Mixed DDL/DML load crashes slaves

[Teemu Ollakka]

To reproduce, first start DML load:

./bin/sqlgen --host 127.0.0.1 --port 3306 --rows 1000 --tables 2 --duration 36000 --create 1 --users 8

Then start DROP/CREATE tables on background:

while true; do ./bin/sqlgen --host 127.0.0.1 --port 3306 --rows 1000 --tables 2 --users 0 --duration 0; sleep 1; done

After a while slaves fail to apply RBR event:

110512 12:07:17 [ERROR] Slave SQL: Error 'Table 'test.comm00' doesn't exist' on opening tables, Error_code: 1146
110512 12:07:17 [Warning] WSREP: RBR event 2 apply warning: 1146, 1963723
110512 12:07:17 [ERROR] WSREP: Failed to apply app buffer: U��M, seqno: 1963723, status: WSREP_FATAL
         at galera/src/replicator_smm.cpp:apply_data():77
         at galera/src/replicator_smm.cpp:apply_ws():100
         at galera/src/replicator_smm.cpp:apply_wscoll():121
         at galera/src/replicator_smm.cpp:apply_trx_ws():143
         at galera/src/replicator_smm.cpp:apply_trx_ws():164
         at galera/src/replicator_smm.cpp:apply_trx():465
         at galera/src/replicator_smm.cpp:process_trx():997
110512 12:07:17 [Note] WSREP: recv thread exiting (code:6)