[4.x, 5.x]: macros with a variable starting with an underscore don't work (known and fixed Twig issue)

[Dollhopf]

What happened?

Description

Twig macro variables don't work properly when starting with an underscore. This Twig issue is only present in Twig v 3.15.0 and is fixed in the next version 3.16.0

Steps to reproduce

1. Create a macro with a variable that starts with an underscore:

{% macro foo(_bar) %}
  {{ _bar|default('NOPE') }}
{% endmacro %}

2. Call macro with set variable:

{{ _self.foo('It works') }}

Expected behavior

It works

Actual behavior

NOPE

Craft CMS version

4, 5

PHP version

No response

Operating system and version

No response

Database type and version

No response

Image driver and version

No response

Installed plugins and versions

[linear]

CMS-1747

[i-just]

Hi, thanks for getting in touch!

We’ve already updated the Twig version that Craft uses from ~3.15.0 to ~3.19.0 for CMS version 4.17.0 and to ~3.21.1 for 5.9.0. They’re both due to be released soon.