[v2] winegstreamer: Avoid zero division in amt_from_gst_caps_video().

[Andrew Eikum]

Signed-off-by: Andrew Eikum <aeikum at codeweavers.com>

On Wed, Jan 25, 2017 at 11:02:20PM +0900, Masanori Kakura wrote:
> Fixes https://bugs.winehq.org/show_bug.cgi?id=42212
> 
> v2: Use MulDiv() to check integer overflow. (thanks Andrew Eikum)
> 
> Signed-off-by: Masanori Kakura <kakurasan at gmail.com>
> ---
>  dlls/winegstreamer/gstdemux.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/dlls/winegstreamer/gstdemux.c b/dlls/winegstreamer/gstdemux.c
> index c33ed9e..759a5db 100644
> --- a/dlls/winegstreamer/gstdemux.c
> +++ b/dlls/winegstreamer/gstdemux.c
> @@ -233,9 +233,8 @@ static gboolean amt_from_gst_caps_video(GstCaps *caps, AM_MEDIA_TYPE *amt)
>          bih->biCompression = amt->subtype.Data1;
>      }
>      bih->biSizeImage = width * height * bih->biBitCount / 8;
> -    vih->AvgTimePerFrame = 10000000;
> -    vih->AvgTimePerFrame *= denom;
> -    vih->AvgTimePerFrame /= nom;
> +    if ((vih->AvgTimePerFrame = (REFERENCE_TIME)MulDiv(10000000, denom, nom)) == -1)
> +        vih->AvgTimePerFrame = 0; /* zero division or integer overflow */
>      vih->rcSource.left = 0;
>      vih->rcSource.right = width;
>      vih->rcSource.top = height;
> -- 
> 2.9.3
> 
> 
>