rootston: map input devices with wlr_input_device.output_name

rootston/seat.c

@@ -141,10 +141,18 @@ static void seat_set_device_output_mappings(struct roots_seat *seat,
 		struct wlr_input_device *device, struct wlr_output *output) {
 	struct wlr_cursor *cursor = seat->cursor->cursor;
 	struct roots_config *config = seat->input->config;
-	struct roots_device_config *dconfig;
-	dconfig = roots_config_get_device(config, device);
-	if (dconfig && dconfig->mapped_output &&
-			strcmp(dconfig->mapped_output, output->name) == 0) {
+	struct roots_device_config *dconfig =
+		roots_config_get_device(config, device);
+
+	const char *mapped_output = NULL;
+	if (dconfig != NULL) {
+		mapped_output = dconfig->mapped_output;
+	}
+	if (mapped_output == NULL) {
+		mapped_output = device->output_name;
+	}
+
+	if (mapped_output && strcmp(mapped_output, output->name) == 0) {
 		wlr_cursor_map_input_to_output(cursor, device, output);
 	}
 }