MDEV#5687: Maria doesn't shutdown following upgrade

to 5.5.35-galera

Restored patch for MDEV#4136 and added a test.

mysql-test/suite/wsrep/r/pool_of_threads.result

+
+#
+# MDEV#5687: Maria doesn't shutdown following upgrade to 5.5.35-galera
+#
+SELECT @@GLOBAL.thread_handling;
+@@GLOBAL.thread_handling
+pool-of-threads
+# End of test.

mysql-test/suite/wsrep/t/pool_of_threads.opt

+--binlog-format=row --innodb_autoinc_lock_mode=2 --innodb_locks_unsafe_for_binlog=1 --wsrep-provider=/usr/lib/galera/libgalera_smm.so --wsrep-cluster-address=gcomm:// --thread_handling=pool-of-threads

mysql-test/suite/wsrep/t/pool_of_threads.test

+--source include/have_wsrep.inc
+
+--echo
+--echo #
+--echo # MDEV#5687: Maria doesn't shutdown following upgrade to 5.5.35-galera
+--echo #
+
+# Note: This test is to ensure that server shuts down properly.
+SELECT @@GLOBAL.thread_handling;
+
+--echo # End of test.

sql/mysqld.cc

@@ -4912,7 +4912,7 @@ pthread_handler_t start_wsrep_THD(void *arg)
     // at server shutdown
   }
 
-#if 0
+  my_thread_end();
   if (thread_handling > SCHEDULER_ONE_THREAD_PER_CONNECTION)
   {
     mysql_mutex_lock(&LOCK_thread_count);
@@ -4920,8 +4920,6 @@ pthread_handler_t start_wsrep_THD(void *arg)
     thread_count--;
     mysql_mutex_unlock(&LOCK_thread_count);
   }
-#endif
-  my_thread_end();
   return(NULL);
 }