fix: MultiLoss.__add__ mutates original loss chain

[andrewwhitecdw]

Problem

fix: MultiLoss.add mutates original loss chain

Fix

Replace:

    def __add__(self, loss2):
        assert isinstance(loss2, MultiLoss)
        res = cur = copy(self)
        # find the end of the chain
        while cur._loss2 is not None:
            cur = cur._loss2
        cur._loss2 = loss2
        return res

with:

    def __add__(self, loss2):
        assert isinstance(loss2, MultiLoss)
        res = cur = deepcopy(self)
        # find the end of the chain
        while cur._loss2 is not None:
            cur = cur._loss2
        cur._loss2 = loss2
        return res

Files changed

• dust3r/losses.py