sa-learn and user preferences

[Mike Jackson <mj...@barking-dog.net>]

On the servers I admin, the user preferences are stored in SQL, yet sa-learn 
insists on there being a .spamassassin directory in the users' home 
directory, creating it and a default user_prefs file if they do not exist. 
Why? What does it need the prefs for? Can it use the SQL preferences? Is 
there no way to turn off this behavior other than passing 
a --prefs-file=/dev/null flag to sa-learn?

Pertinent details: I'm using SA 3.1.0. sa-learn is invoked from a cron job 
running as root, but the -u flag passes in the username for each user whose 
spam folder is learned.