Re: [PATCH 2/6] t1414: document some reflog-walk oddities

From: Jeff King <peff@peff.net>
Date: Jul 7, 2017, 05:19 UTC
Message-ID: <20170707051954.rpej3taew6onv3oo@sigill.intra.peff.net>
In-Reply-To: <xmqq1spth8qy.fsf@gitster.mtv.corp.google.com>

On Thu, Jul 06, 2017 at 08:42:45AM -0700, Junio C Hamano wrote:

Show 15 quoted lines

> >> I somehow feel that the "showing all entries from HEAD and then
> >> showing all from side" is simply a buggy behaviour.  I do not think
> >> our users would terribly mind if we changed it later.  But I may be
> >> missing the reason why (sometimes?) the sequential behaviour may be
> >> useful.
> >
> > If we think it's buggy, we can fix it now. But I'm not convinced that
> > sequential iteration is that bad. It's at least _simple_ and easy to
> > explain.
> 
> Yes, I agree that sequential is easy to explain, but only when I
> consider use of "log" family without "-n 30" or "--since 3.days".
> It still is easy to explain---we show from one and then from the
> other, but because we stop after showing 30 of them, and the first
> one has more than that, you do not see any from the latter.

Ah, right, I didn't think of limiting like that. I agree that makes a strong argument in favor of the date-ordered queue.

I suspect that "--since 3.days" is still quite buggy (even with a single reflog) because it checks commit timestamps and stops traversing when we go too bar back. But in a reflog, the commits may be totally out of order. I'm not sure what it should do. Either:

  1. During a reflog walk, --since and --until should respect reflog
     timestamps instead of commit timestamps. You can already do
     "--until" there by simply starting the traversal later, but there's
     no way to cut it off with --since.

  2. Limit commits shown by --since/--until as usual, but skip the "stop
     traversing" optimization when we see too many "old" commits. I.e.,
     omit a 4.days.ago commit, but keep walking to find other recent
     commits.

-Peff