ResourceLoader: Fix potential infinite recursion in progress reporting

Author: RandomShaper

core/io/resource_loader.cpp

@@ -666,6 +666,11 @@ Ref<ResourceLoader::LoadToken> ResourceLoader::_load_start(const String &p_path,
 float ResourceLoader::_dependency_get_progress(const String &p_path) {
 	if (thread_load_tasks.has(p_path)) {
 		ThreadLoadTask &load_task = thread_load_tasks[p_path];
+		if (load_task.in_progress_check) {
+			// Avoid cycles.
+			return load_task.max_reported_progress;
+		}
+		load_task.in_progress_check = true;
 		float current_progress = 0.0;
 		int dep_count = load_task.sub_tasks.size();
 		if (dep_count > 0) {
@@ -679,6 +684,7 @@ float ResourceLoader::_dependency_get_progress(const String &p_path) {
 			current_progress = load_task.progress;
 		}
 		load_task.max_reported_progress = MAX(load_task.max_reported_progress, current_progress);
+		load_task.in_progress_check = false;
 		return load_task.max_reported_progress;
 	} else {
 		return 1.0; //assume finished loading it so it no longer exists

core/io/resource_loader.h

@@ -176,10 +176,8 @@ class ResourceLoader {
 	struct ThreadLoadTask {
 		WorkerThreadPool::TaskID task_id = 0; // Used if run on a worker thread from the pool.
 		Thread::ID thread_id = 0; // Used if running on an user thread (e.g., simple non-threaded load).
-		bool awaited = false; // If it's in the pool, this helps not awaiting from more than one dependent thread.
 		ConditionVariable *cond_var = nullptr; // In not in the worker pool or already awaiting, this is used as a secondary awaiting mechanism.
 		uint32_t awaiters_count = 0;
-		bool need_wait = true;
 		LoadToken *load_token = nullptr;
 		String local_path;
 		String type_hint;
@@ -190,17 +188,26 @@ class ResourceLoader {
 		ResourceFormatLoader::CacheMode cache_mode = ResourceFormatLoader::CACHE_MODE_REUSE;
 		Error error = OK;
 		Ref<Resource> resource;
-		bool use_sub_threads = false;
 		HashSet<String> sub_tasks;
 
+		bool awaited : 1; // If it's in the pool, this helps not awaiting from more than one dependent thread.
+		bool need_wait : 1;
+		bool in_progress_check : 1;
+		bool use_sub_threads : 1;
+
 		struct ResourceChangedConnection {
 			Resource *source = nullptr;
 			Callable callable;
 			uint32_t flags = 0;
 		};
 		LocalVector<ResourceChangedConnection> resource_changed_connections;
-	};
 
+		ThreadLoadTask() :
+				awaited(false),
+				need_wait(true),
+				in_progress_check(false),
+				use_sub_threads(false) {}
+	};
 	static void _run_load_task(void *p_userdata);
 
 	static thread_local bool import_thread;
@@ -228,7 +235,9 @@ class ResourceLoader {
 	static ThreadLoadStatus load_threaded_get_status(const String &p_path, float *r_progress = nullptr);
 	static Ref<Resource> load_threaded_get(const String &p_path, Error *r_error = nullptr);
 
-	static bool is_within_load() { return load_nesting > 0; }
+	static bool is_within_load() {
+		return load_nesting > 0;
+	}
 
 	static void resource_changed_connect(Resource *p_source, const Callable &p_callable, uint32_t p_flags);
 	static void resource_changed_disconnect(Resource *p_source, const Callable &p_callable);
@@ -253,8 +262,12 @@ class ResourceLoader {
 
 	static void set_is_import_thread(bool p_import_thread);
 
-	static void set_timestamp_on_load(bool p_timestamp) { timestamp_on_load = p_timestamp; }
-	static bool get_timestamp_on_load() { return timestamp_on_load; }
+	static void set_timestamp_on_load(bool p_timestamp) {
+		timestamp_on_load = p_timestamp;
+	}
+	static bool get_timestamp_on_load() {
+		return timestamp_on_load;
+	}
 
 	// Loaders can safely use this regardless which thread they are running on.
 	static void notify_load_error(const String &p_err) {
@@ -280,8 +293,12 @@ class ResourceLoader {
 		dep_err_notify = p_err_notify;
 	}
 
-	static void set_abort_on_missing_resources(bool p_abort) { abort_on_missing_resource = p_abort; }
-	static bool get_abort_on_missing_resources() { return abort_on_missing_resource; }
+	static void set_abort_on_missing_resources(bool p_abort) {
+		abort_on_missing_resource = p_abort;
+	}
+	static bool get_abort_on_missing_resources() {
+		return abort_on_missing_resource;
+	}
 
 	static String path_remap(const String &p_path);
 	static String import_remap(const String &p_path);
@@ -300,7 +317,9 @@ class ResourceLoader {
 	static void remove_custom_loaders();
 
 	static void set_create_missing_resources_if_class_unavailable(bool p_enable);
-	_FORCE_INLINE_ static bool is_creating_missing_resources_if_class_unavailable_enabled() { return create_missing_resources_if_class_unavailable; }
+	_FORCE_INLINE_ static bool is_creating_missing_resources_if_class_unavailable_enabled() {
+		return create_missing_resources_if_class_unavailable;
+	}
 
 	static Ref<Resource> ensure_resource_ref_override_for_outer_load(const String &p_path, const String &p_res_type);
 	static Ref<Resource> get_resource_ref_override(const String &p_path);