Script editor wrongly replaces and quotes non-ASCII letters

[KoBeWi]

Tested versions

4.3 beta1 and earlier

System information

Windows 10.0.19045 - Vulkan (Forward+) - dedicated NVIDIA GeForce GTX 1060 (NVIDIA; 31.0.15.4633) - Intel(R) Core(TM) i7-7700HQ CPU @ 2.80GHz (8 Threads)

Issue description

godot_fAwuz6123l.mp4

The non-ASCII letters are replaced with _, while they make a valid identifier. Also the path is quoted, but it works without the quote.

Steps to reproduce

1. Have a node with some accented letters in name, like bułka
2. Drag and drop it to script editor while holding Ctrl
3. The line ends up as @onready var bu_ka = $"bułka"
4. Change it to @onready var bułka = $bułka
5. It still works, so the identifier processing was unnecessary

Minimal reproduction project (MRP)

N/A

[dalexeev]

This is because validate_identifier() is used.

godot/editor/plugins/script_text_editor.cpp

Lines 1939 to 1952 in 5833f59

	String variable_name = String(node->get_name()).to_snake_case().validate_identifier();
	if (use_type) {
	StringName class_name = node->get_class_name();
	Ref<Script> node_script = node->get_script();
	if (node_script.is_valid()) {
	StringName global_node_script_name = node_script->get_global_name();
	if (global_node_script_name != StringName()) {
	class_name = global_node_script_name;
	}
	}
	text_to_drop += vformat("@onready var %s: %s = %c%s\n", variable_name, class_name, is_unique ? '%' : '$', path);
	} else {
	text_to_drop += vformat("@onready var %s = %c%s\n", variable_name, is_unique ? '%' : '$', path);
	}

godot/core/string/ustring.cpp

Lines 4469 to 4490 in 5833f59

	String String::validate_identifier() const {
	if (is_empty()) {
	return "_"; // Empty string is not a valid identifier;
	}
	String result;
	if (is_digit(operator[](0))) {
	result = "_" + *this;
	} else {
	result = *this;
	}
	int len = result.length();
	char32_t *buffer = result.ptrw();
	for (int i = 0; i < len; i++) {
	if (!is_ascii_identifier_char(buffer[i])) {
	buffer[i] = '_';
	}
	}
	return result;
	}