Merge pull request #1227 from emersion/rootston-segfault-tablet-destroy

rootston: fix segfault on tablet pad destroy

rootston/seat.c

@@ -745,6 +745,7 @@ static void attach_tablet_pad(struct roots_tablet_pad *pad,
 
 	pad->tablet = tool;
 
+	wl_list_remove(&pad->tablet_destroy.link);
 	pad->tablet_destroy.notify = handle_pad_tool_destroy;
 	wl_signal_add(&tool->device->events.destroy, &pad->tablet_destroy);
 }
@@ -812,7 +813,8 @@ static void seat_add_tablet_pad(struct roots_seat *seat,
 		&tablet_pad->device_destroy);
 
 	tablet_pad->attach.notify = handle_tablet_pad_attach;
-	wl_signal_add(&tablet_pad->device->tablet_pad->events.attach_tablet, &tablet_pad->attach);
+	wl_signal_add(&tablet_pad->device->tablet_pad->events.attach_tablet,
+		&tablet_pad->attach);
 
 	tablet_pad->button.notify = handle_tablet_pad_button;
 	wl_signal_add(&tablet_pad->device->tablet_pad->events.button, &tablet_pad->button);
@@ -823,6 +825,8 @@ static void seat_add_tablet_pad(struct roots_seat *seat,
 	tablet_pad->ring.notify = handle_tablet_pad_ring;
 	wl_signal_add(&tablet_pad->device->tablet_pad->events.ring, &tablet_pad->ring);
 
+	wl_list_init(&tablet_pad->tablet_destroy.link);
+
 	struct roots_desktop *desktop = seat->input->server->desktop;
 	tablet_pad->tablet_v2_pad =
 		wlr_tablet_pad_create(desktop->tablet_v2, seat->seat, device);