Re: [PATCH v3] rev-list: exclude promisor objects at walk time

[Josh Steadmon <steadmon@google.com>]

On 2019.04.10 00:43, Junio C Hamano wrote:
> Jeff King <peff@peff.net> writes:
> 
> > On Wed, Apr 10, 2019 at 12:14:41AM +0900, Junio C Hamano wrote:
> >
> >> I've dealt with the stray double-sign-off locally, but is there
> >> anything else planned for v4 or later?  Is this performance-only
> >> change, or does it have an externally observable behaviour change
> >> that we can easily add to our test suite?
> >
> > I am OK if we do not include it, but even if this is "just" a
> > performance-only change, we can always add to our perf regression suite.
> 
> Hmph, that does not say much about a possible change in behaviour in
> corner cases you guys were discuussing near the beginning of the
> thread when an object can be reached from both a non-promisor and a
> promisor object, does it?
> 
> Shouldn't we at least tweak the log message to record that we were
> aware of the possibility even though we couldn't readily come up
> with a case where this optimization breaks things?  I suspect that
> it would help the next person who needs to deal with a possible
> regression coming from this change to understand the problem better
> and hopefully faster.
> 

I'll update the log message and send a v4 in a few minutes.