id	summary	reporter	owner	description	type	status	priority	milestone	component	version	severity	resolution	keywords	cc	focuses
65838	Formatting: CSS function name matching in safecss_filter_attr() is case-sensitive	wildworks		"Split off from [https://github.com/WordPress/wordpress-develop/pull/12942#discussion_r3740198813 a review comment on PR #12942].

CSS function names are [https://www.w3.org/TR/css-values-4/#functional-notation:~:text=function%20names%20are%20ASCII%20case%2Dinsensitive ASCII case-insensitive], so `CALC(1px + 2px)`, `rotatex(45deg)`, and `LINEAR-GRADIENT(red, blue)` are all valid CSS. However, every function-matching regular expression in `safecss_filter_attr()` is case-sensitive, so valid declarations using anything other than all-lowercase function names are silently dropped.

{{{#!php
// ""width: calc(100% - 10px)""
var_dump( safecss_filter_attr( 'width: calc(100% - 10px)' ) );

// """" — expected to be preserved
var_dump( safecss_filter_attr( 'width: CALC(100% - 10px)' ) );
}}}

Make the function matching case-**insensitive**, covering the `url()`, gradient, and generic function patterns alike. The change is small but relaxes the sanitizer rather than tightening it, so it needs strict checking that no malformed or unsafe value slips through,"	defect (bug)	new	normal	Awaiting Review	Formatting		normal		has-patch has-unit-tests