[PATCH weston] screen-share: Set new environment variable to identify server display

[Andrew Wedgbury]

Hi Jason,

On Tue, 29 Apr 2014, Jason Ekstrand wrote:

> Andrew,
> I think it's probably reasonable to pass the original server's socket through to the subsidiary compositor.  However, we should not use WAYLAND_SERVER_DISPLAY. 
> Right now, WAYLAND_DISPLAY and WAYLAND_SOCKET pass the same thing: a way for a clident to attach to the compositor.  On the other hand, WAYLAND_SERVER_SOCKET
> passes a way for the compositor to connect to a client.  The client may not always be another compositor.  If we use WAYLAND_SERVER_DISPLAY as a way for a
> compositor that has connected to a client to connect back to the client (which we are implicitly assuming is a compositor) as a client, I think we've mangled
> names and caused more confusion than it's worth.
>

Yes, this terminology is getting a bit confusing.

> I think the better way to solve this problem is to just not unset WAYLAND_DISPLAY.  As long as we launch weston with --backend=rdp-backend.so, it will be forced
> to always choose the RDP backend and the autodetection will never happen.  Having WAYLAND_DISPLAY lying around won't hurt anything; it will just get overwritten
> when weston opens it's Wayland socket.  This way we can solve your problem and avoid the confusion of having WAYLAN_SERVER_DISPLAY and WAYLAND_SERVER_SOCKET
> going in different directions.
>

Ok, this works for me too.

> Also, it would be worth looking into whether or not we need to actually unset WAYLAND_SOCKET.  I don't think it will ever be set in the main Weston process;  I
> just cleared it to make sure.

Yes it looks like we don't really need to unset this either.

I'll send an updated patch to remove these two lines then.

Thanks,

---
Andrew Wedgbury <andrew.wedgbury at realvnc.com>