From 143fd4c1f71fe7d5f6bd7b64c491d9644d861355 Mon Sep 17 00:00:00 2001
From: davidbaumwald <davidbaumwald@git.wordpress.org>
Date: Thu, 29 Sep 2022 18:55:10 +0000
Subject: [PATCH] Editor: Reintroduce styles that were removed for classic
 themes.

After block CSS was merged with `theme.json` styles in [https://github.com/WordPress/gutenberg/pull/34180 Gutenberg PR #34180], this removed some existing, default styling for some elements, including buttons.  This change re-adds the removed styles by enqueueing `classic.css` for classic themes.

Merges [https://github.com/WordPress/gutenberg/pull/44334 Gutenberg PR #44334] into trunk.

Follow-up to [54257].

Props scruffian, oandregal, ramonopoly, aristath, andrewserong, get_dave, bernhard-reiter.
See #56467.
Built from https://develop.svn.wordpress.org/trunk@54358


git-svn-id: http://core.svn.wordpress.org/trunk@53917 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/default-filters.php |  2 ++
 wp-includes/script-loader.php   | 13 +++++++++++++
 wp-includes/version.php         |  2 +-
 3 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/wp-includes/default-filters.php b/wp-includes/default-filters.php
index 126d276417..725f5ef3cb 100644
--- a/wp-includes/default-filters.php
+++ b/wp-includes/default-filters.php
@@ -557,8 +557,10 @@ add_action( 'wp_default_scripts', 'wp_default_packages' );
 
 add_action( 'wp_enqueue_scripts', 'wp_localize_jquery_ui_datepicker', 1000 );
 add_action( 'wp_enqueue_scripts', 'wp_common_block_scripts_and_styles' );
+add_action( 'wp_enqueue_scripts', 'wp_enqueue_classic_theme_styles' );
 add_action( 'admin_enqueue_scripts', 'wp_localize_jquery_ui_datepicker', 1000 );
 add_action( 'admin_enqueue_scripts', 'wp_common_block_scripts_and_styles' );
+add_action( 'admin_enqueue_scripts', 'wp_enqueue_classic_theme_styles' );
 add_action( 'enqueue_block_assets', 'wp_enqueue_registered_block_scripts_and_styles' );
 add_action( 'enqueue_block_assets', 'enqueue_block_styles_assets', 30 );
 add_action( 'enqueue_block_editor_assets', 'wp_enqueue_registered_block_scripts_and_styles' );
diff --git a/wp-includes/script-loader.php b/wp-includes/script-loader.php
index 3bd0bbcaf2..0c64281843 100644
--- a/wp-includes/script-loader.php
+++ b/wp-includes/script-loader.php
@@ -3640,3 +3640,16 @@ function _wp_theme_json_webfonts_handler() {
 	add_action( 'wp_enqueue_scripts', $fn_generate_and_enqueue_styles );
 	add_action( 'admin_init', $fn_generate_and_enqueue_editor_styles );
 }
+
+/**
+ * Loads classic theme styles on classic themes.
+ *
+ * This is needed for backwards compatibility for button blocks specifically.
+ */
+function wp_enqueue_classic_theme_styles() {
+	if ( ! wp_is_block_theme() ) {
+		$suffix = wp_scripts_get_suffix();
+		wp_register_style( 'classic-theme-styles', "/wp-includes/css/dist/block-library/classic$suffix.css", array(), true );
+		wp_enqueue_style( 'classic-theme-styles' );
+	}
+}
diff --git a/wp-includes/version.php b/wp-includes/version.php
index fdcd857993..531e26a0b3 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.1-beta2-54357';
+$wp_version = '6.1-beta2-54358';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.