rue on success, false on failure.
 */
function wp_unspam_comment( $comment_id ) {
	$comment = get_comment( $comment_id );
	if ( ! $comment ) {
		return false;
	}

	/**
	 * Fires immediately before a comment is unmarked as Spam.
	 *
	 * @since 2.9.0
	 * @since 4.9.0 Added the `$comment` parameter.
	 *
	 * @param int        $comment_id The comment ID.
	 * @param WP_Comment $comment    The comment to be unmarked as spam.
	 */
	do_action( 'unspam_comment', $comment->comment_ID, $comment );

	$status = (string) get_comment_meta( $comment->comment_ID, '_wp_trash_meta_status', true );
	if ( empty($status) )
		$status = '0';

	if ( wp_set_comment_status( $comment, $status ) ) {
		delete_comment_meta( $comment->comment_ID, '_wp_trash_meta_status' );
		delete_comment_meta( $comment->comment_ID, '_wp_trash_meta_time' );
		/**
		 * Fires immediately after a comment is unmarked as Spam.
		 *
		 * @since 2.9.0
		 * @since 4.9.0 Added the `$comment` parameter.
		 *
		 * @param int        $comment_id The comment ID.
		 * @param WP_Comment $comment    The comment unmarked as spam.
		 */
		do_action( 'unspammed_comment', $comment->comment_ID, $comment );
		return true;
	}

	return false;
}

/**
 * The status of a comment by ID.
 *
 * @since 1.0.0
 *
 * @param int|WP_Comment $comment_id Comment ID or WP_Comment object
 * @return false|string Status might be 'trash', 'approved', 'unapproved', 'spam'. False on failure.
 */
function wp_get_comment_status($comment_id) {
	$comment = get_comment($comment_id);
	if ( !$comment )
		return false;

	$approved = $comment->comment_approved;

	if ( $approved == null )
		return false;
	elseif ( $approved == '1' )
		return 'approved';
	elseif ( $approved == '0' )
		return 'unapproved';
	elseif ( $approved == 'spam' )
		return 'spam';
	elseif ( $approved == 'trash' )
		return 'trash';
	else
		return false;
}

/**
 * Call hooks for when a comment status transition occurs.
 *
 * Calls hooks for comment status transitions. If the new comment status is not the same
 * as the previous comment status, then two hooks will be ran, the first is
 * {@see 'transition_comment_status'} with new status, old status, and comment data. The
 * next action called is {@see comment_$old_status_to_$new_status'}. It has the
 * comment data.
 *
 * The final action will run whether or not the comment statuses are the same. The
 * action is named {@see 'comment_$new_status_$comment->comment_type'}.
 *
 * @since 2.7.0
 *
 * @param string $new_status New comment status.
 * @param string $old_status Previous comment status.
 * @param object $comment Comment data.
 */
function wp_transition_comment_status($new_status, $old_status, $comment) {
	/*
	 * Translate raw statuses to human readable formats for the hooks.
	 * This is not a complete list of comment status, it's only the ones
	 * that need to be renamed
	 */
	$comment_statuses = array(
		0         => 'unapproved',
		'hold'    => 'unapproved', // wp_set_comment_status() uses "hold"
		1         => 'approved',
		'approve' => 'approved', // wp_set_comment_status() uses "approve"
	);
	if ( isset($comment_statuses[$new_status]) ) $new_status = $comment_statuses[$new_status];
	if ( isset($comment_statuses[$old_status]) ) $old_status = $comment_statuses[$old_status];

	// Call the hooks
	if ( $new_status != $old_status ) {
		/**
		 * Fires when the comment status is in transition.
		 *
		 * @since 2.7.0
		 *
		 * @param int|string $new_status The new comment status.
		 * @param int|string $old_status The old comment status.
		 * @param object     $comment    The comment data.
		 */
		do_action( 'transition_comment_status', $new_status, $old_status, $comment );
		/**
		 * Fires when the comment status is in transition from one specific status to another.
		 *
		 * The dynamic portions of the hook name, `$old_status`, and `$new_status`,
		 * refer to the old and new comment statuses, respectively.
		 *
		 * @since 2.7.0
		 *
		 * @param WP_Comment $comment Comment object.
		 */
		do_action( "comment_{$old_status}_to_{$new_status}", $comment );
	}
	/**
	 * Fires when the status of a specific comment type is in transition.
	 *
	 * The dynamic portions of the hook name, `$new_status`, and `$comment->comment_type`,
	 * refer to the new comment status, and the type of comment, respectively.
	 *
	 * Typical comment types include an empty string (standard comment), 'pingback',
	 * or 'trackback'.
	 *
	 * @since 2.7.0
	 *
	 * @param int        $comment_ID The comment ID.
	 * @param WP_Comment $comment    Comment object.
	 */
	do_action( "comment_{$new_status}_{$comment->comment_type}", $comment->comment_ID, $comment );
}

/**
 * Clear the lastcommentmodified cached value when a comment status is changed.
 *
 * Deletes the lastcommentmodified cache key when a comment enters or leaves
 * 'approved' status.
 *
 * @since 4.7.0
 * @access private
 *
 * @param string $new_status The new comment status.
 * @param string $old_status The old comment status.
 */
function _clear_modified_cache_on_transition_comment_status( $new_status, $old_status ) {
	if ( 'approved' === $new_status || 'approved' === $old_status ) {
		foreach ( array( 'server', 'gmt', 'blog' ) as $timezone ) {
			wp_cache_delete( "lastcommentmodified:$timezone", 'timeinfo' );
		}
	}
}

/**
 * Get current commenter's name, email, and URL.
 *
 * Expects cookies content to already be sanitized. User of this function might
 * wish to recheck the returned array for validity.
 *
 * @see sanitize_comment_cookies() Use to sanitize cookies
 *
 * @since 2.0.4
 *
 * @return array Comment author, email, url respectively.
 */
function wp_get_current_commenter() {
	// Cookies should already be sanitized.

	$comment_author = '';
	if ( isset($_COOKIE['comment_author_'.COOKIEHASH]) )
		$comment_author = $_COOKIE['comment_author_'.COOKIEHASH];

	$comment_author_email = '';
	if ( isset($_COOKIE['comment_author_email_'.COOKIEHASH]) )
		$comment_author_email = $_COOKIE['comment_author_email_'.COOKIEHASH];

	$comment_author_url = '';
	if ( isset($_COOKIE['comment_author_url_'.COOKIEHASH]) )
		$comment_author_url = $_COOKIE['comment_author_url_'.COOKIEHASH];

	/**
	 * Filters the current commenter's name, email, and URL.
	 *
	 * @since 3.1.0
	 *
	 * @param array $comment_author_data {
	 *     An array of current commenter variables.
	 *
	 *     @type string $comment_author       The name of the author of the comment. Default empty.
	 *     @type string $comment_author_email The email address of the `$comment_author`. Default empty.
	 *     @type string $comment_author_url   The URL address of the `$comment_author`. Default empty.
	 * }
	 */
	return apply_filters( 'wp_get_current_commenter', compact('comment_author', 'comment_author_email', 'comment_author_url') );
}

/**
 * Inserts a comment into the database.
 *
 * @since 2.0.0
 * @since 4.4.0 Introduced `$comment_meta` argument.
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param array $commentdata {
 *     Array of arguments for inserting a new comment.
 *
 *     @type string     $comment_agent        The HTTP user agent of the `$comment_author` when
 *                                            the comment was submitted. Default empty.
 *     @type int|string $comment_approved     Whether the comment has been approved. Default 1.
 *     @type string     $comment_author       The name of the author of the comment. Default empty.
 *     @type string     $comment_author_email The email address of the `$comment_author`. Default empty.
 *     @type string     $comment_author_IP    The IP address of the `$comment_author`. Default empty.
 *     @type string     $comment_author_url   The URL address of the `$comment_author`. Default empty.
 *     @type string     $comment_content      The content of the comment. Default empty.
 *     @type string     $comment_date         The date the comment was submitted. To set the date
 *                                            manually, `$comment_date_gmt` must also be specified.
 *                                            Default is the current time.
 *     @type string     $comment_date_gmt     The date the comment was submitted in the GMT timezone.
 *                                            Default is `$comment_date` in the site's GMT timezone.
 *     @type int        $comment_karma        The karma of the comment. Default 0.
 *     @type int        $comment_parent       ID of this comment's parent, if any. Default 0.
 *     @type int        $comment_post_ID      ID of the post that relates to the comment, if any.
 *                                            Default 0.
 *     @type string     $comment_type         Comment type. Default empty.
 *     @type array      $comment_meta         Optional. Array of key/value pairs to be stored in commentmeta for the
 *                                            new comment.
 *     @type int        $user_id              ID of the user who submitted the comment. Default 0.
 * }
 * @return int|false The new comment's ID on success, false on failure.
 */
function wp_insert_comment( $commentdata ) {
	global $wpdb;
	$data = wp_unslash( $commentdata );

