Weston screen-share module with ivi-shell and ivi-controller.

[Tomasz Zyjewski]

Hello,

I am using Weston with screen-share module. When a desktop shell is used the
screen-share module works fine. In that scenario, the weston.ini file 
looks like
follow

```
[core]
shell=desktop-shell.so
modules=screen-share.so
backend=drm-backend.so

[screen-share]
command=/usr/bin/weston --backend=vnc-backend.so --shell=fullscreen-shell.so
output-id=0
```

The problem occurs when I try to use screen-share module with ivi-shell and
ivi-controller module from wayland-ivi-extension [1]. In that case, the
weston.ini file looks like that

```
[core]
shell=ivi-shell.so
modules=ivi-controller.so,ivi-output-controller.so,screen-share.so
require-input=false

[ivi-shell]
ivi-input-module=ivi-input-controller.so
ivi-client-name=/usr/bin/simple-weston-client
bkgnd-surface-id=1
bkgnd-color=0xFF000000

[screen-share]
command=/usr/bin/weston --backend=vnc-backend.so --shell=fullscreen-shell.so
output-id=0
```

and the screen share module loading fails with `No wl_shm found` error

```
[13:51:38.094] Screen share failed: No wl_shm found
```

In screen-share I use vnc-backend module [2] which is not merged yet, 
but the
same results can be obtained when rdp-backend is used.

It looks like screen-share module cannot find globals like 
`wl_compositor` and
`wl_shm` when `wl_registry_add_listener` is called [3]. I can tell that 
none of
the conditional statements are checked inside `registry_handle_global` 
function
[4].

What's more, if ivi-control module is not loaded and I just use 
ivi-shell then
screen-share module loads successfully and `registry_handle_global` 
function is
executed.

Any suggestions on how to further debug why the globals are not 
available from
screen-share module in that scenario are highly appreciated.

Thank you

[1] 
https://github.com/GENIVI/wayland-ivi-extension/tree/9acdaa1a9c79558691b1513cc4917f2ced91af8a
[2] https://gitlab.freedesktop.org/wayland/weston/-/merge_requests/362
[3] 
https://github.com/3mdeb/weston/blob/use_GL_RGBA/compositor/screen-share.c#L955
[4] 
https://github.com/3mdeb/weston/blob/use_GL_RGBA/compositor/screen-share.c#L711