"Not safe to send CSV data" message

So I went to investigate bug #5196: turned on log_destination = csvlog
etc, and restarted the postmaster.  I got this on stderr:

2009-11-18 20:08:52.104 EST : : LOG:  loaded library "passwordcheck"
Not safe to send CSV data

The first line is a consequence of having still got
shared_preload_libraries set from testing the new contrib/passwordcheck
module.  However, what I'm on the warpath about right now is the second
line.  That message is useless, not to mention not conformant to our
style guidelines.  And the fact that it comes out at all suggests that
the csvlog startup logic is rather broken.  Comments?
        regards, tom lane