Re: [PATCH] Use diff3 instead of merge in merge-recursive.

From: Linus Torvalds <torvalds@osdl.org>
Date: Oct 18, 2006, 15:53 UTC
Message-ID: <Pine.LNX.4.64.0610180835000.3962@g5.osdl.org>
In-Reply-To: <eh4sfr$3ej$1@sea.gmane.org>

On Wed, 18 Oct 2006, Jakub Narebski wrote:

> 
> Doesn't xdiff library git uses have diff3/merge equivalent?

Nope. It has something it calls "merge", but it's really just "apply the diff from the common base to the other end".

IOW, if "a" is your common ancestor, and "b1" and "b2" are the branches, it's literally

	diff a b1 | patch b2

and not actually a real 3-way merge.

As to why git uses "merge" - I have this strong memory of having seen machines that had one but not the other, and that, along with the fact that I've used "merge" personally, is why we call "merge" rather than diff3.

In Linux systems, "merge" usually comes with the RCS package, and "diff3" is usually from "diffutils". It may be that "diff3" is more common. I'm not sure what the history is, and what the situation would tend to be like on other systems..

		Linus