[Dovecot] auth_debug_passwords only on mismatches?

From the configuration notes (1.0.10), it sounds like setting 'auth_debug_passwords' will only log the user supplied password if there was a mismatch.. When I set it (with auth_debug=no), I get a good amount of auth debug info, regardless of password matching..

dovecot.conf: # In case of password mismatches, log the passwords and used scheme so the # problem can be debugged. Requires auth_debug=yes to be set. auth_debug_passwords = yes

I'm basically looking to just add a "login failed" line, with the username, and supplied passsword when a mismatch occurs.. Is there currently a way to do this without modifying the code?

Thanks!

-Mike