/wp-includes/pluggable.php

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<?php
/**
 * These functions can be replaced via plugins. If plugins do not redefine these
 * functions, then these will be used instead.
 *
 * @package WordPress
 */

if ( ! function_exists( 'wp_set_current_user' ) ) :
	/**
	 * Changes the current user by ID or name.
	 *
	 * Set $id to null and specify a name if you do not know a user's ID.
	 *
	 * Some WordPress functionality is based on the current user and not based on
	 * the signed in user. Therefore, it opens the ability to edit and perform
	 * actions on users who aren't signed in.
	 *
	 * @since 2.0.3
	 * @global WP_User $current_user The current user object which holds the user data.
	 *
	 * @param int    $id   User ID
	 * @param string $name User's username
	 * @return WP_User Current user User object
	 */
	function wp_set_current_user( $id, $name = '' ) {
		global $current_user;

		// If `$id` matches the current user, there is nothing to do.
		if ( isset( $current_user )
		&& ( $current_user instanceof WP_User )
		&& ( $id == $current_user->ID )
		&& ( null !== $id )
		) {
			return $current_user;
		}

		$current_user = new WP_User( $id, $name );

		setup_userdata( $current_user->ID );

		/**
		 * Fires after the current user is set.
		 *
		 * @since 2.0.1
		 */
		do_action( 'set_current_user' );

		return $current_user;
	}
endif;

if ( ! function_exists( 'wp_get_current_user' ) ) :
	/**
	 * Retrieve the current user object.
	 *
	 * Will set the current user, if the current user is not set. The current user
	 * will be set to the logged-in person. If no user is logged-in, then it will
	 * set the current user to 0, which is invalid and won't have any permissions.
	 *
	 * @since 2.0.3
	 *
	 * @see _wp_get_current_user()
	 * @global WP_User $current_user Checks if the current user is set.
	 *
	 * @return WP_User Current WP_User instance.
	 */
	function wp_get_current_user() {
		return _wp_get_current_user();
	}
endif;

if ( ! function_exists( 'get_userdata' ) ) :
	/**
	 * Retrieve user info by user ID.
	 *
	 * @since 0.71
	 *
	 * @param int $user_id User ID
	 * @return WP_User|false WP_User object on success, false on failure.
	 */
	function get_userdata( $user_id ) {
		return get_user_by( 'id', $user_id );
	}
endif;

if ( ! function_exists( 'get_user_by' ) ) :
	/**
	 * Retrieve user info by a given field
	 *
	 * @since 2.8.0
	 * @since 4.4.0 Added 'ID' as an alias of 'id' for the `$field` parameter.
	 *
	 * @param string     $field The field to retrieve the user with. id | ID | slug | email | login.
	 * @param int|string $value A value for $field. A user ID, slug, email address, or login name.
	 * @return WP_User|false WP_User object on success, false on failure.
	 */
	function get_user_by( $field, $value ) {
		$userdata = WP_User::get_data_by( $field, $value );

		if ( ! $userdata ) {
			return false;
		}

		$user = new WP_User;
		$user->init( $userdata );

		return $user;
	}
endif;

if ( ! function_exists( 'cache_users' ) ) :
	/**
	 * Retrieve info for user lists to prevent multiple queries by get_userdata()
	 *
	 * @since 3.0.0
	 *
	 * @global wpdb $wpdb WordPress database abstraction object.
	 *
	 * @param array $user_ids User ID numbers list
	 */
	function cache_users( $user_ids ) {
		global $wpdb;

		$clean = _get_non_cached_ids( $user_ids, 'users' );

		if ( empty( $clean ) ) {
			return;
		}

		$list = implode( ',', $clean );

		$users = $wpdb->get_results( "SELECT * FROM $wpdb->users WHERE ID IN ($list)" );

		$ids = array();
		foreach ( $users as $user ) {
			update_user_caches( $user );
			$ids[] = $user->ID;
		}
		update_meta_cache( 'user', $ids );
	}
endif;

if ( ! function_exists( 'wp_mail' ) ) :
	/**
	 * Sends an email, similar to PHP's mail function.
	 *
	 * A true return value does not automatically mean that the user received the
	 * email successfully. It just only means that the method used was able to
	 * process the request without any errors.
	 *
	 * The default content type is `text/plain` which does not allow using HTML.
	 * However, you can set the content type of the email by using the
	 * {@see 'wp_mail_content_type'} filter.
	 *
	 * The default charset is based on the charset used on the blog. The charset can
	 * be set using the {@see 'wp_mail_charset'} filter.
	 *
	 * @since 1.2.1
	 *
	 * @global PHPMailer $phpmailer
	 *
	 * @param string|array $to          Array or comma-separated list of email addresses to send message.
	 * @param string       $subject     Email subject
	 * @param string       $message     Message contents
	 * @param string|array $headers     Optional. Additional headers.
	 * @param string|array $attachments Optional. Files to attach.
	 * @return bool Whether the email contents were sent successfully.
	 */
	function wp_mail( $to, $subject, $message, $headers = '', $attachments = array() ) {
		// Compact the input, apply the filters, and extract them back out.

