Subject: Re: Bring together merge and rebase

From: Theodore Ts'o <[email-masked]>
Date: Sat, 6 Jan 2018 16:38:45 -0500

On Sat, Jan 06, 2018 at 10:29:21AM -0700, Carl Baldwin wrote:
> > When n==m==1, "amended" pointer from X1 to A1 may allow you to
> > answer "Is this the first attempt?  If this is refined, what did the
> > earlier one look like?" when given X1, but you would also want to
> > answer a related question "This was a good start, but did the effort
> > result in a refined patch, and if so what is it?" when given A1, and
> > "amended" pointer won't help at all.  Needless to say, the "pointer"
> > approach breaks down when !(n==m==1).
> 
> It doesn't break down. It merely presents more sophisticated situations
> that may be more work for the tool to help out with. This is where I
> think a prototype will help see these situations and develop the tool to
> manage them.

That's another way of saying "break down".

And if the goal is a prototype, may I gently suggest that the way
forward is trailers in the commit body, ala:

	Change-Id: I0b793feac9664bcc8935d8ec04ca16d5

or

	Upstream-4.15-SHA1: 73875fc2b3934e45b4b9a94eb57ca8cd

Making changes in the commit header is complex, and has all *sorts* of
forward and backwards compatibility challenges, especially when it's
not clear what the proper data model should be.

Cheers,

						 -Ted