Refs MW-255

- popping PS reprepare observer before BF aborted PS replaying begins
  dangling observer will cause failure in open_table() ater on
- test case for this anomaly

mysql-test/suite/galera/r/galera_transaction_replay.result

@@ -30,3 +30,30 @@ SELECT COUNT(*) = 1 FROM t1 WHERE f2 = 'c';
 COUNT(*) = 1
 1
 DROP TABLE t1;
+CREATE TABLE t1 (i int primary key, j int) ENGINE=INNODB;
+INSERT INTO t1 VALUES (1, 0), (3, 0);
+SELECT * FROM t1;
+i	j
+1	0
+3	0
+PREPARE stmt1 FROM "UPDATE t1 SET j = 1 where i > 0";
+SET GLOBAL wsrep_provider_options = 'dbug=d,commit_monitor_enter_sync';
+EXECUTE stmt1;;
+SET SESSION wsrep_sync_wait = 0;
+SET SESSION wsrep_on = 0;
+SET SESSION wsrep_on = 1;
+INSERT INTO t1 VALUES(2,2);
+SET GLOBAL wsrep_provider_options = 'dbug=';
+SET GLOBAL wsrep_provider_options = 'signal=commit_monitor_enter_sync';
+SELECT * FROM t1;
+i	j
+1	1
+2	2
+3	1
+SELECT * FROM t1;
+i	j
+1	1
+2	2
+3	1
+DEALLOCATE PREPARE stmt1;
+DROP TABLE t1;

mysql-test/suite/galera/t/galera_transaction_replay.test

@@ -69,3 +69,56 @@ SELECT COUNT(*) = 1 FROM t1 WHERE f2 = 'b';
 SELECT COUNT(*) = 1 FROM t1 WHERE f2 = 'c';
 
 DROP TABLE t1;
+
+#echo "# test for PS replaying"
+
+#
+# test replaying of prepared statements
+#
+--connection node_1
+CREATE TABLE t1 (i int primary key, j int) ENGINE=INNODB;
+INSERT INTO t1 VALUES (1, 0), (3, 0);
+SELECT * FROM t1;
+
+PREPARE stmt1 FROM "UPDATE t1 SET j = 1 where i > 0";
+
+# block the commit of PS
+--connection node_1a
+--let $galera_sync_point = commit_monitor_enter_sync
+--source include/galera_set_sync_point.inc
+
+--connection node_1
+--send EXECUTE stmt1;
+
+# Wait until commit is blocked
+--connection node_1a
+SET SESSION wsrep_sync_wait = 0;
+--source include/galera_wait_sync_point.inc
+
+# Issue a conflicting update on node_2
+--connection node_2
+#UPDATE t1 SET j=2;
+INSERT INTO t1 VALUES(2,2);
+
+
+# Wait until applying begins in node_1
+--connection node_1a
+--let $wait_condition = SELECT COUNT(*) = 1 FROM INFORMATION_SCHEMA.PROCESSLIST WHERE STATE LIKE 'Write_rows_log_event::write_row%';
+--source include/wait_condition.inc
+
+# Unblock the PS commit
+--connection node_1a
+--source include/galera_clear_sync_point.inc
+--source include/galera_signal_sync_point.inc
+
+# Commit succeeds
+--connection node_1
+--reap
+SELECT * FROM t1;
+
+--connection node_2
+SELECT * FROM t1;
+
+--connection node_1
+DEALLOCATE PREPARE stmt1;
+DROP TABLE t1;

sql/wsrep_thd.cc

@@ -185,6 +185,7 @@ static void wsrep_return_from_bf_mode(THD *thd, struct wsrep_thd_shadow* shadow)
 
 void wsrep_replay_transaction(THD *thd)
 {
+  DBUG_ENTER("wsrep_replay_transaction");
   /* checking if BF trx must be replayed */
   if (thd->wsrep_conflict_state== MUST_REPLAY) {
     DBUG_ASSERT(wsrep_thd_trx_seqno(thd));
@@ -193,6 +194,13 @@ void wsrep_replay_transaction(THD *thd)
       {
         WSREP_ERROR("replay issue, thd has reported status already");
       }
+
+      /*
+        PS reprepare observer should have been removed already.
+        open_table() will fail if we have dangling observer here.
+      */
+      DBUG_ASSERT(thd->m_reprepare_observer == NULL);
+
       thd->get_stmt_da()->reset_diagnostics_area();
 
       thd->wsrep_conflict_state= REPLAYING;
@@ -299,6 +307,7 @@ void wsrep_replay_transaction(THD *thd)
       mysql_mutex_unlock(&LOCK_wsrep_replaying);
     }
   }
+  DBUG_VOID_RETURN;
 }
 
 static void wsrep_replication_process(THD *thd)