use instance name if possible

pandora/archive/models.py

@@ -297,6 +297,7 @@ class File(models.Model):
         return 'unknown'
 
     def get_instance(self):
+        #FIXME: what about other instances?
         if self.instances.all().count() > 0:
             return self.instances.all()[0]
         return None
@@ -318,7 +319,8 @@ class File(models.Model):
         return u''
 
     def get_name(self):
-        if self.is_extra:
+        instance = self.get_instance()
+        if instance:
             return self.get_instance().name
         if self.item:
             name = self.item.get('title', 'Untitled')

pandora/item/views.py

@@ -226,7 +226,7 @@ Positions
             response['data']['items'] = [only_p(m['json']) for m in qs.values('json')]
     else: # otherwise stats
         items = query['qs']
-        files = File.objects.all().filter(item__in=items).filter(size__gt=0)
+        files = File.objects.filter(item__in=items).filter(size__gt=0)
         r = files.aggregate(
             Sum('duration'),
             Sum('pixels'),