From 1660108b59280e9eb99d6ea8bfe1a46481a9c840 Mon Sep 17 00:00:00 2001
From: desrosj <desrosj@git.wordpress.org>
Date: Fri, 27 Aug 2021 19:09:58 +0000
Subject: [PATCH] Editor: Ensure block attribute serialization in PHP matches
 the JavaScript equivalent.

The `serializeAttributes()` function in JavaScript uses `JSON.stringify`, which does not encode slashes and unicode characters by default. This resulted in the PHP serialization through `json_encode()` producing different results.

This also switches from `json_encode()` to `wp_json_encode()` to prevent failures when any non UTF-8 characters are included.

Props kevinfodness, SergeyBiryukov, timothyblynjacobs.
Merges [51674] to the 5.8 branch.
Fixes #53936.
Built from https://develop.svn.wordpress.org/branches/5.8@51681


git-svn-id: http://core.svn.wordpress.org/branches/5.8@51287 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/blocks.php  | 6 +++++-
 wp-includes/version.php | 2 +-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/wp-includes/blocks.php b/wp-includes/blocks.php
index 0a4c1c9afc..fc7c3f9b0d 100644
--- a/wp-includes/blocks.php
+++ b/wp-includes/blocks.php
@@ -488,13 +488,17 @@ function get_dynamic_block_names() {
  * substitution for characters which might otherwise interfere with embedding
  * the result in an HTML comment.
  *
+ * This function must produce output that remains in sync with the output of
+ * the serializeAttributes JavaScript function in the block editor in order
+ * to ensure consistent operation between PHP and JavaScript.
+ *
  * @since 5.3.1
  *
  * @param array $block_attributes Attributes object.
  * @return string Serialized attributes.
  */
 function serialize_block_attributes( $block_attributes ) {
-	$encoded_attributes = json_encode( $block_attributes );
+	$encoded_attributes = wp_json_encode( $block_attributes, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE );
 	$encoded_attributes = preg_replace( '/--/', '\\u002d\\u002d', $encoded_attributes );
 	$encoded_attributes = preg_replace( '/</', '\\u003c', $encoded_attributes );
 	$encoded_attributes = preg_replace( '/>/', '\\u003e', $encoded_attributes );
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 486918919f..f8d7feda19 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.8.1-alpha-51680';
+$wp_version = '5.8.1-alpha-51681';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.