Re: [PATCH 2/2] bugfix: git diff --quiet -w never returns with exit status 1

[Larry D'Anna <larry@elder-gods.org>]

* Junio C Hamano (gitster@pobox.com) [100216 00:42]:
> Larry D'Anna <larry@elder-gods.org> writes:
> 
> > Rationale: diff_flush_patch expects to write its output to options->file.
> > Adding a "silence" flag to diff_flush_patch and everything it calls would be
> > more invasive.
> 
> I would agree that the logic to redirect the output to nowhere may be the
> easiest way out, but because the reason anybody sane would want to give -q
> is to say "I don't care what the actual changes are, but I want to know if
> there is any real quick" (otherwise the call would be "diff -w >/dev/null"),
> shouldn't we at least be exiting the loop early when we see any difference?
> 
> > Signed-off-by: Larry D'Anna <larry@elder-gods.org>
> > ---
> >  diff.c |   20 ++++++++++++++++++++
> >  1 files changed, 20 insertions(+), 0 deletions(-)
> >
> > diff --git a/diff.c b/diff.c
> > index 68def6c..ff00816 100644
> > --- a/diff.c
> > +++ b/diff.c
> > @@ -3522,6 +3522,26 @@ void diff_flush(struct diff_options *options)
> >  		separator++;
> >  	}
> >  
> > +	if (output_format & DIFF_FORMAT_NO_OUTPUT &&
> > +	    DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
> > +	    DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
> > +		/* run diff_flush_patch for the exit status */
> > +		/* setting options->file to /dev/null should be safe, becaue we
> > +		   aren't supposed to produce any output anyways */
> 
> Style?
> 
> > +		static FILE *devnull = NULL;
> 
> Would this cause one file descriptor to leak?  Do we care?

Originally I thought it would be best to just let one leak, because I didn't
know how much longer it would need to stick around.  I didn't notice it's being
closed anyway a few lines down.


> > +		if(!devnull) {
> 
> Style?	if (!devnull)
> 
> > +			devnull = fopen("/dev/null", "w");
> > +			if (!devnull)
> > +				die_errno("Could not open /dev/null");
> > +		}
> > +		options->file = devnull;
> 
> Would this cause the original "options->file" leak?  Do we care?

oops.

> > +		for (i = 0; i < q->nr; i++) {
> > +			struct diff_filepair *p = q->queue[i];
> > +			if (check_pair_status(p))
> > +				diff_flush_patch(p, options);
> > +		}
> > +	}
> > +
> >  	if (output_format & DIFF_FORMAT_PATCH) {
> >  		if (separator) {
> >  			putc(options->line_termination, options->file);
> > -- 
> > 1.7.0.rc2.40.g7d8aa
>