Retry loading addons after filesystem scan

doc/classes/EditorFileSystem.xml

@@ -96,6 +96,11 @@
 				Emitted if at least one resource is reloaded when the filesystem is scanned.
 			</description>
 		</signal>
+		<signal name="script_classes_updated">
+			<description>
+				Emitted when the list of global script classes gets updated.
+			</description>
+		</signal>
 		<signal name="sources_changed">
 			<param index="0" name="exist" type="bool" />
 			<description>

editor/editor_file_system.cpp

@@ -1527,6 +1527,7 @@ void EditorFileSystem::update_script_classes() {
 
 	ScriptServer::save_global_classes();
 	EditorNode::get_editor_data().script_class_save_icon_paths();
+	emit_signal("script_classes_updated");
 
 	// Rescan custom loaders and savers.
 	// Doing the following here because the `filesystem_changed` signal fires multiple times and isn't always followed by script classes update.
@@ -2417,6 +2418,7 @@ void EditorFileSystem::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("reimport_files", "files"), &EditorFileSystem::reimport_files);
 
 	ADD_SIGNAL(MethodInfo("filesystem_changed"));
+	ADD_SIGNAL(MethodInfo("script_classes_updated"));
 	ADD_SIGNAL(MethodInfo("sources_changed", PropertyInfo(Variant::BOOL, "exist")));
 	ADD_SIGNAL(MethodInfo("resources_reimported", PropertyInfo(Variant::PACKED_STRING_ARRAY, "resources")));
 	ADD_SIGNAL(MethodInfo("resources_reload", PropertyInfo(Variant::PACKED_STRING_ARRAY, "resources")));

editor/editor_node.cpp

@@ -630,6 +630,10 @@ void EditorNode::_notification(int p_what) {
 					set_addon_plugin_enabled(addons[i], true);
 				}
 				_initializing_plugins = false;
+
+				if (!pending_addons.is_empty()) {
+					EditorFileSystem::get_singleton()->connect("script_classes_updated", callable_mp(this, &EditorNode::_enable_pending_addons));
+				}
 			}
 
 			RenderingServer::get_singleton()->viewport_set_disable_2d(get_scene_root()->get_viewport_rid(), true);
@@ -3487,6 +3491,12 @@ void EditorNode::set_addon_plugin_enabled(const String &p_addon, bool p_enabled,
 
 		// Errors in the script cause the base_type to be an empty StringName.
 		if (scr->get_instance_base_type() == StringName()) {
+			if (_initializing_plugins) {
+				// However, if it happens during initialization, waiting for file scan might help.
+				pending_addons.push_back(p_addon);
+				return;
+			}
+
 			show_warning(vformat(TTR("Unable to load addon script from path: '%s'. This might be due to a code error in that script.\nDisabling the addon at '%s' to prevent further errors."), script_path, addon_path));
 			_remove_plugin_from_enabled(addon_path);
 			return;
@@ -4394,6 +4404,13 @@ void EditorNode::_build_icon_type_cache() {
 	}
 }
 
+void EditorNode::_enable_pending_addons() {
+	for (uint32_t i = 0; i < pending_addons.size(); i++) {
+		set_addon_plugin_enabled(pending_addons[i], true);
+	}
+	pending_addons.clear();
+}
+
 void EditorNode::_file_dialog_register(FileDialog *p_dialog) {
 	singleton->file_dialogs.insert(p_dialog);
 }

editor/editor_node.h

@@ -292,6 +292,7 @@ private:
 	Vector<EditorPlugin *> editor_plugins;
 	bool _initializing_plugins = false;
 	HashMap<String, EditorPlugin *> addon_name_to_plugin;
+	LocalVector<String> pending_addons;
 
 	PanelContainer *scene_root_parent = nullptr;
 	Control *theme_base = nullptr;
@@ -535,6 +536,7 @@ private:
 	static void _resource_loaded(Ref<Resource> p_resource, const String &p_path);
 
 	void _build_icon_type_cache();
+	void _enable_pending_addons();
 
 	void _dialog_action(String p_file);