler.cc:250
#3 <signal handler called>
#4 internal_fnmatch (pattern=<optimized out>, string=string@entry=0x876b23a "exit", string_end=<optimized out>, no_leading_period=no_leading_period@entry=0, flags=flags@entry=0, ends=ends@entry=0x0, alloca_used=alloca_used@entry=0) at fnmatch_loop.c:62
#5 0xb72cbc1a in __fnmatch (pattern=pattern@entry=0x1f5 <error: Cannot access memory at address 0x1f5>, string=string@entry=0x876b23a "exit", flags=flags@entry=0) at fnmatch.c:454
#6 0x0873c164 in InList (linkp=0x1f0, cp=cp@entry=0x876b23a "exit") at /mnt/workspace/percona-server-5.5-trunk/BUILD_TYPE/debug/Host/debian-jessie-32bit/dbug/dbug.c:1502
#7 0x0873d651 in _db_keyword_ (cs=cs@entry=0xa1f13460, keyword=0x876b23a "exit", strict=65538, strict@entry=0) at /mnt/workspace/percona-server-5.5-trunk/BUILD_TYPE/debug/Host/debian-jessie-32bit/dbug/dbug.c:1719
#8 0x0873d6ad in _db_doprnt_ (format=format@entry=0x8824e63 "ptr: %p") at /mnt/workspace/percona-server-5.5-trunk/BUILD_TYPE/debug/Host/debian-jessie-32bit/dbug/dbug.c:1263
#9 0x08473165 in my_malloc (size=<optimized out>, my_flags=16) at /mnt/workspace/percona-server-5.5-trunk/BUILD_TYPE/debug/Host/debian-jessie-32bit/mysys/my_malloc.c:65
#10 0x083ddd3a in Log_event::read_log_event (file=0x96ed138, log_lock=log_lock@entry=0x0, description_event=0xa1f133b0) at /mnt/workspace/percona-server-5.5-trunk/BUILD_TYPE/debug/Host/debian-jessie-32bit/sql/log_event.cc:1183
#11 0x082961f5 in init_relay_log_pos (rli=rli@entry=0x96ebfa0, log=log@entry=0x96ed47c "./slave-relay-bin.000002", pos=254, need_data_lock=need_data_lock@entry=true, errmsg=errmsg@entry=0xab411d44, look_for_description_event=look_for_description_event@entry=true) at /mnt/workspace/percona-server-5.5-trunk/BUILD_TYPE/debug/Host/debian-jessie-32bit/sql/rpl_rli.cc:572
#12 0x08151b14 in handle_slave_sql (arg=arg@entry=0x96eac40) at /mnt/workspace/percona-server-5.5-trunk/BUILD_TYPE/debug/Host/debian-jessie-32bit/sql/slave.cc:3343
#13 0x086aa68e in pfs_spawn_thread (arg=0xa1d24280) at /mnt/workspace/percona-server-5.5-trunk/BUILD_TYPE/debug/Host/debian-jessie-32bit/storage/perfschema/pfs.cc:1015
#14 0xb7751d97 in start_thread (arg=0xab412b40) at pthread_create.c:309
#15 0xb72f464e in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:129

This is another instance of debug variable being updated concurrently with reading it, e.g. https://bugs.mysql.com/bug.php?id=58754

[Laurynas Biveinis (laurynas-biveinis)]

     https://github.com/percona/percona-server/pull/1198
     https://github.com/percona/percona-server/pull/1199
     https://github.com/percona/percona-server/pull/1200

[Shahriyar Rzayev (rzayev-sehriyar)]

Percona now uses JIRA for bug reports so this bug report is migrated to: https://jira.percona.com/browse/PS-3607