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;
@@ -190,9 +188,15 @@ 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;
 
+		struct {
+			bool awaited = false; // If it's in the pool, this helps not awaiting from more than one dependent thread.
+			bool need_wait = true;
+			bool in_progress_check = false;
+			bool use_sub_threads = false;
+		};
+
 		struct ResourceChangedConnection {
 			Resource *source = nullptr;
 			Callable callable;