Room occupation not computed properly during capacity check

[Job Doesburg]

sagexit/website/room_reservation/views.py

Lines 43 to 53 in a33e48b

 capacity_reached = ( 
     Reservation.objects.filter(room=room) 
     .filter( 
         Q(start_time__lte=start_time, end_time__gt=start_time) 
         | Q(start_time__lt=end_time, end_time__gte=end_time) 
         | Q(start_time__gte=start_time, end_time__lte=end_time) 
     ) 
     .exclude(pk=pk) 
     .count() 
     >= Room.objects.get(id=room).capacity 
 ) 

Currently we count all overlapping reservations when adding a new reservation. However, it is very well possible that in total the amount of overlapping reservations exceeds 6 when some reservations take longer others take shorter. We should count the overlapping reservations that all overlap with each other (so 10:00-12:00 and 12:00-14:00 both overlap with 10:00-14:00, but in the capacity computation, they should count as 1).