MDEV-5386: Server crashes in thd_get_ha_data on maria-5.5-galera tree while...

MDEV-5386: Server crashes in thd_get_ha_data on maria-5.5-galera tree while running 'check testcase before test

Analysis: In Galera binlog is not enabled by default in case
when wsrep provider is not specified. In this case we should
not call thd->binlog_flush_pending_rows_event(TRUE). 

Fix: Added a additional guard on galera not to call binlog
function if wsrep provider is not specified and binlog is
not enabled.

sql/sql_base.cc

@@ -62,7 +62,7 @@
 
 #ifdef WITH_WSREP
 #include "wsrep_mysqld.h"
-
+extern handlerton *binlog_hton;
 #endif // WITH_WSREP
 
 bool
@@ -1575,6 +1575,11 @@ void close_thread_tables(THD *thd)
       handled either before writing a query log event (inside
       binlog_query()) or when preparing a pending event.
      */
+#ifdef WITH_WSREP
+     /* In Galera binlog is not enabled by default in case when
+     wsrep provider is not specified. */
+     if ((WSREP_ON && WSREP_PROVIDER_EXISTS) || binlog_hton->state == SHOW_OPTION_YES)
+#endif
     (void)thd->binlog_flush_pending_rows_event(TRUE);
     mysql_unlock_tables(thd, thd->lock);
     thd->lock=0;