ArchiveIndexView and YearIndexView compute the queryset twice

[Aymeric Augustin]

In the debug toolbar, I noticed that the queryset is evaluated twice, with a different ordering. The call to order_by in get_dated_items appears to be the culprit.

I'm attaching a patch that resolves the issue, but it may not be backwards compatible -- the order of objects in classes inheriting BaseDateListView may change.

[Aymeric Augustin]

A little bit more background:

• MultipleObjectMixin.get_context_data sets context['object_list'] = context[get_context_object_name()] = queryset
• BaseDateListView.get calls MultipleObjectMixin.get_context_data with two keyword arguments, object_list and date_list, that are computed by get_dated_items (a method that the subclasses must implement). Since keyword arguments have precedence over other variable, context['object_list'] is overwritten (and loses pagination).

So we end up with two slightly different variables in the context with similar purposes, one under 'object_list' and the other under the value of get_context_object_name().

[Jannis Leidel]

Hm, this is kinda related to #18355, so this better be fixed together.

[Aymeric Augustin]

It's actually a duplicate of #18354 which I fixed this morning. I forgot I had already reported it.