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From: Alexander Yarygin <yarygin@linux.vnet.ibm.com>
References: <1435583533-5758-1-git-send-email-berto@igalia.com>
Date: Mon, 29 Jun 2015 16:32:49 +0300
In-Reply-To: <1435583533-5758-1-git-send-email-berto@igalia.com> (Alberto
	Garcia's message of "Mon, 29 Jun 2015 16:12:13 +0300")
Message-ID: <87bnfyd4hq.fsf@linux.vnet.ibm.com>
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Subject: Re: [Qemu-devel] [PATCH] block: remove redundant check before
	g_slist_find()
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To: Alberto Garcia <berto@igalia.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>, qemu-devel@nongnu.org, qemu-block@nongnu.org

Alberto Garcia <berto@igalia.com> writes:

> An empty GSList is represented by a NULL pointer, therefore it's a
> perfectly valid argument for g_slist_find() and there's no need to
> make any additional check.
>
> Signed-off-by: Alberto Garcia <berto@igalia.com>
> ---
>  block/io.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/block/io.c b/block/io.c
> index e295992..2f7f889 100644
> --- a/block/io.c
> +++ b/block/io.c
> @@ -283,7 +283,7 @@ void bdrv_drain_all(void)
>          }
>          aio_context_release(aio_context);
>
> -        if (!aio_ctxs || !g_slist_find(aio_ctxs, aio_context)) {
> +        if (!g_slist_find(aio_ctxs, aio_context)) {
>              aio_ctxs = g_slist_prepend(aio_ctxs, aio_context);
>          }
>      }

Seems ok to me.