From: Ulrich Spörlein <uqs@spoerlein.net>
Date: Fri, 09 Nov 2012 15:42:45 GMT
Subject: Re: git merge commits are non-deterministic? what changed?
Message-ID: <20121109154245.GP69724@acme.spoerlein.net>
In-Reply-To: <m2y5iarf5s.fsf@igel.home>

On Fri, 2012-11-09 at 16:04:31 +0100, Andreas Schwab wrote:
> Ulrich Spörlein <uqs@spoerlein.net> writes:
> 
> > Two questions:
> > 1. Can we impose a stable ordering of the commits being recorded in a
> > merge commit? Listing parents in chronological order or something like
> > that.
> 
> The order is determined by the order the refs are given to git merge (or
> git commit-tree when using the plumbing).
> 
> > 2. Why the hell is the commit hash dependent on the ordering of the
> > parent commits? IMHO it should sort the set of parents before
> > calculating the hash ...
> 
> What would be the sort key?

Trivially, the hash of the parents itself. So you'd always get

...
parent 0000
parent 1111
parent aaaa
parent ffff

hth
Uli