From e4004a7c4feb777ee565fd49214dc13bb2bfd27b Mon Sep 17 00:00:00 2001
From: Peter Hutterer <peter.hutterer@who-t.net>
Date: Tue, 20 Aug 2024 12:38:52 +1000
Subject: [PATCH] wayland: Use the tool's current_tablet device instead of
 caching it

The tablet tool is initialized with a device but if that device is later
removed we never update tool->device. This eventually causes a crash
when we're passing that device into
meta_wayland_input_invalidate_focus().

The tool keeps track of the current tablet anyway so instead of caching
this pointer in the tool, use the current tablet's device.

Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/3642
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3959>
---
 src/wayland/meta-wayland-tablet-seat.c | 5 ++---
 src/wayland/meta-wayland-tablet-tool.c | 8 +++-----
 src/wayland/meta-wayland-tablet-tool.h | 1 -
 3 files changed, 5 insertions(+), 9 deletions(-)

diff --git a/src/wayland/meta-wayland-tablet-seat.c b/src/wayland/meta-wayland-tablet-seat.c
index 71e47f8da..58f62a838 100644
--- a/src/wayland/meta-wayland-tablet-seat.c
+++ b/src/wayland/meta-wayland-tablet-seat.c
@@ -362,7 +362,6 @@ meta_wayland_tablet_seat_lookup_pad (MetaWaylandTabletSeat *tablet_seat,
 
 static MetaWaylandTabletTool *
 meta_wayland_tablet_seat_ensure_tool (MetaWaylandTabletSeat  *tablet_seat,
-                                      ClutterInputDevice     *device,
                                       ClutterInputDeviceTool *device_tool)
 {
   MetaWaylandTabletTool *tool;
@@ -371,7 +370,7 @@ meta_wayland_tablet_seat_ensure_tool (MetaWaylandTabletSeat  *tablet_seat,
 
   if (!tool)
     {
-      tool = meta_wayland_tablet_tool_new (tablet_seat, device, device_tool);
+      tool = meta_wayland_tablet_tool_new (tablet_seat, device_tool);
       g_hash_table_insert (tablet_seat->tools, device_tool, tool);
     }
 
@@ -399,7 +398,7 @@ meta_wayland_tablet_seat_update (MetaWaylandTabletSeat *tablet_seat,
       device_tool = clutter_event_get_device_tool (event);
 
       if (device && device_tool)
-        tool = meta_wayland_tablet_seat_ensure_tool (tablet_seat, device, device_tool);
+        tool = meta_wayland_tablet_seat_ensure_tool (tablet_seat, device_tool);
 
       if (!tool)
         return;
diff --git a/src/wayland/meta-wayland-tablet-tool.c b/src/wayland/meta-wayland-tablet-tool.c
index dbafff724..ca0cd59b9 100644
--- a/src/wayland/meta-wayland-tablet-tool.c
+++ b/src/wayland/meta-wayland-tablet-tool.c
@@ -41,7 +41,6 @@
 struct _MetaWaylandTabletTool
 {
   MetaWaylandTabletSeat *seat;
-  ClutterInputDevice *device;
   ClutterInputDeviceTool *device_tool;
   struct wl_list resource_list;
   struct wl_list focus_resource_list;
@@ -423,7 +422,6 @@ tool_cursor_prepare_at (MetaCursorSpriteXcursor *sprite_xcursor,
 
 MetaWaylandTabletTool *
 meta_wayland_tablet_tool_new (MetaWaylandTabletSeat  *seat,
-                              ClutterInputDevice     *device,
                               ClutterInputDeviceTool *device_tool)
 {
   MetaWaylandCompositor *compositor =
@@ -435,7 +433,6 @@ meta_wayland_tablet_tool_new (MetaWaylandTabletSeat  *seat,
 
   tool = g_new0 (MetaWaylandTabletTool, 1);
   tool->seat = seat;
-  tool->device = device;
   tool->device_tool = device_tool;
   wl_list_init (&tool->resource_list);
   wl_list_init (&tool->focus_resource_list);
@@ -634,7 +631,8 @@ meta_wayland_tablet_tool_set_current_surface (MetaWaylandTabletTool *tool,
 
   tablet_seat = tool->seat;
   input = meta_wayland_seat_get_input (tablet_seat->seat);
-  meta_wayland_input_invalidate_focus (input, tool->device, NULL);
+  if (tool->current_tablet)
+    meta_wayland_input_invalidate_focus (input, tool->current_tablet->device, NULL);
 }
 
 static void
@@ -1002,7 +1000,7 @@ meta_wayland_tablet_tool_get_grab_info (MetaWaylandTabletTool *tool,
       meta_wayland_tablet_tool_can_grab_surface (tool, surface, serial))
     {
       if (device_out)
-        *device_out = tool->device;
+        *device_out = tool->current_tablet ? NULL : tool->current_tablet->device;
 
       if (x)
         *x = tool->grab_x;
diff --git a/src/wayland/meta-wayland-tablet-tool.h b/src/wayland/meta-wayland-tablet-tool.h
index d7c0cb6b8..660002fe9 100644
--- a/src/wayland/meta-wayland-tablet-tool.h
+++ b/src/wayland/meta-wayland-tablet-tool.h
@@ -29,7 +29,6 @@
 #include "wayland/meta-wayland-types.h"
 
 MetaWaylandTabletTool * meta_wayland_tablet_tool_new  (MetaWaylandTabletSeat  *seat,
-                                                       ClutterInputDevice     *device,
                                                        ClutterInputDeviceTool *device_tool);
 void                    meta_wayland_tablet_tool_free (MetaWaylandTabletTool  *tool);