Re: [PATCH] rev-list: restore the NUL commit separator in --header mode

[Dennis Kaarsemaker <dennis@kaarsemaker.net>]

On Wed, 2016-10-19 at 15:39 -0700, Junio C Hamano wrote:
> Jacob Keller <jacob.keller@gmail.com> writes:
> 
> > Hi,
> > 
> > On Wed, Oct 19, 2016 at 2:04 PM, Dennis Kaarsemaker
> > <dennis@kaarsemaker.net> wrote:
> > > Commit 660e113 (graph: add support for --line-prefix on all graph-aware
> > > output) changed the way commits were shown. Unfortunately this dropped
> > > the NUL between commits in --header mode. Restore the NUL and add a test
> > > for this feature.
> > > 
> > 
> > 
> > Oops! Thanks for the bug fix.
> > 
> > > Signed-off-by: Dennis Kaarsemaker <dennis@kaarsemaker.net>
> > > ---
> > >  builtin/rev-list.c       | 4 ++++
> > >  t/t6000-rev-list-misc.sh | 7 +++++++
> > >  2 files changed, 11 insertions(+)
> > > 
> > > diff --git a/builtin/rev-list.c b/builtin/rev-list.c
> > > index 8479f6e..cfa6a7d 100644
> > > --- a/builtin/rev-list.c
> > > +++ b/builtin/rev-list.c
> > > @@ -157,6 +157,10 @@ static void show_commit(struct commit *commit, void *data)
> > >                         if (revs->commit_format == CMIT_FMT_ONELINE)
> > >                                 putchar('\n');
> > >                 }
> > > +               if (revs->commit_format == CMIT_FMT_RAW) {
> > > +                       putchar(info->hdr_termination);
> > > +               }
> > > +
> > 
> > 
> > This seems right to me. My one concern is that we make sure we restore
> > it for every case (in case it needs to be there for other formats?)
> > I'm not entirely sure about whether other non-raw modes need this or
> > not?
> 
> 
> Right.  The original didn't do anything special for CMIT_FMT_RAW,
> and 660e113 did not remove anything special for CMIT_FMT_RAW, so it
> isn't immediately obvious why this patch is sufficient.  
> 
> Dennis, care to elaborate?

The original logic was (best seen with git show -w 660e113):

if(showing graphs) {
     do pretty things
}
else {
     just print the buffer and the header terminator
}

660e113 changed that to

do pretty things

Given that the 'do pretty things part' works for other uses of git rev-
list, it made sense that the \0 should only be added back in
CMIT_FMT_RAW mode. Changing the first putchar('\n') as Jacob proposes
(that mail arrived while I'm typing this) might work too, I haven't
tested it.

D.