BUG #5616: psql Doesn't Change Log files on \c

The following bug has been logged online:

Bug reference:      5616
Logged by:          David E. Wheeler
Email address:      david@kineticode.com
PostgreSQL version: 8.4
Operating system:   Mac OS X 10.6.4
Description:        psql Doesn't Change Log files on \c
Details:

I have this in my .psqlrc:

    \set HISTFILE ~/.psql_history- :DBNAME

This is great, except when I change databases in a session:

    % psql foo
    foo % \c bar
    You are now connected to database "bar".
    SELECT true;

The last statement will be logged to ~/.psql_history-foo when it should go
to ~/.psql_history-bar.