SIGSEGV on shutdown with non-default wsrep_slave_threads

Error: Freeing unallocated data or underrun buffer [Thread 0xae5f7b40 (LWP 28976) exited]

mysys/safemalloc.c:191, mysys/my_malloc.c:218, sql/sql_plugin.cc:1272, sql/sql_plugin.cc:3113, sql/sql_plugin.cc:3168, 141002 23:48:50 [Note] Event Scheduler: Purging the queue. 0 events

sql/sql_class.cc:1653, sql/sql_class.cc:1691, sql/mysqld.cc:2837

Program received signal SIGSEGV, Segmentation fault.

[Switching to Thread 0xae640b40 (LWP 28975)]

0x0828eb6f in intern_plugin_unlock (lex=0x0, plugin=0x917c6d18)

    at /home/nirbhay/project/git-repo/mariadb/bld/10.1/sql/sql_plugin.cc:1288

1288	  DBUG_ASSERT(pi->ref_count);

(gdb) bt

#0  0x0828eb6f in intern_plugin_unlock (lex=0x0, plugin=0x917c6d18)

    at /home/nirbhay/project/git-repo/mariadb/bld/10.1/sql/sql_plugin.cc:1288

#1  0x08293aeb in unlock_variables (thd=0x8aa72038, vars=0x8aa72524)

    at /home/nirbhay/project/git-repo/mariadb/bld/10.1/sql/sql_plugin.cc:3112

#2  0x08293d46 in plugin_thdvar_cleanup (thd=0x8aa72038)

    at /home/nirbhay/project/git-repo/mariadb/bld/10.1/sql/sql_plugin.cc:3167

#3  0x0823a529 in THD::~THD (this=0x8aa72038, __in_chrg=<optimized out>)

    at /home/nirbhay/project/git-repo/mariadb/bld/10.1/sql/sql_class.cc:1651

#4  0x0823a8a7 in THD::~THD (this=0x8aa72038, __in_chrg=<optimized out>)

    at /home/nirbhay/project/git-repo/mariadb/bld/10.1/sql/sql_class.cc:1691

#5  0x081b7ff0 in unlink_thd (thd=0x8aa72038)

    at /home/nirbhay/project/git-repo/mariadb/bld/10.1/sql/mysqld.cc:2836

#6  0x081b83a6 in one_thread_per_connection_end (thd=0x8aa72038, put_in_cache=true)

    at /home/nirbhay/project/git-repo/mariadb/bld/10.1/sql/mysqld.cc:2949

#7  0x08406c5c in start_wsrep_THD (arg=0x84157b4)

    at /home/nirbhay/project/git-repo/mariadb/bld/10.1/sql/wsrep_mysqld.cc:1805

#8  0xb7d55d4c in start_thread (arg=0xae640b40) at pthread_create.c:308

#9  0xb7b659de in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:130