	$comment_author       = ! isset( $data['comment_author'] )       ? '' : $data['comment_author'];
	$comment_author_email = ! isset( $data['comment_author_email'] ) ? '' : $data['comment_author_email'];
	$comment_author_url   = ! isset( $data['comment_author_url'] )   ? '' : $data['comment_author_url'];
	$comment_author_IP    = ! isset( $data['comment_author_IP'] )    ? '' : $data['comment_author_IP'];

	$comment_date     = ! isset( $data['comment_date'] )     ? current_time( 'mysql' )            : $data['comment_date'];
	$comment_date_gmt = ! isset( $data['comment_date_gmt'] ) ? get_gmt_from_date( $comment_date ) : $data['comment_date_gmt'];

	$comment_post_ID  = ! isset( $data['comment_post_ID'] )  ? 0  : $data['comment_post_ID'];
	$comment_content  = ! isset( $data['comment_content'] )  ? '' : $data['comment_content'];
	$comment_karma    = ! isset( $data['comment_karma'] )    ? 0  : $data['comment_karma'];
	$comment_approved = ! isset( $data['comment_approved'] ) ? 1  : $data['comment_approved'];
	$comment_agent    = ! isset( $data['comment_agent'] )    ? '' : $data['comment_agent'];
	$comment_type     = ! isset( $data['comment_type'] )     ? '' : $data['comment_type'];
	$comment_parent   = ! isset( $data['comment_parent'] )   ? 0  : $data['comment_parent'];

	$user_id  = ! isset( $data['user_id'] ) ? 0 : $data['user_id'];

	$compacted = compact( 'comment_post_ID', 'comment_author', 'comment_author_email', 'comment_author_url', 'comment_author_IP', 'comment_date', 'comment_date_gmt', 'comment_content', 'comment_karma', 'comment_approved', 'comment_agent', 'comment_type', 'comment_parent', 'user_id' );
	if ( ! $wpdb->insert( $wpdb->comments, $compacted ) ) {
		return false;
	}

	$id = (int) $wpdb->insert_id;

	if ( $comment_approved == 1 ) {
		wp_update_comment_count( $comment_post_ID );

		foreach ( array( 'server', 'gmt', 'blog' ) as $timezone ) {
			wp_cache_delete( "lastcommentmodified:$timezone", 'timeinfo' );
		}
	}

	clean_comment_cache( $id );

	$comment = get_comment( $id );

	// If metadata is provided, store it.
	if ( isset( $commentdata['comment_meta'] ) && is_array( $commentdata['comment_meta'] ) ) {
		foreach ( $commentdata['comment_meta'] as $meta_key => $meta_value ) {
			add_comment_meta( $comment->comment_ID, $meta_key, $meta_value, true );
		}
	}

	/**
	 * Fires immediately after a comment is inserted into the database.
	 *
	 * @since 2.8.0
	 *
	 * @param int        $id      The comment ID.
	 * @param WP_Comment $comment Comment object.
	 */
	do_action( 'wp_insert_comment', $id, $comment );

	return $id;
}

/**
 * Filters and sanitizes comment data.
 *
 * Sets the comment data 'filtered' field to true when finished. This can be
 * checked as to whether the comment should be filtered and to keep from
 * filtering the same comment more than once.
 *
 * @since 2.0.0
 *
 * @param array $commentdata Contains information on the comment.
 * @return array Parsed comment information.
 */
function wp_filter_comment($commentdata) {
	if ( isset( $commentdata['user_ID'] ) ) {
		/**
		 * Filters the comment author's user id before it is set.
		 *
		 * The first time this filter is evaluated, 'user_ID' is checked
		 * (for back-compat), followed by the standard 'user_id' value.
		 *
		 * @since 1.5.0
		 *
		 * @param int $user_ID The comment author's user ID.
		 */
		$commentdata['user_id'] = apply_filters( 'pre_user_id', $commentdata['user_ID'] );
	} elseif ( isset( $commentdata['user_id'] ) ) {
		/** This filter is documented in wp-includes/comment.php */
		$commentdata['user_id'] = apply_filters( 'pre_user_id', $commentdata['user_id'] );
	}

	/**
	 * Filters the comment author's browser user agent before it is set.
	 *
	 * @since 1.5.0
	 *
	 * @param string $comment_agent The comment author's browser user agent.
	 */
	$commentdata['comment_agent'] = apply_filters( 'pre_comment_user_agent', ( isset( $commentdata['comment_agent'] ) ? $commentdata['comment_agent'] : '' ) );
	/** This filter is documented in wp-includes/comment.php */
	$commentdata['comment_author'] = apply_filters( 'pre_comment_author_name', $commentdata['comment_author'] );
	/**
	 * Filters the comment content before it is set.
	 *
	 * @since 1.5.0
	 *
	 * @param string $comment_content The comment content.
	 */
	$commentdata['comment_content'] = apply_filters( 'pre_comment_content', $commentdata['comment_content'] );
	/**
	 * Filters the comment author's IP address before it is set.
	 *
	 * @since 1.5.0
	 *
	 * @param string $comment_author_ip The comment author's IP address.
	 */
	$commentdata['comment_author_IP'] = apply_filters( 'pre_comment_user_ip', $commentdata['comment_author_IP'] );
	/** This filter is documented in wp-includes/comment.php */
	$commentdata['comment_author_url'] = apply_filters( 'pre_comment_author_url', $commentdata['comment_author_url'] );
	/** This filter is documented in wp-includes/comment.php */
	$commentdata['comment_author_email'] = apply_filters( 'pre_comment_author_email', $commentdata['comment_author_email'] );
	$commentdata['filtered'] = true;
	return $commentdata;
}

/**
 * Whether a comment should be blocked because of comment flood.
 *
 * @since 2.1.0
 *
 * @param bool $block Whether plugin has already blocked comment.
 * @param int $time_lastcomment Timestamp for last comment.
 * @param int $time_newcomment Timestamp for new comment.
 * @return bool Whether comment should be blocked.
 */
function wp_throttle_comment_flood($block, $time_lastcomment, $time_newcomment) {
	if ( $block ) // a plugin has already blocked... we'll let that decision stand
		return $block;
	if ( ($time_newcomment - $time_lastcomment) < 15 )
		return true;
	return false;
}

/**
 * Adds a new comment to the database.
 *
 * Filters new comment to ensure that the fields are sanitized and valid before
 * inserting comment into database. Calls {@see 'comment_post'} action with comment ID
 * and whether comment is approved by WordPress. Also has {@see 'preprocess_comment'}
 * filter for processing the comment data before the function handles it.
 *
 * We use `REMOTE_ADDR` here directly. If you are behind a proxy, you should ensure
 * that it is properly set, such as in wp-config.php, for your environment.
 *
 * See {@link https://core.trac.wordpress.org/ticket/9235}
 *
 * @since 1.5.0
 * @since 4.3.0 'comment_agent' and 'comment_author_IP' can be set via `$commentdata`.
 * @since 4.7.0 The `$avoid_die` parameter was added, allowing the function to
 *              return a WP_Error object instead of dying.
 *
 * @see wp_insert_comment()
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param array $commentdata {
 *     Comment data.
 *
 *     @type string $comment_author       The name of the comment author.
 *     @type string $comment_author_email The comment author email address.
 *     @type string $comment_author_url   The comment author URL.
 *     @type string $comment_content      The content of the comment.
 *     @type string $comment_date         The date the comment was submitted. Default is the current time.
 *     @type string $comment_date_gmt     The date the comment was submitted in the GMT timezone.
 *                                        Default is `$comment_date` in the GMT timezone.
 *     @type int    $comment_parent       The ID of this comment's parent, if any. Default 0.
 *     @type int    $comment_post_ID      The ID of the post that relates to the comment.
 *     @type int    $user_id              The ID of the user who submitted the comment. Default 0.
 *     @type int    $user_ID              Kept for backward-compatibility. Use `$user_id` instead.
 *     @type string $comment_agent        Comment author user agent. Default is the value of 'HTTP_USER_AGENT'
 *                                        in the `$_SERVER` superglobal sent in the original request.
 *     @type string $comment_author_IP    Comment author IP address in IPv4 format. Default is the value of
 *                                        'REMOTE_ADDR' in the `$_SERVER` superglobal sent in the original request.
 * }
 * @param bool $avoid_die Should errors be returned as WP_Error objects instead of
 *                        executing wp_die()? Default false.
 * @return int|false|WP_Error The ID of the comment on success, false or WP_Error on failure.
 */
function wp_new_comment( $commentdata, $avoid_die = false ) {
	global $wpdb;

	if ( isset( $commentdata['user_ID'] ) ) {
		$commentdata['user_id'] = $commentdata['user_ID'] = (int) $commentdata['user_ID'];
	}

