From 134e355f13c4fb53d4dc0f16be267fd0812060e2 Mon Sep 17 00:00:00 2001
From: Joe McGill <joemcgill@gmail.com>
Date: Wed, 20 Nov 2024 21:29:22 +0000
Subject: [PATCH] Editor: Avoid unnecessary array_merge in
 WP_Style_Engine::parse_block_styles().

This adds an `! empty()` check for classnames and declarations to avoid calling array_merge() with an empty value.

Props mukesh27, ramonopoly, aaronrobertshaw.
Fixes #62317.

Built from https://develop.svn.wordpress.org/trunk@59442


git-svn-id: http://core.svn.wordpress.org/trunk@58828 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/style-engine/class-wp-style-engine.php | 11 +++++++++--
 wp-includes/version.php                            |  2 +-
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/wp-includes/style-engine/class-wp-style-engine.php b/wp-includes/style-engine/class-wp-style-engine.php
index 5582aacbb1..1234efdc64 100644
--- a/wp-includes/style-engine/class-wp-style-engine.php
+++ b/wp-includes/style-engine/class-wp-style-engine.php
@@ -454,8 +454,15 @@ final class WP_Style_Engine {
 					continue;
 				}
 
-				$parsed_styles['classnames']   = array_merge( $parsed_styles['classnames'], static::get_classnames( $style_value, $style_definition ) );
-				$parsed_styles['declarations'] = array_merge( $parsed_styles['declarations'], static::get_css_declarations( $style_value, $style_definition, $options ) );
+				$classnames = static::get_classnames( $style_value, $style_definition );
+				if ( ! empty( $classnames ) ) {
+					$parsed_styles['classnames'] = array_merge( $parsed_styles['classnames'], $classnames );
+				}
+
+				$css_declarations = static::get_css_declarations( $style_value, $style_definition, $options );
+				if ( ! empty( $css_declarations ) ) {
+					$parsed_styles['declarations'] = array_merge( $parsed_styles['declarations'], $css_declarations );
+				}
 			}
 		}
 
diff --git a/wp-includes/version.php b/wp-includes/version.php
index ab7c1bc1e3..f2c8eb091d 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.8-alpha-59441';
+$wp_version = '6.8-alpha-59442';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.