8.3 vs HEAD difference in Interval output?

Unless I'm compiling stuff wrong, it seems HEAD is giving me
slightly different output on Intervals than 8.3 in the roundoff
of seconds. 8.3 was rounding to the nearest fraction of a second,
HEAD seems to be truncating.

In the psql output below it shows 8.3.1 outputting "6.70 secs"
while the similar output for head is showing "6.69 secs".

At first glance it seems this might be because HEAD defaults
to USE_INTEGER_DATETIMES, which leads to HAVE_INT64_TIMESTAMP
which leads to
sprintf(cp, "%s%d.%02d secs", is_nonzero ? " " : "",
tm->tm_sec, ((int) sec) / 10000);
in EncodeInterval in datetime.c which doesn't seem to be
doing any rounding.

Am I interpreting this right? If so, shall I submit a patch
that rounds it to hundredths of a second (hundredths seems
hardcoded in the sprintf), or perhaps just silently add that
fix to the EncodeInterval patch I'm doing any for SQL Standard
and ISO intervals?

========================================================================
psql (8.4devel)
Type "help" for help.
regression=# set datestyle to sql;
SET
regression=# select '1 year 2 mons 3 days 04:05:06.699999'::interval;
interval
-------------------------------------------------
@ 1 year 2 mons 3 days 4 hours 5 mins 6.69 secs
(1 row)

========================================================================
Welcome to psql 8.3.1, the PostgreSQL interactive terminal.
...
pg83=# set datestyle to sql;
SET
pg83=# select '1 year 2 mons 3 days 04:05:06.699999'::interval;
interval
-------------------------------------------------
@ 1 year 2 mons 3 days 4 hours 5 mins 6.70 secs
(1 row)