From 5951111cba85e5134db2c3f4fee5b08d61c32ff2 Mon Sep 17 00:00:00 2001
From: isabel_brison <isabel_brison@git.wordpress.org>
Date: Tue, 10 Oct 2023 03:43:22 +0000
Subject: [PATCH] Editor: fix incorrect block custom CSS output.

Fixes output of block custom CSS when multiple rules require a descendant selector.

Props wildworks, mikachan.
Fixes #59499.

Built from https://develop.svn.wordpress.org/trunk@56812


git-svn-id: http://core.svn.wordpress.org/trunk@56324 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/class-wp-theme-json.php | 20 +++++++++++++++++---
 wp-includes/version.php             |  2 +-
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/wp-includes/class-wp-theme-json.php b/wp-includes/class-wp-theme-json.php
index 4955fcc264..e5f174138d 100644
--- a/wp-includes/class-wp-theme-json.php
+++ b/wp-includes/class-wp-theme-json.php
@@ -1146,9 +1146,23 @@ class WP_Theme_JSON {
 		// Split CSS nested rules.
 		$parts = explode( '&', $css );
 		foreach ( $parts as $part ) {
-			$processed_css .= ( ! str_contains( $part, '{' ) )
-				? trim( $selector ) . '{' . trim( $part ) . '}' // If the part doesn't contain braces, it applies to the root level.
-				: trim( $selector . $part ); // Prepend the selector, which effectively replaces the "&" character.
+			$is_root_css = ( ! str_contains( $part, '{' ) );
+			if ( $is_root_css ) {
+				// If the part doesn't contain braces, it applies to the root level.
+				$processed_css .= trim( $selector ) . '{' . trim( $part ) . '}';
+			} else {
+				// If the part contains braces, it's a nested CSS rule.
+				$part = explode( '{', str_replace( '}', '', $part ) );
+				if ( count( $part ) !== 2 ) {
+					continue;
+				}
+				$nested_selector = $part[0];
+				$css_value       = $part[1];
+				$part_selector   = str_starts_with( $nested_selector, ' ' )
+					? static::scope_selector( $selector, $nested_selector )
+					: static::append_to_selector( $selector, $nested_selector );
+				$processed_css  .= $part_selector . '{' . trim( $css_value ) . '}';
+			}
 		}
 		return $processed_css;
 	}
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 09b51ab409..7db313e635 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.4-beta2-56811';
+$wp_version = '6.4-beta2-56812';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.