Re: [PATCH 0/2] Make diff plumbing commands respect the indentHeuristic.

From: Junio C Hamano <gitster@pobox.com>
Date: May 9, 2017, 04:06 UTC
Message-ID: <xmqqbmr24qt2.fsf@gitster.mtv.corp.google.com>
In-Reply-To: <20170509031653.7hc36pil3vzrobsz@sigill.intra.peff.net>

Jeff King <peff@peff.net> writes:

Show 6 quoted lines

> 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.