userdb cache expiry

[Havoc Pennington]

Tim Dijkstra wrote:
> FWIW, I commented out the part that gets the user from the cache
> (AFAICS there is only one function that directly access the cache). Not
> the part that puts it in, because that would create a memleak, which
> would abort the test (I didn't feel like investigating it further). So
> the test is even a bit unfair, in addition to looking up the user the
> nocache case also tries to add the user all time. 
> Despite all this there doesn't seem to be significant difference
> between the to cases; 
> 

Hmm, who knows then - maybe the issue is only on certain configurations, 
or maybe it vanished due to other changes over time, who knows.

If we can cook up a clean patch to keep the same basic code structure 
but maintain a cache size of 0, that will let us test the theory that 
it's OK to drop the cache, but still keep the code there if it turns out 
to be needed.

Havoc