From 2e09985c0d2579d32238272b0dd3c70ef4821430 Mon Sep 17 00:00:00 2001
From: kobewi <kobewi4e@gmail.com>
Date: Tue, 9 Jan 2024 15:48:48 +0100
Subject: [PATCH] =?UTF-8?q?Fix=C2=B2=20behavior=20of=20ResourceFormatLoade?=
 =?UTF-8?q?r=20CACHE=5FMODE=5FREPLACE?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 core/io/resource_loader.cpp | 23 +++++++++++++++++++++--
 editor/editor_node.cpp      |  6 ++----
 2 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/core/io/resource_loader.cpp b/core/io/resource_loader.cpp
index 1fbb6ff2ed2..d4a187e65c5 100644
--- a/core/io/resource_loader.cpp
+++ b/core/io/resource_loader.cpp
@@ -340,7 +340,15 @@ void ResourceLoader::_thread_load_function(void *p_userdata) {
 
 	if (load_task.resource.is_valid()) {
 		if (load_task.cache_mode != ResourceFormatLoader::CACHE_MODE_IGNORE) {
-			load_task.resource->set_path(load_task.local_path);
+			if (load_task.cache_mode == ResourceFormatLoader::CACHE_MODE_REPLACE) {
+				Ref<Resource> old_res = ResourceCache::get_ref(load_task.local_path);
+				if (old_res.is_valid() && old_res != load_task.resource) {
+					// If resource is already loaded, only replace its data, to avoid existing invalidating instances.
+					old_res->copy_from(load_task.resource);
+					load_task.resource = old_res;
+				}
+			}
+			load_task.resource->set_path(load_task.local_path, load_task.cache_mode == ResourceFormatLoader::CACHE_MODE_REPLACE);
 		} else if (!load_task.local_path.is_resource_file()) {
 			load_task.resource->set_path_cache(load_task.local_path);
 		}
@@ -361,6 +369,17 @@ void ResourceLoader::_thread_load_function(void *p_userdata) {
 		if (_loaded_callback) {
 			_loaded_callback(load_task.resource, load_task.local_path);
 		}
+	} else if (load_task.cache_mode != ResourceFormatLoader::CACHE_MODE_IGNORE) {
+		Ref<Resource> existing = ResourceCache::get_ref(load_task.local_path);
+		if (existing.is_valid()) {
+			load_task.resource = existing;
+			load_task.status = THREAD_LOAD_LOADED;
+			load_task.progress = 1.0;
+
+			if (_loaded_callback) {
+				_loaded_callback(load_task.resource, load_task.local_path);
+			}
+		}
 	}
 
 	thread_load_mutex.unlock();
@@ -463,7 +482,7 @@ Ref<ResourceLoader::LoadToken> ResourceLoader::_load_start(const String &p_path,
 			load_task.type_hint = p_type_hint;
 			load_task.cache_mode = p_cache_mode;
 			load_task.use_sub_threads = p_thread_mode == LOAD_THREAD_DISTRIBUTE;
-			if (p_cache_mode != ResourceFormatLoader::CACHE_MODE_IGNORE) {
+			if (p_cache_mode == ResourceFormatLoader::CACHE_MODE_REUSE) {
 				Ref<Resource> existing = ResourceCache::get_ref(local_path);
 				if (existing.is_valid()) {
 					//referencing is fine
diff --git a/editor/editor_node.cpp b/editor/editor_node.cpp
index 549f62276d7..3eb40b1931d 100644
--- a/editor/editor_node.cpp
+++ b/editor/editor_node.cpp
@@ -6170,8 +6170,7 @@ void EditorNode::reload_instances_with_path_in_edited_scenes(const String &p_ins
 	if (edited_scene_map.size() > 0) {
 		// Reload the new instance.
 		Error err;
-		Ref<PackedScene> instance_scene_packed_scene = ResourceLoader::load(p_instance_path, "", ResourceFormatLoader::CACHE_MODE_IGNORE, &err);
-		instance_scene_packed_scene->set_path(p_instance_path, true);
+		Ref<PackedScene> instance_scene_packed_scene = ResourceLoader::load(p_instance_path, "", ResourceFormatLoader::CACHE_MODE_REPLACE, &err);
 
 		ERR_FAIL_COND(err != OK);
 		ERR_FAIL_COND(instance_scene_packed_scene.is_null());
@@ -6278,8 +6277,7 @@ void EditorNode::reload_instances_with_path_in_edited_scenes(const String &p_ins
 					// be properly updated.
 					for (String path : required_load_paths) {
 						if (!local_scene_cache.find(path)) {
-							current_packed_scene = ResourceLoader::load(path, "", ResourceFormatLoader::CACHE_MODE_IGNORE, &err);
-							current_packed_scene->set_path(path, true);
+							current_packed_scene = ResourceLoader::load(path, "", ResourceFormatLoader::CACHE_MODE_REPLACE, &err);
 							local_scene_cache[path] = current_packed_scene;
 						} else {
 							current_packed_scene = local_scene_cache[path];