Bug #3401 Rare replication bug which leads to "Binlog has bad magic number" from slave

Description:
Hard to explain and repeat. The 4.1 source tree contains a test rpl_relayrotate which has the relevant synchronization options to trigger the crash.
The symptom is that the slave says its relay log has a "bad magic number".

How to repeat:
hard

Suggested fix:
This is already fixed in 4.1, I am going to port back from the fix from 4.1 into 4.0

Thank you for your bug report. This issue has been committed to our
source repository of that product and will be incorporated into the
next release.

If necessary, you can access the source repository and build the latest
available version, including the bugfix, yourself. More information 
about accessing the source trees is available at
    http://www.mysql.com/doc/en/Installing_source_tree.html

Additional info:

Fixed in ChangeSet@1.1771, 2004-04-07 01:14:11+02:00, guilhem@mysql.com