[Spambayes] spam that crashes my spambayes

[Tim Peters]

[Gerald Pine]
>> This is an example of a spam email that crashes my spambayes
>> installation.  Am running spambayes 1.0.1 on SuSE Linux 9.1.  Some of
>> the log output follows.
>> [...]
>>   File "/usr/lib/python2.3/shelve.py", line 119, in __getitem__
>>     value = Unpickler(f).load()
>> UnpicklingError: unpickling stack underflow

[Tony Meyer]
> This is a very unusual error.  My best guess would be that the database is
> corrupted somehow and should be replaced (retraining would be the easiest
> way).  If this happens with lots of messages, irregardless of whether they
> are ham or spam, that would strengthen the guess.

Unfortunately, I have to agree, although it screams "corruption" to me
without more evidence than we already have.  This can only happen if
the pickle is ill-formed, and the only way to get an ill-formed pickle
is for bytes to get corrupted (on disk, or in RAM, or on a
communication path between disk and RAM, or ...).  Even if it's disk
corruption, databases aren't likely to notice it, since it occurs
inside the user's stored data, not in the database's own
administrative structures (to which latter database code *is*
sensitive).