_attribute;
			}
		}
	}

	/*
	 * If necessary, advance to what is likely to be an inner block wrapper tag.
	 *
	 * This advances until it finds the first tag containing the original class
	 * attribute from above. If none is found it will scan to the end of the block
	 * and fail to add any class names.
	 *
	 * If there is no block wrapper it won't advance at all, in which case the
	 * class names will be added to the first and outermost tag of the block.
	 * For cases where this outermost tag is the only tag surrounding inner
	 * blocks then the outer wrapper and inner wrapper are the same.
	 */
	do {
		if ( ! $inner_block_wrapper_classes ) {
			break;
		}

		if ( false !== strpos( $processor->get_attribute( 'class' ), $inner_block_wrapper_classes ) ) {
			break;
		}
	} while ( $processor->next_tag() );

	// Add the remaining class names.
	foreach ( $class_names as $class_name ) {
		$processor->add_class( $class_name );
	}

	return $processor->get_updated_html();
}

// Register the block support.
WP_Block_Supports::get_instance()->register(
	'layout',
	array(
		'register_attribute' => 'wp_register_layout_support',
	)
);
add_filter( 'render_block', 'wp_render_layout_support_flag', 10, 2 );

/**
 * For themes without theme.json file, make sure
 * to restore the inner div for the group block
 * to avoid breaking styles relying on that div.
 *
 * @since 5.8.0
 * @access private
 *
 * @param string $block_content Rendered block content.
 * @param array  $block         Block object.
 * @return string Filtered block content.
 */
function wp_restore_group_inner_container( $block_content, $block ) {
	$tag_name                         = isset( $block['attrs']['tagName'] ) ? $block['attrs']['tagName'] : 'div';
	$group_with_inner_container_regex = sprintf(
		'/(^\s*<%1$s\b[^>]*wp-block-group(\s|")[^>]*>)(\s*<div\b[^>]*wp-block-group__inner-container(\s|")[^>]*>)((.|\S|\s)*)/U',
		preg_quote( $tag_name, '/' )
	);

	if (
		wp_theme_has_theme_json() ||
		1 === preg_match( $group_with_inner_container_regex, $block_content ) ||
		( isset( $block['attrs']['layout']['type'] ) && 'flex' === $block['attrs']['layout']['type'] )
	) {
		return $block_content;
	}

	$replace_regex   = sprintf(
		'/(^\s*<%1$s\b[^>]*wp-block-group[^>]*>)(.*)(<\/%1$s>\s*$)/ms',
		preg_quote( $tag_name, '/' )
	);
	$updated_content = preg_replace_callback(
		$replace_regex,
		static function ( $matches ) {
			return $matches[1] . '<div class="wp-block-group__inner-container">' . $matches[2] . '</div>' . $matches[3];
		},
		$block_content
	);
	return $updated_content;
}

add_filter( 'render_block_core/group', 'wp_restore_group_inner_container', 10, 2 );

/**
 * For themes without theme.json file, make sure
 * to restore the outer div for the aligned image block
 * to avoid breaking styles relying on that div.
 *
 * @since 6.0.0
 * @access private
 *
 * @param string $block_content Rendered block content.
 * @param  array  $block        Block object.
 * @return string Filtered block content.
 */
function wp_restore_image_outer_container( $block_content, $block ) {
	$image_with_align = "
/# 1) everything up to the class attribute contents
(
	^\s*
	<figure\b
	[^>]*
	\bclass=
	[\"']
)
# 2) the class attribute contents
(
	[^\"']*
	\bwp-block-image\b
	[^\"']*
	\b(?:alignleft|alignright|aligncenter)\b
	[^\"']*
)
# 3) everything after the class attribute contents
(
	[\"']
	[^>]*
	>
	.*
	<\/figure>
)/iUx";

	if (
		wp_theme_has_theme_json() ||
		0 === preg_match( $image_with_align, $block_content, $matches )
	) {
		return $block_content;
	}

	$wrapper_classnames = array( 'wp-block-image' );

	// If the block has a classNames attribute these classnames need to be removed from the content and added back
	// to the new wrapper div also.
	if ( ! empty( $block['attrs']['className'] ) ) {
		$wrapper_classnames = array_merge( $wrapper_classnames, explode( ' ', $block['attrs']['className'] ) );
	}
	$content_classnames          = explode( ' ', $matches[2] );
	$filtered_content_classnames = array_diff( $content_classnames, $wrapper_classnames );

	return '<div class="' . implode( ' ', $wrapper_classnames ) . '">' . $matches[1] . implode( ' ', $filtered_content_classnames ) . $matches[3] . '</div>';
}

add_filter( 'render_block_core/image', 'wp_restore_image_outer_container', 10, 2 );