	$prefiltered_user_id = ( isset( $commentdata['user_id'] ) ) ? (int) $commentdata['user_id'] : 0;

	/**
	 * Filters a comment's data before it is sanitized and inserted into the database.
	 *
	 * @since 1.5.0
	 *
	 * @param array $commentdata Comment data.
	 */
	$commentdata = apply_filters( 'preprocess_comment', $commentdata );

	$commentdata['comment_post_ID'] = (int) $commentdata['comment_post_ID'];
	if ( isset( $commentdata['user_ID'] ) && $prefiltered_user_id !== (int) $commentdata['user_ID'] ) {
		$commentdata['user_id'] = $commentdata['user_ID'] = (int) $commentdata['user_ID'];
	} elseif ( isset( $commentdata['user_id'] ) ) {
		$commentdata['user_id'] = (int) $commentdata['user_id'];
	}

	$commentdata['comment_parent'] = isset($commentdata['comment_parent']) ? absint($commentdata['comment_parent']) : 0;
	$parent_status = ( 0 < $commentdata['comment_parent'] ) ? wp_get_comment_status($commentdata['comment_parent']) : '';
	$commentdata['comment_parent'] = ( 'approved' == $parent_status || 'unapproved' == $parent_status ) ? $commentdata['comment_parent'] : 0;

	if ( ! isset( $commentdata['comment_author_IP'] ) ) {
		$commentdata['comment_author_IP'] = $_SERVER['REMOTE_ADDR'];
	}
	$commentdata['comment_author_IP'] = preg_replace( '/[^0-9a-fA-F:., ]/', '', $commentdata['comment_author_IP'] );

	if ( ! isset( $commentdata['comment_agent'] ) ) {
		$commentdata['comment_agent'] = isset( $_SERVER['HTTP_USER_AGENT'] ) ? $_SERVER['HTTP_USER_AGENT']: '';
	}
	$commentdata['comment_agent'] = substr( $commentdata['comment_agent'], 0, 254 );

	if ( empty( $commentdata['comment_date'] ) ) {
		$commentdata['comment_date'] = current_time('mysql');
	}

	if ( empty( $commentdata['comment_date_gmt'] ) ) {
		$commentdata['comment_date_gmt'] = current_time( 'mysql', 1 );
	}

	$commentdata = wp_filter_comment($commentdata);

	$commentdata['comment_approved'] = wp_allow_comment( $commentdata, $avoid_die );
	if ( is_wp_error( $commentdata['comment_approved'] ) ) {
		return $commentdata['comment_approved'];
	}

	$comment_ID = wp_insert_comment($commentdata);
	if ( ! $comment_ID ) {
		$fields = array( 'comment_author', 'comment_author_email', 'comment_author_url', 'comment_content' );

		foreach ( $fields as $field ) {
			if ( isset( $commentdata[ $field ] ) ) {
				$commentdata[ $field ] = $wpdb->strip_invalid_text_for_column( $wpdb->comments, $field, $commentdata[ $field ] );
			}
		}

		$commentdata = wp_filter_comment( $commentdata );

		$commentdata['comment_approved'] = wp_allow_comment( $commentdata, $avoid_die );
		if ( is_wp_error( $commentdata['comment_approved'] ) ) {
			return $commentdata['comment_approved'];
		}

		$comment_ID = wp_insert_comment( $commentdata );
		if ( ! $comment_ID ) {
			return false;
		}
	}

	/**
	 * Fires immediately after a comment is inserted into the database.
	 *
	 * @since 1.2.0
	 * @since 4.5.0 The `$commentdata` parameter was added.
	 *
	 * @param int        $comment_ID       The comment ID.
	 * @param int|string $comment_approved 1 if the comment is approved, 0 if not, 'spam' if spam.
	 * @param array      $commentdata      Comment data.
	 */
	do_action( 'comment_post', $comment_ID, $commentdata['comment_approved'], $commentdata );

	return $comment_ID;
}

/**
 * Send a comment moderation notification to the comment moderator.
 *
 * @since 4.4.0
 *
 * @param int $comment_ID ID of the comment.
 * @return bool True on success, false on failure.
 */
function wp_new_comment_notify_moderator( $comment_ID ) {
	$comment = get_comment( $comment_ID );

	// Only send notifications for pending comments.
	$maybe_notify = ( '0' == $comment->comment_approved );

	/** This filter is documented in wp-includes/comment.php */
	$maybe_notify = apply_filters( 'notify_moderator', $maybe_notify, $comment_ID );

	if ( ! $maybe_notify ) {
		return false;
	}

	return wp_notify_moderator( $comment_ID );
}

/**
 * Send a notification of a new comment to the post author.
 *
 * @since 4.4.0
 *
 * Uses the {@see 'notify_post_author'} filter to determine whether the post author
 * should be notified when a new comment is added, overriding site setting.
 *
 * @param int $comment_ID Comment ID.
 * @return bool True on success, false on failure.
 */
function wp_new_comment_notify_postauthor( $comment_ID ) {
	$comment = get_comment( $comment_ID );

	$maybe_notify = get_option( 'comments_notify' );

	/**
	 * Filters whether to send the post author new comment notification emails,
	 * overriding the site setting.
	 *
	 * @since 4.4.0
	 *
	 * @param bool $maybe_notify Whether to notify the post author about the new comment.
	 * @param int  $comment_ID   The ID of the comment for the notification.
	 */
	$maybe_notify = apply_filters( 'notify_post_author', $maybe_notify, $comment_ID );

	/*
	 * wp_notify_postauthor() checks if notifying the author of their own comment.
	 * By default, it won't, but filters can override this.
	 */
	if ( ! $maybe_notify ) {
		return false;
	}

	// Only send notifications for approved comments.
	if ( ! isset( $comment->comment_approved ) || '1' != $comment->comment_approved ) {
		return false;
	}

	return wp_notify_postauthor( $comment_ID );
}

/**
 * Sets the status of a comment.
 *
 * The {@see 'wp_set_comment_status'} action is called after the comment is handled.
 * If the comment status is not in the list, then false is returned.
 *
 * @since 1.0.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param int|WP_Comment $comment_id     Comment ID or WP_Comment object.
 * @param string         $comment_status New comment status, either 'hold', 'approve', 'spam', or 'trash'.
 * @param bool           $wp_error       Whether to return a WP_Error object if there is a failure. Default is false.
 * @return bool|WP_Error True on success, false or WP_Error on failure.
 */
function wp_set_comment_status($comment_id, $comment_status, $wp_error = false) {
	global $wpdb;

	switch ( $comment_status ) {
		case 'hold':
		case '0':
			$status = '0';
			break;
		case 'approve':
		case '1':
			$status = '1';
			add_action( 'wp_set_comment_status', 'wp_new_comment_notify_postauthor' );
			break;
		case 'spam':
			$status = 'spam';
			break;
		case 'trash':
			$status = 'trash';
			break;
		default:
			return false;
	}

	$comment_old = clone get_comment($comment_id);

	if ( !$wpdb->update( $wpdb->comments, array('comment_approved' => $status), array( 'comment_ID' => $comment_old->comment_ID ) ) ) {
		if ( $wp_error )
			return new WP_Error('db_update_error', __('Could not update comment status'), $wpdb->last_error);
		else
			return false;
	}

	clean_comment_cache( $comment_old->comment_ID );

