weird behavior in app handler callbacks

[ihm-tswow]

bxx/bxx/app_handlers.cpp

Lines 13 to 27 in d89632f

	void register_handler(std::string const& target, std::function<void(bxx::python_tuple const&)> func)
	{
	// todo: for some bizarre reason this stops working if i don't pass all varargs python-side,
	// but everything is still in the first tuple once it reaches C++
	size_t event_idx = lib_register_event([=](bxx::python_tuple const& tuple) {
	func(tuple.get<python_tuple>(0));
	return bxx::python_object();
	});
	exec({
	fmt::format("@bpy.app.handlers.persistent"),
	fmt::format("def event_{}_{}(*args):",get_script_index(),event_idx),
	fmt::format(" fire_event({},{}, args)",get_script_index(),event_idx),
	fmt::format("register_app_handler({}, bpy.app.handlers.{}, event_{}_{})", get_script_index(), target, get_script_index(), event_idx, target)
	});
	}