Fix block style registry variations

lib/class-wp-theme-json-resolver-gutenberg.php

@@ -260,6 +260,12 @@ public static function get_theme_data( $deprecated = array(), $options = array()
 			 */
 			$theme_json_data = static::inject_shared_variations_from_theme_json_partials( $theme_json_data, $variations );
 
+			/*
+			 * Merge any block style variations registered through the WP_Block_Styles_Registry
+			 * with a style object.
+			 */
+			$theme_json_data = static::inject_shared_variations_from_style_registry( $theme_json_data );
+
 			/**
 			 * Filters the data provided by the theme for global styles and settings.
 			 *
@@ -865,6 +871,8 @@ public static function resolve_theme_file_uris( $theme_json ) {
 	 * Adds shared block style variation definitions sourced from theme.json partials
 	 * to the supplied theme.json data.
 	 *
+	 * @since 6.6.0
+	 *
 	 * @param array $data   Array following the theme.json specification.
 	 * @param array $variations Shared block style variations.
 	 * @return array Theme json data including shared block style variation definitions.
@@ -899,4 +907,35 @@ private static function inject_shared_variations_from_theme_json_partials( $data
 
 		return $data;
 	}
+
+	/**
+	 * Adds shared block style variation definitions sourced from the WP_Block_Styles_Registry.
+	 *
+	 * @since 6.6.0
+	 *
+	 * @param array $data   Array following the theme.json specification.
+	 * @return array Theme json data including shared block style variation definitions.
+	 */
+	private static function inject_shared_variations_from_style_registry( $data ) {
+		$registry        = WP_Block_Styles_Registry::get_instance();
+		$styles          = $registry->get_all_registered();
+		$variations_data = array();
+
+		/*
+		 * As the block style registry stores the styles per block type we don't have
+		 * a shared variation to inject. It will go directly into the block type's variations.
+		 */
+		foreach ( $styles as $block_type => $variations ) {
+			foreach ( $variations as $variation_name => $variation ) {
+				if ( ! empty( $variation['style_data'] ) ) {
+					$current_variation = $theme_json_data['styles']['blocks'][ $block_type ]['variations'][ $variation_name ] ?? array();
+					$merged_variation  = array_replace_recursive( $variation['style_data'], $current_variation );
+					$path              = array( 'styles', 'blocks', $block_type, 'variations', $variation_name );
+					_wp_array_set( $data, $path, $merged_variation );
+				}
+			}
+		}
+
+		return $data;
+	}
 }