Re: [PATCH v3 5/5] diff: the -w option breaks --exit-code for --raw and other output modes

[Jeff King <peff@peff.net>]

On Mon, Aug 21, 2023 at 05:08:05PM -0400, Jeff King wrote:

> On Mon, Aug 21, 2023 at 05:00:58PM -0400, Jeff King wrote:
> 
> > Alternatively, we could put it in the caller, like so:
> > 
> > diff --git a/diff.c b/diff.c
> > index 78f4e7518f..e7281e75eb 100644
> > --- a/diff.c
> > +++ b/diff.c
> > @@ -6528,6 +6528,7 @@ void diff_flush(struct diff_options *options)
> >  			if (check_pair_status(p))
> >  				flush_one_pair(p, options);
> >  		}
> > +		options->found_changes = !!q->nr;
> >  		separator++;
> >  	}
> >  
> > 
> > which matches the diffstat technique (I almost thought we could share
> > the code, but for the diffstat we are counting what ends up in the
> > diffstat struct; it does not clean out the original diff_queue when it
> > sees a noop pair).
> > 
> > I don't see a real reason to prefer one over the other.
> 
> Actually, on second look these are not quite the same. Yours only
> triggers if check_pair_status() is true. So something like
> --diff-filter should affect both output and exit code. Yours gets that
> right, and mine does not. Sorry for the noise. :)

Sorry, I'm dumb again. That is not where diff-filter is handled (it is
handled by diffcore, duh). check_pair_status() is only checking for
DIFF_STATUS_UNKNOWN. I'm not sure when that would ever be set, but it
seems like we should be matching the "if it is output" logic, which is
what you get by calling flush_one_pair(). So yours is definitely
preferable, even if I don't understand the possible differences. ;)

-Peff