We see rare, sporadic failures of the test case rpl.rpl_stm_until in Buildbot
for the MariaDB 5.1 tree.

rpl.rpl_stm_until 'stmt' w3 [ fail ] Found warnings/errors in server log file!

100325 0:57:29 [ERROR] I/O error reading the header from the binary log, errno=175, io cache code=0 ^ Found warnings in /var/lib/buildbot/maria-slave/work-opensuse-amd64/build/mysql-test/var/3/log/mysqld.1.err

100325 0:57:29 [ERROR] Slave I/O: Got fatal error 1236 from master when reading data from binary log: 'I/O error reading the header from the binary log', Error_code: 1236 ^ Found warnings in /var/lib/buildbot/maria-slave/work-opensuse-amd64/build/mysql-test/var/3/log/mysqld.2.err

Cross-reference search for this failure:

http://buildbot.askmonty.org/buildbot/reports/cross_reference#branch=&revision=&platform=&dt=&bbnum=&typ=&info=&fail_name=rpl.rpl_stm_until&fail_variant=&fail_info_short=&fail_info_full=I/O+error+reading+the+header+from+the+binary+log&limit=100

These failures started to appear shortly after we merged MySQL 5.1.44, so it
is likely (though not 100% certain) that the errors were introduced with this
merge.