Sync with #66543

lib/compat/wordpress-6.6/rest-api.php

@@ -207,7 +207,9 @@ function gutenberg_register_wp_rest_post_types_controller_fields() {
  */
 function gutenberg_block_editor_preload_paths_6_6( $paths, $context ) {
 	if ( 'core/edit-post' === $context->name ) {
+		$paths[] = '/wp/v2/global-styles/themes/' . get_stylesheet();
 		$paths[] = '/wp/v2/themes?context=edit&status=active';
+		$paths[] = '/wp/v2/global-styles/' . WP_Theme_JSON_Resolver_Gutenberg::get_user_global_styles_post_id() . '?context=edit';
 	}
 	return $paths;
 }

lib/compat/wordpress-6.7/rest-api.php

@@ -51,22 +51,36 @@ function gutenberg_block_editor_preload_paths_6_7( $paths, $context ) {
 	}
 
 	// Preload theme and global styles paths.
-	$excluded_paths = array();
 	if ( 'core/edit-site' === $context->name || 'core/edit-post' === $context->name ) {
 		$active_theme     = get_stylesheet();
+		$excluded_paths   = array();
 		$global_styles_id = WP_Theme_JSON_Resolver_Gutenberg::get_user_global_styles_post_id();
+		$paths[]          = array( '/wp/v2/global-styles/' . $global_styles_id, 'OPTIONS' );
 		$paths[]          = '/wp/v2/global-styles/themes/' . $active_theme . '?context=view';
 		$paths[]          = '/wp/v2/global-styles/themes/' . $active_theme . '/variations?context=view';
-		$paths[]          = array( '/wp/v2/global-styles/' . $global_styles_id, 'OPTIONS' );
 
 		// Remove duplicate or unnecessary global styles paths.
 		$excluded_paths[] = '/wp/v2/global-styles/themes/' . $active_theme;
 		$excluded_paths[] = '/wp/v2/global-styles/' . $global_styles_id;
+		// Removes the edit context path originating Core's preload paths.
+		$excluded_paths[] = '/wp/v2/global-styles/' . $global_styles_id . '?context=view';
+		// Removes the edit context path originating from gutenberg_block_editor_preload_paths_6_6().
+		$excluded_paths[] = '/wp/v2/global-styles/' . $global_styles_id . '?context=edit';
+
+		// Remove excluded paths so they are not preloaded.
 		foreach ( $paths as $key => $path ) {
 			if ( in_array( $path, $excluded_paths, true ) ) {
 				unset( $paths[ $key ] );
 			}
 		}
+
+		/*
+		 * Add the global styles path with the correct context based on user caps.
+		 * The corresponding paths are removed above so their output is not rendered into the HTML
+		 * unnecessarily.
+		 */
+		$context = current_user_can( 'edit_theme_options' ) ? 'edit' : 'view';
+		$paths[] = "/wp/v2/global-styles/$global_styles_id?context=$context";
 	}
 
 	return $paths;