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

[Andrew Wedgbury]

Some background on this: I am writing a fullscreen shell implementation to
share Wayland displays over VNC, which can be launched in place of weston from
weston's screen-share module.

In screen-share, variables WAYLAND_DISPLAY and WAYLAND_SOCKET are removed from
the environment when launching the fullscreen shell server to prevent it from 
connecting back to the original server in a circular manner (since the presence
of these would cause weston to use the wayland backend).

However, the fullscreen shell server may need to know the original server's
display name - to display a configuration UI, for example. This patch saves the
display name under a new environment variable "WAYLAND_SERVER_DISPLAY" before 
removing it from the environment, so the fullscreen shell server can use it if 
it needs to (the default fullscreen shell implementation in weston doesn't use
it currently). I picked the name "WAYLAND_SERVER_DISPLAY" as it is used in a
similar way to "WAYLAND_SERVER_SOCKET" in the screen-share module.

Signed-off-by: Andrew Wedgbury <andrew.wedgbury at realvnc.com>
---
 src/screen-share.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/screen-share.c b/src/screen-share.c
index d3e3f05..b642072 100644
--- a/src/screen-share.c
+++ b/src/screen-share.c
@@ -1006,6 +1006,7 @@ weston_output_share(struct weston_output *output,
 
 	if (pid == 0) {
 		/* We don't want anything circular */
+		setenv("WAYLAND_SERVER_DISPLAY", getenv("WAYLAND_DISPLAY"), 1);
 		unsetenv("WAYLAND_DISPLAY");
 		unsetenv("WAYLAND_SOCKET");
 
-- 
1.9.2