	$comment = get_comment( $comment_old->comment_ID );

	/**
	 * Fires immediately before transitioning a comment's status from one to another
	 * in the database.
	 *
	 * @since 1.5.0
	 *
	 * @param int         $comment_id     Comment ID.
	 * @param string|bool $comment_status Current comment status. Possible values include
	 *                                    'hold', 'approve', 'spam', 'trash', or false.
	 */
	do_action( 'wp_set_comment_status', $comment->comment_ID, $comment_status );

	wp_transition_comment_status($comment_status, $comment_old->comment_approved, $comment);

	wp_update_comment_count($comment->comment_post_ID);

	return true;
}

/**
 * Updates an existing comment in the database.
 *
 * Filters the comment and makes sure certain fields are valid before updating.
 *
 * @since 2.0.0
 * @since 4.9.0 Add updating comment meta during comment update.
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param array $commentarr Contains information on the comment.
 * @return int Comment was updated if value is 1, or was not updated if value is 0.
 */
function wp_update_comment($commentarr) {
	global $wpdb;

	// First, get all of the original fields
	$comment = get_comment($commentarr['comment_ID'], ARRAY_A);
	if ( empty( $comment ) ) {
		return 0;
	}

	// Make sure that the comment post ID is valid (if specified).
	if ( ! empty( $commentarr['comment_post_ID'] ) && ! get_post( $commentarr['comment_post_ID'] ) ) {
		return 0;
	}

	$filter_comment = false;
	if ( ! has_filter( 'pre_comment_content', 'wp_filter_kses' ) ) {
		$filter_comment = ! user_can( isset( $comment['user_id'] ) ? $comment['user_id'] : 0, 'unfiltered_html' );
	}

	if ( $filter_comment ) {
		add_filter( 'pre_comment_content', 'wp_filter_kses' );
	}

	// Escape data pulled from DB.
	$comment = wp_slash($comment);

	$old_status = $comment['comment_approved'];

	// Merge old and new fields with new fields overwriting old ones.
	$commentarr = array_merge($comment, $commentarr);

	$commentarr = wp_filter_comment( $commentarr );

	if ( $filter_comment ) {
		remove_filter( 'pre_comment_content', 'wp_filter_kses' );
	}

	// Now extract the merged array.
	$data = wp_unslash( $commentarr );

	/**
	 * Filters the comment content before it is updated in the database.
	 *
	 * @since 1.5.0
	 *
	 * @param string $comment_content The comment data.
	 */
	$data['comment_content'] = apply_filters( 'comment_save_pre', $data['comment_content'] );

	$data['comment_date_gmt'] = get_gmt_from_date( $data['comment_date'] );

	if ( ! isset( $data['comment_approved'] ) ) {
		$data['comment_approved'] = 1;
	} elseif ( 'hold' == $data['comment_approved'] ) {
		$data['comment_approved'] = 0;
	} elseif ( 'approve' == $data['comment_approved'] ) {
		$data['comment_approved'] = 1;
	}

	$comment_ID = $data['comment_ID'];
	$comment_post_ID = $data['comment_post_ID'];

	/**
	 * Filters the comment data immediately before it is updated in the database.
	 *
	 * Note: data being passed to the filter is already unslashed.
	 *
	 * @since 4.7.0
	 *
	 * @param array $data       The new, processed comment data.
	 * @param array $comment    The old, unslashed comment data.
	 * @param array $commentarr The new, raw comment data.
	 */
	$data = apply_filters( 'wp_update_comment_data', $data, $comment, $commentarr );

	$keys = array( 'comment_post_ID', 'comment_content', 'comment_author', 'comment_author_email', 'comment_approved', 'comment_karma', 'comment_author_url', 'comment_date', 'comment_date_gmt', 'comment_type', 'comment_parent', 'user_id', 'comment_agent', 'comment_author_IP' );
	$data = wp_array_slice_assoc( $data, $keys );

	$rval = $wpdb->update( $wpdb->comments, $data, compact( 'comment_ID' ) );

	// If metadata is provided, store it.
	if ( isset( $commentarr['comment_meta'] ) && is_array( $commentarr['comment_meta'] ) ) {
		foreach ( $commentarr['comment_meta'] as $meta_key => $meta_value ) {
			update_comment_meta( $comment_ID, $meta_key, $meta_value );
		}
	}

	clean_comment_cache( $comment_ID );
	wp_update_comment_count( $comment_post_ID );
	/**
	 * Fires immediately after a comment is updated in the database.
	 *
	 * The hook also fires immediately before comment status transition hooks are fired.
	 *
	 * @since 1.2.0
	 * @since 4.6.0 Added the `$data` parameter.
	 *
	 * @param int   $comment_ID The comment ID.
	 * @param array $data       Comment data.
	 */
	do_action( 'edit_comment', $comment_ID, $data );
	$comment = get_comment($comment_ID);
	wp_transition_comment_status($comment->comment_approved, $old_status, $comment);
	return $rval;
}

/**
 * Whether to defer comment counting.
 *
 * When setting $defer to true, all post comment counts will not be updated
 * until $defer is set to false. When $defer is set to false, then all
 * previously deferred updated post comment counts will then be automatically
 * updated without having to call wp_update_comment_count() after.
 *
 * @since 2.5.0
 * @staticvar bool $_defer
 *
 * @param bool $defer
 * @return bool
 */
function wp_defer_comment_counting($defer=null) {
	static $_defer = false;

	if ( is_bool($defer) ) {
		$_defer = $defer;
		// flush any deferred counts
		if ( !$defer )
			wp_update_comment_count( null, true );
	}

	return $_defer;
}

/**
 * Updates the comment count for post(s).
 *
 * When $do_deferred is false (is by default) and the comments have been set to
 * be deferred, the post_id will be added to a queue, which will be updated at a
 * later date and only updated once per post ID.
 *
 * If the comments have not be set up to be deferred, then the post will be
 * updated. When $do_deferred is set to true, then all previous deferred post
 * IDs will be updated along with the current $post_id.
 *
 * @since 2.1.0
 * @see wp_update_comment_count_now() For what could cause a false return value
 *
 * @staticvar array $_deferred
 *
 * @param int|null $post_id     Post ID.
 * @param bool     $do_deferred Optional. Whether to process previously deferred
 *                              post comment counts. Default false.
 * @return bool|void True on success, false on failure or if post with ID does
 *                   not exist.
 */
function wp_update_comment_count($post_id, $do_deferred=false) {
	static $_deferred = array();

	if ( empty( $post_id ) && ! $do_deferred ) {
		return false;
	}

	if ( $do_deferred ) {
		$_deferred = array_unique($_deferred);
		foreach ( $_deferred as $i => $_post_id ) {
			wp_update_comment_count_now($_post_id);
			unset( $_deferred[$i] ); /** @todo Move this outside of the foreach and reset $_deferred to an array instead */
		}
	}

	if ( wp_defer_comment_counting() ) {
		$_deferred[] = $post_id;
		return true;
	}
	elseif ( $post_id ) {
		return wp_update_comment_count_now($post_id);
	}

}

/**
 * Updates the comment count for the post.
 *
 * @since 2.5.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param int $post_id Post ID
 * @return bool True on success, false on '0' $post_id or if post with ID does not exist.
 */
function wp_update_comment_count_now($post_id) {
	global $wpdb;
	$post_id = (int) $post_id;
	if ( !$post_id )
		return false;

	wp_cache_delete( 'comments-0', 'counts' );
	wp_cache_delete( "comments-{$post_id}", 'counts' );

	if ( !$post = get_post($post_id) )
		return false;

	$old = (int) $post->comment_count;

	/**
	 * Filters a post's comment count before it is updated in the database.
	 *
	 * @since 4.5.0
	 *
	 * @param int $new     The new comment count. Default null.
	 * @param int $old     The old comment count.
	 * @param int $post_id Post ID.
	 */
	$new = apply_filters( 'pre_wp_update_comment_count_now', null, $old, $post_id );

	if ( is_null( $new ) ) {
		$new = (int) $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(*) FROM $wpdb->comments WHERE comment_post_ID = %d AND comment_approved = '1'", $post_id ) );
	} else {
		$new = (int) $new;
	}

