Re: [PATCH] format-patch: respect --stat when explicitly specified

[Leif Lindholm <leif.lindholm@linaro.org>]

On Tue, Nov 06, 2018 at 04:56:11PM +0100, Duy Nguyen wrote:
> On Tue, Nov 6, 2018 at 11:48 AM Leif Lindholm <leif.lindholm@linaro.org> wrote:
> >
> > Commit 43662b23abbd
> > ("format-patch: keep cover-letter diffstat wrapped in 72 columns") made
> > format-patch keep the diffstat to within 72 characters. However, it does
> > this even when --stat is explicitly set on the command line.
> >
> > Make it possible to explicitly override the new mechanism, using --stat,
> > matching the functionality before this change. This also matches the
> > output in the case of non-cover-letter files.
> >
> > Cc: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
> > Cc: Junio C Hamano <gitster@pobox.com>
> > Reported-by: Laszlo Ersek <lersek@redhat.com>
> > Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
> > ---
> >
> > Note:
> > In TianoCore we have LotsOfGloriousFilesNamedInReallyLongCamelCase, so
> > our official submission guidelines specify the use of --stat.
> >
> >  builtin/log.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/builtin/log.c b/builtin/log.c
> > index 061d4fd86..07e6ae2c1 100644
> > --- a/builtin/log.c
> > +++ b/builtin/log.c
> > @@ -1009,7 +1009,8 @@ static void show_diffstat(struct rev_info *rev,
> >
> >         memcpy(&opts, &rev->diffopt, sizeof(opts));
> >         opts.output_format = DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
> > -       opts.stat_width = MAIL_DEFAULT_WRAP;
> > +       if (rev->diffopt.stat_width == -1)
> 
> I don't think we get -1 here when stat_width is not defined. The
> "undefined" value is zero but I'm pretty sure we get MAIL_DEFAULT_WRAP
> in here unless you specify --stat.

From what I could tell, if nothing is specified on command line,
rev->diffopt.stat_width is set to -1 at this point (I assumed by
rev->cmd_log_init_defaults(), but didn't go digging).

The patched version certainly gives the <= 2.16.* behaviour with
--stat and still restricts stat lines to 72 characters without.

> So I think you can just drop the below assignment. But if you want to
> be on the safe side, check for zero stat_width instead of -1 and set
> MAIL_DEFAULT_WRAP.
> 
> > +               opts.stat_width = MAIL_DEFAULT_WRAP;
> 
> How about a test to make sure this will not be broken in future?

Sure. Only today was the first time I had a look at the git sources,
so some guidance would be most appreciated.

Should I add a function to t/t4014-format-patch.sh and just put
something longer than a/file for the expect template?

/
    Leif

> >
> >         diff_setup_done(&opts);
> >
> > --
> > 2.11.0
> -- 
> Duy