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Date: Tue, 19 May 2009 21:37:04 +0100
From: Jamie Lokier <jamie@shareable.org>
Subject: Re: [Qemu-devel] [PATCH] fix qemu_malloc() error check for size==0
Message-ID: <20090519203704.GE3986@shareable.org>
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To: malc <av1474@comtv.ru>
Cc: qemu-devel@nongnu.org, Eduardo Habkost <ehabkost@redhat.com>, Markus Armbruster <armbru@redhat.com>

malc wrote:
>   3) Test the returned value against NULL

Indeed, that makes malloc(0) a bad idea, and why GNU/Linux sensibly
makes it return a non-NULL pointer, to minimise unexpected behaviour
of programs.

>   4) Accidentally derefence it
> 
> And here one would get away with it on certain subset of systems.

That's not in the list of reliable things, though.

You mustn't accidentally dereference p[n] after calling p = malloc(n) either.

-- Jamie