From: Junio C Hamano <gitster@pobox.com>
Date: Tue, 06 Mar 2018 19:29:44 GMT
Subject: Re: [PATCH] xdiff: improve trimming preprocessing
Message-ID: <xmqq7eqp3suv.fsf@gitster-ct.c.googlers.com>
In-Reply-To: <CAPig+cRYsf161-Xomw7daj8XdEBxZAEQQRdOn4krRTpSAFkPOw@mail.gmail.com>

Eric Sunshine <sunshine@sunshineco.com> writes:

> On Tue, Mar 6, 2018 at 6:53 AM, Jun Wu <quark@fb.com> wrote:
>> xdiff-interface trims common suffix if ctxlen is 0. Teach it to also
>> trim common prefix, and trim less lines if ctxlen > 0. So it can benefit
>> the default diff command, as seen by profiling: [...]

I vaguely recall that we have tried this in the distant past, found
that it produced incorrect result, and that is why we limit the
optimization for no-context case.

Does anybody have an archive reference?