From: Jeff King <peff@peff.net>
Date: Wed, 29 Jun 2016 21:43:44 GMT
Subject: Re: topological index field for commit objects
Message-ID: <20160629214343.GA3682@sigill.intra.peff.net>
In-Reply-To: <CAGZ79kbjntaTQPNdw9u07AJX3pTWdyKB1fiPqJZ=DZRzNvnKzg@mail.gmail.com>

On Wed, Jun 29, 2016 at 02:37:17PM -0700, Stefan Beller wrote:

> On Wed, Jun 29, 2016 at 1:54 PM, Stefan Beller <sbeller@google.com> wrote:
> > Chances are that the 10 years of history may be correct time wise as long
> > as people don't introduce a bad date malevolently.
> >
> 
> To answer my own speculation:
> Even git.git violates the timing property, so there is no hope to find
> many projects
> to have "parents committer date < committer date"

It's expected and reasonable for there to be some skew. People's clocks
aren't all perfectly synced. The question is one of how _much_ skew
you're willing to tolerate (and any algorithms obviously need to allow
that much, too).

In some places we allow 24 hours of skew between any two commits. In
others we allow up to 5 skewed commits in a row.

That may not be enough in general, though. E.g.:

> 619a644d6daef56d70aeca85514e2d281eb483a5

This one is a 3-day skew.

-Peff