miconda left a comment (kamailio/kamailio#4297)
It is a stricter check, but still changing the existing behaviour, so I am not sure what would be the best. Personally I don't think that I am affected, I don't remember having need to have records of overlapping subnets, but maybe there are others that are affected, so they have to comment.
My concern comes from another perspective, whether now the behaviour is consistent with the matching a subnet record with `allow_[source_]address()`. If one has overlapping subnets in the same group, will the same record as `allow_[source_]address_group()` be matched? Even I don't have it so far, one reason I could think of right now to have overlapping subnets is to return different values from the tag column.
So whatever mode it ends up with, new parameter or not, matching should be coherent across the module functions.