	$wpdb->update( $wpdb->posts, array('comment_count' => $new), array('ID' => $post_id) );

	clean_post_cache( $post );

	/**
	 * Fires immediately after a post's comment count is updated in the database.
	 *
	 * @since 2.3.0
	 *
	 * @param int $post_id Post ID.
	 * @param int $new     The new comment count.
	 * @param int $old     The old comment count.
	 */
	do_action( 'wp_update_comment_count', $post_id, $new, $old );
	/** This action is documented in wp-includes/post.php */
	do_action( 'edit_post', $post_id, $post );

	return true;
}

//
// Ping and trackback functions.
//

/**
 * Finds a pingback server URI based on the given URL.
 *
 * Checks the HTML for the rel="pingback" link and x-pingback headers. It does
 * a check for the x-pingback headers first and returns that, if available. The
 * check for the rel="pingback" has more overhead than just the header.
 *
 * @since 1.5.0
 *
 * @param string $url URL to ping.
 * @param int $deprecated Not Used.
 * @return false|string False on failure, string containing URI on success.
 */
function discover_pingback_server_uri( $url, $deprecated = '' ) {
	if ( !empty( $deprecated ) )
		_deprecated_argument( __FUNCTION__, '2.7.0' );

	$pingback_str_dquote = 'rel="pingback"';
	$pingback_str_squote = 'rel=\'pingback\'';

	/** @todo Should use Filter Extension or custom preg_match instead. */
	$parsed_url = parse_url($url);

	if ( ! isset( $parsed_url['host'] ) ) // Not a URL. This should never happen.
		return false;

	//Do not search for a pingback server on our own uploads
	$uploads_dir = wp_get_upload_dir();
	if ( 0 === strpos($url, $uploads_dir['baseurl']) )
		return false;

	$response = wp_safe_remote_head( $url, array( 'timeout' => 2, 'httpversion' => '1.0' ) );

	if ( is_wp_error( $response ) )
		return false;

	if ( wp_remote_retrieve_header( $response, 'x-pingback' ) )
		return wp_remote_retrieve_header( $response, 'x-pingback' );

	// Not an (x)html, sgml, or xml page, no use going further.
	if ( preg_match('#(image|audio|video|model)/#is', wp_remote_retrieve_header( $response, 'content-type' )) )
		return false;

	// Now do a GET since we're going to look in the html headers (and we're sure it's not a binary file)
	$response = wp_safe_remote_get( $url, array( 'timeout' => 2, 'httpversion' => '1.0' ) );

	if ( is_wp_error( $response ) )
		return false;

	$contents = wp_remote_retrieve_body( $response );

	$pingback_link_offset_dquote = strpos($contents, $pingback_str_dquote);
	$pingback_link_offset_squote = strpos($contents, $pingback_str_squote);
	if ( $pingback_link_offset_dquote || $pingback_link_offset_squote ) {
		$quote = ($pingback_link_offset_dquote) ? '"' : '\'';
		$pingback_link_offset = ($quote=='"') ? $pingback_link_offset_dquote : $pingback_link_offset_squote;
		$pingback_href_pos = @strpos($contents, 'href=', $pingback_link_offset);
		$pingback_href_start = $pingback_href_pos+6;
		$pingback_href_end = @strpos($contents, $quote, $pingback_href_start);
		$pingback_server_url_len = $pingback_href_end - $pingback_href_start;
		$pingback_server_url = substr($contents, $pingback_href_start, $pingback_server_url_len);

		// We may find rel="pingback" but an incomplete pingback URL
		if ( $pingback_server_url_len > 0 ) { // We got it!
			return $pingback_server_url;
		}
	}

	return false;
}

/**
 * Perform all pingbacks, enclosures, trackbacks, and send to pingback services.
 *
 * @since 2.1.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 */
function do_all_pings() {
	global $wpdb;

	// Do pingbacks
	while ($ping = $wpdb->get_row("SELECT ID, post_content, meta_id FROM {$wpdb->posts}, {$wpdb->postmeta} WHERE {$wpdb->posts}.ID = {$wpdb->postmeta}.post_id AND {$wpdb->postmeta}.meta_key = '_pingme' LIMIT 1")) {
		delete_metadata_by_mid( 'post', $ping->meta_id );
		pingback( $ping->post_content, $ping->ID );
	}

	// Do Enclosures
	while ($enclosure = $wpdb->get_row("SELECT ID, post_content, meta_id FROM {$wpdb->posts}, {$wpdb->postmeta} WHERE {$wpdb->posts}.ID = {$wpdb->postmeta}.post_id AND {$wpdb->postmeta}.meta_key = '_encloseme' LIMIT 1")) {
		delete_metadata_by_mid( 'post', $enclosure->meta_id );
		do_enclose( $enclosure->post_content, $enclosure->ID );
	}

	// Do Trackbacks
	$trackbacks = $wpdb->get_col("SELECT ID FROM $wpdb->posts WHERE to_ping <> '' AND post_status = 'publish'");
	if ( is_array($trackbacks) )
		foreach ( $trackbacks as $trackback )
			do_trackbacks($trackback);

	//Do Update Services/Generic Pings
	generic_ping();
}

/**
 * Perform trackbacks.
 *
 * @since 1.5.0
 * @since 4.7.0 $post_id can be a WP_Post object.
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param int|WP_Post $post_id Post object or ID to do trackbacks on.
 */
function do_trackbacks( $post_id ) {
	global $wpdb;
	$post = get_post( $post_id );
	if ( ! $post ) {
		return false;
	}

	$to_ping = get_to_ping( $post );
	$pinged  = get_pung( $post );
	if ( empty( $to_ping ) ) {
		$wpdb->update($wpdb->posts, array( 'to_ping' => '' ), array( 'ID' => $post->ID ) );
		return;
	}

	if ( empty($post->post_excerpt) ) {
		/** This filter is documented in wp-includes/post-template.php */
		$excerpt = apply_filters( 'the_content', $post->post_content, $post->ID );
	} else {
		/** This filter is documented in wp-includes/post-template.php */
		$excerpt = apply_filters( 'the_excerpt', $post->post_excerpt );
	}

	$excerpt = str_replace(']]>', ']]&gt;', $excerpt);
	$excerpt = wp_html_excerpt($excerpt, 252, '&#8230;');

	/** This filter is documented in wp-includes/post-template.php */
	$post_title = apply_filters( 'the_title', $post->post_title, $post->ID );
	$post_title = strip_tags($post_title);

	if ( $to_ping ) {
		foreach ( (array) $to_ping as $tb_ping ) {
			$tb_ping = trim($tb_ping);
			if ( !in_array($tb_ping, $pinged) ) {
				trackback( $tb_ping, $post_title, $excerpt, $post->ID );
				$pinged[] = $tb_ping;
			} else {
				$wpdb->query( $wpdb->prepare( "UPDATE $wpdb->posts SET to_ping = TRIM(REPLACE(to_ping, %s,
					'')) WHERE ID = %d", $tb_ping, $post->ID ) );
			}
		}
	}
}

/**
 * Sends pings to all of the ping site services.
 *
 * @since 1.2.0
 *
 * @param int $post_id Post ID.
 * @return int Same as Post ID from parameter
 */
function generic_ping( $post_id = 0 ) {
	$services = get_option('ping_sites');

	$services = explode("\n", $services);
	foreach ( (array) $services as $service ) {
		$service = trim($service);
		if ( '' != $service )
			weblog_ping($service);
	}

	return $post_id;
}

/**
 * Pings back the links found in a post.
 *
 * @since 0.71
 * @since 4.7.0 $post_id can be a WP_Post object.
 *
 * @param string $content Post content to check for links. If empty will retrieve from post.
 * @param int|WP_Post $post_id Post Object or ID.
 */
function pingback( $content, $post_id ) {
	include_once( ABSPATH . WPINC . '/class-IXR.php' );
	include_once( ABSPATH . WPINC . '/class-wp-http-ixr-client.php' );

	// original code by Mort (http://mort.mine.nu:8080)
	$post_links = array();

	$post = get_post( $post_id );
	if ( ! $post ) {
		return;
	}

	$pung = get_pung( $post );

	if ( empty( $content ) ) {
		$content = $post->post_content;
	}

	// Step 1
	// Parsing the post, external links (if any) are stored in the $post_links array
	$post_links_temp = wp_extract_urls( $content );

