From cdcbfd19f4ff3dc5368424cf03ada7c829d32e3c Mon Sep 17 00:00:00 2001
From: Tonya Mork <hellofromtonya@git.wordpress.org>
Date: Mon, 20 Feb 2023 21:11:57 +0000
Subject: [PATCH] Editor: Fix 'wp-block-library-theme' style enqueue
 conditions.

Fixes the conditions for when to enqueue the opinionated block styles (i.e. `'wp-block-library-theme'` stylesheet):

* the theme adds `'wp-block-styles'` theme support;
* and no editor styles are declared.

This resolves an issue with themes that do not add the `'wp-block-styles'` theme support while not impacting themes that do.

Follow-up to [53419], [52069], [50761], [44157].

Props mikachan, costdev, glendaviesnz, hellofromTonya, jffng, mamaduka, ndiego, poena, sannevndrmeulen, scruffian.
Fixes #57561.

git-svn-id: https://develop.svn.wordpress.org/trunk@55368 602fd350-edb4-49c9-b593-d223f7449a82
---
 src/wp-admin/site-editor.php                |  2 +-
 src/wp-includes/block-editor.php            |  7 +++++--
 src/wp-includes/script-loader.php           | 10 ++++++++--
 tests/phpunit/tests/dependencies/styles.php |  6 +++---
 4 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/src/wp-admin/site-editor.php b/src/wp-admin/site-editor.php
index dd5211dc0b..9302c42389 100644
--- a/src/wp-admin/site-editor.php
+++ b/src/wp-admin/site-editor.php
@@ -120,7 +120,7 @@ wp_enqueue_style( 'wp-format-library' );
 wp_enqueue_media();
 
 if (
-	current_theme_supports( 'wp-block-styles' ) ||
+	current_theme_supports( 'wp-block-styles' ) &&
 	( ! is_array( $editor_styles ) || count( $editor_styles ) === 0 )
 ) {
 	wp_enqueue_style( 'wp-block-library-theme' );
diff --git a/src/wp-includes/block-editor.php b/src/wp-includes/block-editor.php
index acf7b5d550..b42c0c09f0 100644
--- a/src/wp-includes/block-editor.php
+++ b/src/wp-includes/block-editor.php
@@ -296,7 +296,7 @@ function get_legacy_widget_block_editor_settings() {
  * }
  */
 function _wp_get_iframed_editor_assets() {
-	global $pagenow;
+	global $pagenow, $editor_styles;
 
 	$script_handles = array(
 		'wp-polyfill',
@@ -305,7 +305,10 @@ function _wp_get_iframed_editor_assets() {
 		'wp-edit-blocks',
 	);
 
-	if ( current_theme_supports( 'wp-block-styles' ) ) {
+	if (
+		current_theme_supports( 'wp-block-styles' ) &&
+		( ! is_array( $editor_styles ) || count( $editor_styles ) === 0 )
+	) {
 		$style_handles[] = 'wp-block-library-theme';
 	}
 
diff --git a/src/wp-includes/script-loader.php b/src/wp-includes/script-loader.php
index 5216ff299a..acdfac640d 100644
--- a/src/wp-includes/script-loader.php
+++ b/src/wp-includes/script-loader.php
@@ -1635,8 +1635,14 @@ function wp_default_styles( $styles ) {
 		$wp_edit_blocks_dependencies[] = 'wp-editor-classic-layout-styles';
 	}
 
-	if ( ! is_array( $editor_styles ) || count( $editor_styles ) === 0 ) {
-		// Include opinionated block styles if no $editor_styles are declared, so the editor never appears broken.
+	if (
+		current_theme_supports( 'wp-block-styles' ) &&
+		( ! is_array( $editor_styles ) || count( $editor_styles ) === 0 )
+	) {
+		/*
+		 * Include opinionated block styles if the theme supports block styles and
+		 * no $editor_styles are declared, so the editor never appears broken.
+		 */
 		$wp_edit_blocks_dependencies[] = 'wp-block-library-theme';
 	}
 
diff --git a/tests/phpunit/tests/dependencies/styles.php b/tests/phpunit/tests/dependencies/styles.php
index 34a9847f2f..0d2f8e664b 100644
--- a/tests/phpunit/tests/dependencies/styles.php
+++ b/tests/phpunit/tests/dependencies/styles.php
@@ -405,9 +405,9 @@ CSS;
 	}
 
 	/**
-	 * Tests that visual block styles are enqueued in the editor even when there is not theme support for 'wp-block-styles'.
+	 * Tests that visual block styles are not be enqueued in the editor when there is not theme support for 'wp-block-styles'.
 	 *
-	 * Visual block styles should always be enqueued when editing to avoid the appearance of a broken editor.
+	 * @ticket 57561
 	 *
 	 * @covers ::wp_enqueue_style
 	 */
@@ -419,7 +419,7 @@ CSS;
 
 		$this->assertFalse( wp_style_is( 'wp-block-library-theme' ) );
 		wp_enqueue_style( 'wp-edit-blocks' );
-		$this->assertTrue( wp_style_is( 'wp-block-library-theme' ) );
+		$this->assertFalse( wp_style_is( 'wp-block-library-theme' ), "The 'wp-block-library-theme' style should not be in the queue after enqueuing 'wp-edit-blocks'" );
 	}
 
 	/**