`TileMapEditorPlugin` crash when closing tab

[lawnjelly]

Godot version

4.x latest 0308422

System information

All

Issue description

Editor tab with TileMap can crash on closing the tab.

1   TileMapEditorPlugin::edit                                                                                                                                       tiles_editor_plugin.cpp   351  0x55555d13b2e4 
2   EditorNode::_plugin_over_edit                                                                                                                                   editor_node.cpp           890  0x55555bf70ce7 
3   EditorNode::hide_unused_editors                                                                                                                                 editor_node.cpp           2242 0x55555bf88b6c 
4   SceneTreeDock::_push_item                                                                                                                                       scene_tree_dock.cpp       1488 0x55555c3386e2 
5   SceneTreeDock::_selection_changed                                                                                                                               scene_tree_dock.cpp       2276 0x55555c3582a1 
6   call_with_variant_args_helper<SceneTreeDock>(SceneTreeDock *, void (SceneTreeDock:: *)(), Variant const * *, Callable::CallError&, IndexSequence<>)             binder_common.h           303  0x55555c42af09 
7   call_with_variant_args<SceneTreeDock>                                                                                                                           binder_common.h           417  0x55555c42ae79 
8   CallableCustomMethodPointer<SceneTreeDock>::call                                                                                                                callable_method_pointer.h 104  0x55555c42ad64 
9   Callable::callp                                                                                                                                                 callable.cpp              50   0x55555f921a7a 
10  Object::emit_signalp                                                                                                                                            object.cpp                1072 0x55555fcff623 
11  Object::emit_signal<>(StringName const&)                                                                                                                        object.h                  891  0x55555b28b203 
12  EditorSelection::_emit_change                                                                                                                                   editor_data.cpp           1292 0x55555bd07649 
13  call_with_variant_args_helper<__UnexistingClass>(__UnexistingClass *, void (__UnexistingClass:: *)(), Variant const * *, Callable::CallError&, IndexSequence<>) binder_common.h           303  0x55555a859f19 
14  call_with_variant_args_dv<__UnexistingClass>                                                                                                                    binder_common.h           450  0x55555a859e7c 
15  MethodBindT<>::call(Object *, Variant const * *, int, Callable::CallError&) const                                                                               method_bind.h             331  0x55555a859c46 
16  Object::callp                                                                                                                                                   object.cpp                741  0x55555fcfcdcf 
17  Callable::callp                                                                                                                                                 callable.cpp              62   0x55555f921e77 
18  CallQueue::_call_function                                                                                                                                       message_queue.cpp         219  0x55555fcf7640 
19  CallQueue::flush                                                                                                                                                message_queue.cpp         324  0x55555fcf7eca 
20  SceneTree::physics_process                                                                                                                                      scene_tree.cpp            471  0x55555d2b1935 
... <More>                                                                                                                                                                                                        

It's crashing here:

void TileMapEditorPlugin::edit(Object *p_object) {
	if (tile_map) {
		tile_map->disconnect("changed", callable_mp(this, &TileMapEditorPlugin::_tile_map_changed));
	}

Where p_object is NULL, so it looks like it's trying to wipe the old tilemap from the plugin, but it is still accessing the old deleted tilemap.

There's no need to call this on a deleted tilemap as the destructor already does this:

TileMap::~TileMap() {
	if (tile_set.is_valid()) {
		tile_set->disconnect_changed(callable_mp(this, &TileMap::_tile_set_changed));
	}

Steps to reproduce

Use MRP from #80088.

1. Open scene
2. Open TileSet dropdown in the TileMap inspector
3. Close tab
4. CRASH

Minimal reproduction project

See above.

Discussion

A number of ways of fixing, e.g.:

• Check validity by storing ObjectID and checking valid before use
• Signal to let tilemap editor know has been destroyed
• Use reference instead of raw pointer, so the object is preserved until edit() is called and it is assigned to something else.