Jeff King <peff@xxxxxxxx> writes: > I do feel a bit sad about breaking this case (or at the very least > forcing you to set an option to retain cross-version compatibility). But > my gut says that we don't want to lock ourselves into never changing the > diff algorithm (and I'm sure we've done it inadvertently a few times > over the years; even the recent switch to turning on renames would have > had that impact). IIRC, we never promised that different versions of Git produce the same patch ID for the same change. I do share that sadness, as not making that promise would affect not just such an external database keyed with patch-ids but also affects the rerere database, and those who heavily depend on the rerere database would need to refresh them every time diff/merge algorithm is updated, using something like contrib/rerere-train.sh script. But at the same time, I am very much against promising that the textual diff output will never improve for human readability.