	// Step 2.
	// Walking thru the links array
	// first we get rid of links pointing to sites, not to specific files
	// Example:
	// http://dummy-weblog.org
	// http://dummy-weblog.org/
	// http://dummy-weblog.org/post.php
	// We don't wanna ping first and second types, even if they have a valid <link/>

	foreach ( (array) $post_links_temp as $link_test ) :
		if ( ! in_array( $link_test, $pung ) && ( url_to_postid( $link_test ) != $post->ID ) // If we haven't pung it already and it isn't a link to itself
				&& !is_local_attachment($link_test) ) : // Also, let's never ping local attachments.
			if ( $test = @parse_url($link_test) ) {
				if ( isset($test['query']) )
					$post_links[] = $link_test;
				elseif ( isset( $test['path'] ) && ( $test['path'] != '/' ) && ( $test['path'] != '' ) )
					$post_links[] = $link_test;
			}
		endif;
	endforeach;

	$post_links = array_unique( $post_links );
	/**
	 * Fires just before pinging back links found in a post.
	 *
	 * @since 2.0.0
	 *
	 * @param array $post_links An array of post links to be checked (passed by reference).
	 * @param array $pung       Whether a link has already been pinged (passed by reference).
	 * @param int   $post_ID    The post ID.
	 */
	do_action_ref_array( 'pre_ping', array( &$post_links, &$pung, $post->ID ) );

	foreach ( (array) $post_links as $pagelinkedto ) {
		$pingback_server_url = discover_pingback_server_uri( $pagelinkedto );

		if ( $pingback_server_url ) {
			@ set_time_limit( 60 );
			// Now, the RPC call
			$pagelinkedfrom = get_permalink( $post );

			// using a timeout of 3 seconds should be enough to cover slow servers
			$client = new WP_HTTP_IXR_Client($pingback_server_url);
			$client->timeout = 3;
			/**
			 * Filters the user agent sent when pinging-back a URL.
			 *
			 * @since 2.9.0
			 *
			 * @param string $concat_useragent    The user agent concatenated with ' -- WordPress/'
			 *                                    and the WordPress version.
			 * @param string $useragent           The useragent.
			 * @param string $pingback_server_url The server URL being linked to.
			 * @param string $pagelinkedto        URL of page linked to.
			 * @param string $pagelinkedfrom      URL of page linked from.
			 */
			$client->useragent = apply_filters( 'pingback_useragent', $client->useragent . ' -- WordPress/' . get_bloginfo( 'version' ), $client->useragent, $pingback_server_url, $pagelinkedto, $pagelinkedfrom );
			// when set to true, this outputs debug messages by itself
			$client->debug = false;

			if ( $client->query('pingback.ping', $pagelinkedfrom, $pagelinkedto) || ( isset($client->error->code) && 48 == $client->error->code ) ) // Already registered
				add_ping( $post, $pagelinkedto );
		}
	}
}

/**
 * Check whether blog is public before returning sites.
 *
 * @since 2.1.0
 *
 * @param mixed $sites Will return if blog is public, will not return if not public.
 * @return mixed Empty string if blog is not public, returns $sites, if site is public.
 */
function privacy_ping_filter($sites) {
	if ( '0' != get_option('blog_public') )
		return $sites;
	else
		return '';
}

/**
 * Send a Trackback.
 *
 * Updates database when sending trackback to prevent duplicates.
 *
 * @since 0.71
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param string $trackback_url URL to send trackbacks.
 * @param string $title Title of post.
 * @param string $excerpt Excerpt of post.
 * @param int $ID Post ID.
 * @return int|false|void Database query from update.
 */
function trackback($trackback_url, $title, $excerpt, $ID) {
	global $wpdb;

	if ( empty($trackback_url) )
		return;

	$options = array();
	$options['timeout'] = 10;
	$options['body'] = array(
		'title' => $title,
		'url' => get_permalink($ID),
		'blog_name' => get_option('blogname'),
		'excerpt' => $excerpt
	);

	$response = wp_safe_remote_post( $trackback_url, $options );

	if ( is_wp_error( $response ) )
		return;

	$wpdb->query( $wpdb->prepare("UPDATE $wpdb->posts SET pinged = CONCAT(pinged, '\n', %s) WHERE ID = %d", $trackback_url, $ID) );
	return $wpdb->query( $wpdb->prepare("UPDATE $wpdb->posts SET to_ping = TRIM(REPLACE(to_ping, %s, '')) WHERE ID = %d", $trackback_url, $ID) );
}

/**
 * Send a pingback.
 *
 * @since 1.2.0
 *
 * @param string $server Host of blog to connect to.
 * @param string $path Path to send the ping.
 */
function weblog_ping($server = '', $path = '') {
	include_once( ABSPATH . WPINC . '/class-IXR.php' );
	include_once( ABSPATH . WPINC . '/class-wp-http-ixr-client.php' );

	// using a timeout of 3 seconds should be enough to cover slow servers
	$client = new WP_HTTP_IXR_Client($server, ((!strlen(trim($path)) || ('/' == $path)) ? false : $path));
	$client->timeout = 3;
	$client->useragent .= ' -- WordPress/' . get_bloginfo( 'version' );

	// when set to true, this outputs debug messages by itself
	$client->debug = false;
	$home = trailingslashit( home_url() );
	if ( !$client->query('weblogUpdates.extendedPing', get_option('blogname'), $home, get_bloginfo('rss2_url') ) ) // then try a normal ping
		$client->query('weblogUpdates.ping', get_option('blogname'), $home);
}

/**
 * Default filter attached to pingback_ping_source_uri to validate the pingback's Source URI
 *
 * @since 3.5.1
 * @see wp_http_validate_url()
 *
 * @param string $source_uri
 * @return string
 */
function pingback_ping_source_uri( $source_uri ) {
	return (string) wp_http_validate_url( $source_uri );
}

/**
 * Default filter attached to xmlrpc_pingback_error.
 *
 * Returns a generic pingback error code unless the error code is 48,
 * which reports that the pingback is already registered.
 *
 * @since 3.5.1
 * @link https://www.hixie.ch/specs/pingback/pingback#TOC3
 *
 * @param IXR_Error $ixr_error
 * @return IXR_Error
 */
function xmlrpc_pingback_error( $ixr_error ) {
	if ( $ixr_error->code === 48 )
		return $ixr_error;
	return new IXR_Error( 0, '' );
}

//
// Cache
//

/**
 * Removes a comment from the object cache.
 *
 * @since 2.3.0
 *
 * @param int|array $ids Comment ID or an array of comment IDs to remove from cache.
 */
function clean_comment_cache($ids) {
	foreach ( (array) $ids as $id ) {
		wp_cache_delete( $id, 'comment' );

		/**
		 * Fires immediately after a comment has been removed from the object cache.
		 *
		 * @since 4.5.0
		 *
		 * @param int $id Comment ID.
		 */
		do_action( 'clean_comment_cache', $id );
	}

	wp_cache_set( 'last_changed', microtime(), 'comment' );
}

/**
 * Updates the comment cache of given comments.
 *
 * Will add the comments in $comments to the cache. If comment ID already exists
 * in the comment cache then it will not be updated. The comment is added to the
 * cache using the comment group with the key using the ID of the comments.
 *
 * @since 2.3.0
 * @since 4.4.0 Introduced the `$update_meta_cache` parameter.
 *
 * @param array $comments          Array of comment row objects
 * @param bool  $update_meta_cache Whether to update commentmeta cache. Default true.
 */
function update_comment_cache( $comments, $update_meta_cache = true ) {
	foreach ( (array) $comments as $comment )
		wp_cache_add($comment->comment_ID, $comment, 'comment');

	if ( $update_meta_cache ) {
		// Avoid `wp_list_pluck()` in case `$comments` is passed by reference.
		$comment_ids = array();
		foreach ( $comments as $comment ) {
			$comment_ids[] = $comment->comment_ID;
		}
		update_meta_cache( 'comment', $comment_ids );
	}
}

