Compiling string flag with -autofree ends in heap-corruption

[bstnbuck]

V version: 0.2.2 4a1f75c
OS: all

What did you do?

import flag
import os

fn main() {
	mut fp := flag.new_flag_parser(os.args)
	test := fp.string('test', 0, '', 'this is a test')

	_ := fp.finalize() or {
		println(fp.usage())
		return
	}
	println(test)
}

Built it with: v -autofree -prod -cc [gcc, msvc, tcc] test.v
Executed with: test.exe --test sometext

What did you expect to see?
sometext

What did you see instead?
some garbage and after repeating several times (on Windows):

Unhandled Exception 0xC0000374
11: RtlIsZeroMemory            ?? : address = 0x61c4dce108
10: RtlpNtSetValueKey          ?? : address = 0x61c4dce108
9 : RtlpNtSetValueKey          ?? : address = 0x61c4dce108
8 : RtlpNtSetValueKey          ?? : address = 0x61c4dce108
7 : RtlGetCurrentServiceSessionId  ?? : address = 0x61c4dce108
6 : RtlFreeHeap                ?? : address = 0x61c4dce108
5 : free_base                  ?? : address = 0x61c4dce108
4 : flag__FlagParser_usage     ?? : address = 0x61c4dce108
3 : wmain                      ?? : address = 0x61c4dce108
2 : __scrt_common_main_seh     d:\agent\_work\63\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288
1 : BaseThreadInitThunk        ?? : address = 0x61c4dce108
0 : RtlUserThreadStart         ?? : address = 0x61c4dce108

I think the error is related to os.args and -autofree

[bstnbuck]

Compiling with -o test.c gives the following C-Code and I think the error too.

VV_LOCAL_SYMBOL void main__main(void) {
	flag__FlagParser* fp = flag__new_flag_parser(_const_os__args);
	string test = flag__FlagParser_string(fp, _SLIT("test"), 0, _SLIT(""), _SLIT("this is a test"));
	Option_Array_string _t352 = flag__FlagParser_finalize(/*rec*/*fp);
	if (_t352.state != 0) { /*or block*/ 
		IError err = _t352.err;
string _arg_expr_println_1_156 = flag__FlagParser_usage(/*rec*/*fp);// new af2 pre/* inserted before */
				println(/*af arg2*/_arg_expr_println_1_156);
		// free before return (no values returned)
		// autofree_scope_vars(pos=177 line_nr=9 scope.pos=152 scope.end_pos=186)
		// var "err" var.pos=152 var.line_nr=7
		// var "_arg_expr_println_1_156" var.pos=156 var.line_nr=8
			string_free(&_arg_expr_println_1_156); // autofreed var main false
		// af parent scope:
		// var "fp" var.pos=40 var.line_nr=4
			flag__FlagParser_free(fp); // autofreed ptr var
		// var "test" var.pos=77 var.line_nr=5
			string_free(&test); // autofreed var main false
		// af parent scope:
		// af parent scope:
		return;
	// autofree_scope_vars(pos=155 line_nr=8 scope.pos=152 scope.end_pos=186)
	// var "err" var.pos=152 var.line_nr=7
	// var "_arg_expr_println_1_156" var.pos=156 var.line_nr=8
		string_free(&_arg_expr_println_1_156); // autofreed var main false
	};
	println(test);
// autofree_scope_vars(pos=42 line_nr=4 scope.pos=26 scope.end_pos=203)
// var "fp" var.pos=40 var.line_nr=4
	flag__FlagParser_free(fp); // autofreed ptr var    <=== THIS pointer should be freed after
// var "test" var.pos=77 var.line_nr=5
	string_free(&test); // autofreed var main false   <=== THAT one
}