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From:   Andreas Schwab <schwab@linux-m68k.org>
To:     Jonathan Nieder <jrnieder@gmail.com>
Cc:     Junio C Hamano <gitster@pobox.com>,
        Kaartic Sivaraam <kaarticsivaraam91196@gmail.com>,
        Michael Haggerty <mhagger@alum.mit.edu>,
        Alex Riesen <raa.lkml@gmail.com>, git@vger.kernel.org
Subject: Re: [PATCH v2] for_each_string_list_item: avoid undefined behavior for empty list
References: <cb2d4d71c7c1db452b86c8076c153cabe7384e28.1505490776.git.mhagger@alum.mit.edu>
        <20170915184323.GU27425@aiede.mtv.corp.google.com>
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X-Yow:  Do you guys know we just passed thru a BLACK HOLE in space?
Date:   Wed, 20 Sep 2017 18:28:53 +0200
In-Reply-To: <20170920052705.GC126984@aiede.mtv.corp.google.com> (Jonathan
        Nieder's message of "Tue, 19 Sep 2017 22:27:05 -0700")
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On Sep 19 2017, Jonathan Nieder <jrnieder@gmail.com> wrote:

> B. #define for_each_string_list_item(item, list) \
> 	if (list->items) \
> 		for (item = ...; ...; ... )
>
>    This breaks a caller like
> 	if (foo)
> 		for_each_string_list_item(item, list)
> 			...
> 	else
> 		...
>
>    making it a non-starter.

That can be fixed with a dangling else.

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
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"And now for something completely different."