I've noted that the generic view implementations use the private `_clone` method when returning the queryset attribute<https://github.com/django/django/blob/master/django/views/generic/detail.py#L72> .
Presumably the need for that is something to do with the potential for querysets to be cached or otherwise incorrectly stateful if this cloning isn't performed. What's confusing me is that it's not at all obvious *exactly* what the implications of making (or failing to make) this call are. Furthermore if it *is* something that's strictly required in this circumstance then do we need to be documenting whatever behavior is being triggered, so that developers writing their own class based views don't make the (mistake?) of simply returning/using a queryset attribute without having first cloned it? For example, is the following incorrect? class SomeBaseGenericView(View): queryset = None def get_queryset(self): """ Simply return `.queryset` by default. Subclasses may override this behavior. """ return self.queryset If so, under what set of conditions can it fail, and is it possible to unit test for the failing behavior? I've dug into the source, but the `_clone` method isn't documented, nor can I find anything terribly helpful related to queryset cloning after googling around for a while. Many thanks, Tom -- You received this message because you are subscribed to the Google Groups "Django developers" group. To unsubscribe from this group and stop receiving emails from it, send an email to django-developers+unsubscr...@googlegroups.com. To post to this group, send email to django-developers@googlegroups.com. Visit this group at http://groups.google.com/group/django-developers. For more options, visit https://groups.google.com/groups/opt_out.