/**
 * Adds any comments from the given IDs to the cache that do not already exist in cache.
 *
 * @since 4.4.0
 * @access private
 *
 * @see update_comment_cache()
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param array $comment_ids       Array of comment IDs.
 * @param bool  $update_meta_cache Optional. Whether to update the meta cache. Default true.
 */
function _prime_comment_caches( $comment_ids, $update_meta_cache = true ) {
	global $wpdb;

	$non_cached_ids = _get_non_cached_ids( $comment_ids, 'comment' );
	if ( !empty( $non_cached_ids ) ) {
		$fresh_comments = $wpdb->get_results( sprintf( "SELECT $wpdb->comments.* FROM $wpdb->comments WHERE comment_ID IN (%s)", join( ",", array_map( 'intval', $non_cached_ids ) ) ) );

		update_comment_cache( $fresh_comments, $update_meta_cache );
	}
}

//
// Internal
//

/**
 * Close comments on old posts on the fly, without any extra DB queries. Hooked to the_posts.
 *
 * @access private
 * @since 2.7.0
 *
 * @param WP_Post  $posts Post data object.
 * @param WP_Query $query Query object.
 * @return array
 */
function _close_comments_for_old_posts( $posts, $query ) {
	if ( empty( $posts ) || ! $query->is_singular() || ! get_option( 'close_comments_for_old_posts' ) )
		return $posts;

	/**
	 * Filters the list of post types to automatically close comments for.
	 *
	 * @since 3.2.0
	 *
	 * @param array $post_types An array of registered post types. Default array with 'post'.
	 */
	$post_types = apply_filters( 'close_comments_for_post_types', array( 'post' ) );
	if ( ! in_array( $posts[0]->post_type, $post_types ) )
		return $posts;

	$days_old = (int) get_option( 'close_comments_days_old' );
	if ( ! $days_old )
		return $posts;

	if ( time() - strtotime( $posts[0]->post_date_gmt ) > ( $days_old * DAY_IN_SECONDS ) ) {
		$posts[0]->comment_status = 'closed';
		$posts[0]->ping_status = 'closed';
	}

	return $posts;
}

/**
 * Close comments on an old post. Hooked to comments_open and pings_open.
 *
 * @access private
 * @since 2.7.0
 *
 * @param bool $open Comments open or closed
 * @param int $post_id Post ID
 * @return bool $open
 */
function _close_comments_for_old_post( $open, $post_id ) {
	if ( ! $open )
		return $open;

	if ( !get_option('close_comments_for_old_posts') )
		return $open;

	$days_old = (int) get_option('close_comments_days_old');
	if ( !$days_old )
		return $open;

	$post = get_post($post_id);

	/** This filter is documented in wp-includes/comment.php */
	$post_types = apply_filters( 'close_comments_for_post_types', array( 'post' ) );
	if ( ! in_array( $post->post_type, $post_types ) )
		return $open;

	// Undated drafts should not show up as comments closed.
	if ( '0000-00-00 00:00:00' === $post->post_date_gmt ) {
		return $open;
	}

	if ( time() - strtotime( $post->post_date_gmt ) > ( $days_old * DAY_IN_SECONDS ) )
		return false;

	return $open;
}

/**
 * Handles the submission of a comment, usually posted to wp-comments-post.php via a comment form.
 *
 * This function expects unslashed data, as opposed to functions such as `wp_new_comment()` which
 * expect slashed data.
 *
 * @since 4.4.0
 *
 * @param array $comment_data {
 *     Comment data.
 *
 *     @type string|int $comment_post_ID             The ID of the post that relates to the comment.
 *     @type string     $author                      The name of the comment author.
 *     @type string     $email                       The comment author email address.
 *     @type string     $url                         The comment author URL.
 *     @type string     $comment                     The content of the comment.
 *     @type string|int $comment_parent              The ID of this comment's parent, if any. Default 0.
 *     @type string     $_wp_unfiltered_html_comment The nonce value for allowing unfiltered HTML.
 * }
 * @return WP_Comment|WP_Error A WP_Comment object on success, a WP_Error object on failure.
 */
function wp_handle_comment_submission( $comment_data ) {

	$comment_post_ID = $comment_parent = 0;
	$comment_author = $comment_author_email = $comment_author_url = $comment_content = null;

	if ( isset( $comment_data['comment_post_ID'] ) ) {
		$comment_post_ID = (int) $comment_data['comment_post_ID'];
	}
	if ( isset( $comment_data['author'] ) && is_string( $comment_data['author'] ) ) {
		$comment_author = trim( strip_tags( $comment_data['author'] ) );
	}
	if ( isset( $comment_data['email'] ) && is_string( $comment_data['email'] ) ) {
		$comment_author_email = trim( $comment_data['email'] );
	}
	if ( isset( $comment_data['url'] ) && is_string( $comment_data['url'] ) ) {
		$comment_author_url = trim( $comment_data['url'] );
	}
	if ( isset( $comment_data['comment'] ) && is_string( $comment_data['comment'] ) ) {
		$comment_content = trim( $comment_data['comment'] );
	}
	if ( isset( $comment_data['comment_parent'] ) ) {
		$comment_parent = absint( $comment_data['comment_parent'] );
	}

	$post = get_post( $comment_post_ID );

	if ( empty( $post->comment_status ) ) {

		/**
		 * Fires when a comment is attempted on a post that does not exist.
		 *
		 * @since 1.5.0
		 *
		 * @param int $comment_post_ID Post ID.
		 */
		do_action( 'comment_id_not_found', $comment_post_ID );

		return new WP_Error( 'comment_id_not_found' );

	}

	// get_post_status() will get the parent status for attachments.
	$status = get_post_status( $post );

	if ( ( 'private' == $status ) && ! current_user_can( 'read_post', $comment_post_ID ) ) {
		return new WP_Error( 'comment_id_not_found' );
	}

	$status_obj = get_post_status_object( $status );

	if ( ! comments_open( $comment_post_ID ) ) {

		/**
		 * Fires when a comment is attempted on a post that has comments closed.
		 *
		 * @since 1.5.0
		 *
		 * @param int $comment_post_ID Post ID.
		 */
		do_action( 'comment_closed', $comment_post_ID );

		return new WP_Error( 'comment_closed', __( 'Sorry, comments are closed for this item.' ), 403 );

	} elseif ( 'trash' == $status ) {

		/**
		 * Fires when a comment is attempted on a trashed post.
		 *
		 * @since 2.9.0
		 *
		 * @param int $comment_post_ID Post ID.
		 */
		do_action( 'comment_on_trash', $comment_post_ID );

		return new WP_Error( 'comment_on_trash' );

	} elseif ( ! $status_obj->public && ! $status_obj->private ) {

		/**
		 * Fires when a comment is attempted on a post in draft mode.
		 *
		 * @since 1.5.1
		 *
		 * @param int $comment_post_ID Post ID.
		 */
		do_action( 'comment_on_draft', $comment_post_ID );
		
		if ( current_user_can( 'read_post', $comment_post_ID ) ) {
			return new WP_Error( 'comment_on_draft', __( 'Sorry, comments are not allowed for this item.' ), 403 );
		} else {
			return new WP_Error( 'comment_on_draft' );
		}

	} elseif ( post_password_required( $comment_post_ID ) ) {

		/**
		 * Fires when a comment is attempted on a password-protected post.
		 *
		 * @since 2.9.0
		 *
		 * @param int $comment_post_ID Post ID.
		 */
		do_action( 'comment_on_password_protected', $comment_post_ID );

		return new WP_Error( 'comment_on_password_protected' );

	} else {

		/**
		 * Fires before a comment is posted.
		 *
		 * @since 2.8.0
		 *
		 * @param int $comment_post_ID Post ID.
		 */
		do_action( 'pre_comment_on_post', $comment_post_ID );

	}

	// If the user is logged in
	$user = wp_get_current_user();
	if ( $user->exists() ) {
		if ( empty( $user->display_name ) ) {
			$user->display_name=$user->user_login;
		}
		$comment_author       = $user->display_name;
		$comment_author_email = $user->user_email;
		$comment_author_url   = $user->user_url;
		$user_ID              = $user->ID;
		if ( current_user_can( 'unfiltered_html' ) ) {
			if ( ! isset( $comment_data['_wp_unfiltered_html_comment'] )
				|| ! wp_verify_nonce( $comment_data['_wp_unfiltered_html_comment'], 'unfiltered-html-comment_' . $comment_post_ID )
			) {
				kses_remove_filters(); // start with a clean slate
				kses_init_filters(); // set up the filters
				remove_filter( 'pre_comment_content', 'wp_filter_post_kses' );
				add_filter( 'pre_comment_content', 'wp_filter_kses' );
			}
		}
	} else {
		if ( get_option( 'comment_registration' ) ) {
			return new WP_Error( 'not_logged_in', __( 'Sorry, you must be logged in to comment.' ), 403 );
		}
	}

