Correctly calculate the ``aggregate_start`` offset from loaded fields, if any are deferred, instead of ``self.query.select`` which includes all fields on the model. Backpatch of 69f7db153d8108dcef033207d49f4c80febf3d70 from master.
Correctly calculate the ``aggregate_start`` offset from loaded fields, if any are deferred, instead of ``self.query.select`` which includes all fields on the model. Backpatch of 69f7db153d8108dcef033207d49f4c80febf3d70 from master.