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Re: [PATCH 1/1] general style: replaces memcmp() with starts_with()

From
Junio C Hamano <gitster@pobox.com>
Date
Mar 17, 2014, 23:07 UTC
Message-ID
<xmqqd2hka0h7.fsf@gitster.dls.corp.google.com>
In-Reply-To
<20140317230139.GB19578@sigill.intra.peff.net>
Jeff King <peff@peff.net> writes:
Show 28 quoted lines
> On Mon, Mar 17, 2014 at 03:52:51PM -0700, Junio C Hamano wrote:
>
>> > diff --git a/builtin/for-each-ref.c b/builtin/for-each-ref.c
>> > index 3e1d5c3..4135980 100644
>> > --- a/builtin/for-each-ref.c
>> > +++ b/builtin/for-each-ref.c
>> > @@ -193,7 +193,7 @@ static int verify_format(const char *format)
>> >  		at = parse_atom(sp + 2, ep);
>> >  		cp = ep + 1;
>> >  
>> > -		if (!memcmp(used_atom[at], "color:", 6))
>> > +		if (starts_with(used_atom[at], "color:"))
>> >  			need_color_reset_at_eol = !!strcmp(used_atom[at], color_reset);
>> >  	}
>> >  	return 0;
>> 
>> Good.
>
> Actually, I found this one confusing. We are looking for "color:", but
> if we find it, we _don't_ skip past and look at what comes after.
> Instead, we compare the whole string. Which works because color_reset
> actually contains "color:reset", and we end up just re-comparing the
> first bit of the string. So the memcmp here is redundant, and this can
> simply become:
>
>   need_color_reset_at_eol = !!strcmp(used_atom[at], color_reset);
>
> Or am I missing something?

What if used_atom[at] is not related to color at all? We do not want to touch the variable.

Previous: Jeff KingNext: Jeff King
Message 5 of 12 in “general style: replaces memcmp() with starts_with()”
  1. 0/1 general style: replaces memcmp() with starts_with()Quint Guvernator, Mar 17, 2014
  2. 1/1 general style: replaces memcmp() with starts_with()Quint Guvernator, Mar 17, 2014
  3. Junio C HamanoMar 17, 2014
  4. Jeff KingMar 17, 2014
  5. Junio C HamanoMar 17, 2014
  6. Jeff KingMar 18, 2014
  7. Quint GuvernatorMar 17, 2014
  8. Eric SunshineMar 18, 2014
  9. Quint GuvernatorMar 18, 2014
  10. Eric SunshineMar 18, 2014
  11. Junio C HamanoMar 18, 2014
  12. Quint GuvernatorMar 17, 2014

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