`add_autoload_singleton` adds the autoload later than expected when plugin is enabled

[martinhoT]

Tested versions

• Reproducible in v4.4.1.stable.official [49a5bc7], v4.3.stable.official [77dcf97], v4.2.2.stable.official [15073af]
• I could not reproduce in versions prior to 4.2 since the MRP does not work there

System information

Godot v4.4.1.stable - Steam Runtime 2 (soldier) 2 on X11 - X11 display driver, Multi-window, 2 monitors - Vulkan (Forward+) - dedicated AMD Radeon RX 5700 XT (RADV NAVI10) - AMD Ryzen 5 3600 6-Core Processor (12 threads)

Issue description

In an EditorPlugin, an autoload added in the _enable_plugin method using add_autload_singleton, as is recommended in the documentation, seems to be loaded later than nodes instantiated in _enter_tree. Trying to access the dynamically-added autoload in the _ready method of one of these nodes produces an error:

ERROR: modules/gdscript/gdscript_vm.cpp:3677 - Condition ' !GDScriptLanguage::get_singleton()->get_named_globals_map().has(*globalname) ' is true. Breaking..:
ERROR: res://addons/example/test.gd:7 - Internal script error! Opcode: 113 (please report).

I believe this is contrary to what would be expected, since when the plugin is loaded along with the project (if it is enabled), the autoload will be ready before the _ready method of the nodes in instantiated in _enter_tree is called. This is also the behavior that occurs when these nodes are run directly; the autoload is already ready when their _ready is called.

I am not sure if this is intended behavior, but I found it confusing. I do not know if it is an issue with the engine, or if the documentation could be clearer on this behavior.

Steps to reproduce

This assumes the attached minimal reproduction project is used.

1. When the project is loaded, there should be no errors
   • The console should print the messages of ExampleContext, and then of Test
     • I found this to be the opposite in v4.2.2.stable.official [15073af]
     • An extra set of messages for Test is printed since it should be automatically opened in the Editor when the project is loaded
   • `Successful!" is printed
2. Run the project
   • There should be no errors
   • The console should print the messages of ExampleContext, and then of Test
   • `Successful!" is printed
3. In the project settings, disable and enable the plugin
   • The abovementioned error should be shown
   • The print messages of Test should have been printed before those of ExampleContext
   • `Successful!" is not printed

Minimal reproduction project (MRP)

add-autoload-singleton-mrp.zip

This minimal reproduction project has a single example addon with:

• A Test scene that is loaded when the plugin enters the tree
• An ExampleContext autoload, with a do_something method that Test attempts to call in its _ready method

This example plugin is already enabled.

[AThousandShips]

Can confirm, adding some additional prints it seems that _enter_tree method is called on a plugin earlier when re-enabled, will see if I can find where this is occurring

Edit, code is here it seems, and it does seem to enable after entering:

godot/editor/editor_node.cpp

Lines 3898 to 3907 in 9a39760

	void EditorNode::add_editor_plugin(EditorPlugin *p_editor, bool p_config_changed) {
	if (p_editor->has_main_screen()) {
	singleton->editor_main_screen->add_main_plugin(p_editor);
	}
	singleton->editor_data.add_editor_plugin(p_editor);
	singleton->add_child(p_editor);
	if (p_config_changed) {
	p_editor->enable_plugin();
	}
	}