duplicate connection failure messages

This surprised me:

psql -p 55555 -h localhost
psql: could not connect to server: Connection refused       Is the server running on host "localhost" and accepting
 TCP/IP connections on port 55555?
 
could not connect to server: Connection refused       Is the server running on host "localhost" and accepting
TCP/IPconnections on port 55555?
 

It shows the same error message twice.  I can reproduce this back to PG
8.2.

It appears to have something to do with localhost resolving to an IPv4
and an IPv6 address, since it doesn't happen with other host names that
only resolve to one address.  However, fe-connect.c claims:
   /*    * Try to initiate a connection to one of the addresses    * returned by pg_getaddrinfo_all().  conn->addr_cur
isthe    * next one to try. We fail when we run out of addresses    * (reporting the error returned for the *last*
alternative,   * which may not be what users expect :-().    */