Fix cursor role name, fix segfault when surface->resource is NULL

rootston/cursor.c

@@ -306,8 +306,8 @@ static void handle_request_set_cursor(struct wl_listener *listener,
 
 	struct wlr_surface *focused_surface =
 		event->seat_handle->wlr_seat->pointer_state.focused_surface;
-	bool ok = focused_surface != NULL;
+	bool ok = focused_surface != NULL && focused_surface->resource != NULL;
-	if (focused_surface != NULL) {
+	if (ok) {
 		struct wl_client *focused_client =
 			wl_resource_get_client(focused_surface->resource);
 		ok = event->client == focused_client;

types/wlr_output.c

@@ -231,7 +231,7 @@ static void handle_cursor_surface_destroy(struct wl_listener *listener,
 
 void wlr_output_set_cursor_surface(struct wlr_output *output,
 		struct wlr_surface *surface, int32_t hotspot_x, int32_t hotspot_y) {
-	if (surface && strcmp(surface->role, "cursor") != 0) {
+	if (surface && strcmp(surface->role, "wl_pointer-cursor") != 0) {
 		return;
 	}
 

types/wlr_seat.c

@@ -28,7 +28,7 @@ static void wl_pointer_set_cursor(struct wl_client *client,
 	if (surface_resource != NULL) {
 		surface = wl_resource_get_user_data(surface_resource);
 
-		if (wlr_surface_set_role(surface, "cursor", resource,
+		if (wlr_surface_set_role(surface, "wl_pointer-cursor", resource,
 				WL_POINTER_ERROR_ROLE) < 0) {
 			return;
 		}