Assertion failure on hot standby

Hi,

http://archives.postgresql.org/pgsql-hackers/2010-11/msg01303.php

When I did unusual operations (e.g., suspend bgwriter by gdb,
pgbench -i and issue txid_current many times) on the master
in order to try to reproduce the above HS error, I encountered
the following assertion error.

Since I compiled the standby postgres with WAL_DEBUG and
ran it with wal_debug = on, all the replayed WAL records were
logged.

------------------------
sby LOG: REDO @ 0/134C0490; LSN 0/134C04D0: prev 0/134C0450; xid
23253; len 32: Transaction - commit: 2010-11-24 12:15:02.315634+09
sby LOG: REDO @ 0/134C04D0; LSN 0/134C0510: prev 0/134C0490; xid
23254; len 32: Transaction - commit: 2010-11-24 12:15:02.325252+09
sby LOG: consistent recovery state reached at 0/134C0510
sby LOG: REDO @ 0/134C0510; LSN 0/134C0550: prev 0/134C04D0; xid
23255; len 32: Transaction - commit: 2010-11-24 12:15:09.224343+09
sby LOG: REDO @ 0/134C0550; LSN 0/134C0580: prev 0/134C0510; xid 0;
len 16: Standby - AccessExclusive locks: xid 0 db 11910 rel 16409
sby LOG: REDO @ 0/134C0580; LSN 0/134C05B8: prev 0/134C0550; xid 0;
len 20: Standby - running xacts: nextXid 23256 latestCompletedXid
23255 oldestRunningXid 23256
TRAP: FailedAssertion("!(((xid) != ((TransactionId) 0)))", File:
"twophase.c", Line: 1209)
sby LOG: database system is ready to accept read only connections
sby LOG: startup process (PID 32666) was terminated by signal 6: Aborted
sby LOG: terminating any other active server processes
------------------------

Does anyone know what the cause of the problem is?

Regards,

--
Fujii Masao
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center