event_is_dst called with incorrect parameters

I came across what looks like a code problem while looking through event.module . I haven't linked this to observable behaviour but I'd expect there to be some.
Version: event-6.x-2.x-dev dated 2nd Dec 2008.

The definition of function event_is_dst has:

function event_is_dst($dst_region, $time)

However AFAICS the function is called with incorrect parameters in the following places:
event_nodeapi case 'presave' (lines 2364-5):

        $node->event['start_in_dst'] = event_is_dst($node->event['timezone'], $node->event['start_exploded']);
        $node->event['end_in_dst'] = event_is_dst($node->event['timezone'], $node->event['end_exploded']);

- First parameter given as time zone instead of dst_region.

event_check_dst (line 2541):

    return (event_is_dst($event) ? $event->event['offset_dst'] : $event->event['offset']);

- Only one parameter given.

Hope this is helpful - I appreciate that I'm reporting against a dev snapshot, which may therefore be in the middle of planned changes.

Dave