From: Tom Jones <thj@freebsd.org>
Subject: Re: diff.git: Fix ed script output
To: gameoftrees@openbsd.org
Date: Fri, 2 Sep 2022 09:48:18 +0100

On Fri, Sep 02, 2022 at 10:43:15AM +0200, Stefan Sperling wrote:
> On Wed, Aug 31, 2022 at 01:24:44PM +0100, Tom Jones wrote:
> > I have looked into this. getchange in diff3.c takes any line that starts
> > with an integer and treats it as a hunk header. 
> > 
> > The current diff_output_edscript.c is creating valid classic diff
> > headers rather than ed edits. This seems to mean that while the edscript
> > output works, it is isn't correct just in the way that diff3 wants.
> > 
> > I have substituted in the updated diff_output_plain.c from yesterday and
> > am able to pass got's `make regress`.
> > 
> > For this case there is an optimisation where diff_output_plain only
> > generates the headers for a hunk, but I'll leave that path for future
> > hackers.
> > 
> > Follows is a diff with the changes I made to got, they are minimal
> > beyond copying over the updated diff_output_plain.c
> 
> Thanks for digging into this. I've committed your changes to got.git.
> 
> A hunk-header-only option for plain mode would be nice to have, it
> should speed up merges of large files.
> 
> Is your previously proposed ed-script diff for diff.git still valid?
> Or will it need to be updated?

It is still correct, the changes to the diff stuff was on the got side
this time.

Thanks

- Tom