_get_comment_reply_id()

_get_comment_reply_id( int|WP_Post|null $post = null ): int

function _get_comment_reply_id( $post = null ) {
	$post = get_post( $post );

	if ( ! $post || ! isset( $_GET['replytocom'] ) || ! is_numeric( $_GET['replytocom'] ) ) {
		return 0;
	}

	$reply_to_id = (int) $_GET['replytocom'];

	/*
	 * Validate the comment.
	 * Bail out if it does not exist, is not approved, or its
	 * `comment_post_ID` does not match the given post ID.
	 */
	$comment = get_comment( $reply_to_id );

	if (
		! $comment instanceof WP_Comment ||
		0 === (int) $comment->comment_approved ||
		$post->ID !== (int) $comment->comment_post_ID
	) {
		return 0;
	}

	return $reply_to_id;
}