Merging upstream version 6.6.1+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 13 insertions, 2 deletions

diff --git a/wp-includes/style-engine/class-wp-style-engine-css-rules-store.php b/wp-includes/style-engine/class-wp-style-engine-css-rules-store.php
index 371e59f..4a82f28 100644
--- a/wp-includes/style-engine/class-wp-style-engine-css-rules-store.php
+++ b/wp-includes/style-engine/class-wp-style-engine-css-rules-store.php
@@ -121,19 +121,30 @@ class WP_Style_Engine_CSS_Rules_Store {
 	 * If the rule does not exist, it will be created.
 	 *
 	 * @since 6.1.0
+	 * @since 6.6.0 Added the $rules_group parameter.
 	 *
 	 * @param string $selector The CSS selector.
+	 * @param string $rules_group A parent CSS selector in the case of nested CSS, or a CSS nested @rule,
+	 *                            such as `@media (min-width: 80rem)` or `@layer module`.
 	 * @return WP_Style_Engine_CSS_Rule|void Returns a WP_Style_Engine_CSS_Rule object,
 	 *                                       or void if the selector is empty.
 	 */
-	public function add_rule( $selector ) {
-		$selector = trim( $selector );
+	public function add_rule( $selector, $rules_group = '' ) {
+		$selector    = $selector ? trim( $selector ) : '';
+		$rules_group = $rules_group ? trim( $rules_group ) : '';
 
 		// Bail early if there is no selector.
 		if ( empty( $selector ) ) {
 			return;
 		}
 
+		if ( ! empty( $rules_group ) ) {
+			if ( empty( $this->rules[ "$rules_group $selector" ] ) ) {
+				$this->rules[ "$rules_group $selector" ] = new WP_Style_Engine_CSS_Rule( $selector, array(), $rules_group );
+			}
+			return $this->rules[ "$rules_group $selector" ];
+		}
+
 		// Create the rule if it doesn't exist.
 		if ( empty( $this->rules[ $selector ] ) ) {
 			$this->rules[ $selector ] = new WP_Style_Engine_CSS_Rule( $selector );