[FFmpeg-devel] [PATCH 1/2] dshow: fix return code when opening device

[Stefano Sabatini]

On date Tuesday 2012-12-04 04:22:06 -0200, Ramiro Polla encoded:
> Hi,
> 
> I've sent this patch before, but I had forgotten why I had written it.
> Thanks to Don Moir for pointing out why it was necessary.
> 
> Ramiro

> From d2d9631a110bbb28d5aa2082fe508df5739543ac Mon Sep 17 00:00:00 2001
> From: Ramiro Polla <ramiro.polla at gmail.com>
> Date: Tue, 4 Dec 2012 02:29:43 -0200
> Subject: [PATCH 1/2] dshow: fix return code when opening device
> 
> Successfully opening a device altered the ret variable, making the function
> not cleanup properly and return an incorrect value for errors that happened
> afterwards.
> ---
>  libavdevice/dshow.c |   18 ++++++++----------
>  1 files changed, 8 insertions(+), 10 deletions(-)
> 
> diff --git a/libavdevice/dshow.c b/libavdevice/dshow.c
> index ea01b2a..18a4ee9 100644
> --- a/libavdevice/dshow.c
> +++ b/libavdevice/dshow.c
> @@ -929,20 +929,18 @@ static int dshow_read_header(AVFormatContext *avctx)
>      }
>  
>      if (ctx->device_name[VideoDevice]) {
> -        ret = dshow_open_device(avctx, devenum, VideoDevice);
> -        if (ret < 0)
> -            goto error;
> -        ret = dshow_add_device(avctx, VideoDevice);
> -        if (ret < 0)
> +        if ((r = dshow_open_device(avctx, devenum, VideoDevice)) < 0 ||
> +            (r = dshow_add_device(avctx, VideoDevice) < 0)) {
> +            ret = r;
>              goto error;
> +        }

Isn't this perfectly equivalent to the pre-existing code? The only
difference is that in case of success it sets the ret value to the
return code of dshow_open/add_device, which is finally returned (while
the other failures, e.g. if (!ctx->mutex), don't change the default
return value of 0, so won't cause a failure, is this intended?).

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