CSS Minification - custom properties with value 0 followed by a unit is rewritten to 0 without a unit.

[gustavo-roganti]

Linked to #1538

A css custom property (see https://developer.mozilla.org/en-US/docs/Web/CSS/Using_CSS_custom_properties) is defined as
--custom-offset: 0px
and is then used in a CSS rule
top: calc(50% + var(--custom-offset))

but mod_pagespeed (version 1.13.35.2-0) rewrites the variable removing the px as
--custom-offset:0

and the calc() rule breaks.

The fix to bug 1538 checks if the css value is used in "calc(" but this does not work if the value is stored in a custom variable

[Lofesa]

Have you tried the latest version 1.14.36.1 or latest-beta?

[gustavo-roganti]

I'm sorry but I am not able to try in a newer version. I'm using a pre-made docker image (bitnami wordpress) with version 1.13.35.2-0 in it. I know too little to set up a testing environment with the latest version.

If anyone else could check if --custom-offset: 0px gets converted to --custom-offset: 0 on the latest versions, it would point to this bug still being present.