Empty Query Set not really empty

[nithyamary]

I have a use case where I need to return empty query set. I used MyModel.objects.none() query. But, the resulting queryset doesnt give proper result for functions like .sum()

For eg.
I have a model called Plot with a field area.
If I have a queryset with n number of plots, and do .sum('area'), it gives me sum of area of objects in the qureyset as expected. But, when the queryset is empty, it returns sum of area of all objects in Plot, rather than the expected 0.

[last-partizan]

Yeah, i've seen similar bug but not have time to dig around.
If you can - take a look at sources and try to figure out what's happening.