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Subject: Re: [PATCH] Use NULL instead of integer 0 in security/selinux/
From: Tim Wright <timw@splhi.com>
Reply-To: timw@splhi.com
To: Paul Jackson <pj@sgi.com>
Cc: Eyal Lebedinsky <eyal@eyal.emu.id.au>, linux-kernel@vger.kernel.org
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Date: Sat, 10 Jul 2004 17:12:43 -0700
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It was because

if (0 = i)

will give an error where you obviously meant '=='. It prevents
accidental "assignment in conditional context".

Tim

On Sat, 2004-07-10 at 16:52, Paul Jackson wrote:
> (off-topic alert)
> 
> >	if (0 != i)
> 
> Does anyone know of the origins of writing such tests this way, rather
> than:
> 
> 	if (i != 0)
> 
> I read the first as testing whether "0" has a certain property, which is
> a silly thing to test, since the properties of "0" are rather constant.
> 
> The second form I read as testing a property of "i" - much more
> interesting.  Logically, the same, of course.  Just a question of which
> form is more idiomatic.
> 
> Back in the days when it was Ken, Dennis and Brian, not K & R, I don't
> recall seeing the first form used much.  Even now I see _zero_ matches
> on "if (0 " in kernel or mm - only in arch, drivers, net, scripts, and
> sound (with a single time.h exception).
> 
> If I were Linus, I'd vote the first form off the island.  Then again,
> if I were Linus, you would never have heard of Linux ;).