Correctly display track number 0 in show_change
fixes issue When the per_disc_numbering option was set, the UI would
previously show a -> change when actually the index would be set
to 0 (a valid index, such as for hidden tracks).  Now, properly
distinguish index 0 and None (i.e. not set)
@@ -241,7 +241,8 @@ def show_change(cur_artist, cur_album, match):
if mediums and mediums > 1:
return u'{0}-{1}'.format(medium, medium_index)
else:
- return six.text_type(medium_index or index)
+ return six.text_type(medium_index if medium_index is not None
+ else index)
else:
return six.text_type(index)
