prefetch_related are re-evaluated

[makinacorpus]

prefetch_related are re-evaluated

[sathoro]

This is because of the implementation of all on SafeDeleteManager. It calls the queryset's all method, however Django's default implementation does not. Calling all on a queryset creates a clone. Clones do not copy over cached prefetch_related lookups.

This is what the Django source code looks like (django/db/models/manager.py), with a comment about why it doesn't call all:

def all(self):
    # We can't proxy this method through the `QuerySet` like we do for the
    # rest of the `QuerySet` methods. This is because `QuerySet.all()`
    # works by creating a "copy" of the current queryset and in making said
    # copy, all the cached `prefetch_related` lookups are lost. See the
    # implementation of `RelatedManager.get_queryset()` for a better
    # understanding of how this comes into play.
    return self.get_queryset()

I removed the all call and it no longer re-evaluates prefetch_related lookups but I'm wondering if it was calling all for a reason or if it is safe to remove?

[sathoro]

Here is what I have changed the SafeDeleteManager.all method to in order to support force_visibility and still keep the cached lookups.

def all(self, *args, **kwargs):
    force_visibility = kwargs.pop('force_visibility', None)

    qs = self.get_queryset()

    if force_visibility is not None:
        qs._safedelete_force_visibility = force_visibility

    return qs

[Gagaro]

Thanks a lot and sorry for the delay, it's fixed on master.