Don't crash when there's no primary surface.
diff --git a/wayland-system-compositor.c b/wayland-system-compositor.c
index a0ab5f9..384b86d 100644
--- a/wayland-system-compositor.c
+++ b/wayland-system-compositor.c
@@ -1014,7 +1014,7 @@
case KEY_LEFTMETA | META_DOWN:
case KEY_RIGHTMETA | META_DOWN:
ec->meta_state = state ? META_DOWN : 0;
- if (state == 0) {
+ if (state == 0 && ec->primary != NULL) {
ec->primary->target.z = 0;
wl_list_remove(&ec->primary->animate.link);
wl_list_insert(&ec->animate_list,