From fcd5d3b4951043ab7bcb5a41ed6cfe604e160115 Mon Sep 17 00:00:00 2001
From: Dominik Schilling <ocean90@git.wordpress.org>
Date: Thu, 17 Feb 2022 14:45:53 +0000
Subject: [PATCH] Script Loader: Prevent normalizing data URIs in
 `_wp_normalize_relative_css_links()`.

This prevents making data URIs as in `mask-image:url('data:image/svg+xml;utf8,<svg...` relative to the WordPress installation.

Props staatic.
See #54243.
Fixes #55177.

git-svn-id: https://develop.svn.wordpress.org/trunk@52754 602fd350-edb4-49c9-b593-d223f7449a82
---
 src/wp-includes/script-loader.php           | 5 +++++
 tests/phpunit/tests/dependencies/styles.php | 4 ++++
 2 files changed, 9 insertions(+)

diff --git a/src/wp-includes/script-loader.php b/src/wp-includes/script-loader.php
index 824748b17b..0957dce2d7 100644
--- a/src/wp-includes/script-loader.php
+++ b/src/wp-includes/script-loader.php
@@ -2781,6 +2781,11 @@ function _wp_normalize_relative_css_links( $css, $stylesheet_url ) {
 				continue;
 			}
 
+			// Skip if the URL is a data URI.
+			if ( str_starts_with( $src_result, 'data:' ) ) {
+				continue;
+			}
+
 			// Build the absolute URL.
 			$absolute_url = dirname( $stylesheet_url ) . '/' . $src_result;
 			$absolute_url = str_replace( '/./', '/', $absolute_url );
diff --git a/tests/phpunit/tests/dependencies/styles.php b/tests/phpunit/tests/dependencies/styles.php
index 6af0b09866..8e7721d1e9 100644
--- a/tests/phpunit/tests/dependencies/styles.php
+++ b/tests/phpunit/tests/dependencies/styles.php
@@ -236,6 +236,10 @@ class Tests_Dependencies_Styles extends WP_UnitTestCase {
 				'css'      => 'clip-path: url(#image1);',
 				'expected' => 'clip-path: url(#image1);',
 			),
+			'Data URIs, shouldn\'t change'                 => array(
+				'css'      => 'img {mask-image: url(\'data:image/svg+xml;utf8,<svg></svg>\');}',
+				'expected' => 'img {mask-image: url(\'data:image/svg+xml;utf8,<svg></svg>\');}',
+			),
 		);
 	}