Re: [PATCH] docs/format-patch: mention handling of merges

From: Jeff King <peff@peff.net>
Date: Feb 23, 2021, 01:48 UTC
Message-ID: <YDRe7AAOnHPmAhp4@coredump.intra.peff.net>
In-Reply-To: <xmqqblcb60fz.fsf@gitster.g>

On Mon, Feb 22, 2021 at 05:24:16PM -0800, Junio C Hamano wrote:

Show 14 quoted lines

> > I think one could argue that any merge information (including conflict
> > resolution) works against the root notion of format-patch, which is a
> > set of changes that can be applied on a range of basesa.
> 
> That's true and it was the primary motive for omiting merges.
> 
> > But even that I
> > would be hesitant to commit to (since --base exists now).
> 
> I am not quite sure what --base has to throw into the equation.  The
> information --base gives is often useful when I want to learn where
> the patches were taken from, but that does not restrict where the
> patches are actually applied to in any meaningful way (iow, "on a
> range of bases" part is not affected).

What I meant is that without "--base", telling somebody "here is the merge you should replay on top of these other patches" is virtually meaningless. You cannot know what the merge base would be! So you might be merging in other random crap, and you might or might not see the same conflicts.

But in a world with --base, I can imagine some people recreating whole sequences of the history graph by using "--base" along with some (to be invented) format for representing a merge via email. That mode would certainly not be the default, but at least at that point it is conceivably useful. Sort of like a bundle, but more human-readable (it would also need committer info to recreate the commit ids perfectly, of course).

All of which meant only to argue that "it is not possible or not useful to represent a merge in an email" is something that could change in the future. :)

-Peff