From be1b61326b5f1c9d5b32a487dc59c5d47633d051 Mon Sep 17 00:00:00 2001
From: Joe McGill <joemcgill@gmail.com>
Date: Wed, 6 Sep 2023 18:08:17 +0000
Subject: [PATCH] Themes: Avoid stale caches for core block styles.

This fixes an issue introduced in [56044] in which the path to core block styles are cached to avoid expensive file operations on every page load. The original caching strategy is now modified so that only the path relative to the blocks location are stored, rather than the full path, since the path to the `wp-includes` folder can change after the value is generated. The new cached value also includes the current WordPress version value to ensure it is rebuilt when the version changes.

Props lhe2012, coreyw, colorful tones, petitphp, mukesh27, spacedmonkey, joemcgill, flixos90, kimannwall, desmith.
Fixes #59111.


Built from https://develop.svn.wordpress.org/trunk@56524


git-svn-id: http://core.svn.wordpress.org/trunk@56036 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/blocks/index.php | 78 +++++++++++++++++++++++++-----------
 wp-includes/version.php      |  2 +-
 2 files changed, 56 insertions(+), 24 deletions(-)

diff --git a/wp-includes/blocks/index.php b/wp-includes/blocks/index.php
index 4a95b90351..a966248c79 100644
--- a/wp-includes/blocks/index.php
+++ b/wp-includes/blocks/index.php
@@ -20,46 +20,78 @@ require BLOCKS_PATH . 'require-dynamic-blocks.php';
  * avoids unnecessary logic and filesystem lookups in the other function.
  *
  * @since 6.3.0
+ *
+ * @global string $wp_version The WordPress version string.
  */
 function register_core_block_style_handles() {
+	global $wp_version;
+
 	if ( ! wp_should_load_separate_core_block_assets() ) {
 		return;
 	}
 
-	static $core_blocks_meta;
-	if ( ! $core_blocks_meta ) {
-		$core_blocks_meta = require ABSPATH . WPINC . '/blocks/blocks-json.php';
-	}
-
-	$includes_url  = includes_url();
-	$includes_path = ABSPATH . WPINC . '/';
-	$suffix        = wp_scripts_get_suffix();
-	$wp_styles     = wp_styles();
-	$style_fields  = array(
+	$blocks_url   = includes_url( 'blocks/' );
+	$suffix       = wp_scripts_get_suffix();
+	$wp_styles    = wp_styles();
+	$style_fields = array(
 		'style'       => 'style',
 		'editorStyle' => 'editor',
 	);
 
+	static $core_blocks_meta;
+	if ( ! $core_blocks_meta ) {
+		$core_blocks_meta = require BLOCKS_PATH . 'blocks-json.php';
+	}
+
+	$files          = false;
+	$transient_name = 'wp_core_block_css_files';
+
 	/*
 	 * Ignore transient cache when the development mode is set to 'core'. Why? To avoid interfering with
 	 * the core developer's workflow.
 	 */
-	if ( ! wp_is_development_mode( 'core' ) ) {
-		$transient_name = 'wp_core_block_css_files';
-		$files          = get_transient( $transient_name );
-		if ( ! $files ) {
-			$files = glob( wp_normalize_path( __DIR__ . '/**/**.css' ) );
-			set_transient( $transient_name, $files );
+	$can_use_cached = ! wp_is_development_mode( 'core' );
+
+	if ( $can_use_cached ) {
+		$cached_files = get_transient( $transient_name );
+
+		// Check the validity of cached values by checking against the current WordPress version.
+		if (
+			is_array( $cached_files )
+			&& isset( $cached_files['version'] )
+			&& $cached_files['version'] === $wp_version
+			&& isset( $cached_files['files'] )
+		) {
+			$files = $cached_files['files'];
 		}
-	} else {
-		$files = glob( wp_normalize_path( __DIR__ . '/**/**.css' ) );
 	}
 
-	$register_style = static function( $name, $filename, $style_handle ) use ( $includes_path, $includes_url, $suffix, $wp_styles, $files ) {
-		$style_path = "blocks/{$name}/{$filename}{$suffix}.css";
-		$path       = wp_normalize_path( $includes_path . $style_path );
+	if ( ! $files ) {
+		$files = glob( wp_normalize_path( BLOCKS_PATH . '**/**.css' ) );
+		$files = array_map(
+			static function ( $file ) {
+				return str_replace( BLOCKS_PATH, '', $file );
+			},
+			$files
+		);
 
-		if ( ! in_array( $path, $files, true ) ) {
+		// Save core block style paths in cache when not in development mode.
+		if ( $can_use_cached ) {
+			set_transient(
+				$transient_name,
+				array(
+					'version' => $wp_version,
+					'files'   => $files,
+				)
+			);
+		}
+	}
+
+	$register_style = static function( $name, $filename, $style_handle ) use ( $blocks_url, $suffix, $wp_styles, $files ) {
+		$style_path = "{$name}/{$filename}{$suffix}.css";
+		$path       = wp_normalize_path( BLOCKS_PATH . $style_path );
+
+		if ( ! in_array( $style_path, $files, true ) ) {
 			$wp_styles->add(
 				$style_handle,
 				false
@@ -67,7 +99,7 @@ function register_core_block_style_handles() {
 			return;
 		}
 
-		$wp_styles->add( $style_handle, $includes_url . $style_path );
+		$wp_styles->add( $style_handle, $blocks_url . $style_path );
 		$wp_styles->add_data( $style_handle, 'path', $path );
 
 		$rtl_file = str_replace( "{$suffix}.css", "-rtl{$suffix}.css", $path );
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 07d9c40ceb..38ce9be351 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.4-alpha-56523';
+$wp_version = '6.4-alpha-56524';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.