The V4L2VideoDevice::open() function that takes an open file handle duplicates it internally, and leaves the original handle untouched. This is documented but not enforced through language constructs. Fix it by passing a FileDescriptor to the function. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Hirokazu Honda <hiroh@chromium.org> Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>