[RFC wayland] Track protocol object versions inside wl_proxy.

[Derek Foreman]

On 13/11/15 12:21 PM, Jason Ekstrand wrote:
> On Fri, Nov 13, 2015 at 3:18 AM, Giulio Camuffo <giuliocamuffo at gmail.com> wrote:
>> So do i understand correctly that if the app creating the
>> wl_compositor was built against a libwayland without this patch the
>> version returned in mesa by wl_proxy_get_version() for every proxy
>> will be always 1?
> 
> Yes, see also the second e-mail link below.  I proposed to make
> wl_display version 0 so that libraries can detect whether the client
> was built against old or new libwayland.
> 
> --Jason

We can do a test like...
if (proxy == (struct wl_proxy *)proxy->display)
	return 1;

in wl_proxy_get_version() if we want to return non-0 values from
wl_display_get_version(display);

Is this worth the trouble, or is it safe to always consider wl_display
to be "unversioned"?