[4.4.dev7] The Default Environment setting is reset after the "cold" project loading (res:// | uid:// issue)

[MikkBenelis]

Tested versions

• reproducible in 4.4.dev7 (maybe 4.4.x)
• not reproducible: 4.3.stable

System information

Godot v4.4.dev7 - Windows 11 (build 26100) - Multi-window, 1 monitor - Vulkan (Forward+) - dedicated NVIDIA GeForce RTX 3060 Ti (NVIDIA; 32.0.15.6636) - 12th Gen Intel(R) Core(TM) i5-12400 (12 threads)

Issue description

The default environment setting (rendering/environment/defaults/default_environment) is reset after the "cold" project loading (deleting the .godot folder and loading project for the first time). However, it stays on place if it was saved as res://... path, not as uid://... value. Seems like uid related bug.

Steps to reproduce

Steps for 4.4.dev7:

• create new project;
• create an Environment asset;
• set it as default in Project Settings;
• close the project;
• delete the .godot folder;
• open the project.

Not reproduced with 4.3 -> 4.4 migration because its value will still be saved as res://, not uid://.

Minimal reproduction project (MRP)

test.zip

[MikkBenelis]

Seems like the Main Scene (run/main_scene) setting has a similar issue: Godot will not open the Main Scene after the "cold" loading if it is saved as uid:// value, but open perfectly fine if it is saved as res://. Shoud I create a separate issue for that? Pretty sure it is the same, but in theory can require a fix in several places.
P.S.: The Main Scene setting is automatically replaced with uid after manually changing it to res.

[Summersay415]

This maybe due to running scan of filesystem after loading environment and main scene, or something like what. Needs investigating

[KoBeWi]

The environment is loaded in SceneTree constructor, which happens before any filesystem scan that could load the UID. And interestingly, the code deletes the settting if file can't be found.

godot/scene/main/scene_tree.cpp

Lines 1970 to 1984 in 9630d4e

	String env_path = GLOBAL_DEF(PropertyInfo(Variant::STRING, "rendering/environment/defaults/default_environment", PROPERTY_HINT_FILE, ext_hint), "");
	// Setup property.
	env_path = env_path.strip_edges();
	if (!env_path.is_empty()) {
	Ref<Environment> env = ResourceLoader::load(env_path);
	if (env.is_valid()) {
	root->get_world_3d()->set_fallback_environment(env);
	} else {
	if (Engine::get_singleton()->is_editor_hint()) {
	// File was erased, clear the field.
	ProjectSettings::get_singleton()->set("rendering/environment/defaults/default_environment", "");
	} else {
	// File was erased, notify user.
	ERR_PRINT("Default Environment as specified in the project setting \"rendering/environment/defaults/default_environment\" could not be loaded.");
	}