	$comment_type = '';

	if ( get_option( 'require_name_email' ) && ! $user->exists() ) {
		if ( '' == $comment_author_email || '' == $comment_author ) {
			return new WP_Error( 'require_name_email', __( '<strong>ERROR</strong>: please fill the required fields (name, email).' ), 200 );
		} elseif ( ! is_email( $comment_author_email ) ) {
			return new WP_Error( 'require_valid_email', __( '<strong>ERROR</strong>: please enter a valid email address.' ), 200 );
		}
	}

	if ( '' == $comment_content ) {
		return new WP_Error( 'require_valid_comment', __( '<strong>ERROR</strong>: please type a comment.' ), 200 );
	}

	$commentdata = compact(
		'comment_post_ID',
		'comment_author',
		'comment_author_email',
		'comment_author_url',
		'comment_content',
		'comment_type',
		'comment_parent',
		'user_ID'
	);

	$check_max_lengths = wp_check_comment_data_max_lengths( $commentdata );
	if ( is_wp_error( $check_max_lengths ) ) {
		return $check_max_lengths;
	}

	$comment_id = wp_new_comment( wp_slash( $commentdata ), true );
	if ( is_wp_error( $comment_id ) ) {
		return $comment_id;
	}

	if ( ! $comment_id ) {
		return new WP_Error( 'comment_save_error', __( '<strong>ERROR</strong>: The comment could not be saved. Please try again later.' ), 500 );
	}

	return get_comment( $comment_id );
}

/**
 * Registers the personal data exporter for comments.
 *
 * @since 4.9.6
 *
 * @param array $exporters An array of personal data exporters.
 * @return array $exporters An array of personal data exporters.
 */
function wp_register_comment_personal_data_exporter( $exporters ) {
	$exporters['wordpress-comments'] = array(
		'exporter_friendly_name' => __( 'WordPress Comments' ),
		'callback'               => 'wp_comments_personal_data_exporter',
	);

	return $exporters;
}

/**
 * Finds and exports personal data associated with an email address from the comments table.
 *
 * @since 4.9.6
 *
 * @param string $email_address The comment author email address.
 * @param int    $page          Comment page.
 * @return array $return An array of personal data.
 */
function wp_comments_personal_data_exporter( $email_address, $page = 1 ) {
	// Limit us to 500 comments at a time to avoid timing out.
	$number = 500;
	$page   = (int) $page;

	$data_to_export = array();

	$comments = get_comments(
		array(
			'author_email'              => $email_address,
			'number'                    => $number,
			'paged'                     => $page,
			'order_by'                  => 'comment_ID',
			'order'                     => 'ASC',
			'update_comment_meta_cache' => false,
		)
	);

	$comment_prop_to_export = array(
		'comment_author'       => __( 'Comment Author' ),
		'comment_author_email' => __( 'Comment Author Email' ),
		'comment_author_url'   => __( 'Comment Author URL' ),
		'comment_author_IP'    => __( 'Comment Author IP' ),
		'comment_agent'        => __( 'Comment Author User Agent' ),
		'comment_date'         => __( 'Comment Date' ),
		'comment_content'      => __( 'Comment Content' ),
		'comment_link'         => __( 'Comment URL' ),
	);

	foreach ( (array) $comments as $comment ) {
		$comment_data_to_export = array();

		foreach ( $comment_prop_to_export as $key => $name ) {
			$value = '';

			switch ( $key ) {
				case 'comment_author':
				case 'comment_author_email':
				case 'comment_author_url':
				case 'comment_author_IP':
				case 'comment_agent':
				case 'comment_date':
					$value = $comment->{$key};
					break;

				case 'comment_content':
					$value = get_comment_text( $comment->comment_ID );
					break;

				case 'comment_link':
					$value = get_comment_link( $comment->comment_ID );
					$value = sprintf(
						'<a href="%s" target="_blank" rel="noreferrer noopener">%s</a>',
						esc_url( $value ),
						esc_html( $value )
					);
					break;
			}

			if ( ! empty( $value ) ) {
				$comment_data_to_export[] = array(
					'name'  => $name,
					'value' => $value,
				);
			}
		}

		$data_to_export[] = array(
			'group_id'    => 'comments',
			'group_label' => __( 'Comments' ),
			'item_id'     => "comment-{$comment->comment_ID}",
			'data'        => $comment_data_to_export,
		);
	}

	$done = count( $comments ) < $number;

	return array(
		'data' => $data_to_export,
		'done' => $done,
	);
}

/**
 * Registers the personal data eraser for comments.
 *
 * @since 4.9.6
 *
 * @param  array $erasers An array of personal data erasers.
 * @return array $erasers An array of personal data erasers.
 */
function wp_register_comment_personal_data_eraser( $erasers ) {
	$erasers['wordpress-comments'] = array(
		'eraser_friendly_name' => __( 'WordPress Comments' ),
		'callback'             => 'wp_comments_personal_data_eraser',
	);

	return $erasers;
}

/**
 * Erases personal data associated with an email address from the comments table.
 *
 * @since 4.9.6
 *
 * @param  string $email_address The comment author email address.
 * @param  int    $page          Comment page.
 * @return array
 */
function wp_comments_personal_data_eraser( $email_address, $page = 1 ) {
	global $wpdb;

	if ( empty( $email_address ) ) {
		return array(
			'items_removed'  => false,
			'items_retained' => false,
			'messages'       => array(),
			'done'           => true,
		);
	}

	// Limit us to 500 comments at a time to avoid timing out.
	$number         = 500;
	$page           = (int) $page;
	$items_removed  = false;
	$items_retained = false;

	$comments = get_comments(
		array(
			'author_email'       => $email_address,
			'number'             => $number,
			'paged'              => $page,
			'order_by'           => 'comment_ID',
			'order'              => 'ASC',
			'include_unapproved' => true,
		)
	);

	/* translators: Name of a comment's author after being anonymized. */
	$anon_author = __( 'Anonymous' );
	$messages    = array();

	foreach ( (array) $comments as $comment ) {
		$anonymized_comment                         = array();
		$anonymized_comment['comment_agent']        = '';
		$anonymized_comment['comment_author']       = $anon_author;
		$anonymized_comment['comment_author_email'] = '';
		$anonymized_comment['comment_author_IP']    = wp_privacy_anonymize_data( 'ip', $comment->comment_author_IP );
		$anonymized_comment['comment_author_url']   = '';
		$anonymized_comment['user_id']              = 0;

		$comment_id = (int) $comment->comment_ID;

		/**
		 * Filters whether to anonymize the comment.
		 *
		 * @since 4.9.6
		 *
		 * @param bool|string                    Whether to apply the comment anonymization (bool).
		 *                                       Custom prevention message (string). Default true.
		 * @param WP_Comment $comment            WP_Comment object.
		 * @param array      $anonymized_comment Anonymized comment data.
		 */
		$anon_message = apply_filters( 'wp_anonymize_comment', true, $comment, $anonymized_comment );

		if ( true !== $anon_message ) {
			if ( $anon_message && is_string( $anon_message ) ) {
				$messages[] = esc_html( $anon_message );
			} else {
				/* translators: %d: Comment ID */
				$messages[] = sprintf( __( 'Comment %d contains personal data but could not be anonymized.' ), $comment_id );
			}

			$items_retained = true;

			continue;
		}

		$args = array(
			'comment_ID' => $comment_id,
		);

		$updated = $wpdb->update( $wpdb->comments, $anonymized_comment, $args );

		if ( $updated ) {
			$items_removed = true;
			clean_comment_cache( $comment_id );
		} else {
			$items_retained = true;
		}
	}

	$done = count( $comments ) < $number;

	return array(
		'items_removed'  => $items_removed,
		'items_retained' => $items_retained,
		'messages'       => $messages,
		'done'           => $done,
	);
}