		/**
		 * Filters the wp_mail() arguments.
		 *
		 * @since 2.2.0
		 *
		 * @param array $args A compacted array of wp_mail() arguments, including the "to" email,
		 *                    subject, message, headers, and attachments values.
		 */
		$atts = apply_filters( 'wp_mail', compact( 'to', 'subject', 'message', 'headers', 'attachments' ) );

		if ( isset( $atts['to'] ) ) {
			$to = $atts['to'];
		}

		if ( ! is_array( $to ) ) {
			$to = explode( ',', $to );
		}

		if ( isset( $atts['subject'] ) ) {
			$subject = $atts['subject'];
		}

		if ( isset( $atts['message'] ) ) {
			$message = $atts['message'];
		}

		if ( isset( $atts['headers'] ) ) {
			$headers = $atts['headers'];
		}

		if ( isset( $atts['attachments'] ) ) {
			$attachments = $atts['attachments'];
		}

		if ( ! is_array( $attachments ) ) {
			$attachments = explode( "\n", str_replace( "\r\n", "\n", $attachments ) );
		}
		global $phpmailer;

		// (Re)create it, if it's gone missing.
		if ( ! ( $phpmailer instanceof PHPMailer ) ) {
			require_once ABSPATH . WPINC . '/class-phpmailer.php';
			require_once ABSPATH . WPINC . '/class-smtp.php';
			$phpmailer = new PHPMailer( true );
		}

		// Headers.
		$cc       = array();
		$bcc      = array();
		$reply_to = array();

		if ( empty( $headers ) ) {
			$headers = array();
		} else {
			if ( ! is_array( $headers ) ) {
				// Explode the headers out, so this function can take
				// both string headers and an array of headers.
				$tempheaders = explode( "\n", str_replace( "\r\n", "\n", $headers ) );
			} else {
				$tempheaders = $headers;
			}
			$headers = array();

			// If it's actually got contents.
			if ( ! empty( $tempheaders ) ) {
				// Iterate through the raw headers.
				foreach ( (array) $tempheaders as $header ) {
					if ( strpos( $header, ':' ) === false ) {
						if ( false !== stripos( $header, 'boundary=' ) ) {
							$parts    = preg_split( '/boundary=/i', trim( $header ) );
							$boundary = trim( str_replace( array( "'", '"' ), '', $parts[1] ) );
						}
						continue;
					}
					// Explode them out.
					list( $name, $content ) = explode( ':', trim( $header ), 2 );

					// Cleanup crew.
					$name    = trim( $name );
					$content = trim( $content );

					switch ( strtolower( $name ) ) {
						// Mainly for legacy -- process a "From:" header if it's there.
						case 'from':
							$bracket_pos = strpos( $content, '<' );
							if ( false !== $bracket_pos ) {
								// Text before the bracketed email is the "From" name.
								if ( $bracket_pos > 0 ) {
									$from_name = substr( $content, 0, $bracket_pos - 1 );
									$from_name = str_replace( '"', '', $from_name );
									$from_name = trim( $from_name );
								}

								$from_email = substr( $content, $bracket_pos + 1 );
								$from_email = str_replace( '>', '', $from_email );
								$from_email = trim( $from_email );

								// Avoid setting an empty $from_email.
							} elseif ( '' !== trim( $content ) ) {
								$from_email = trim( $content );
							}
							break;
						case 'content-type':
							if ( strpos( $content, ';' ) !== false ) {
								list( $type, $charset_content ) = explode( ';', $content );
								$content_type                   = trim( $type );
								if ( false !== stripos( $charset_content, 'charset=' ) ) {
									$charset = trim( str_replace( array( 'charset=', '"' ), '', $charset_content ) );
								} elseif ( false !== stripos( $charset_content, 'boundary=' ) ) {
									$boundary = trim( str_replace( array( 'BOUNDARY=', 'boundary=', '"' ), '', $charset_content ) );
									$charset  = '';
								}

								// Avoid setting an empty $content_type.
							} elseif ( '' !== trim( $content ) ) {
								$content_type = trim( $content );
							}
							break;
						case 'cc':
							$cc = array_merge( (array) $cc, explode( ',', $content ) );
							break;
						case 'bcc':
							$bcc = array_merge( (array) $bcc, explode( ',', $content ) );
							break;
						case 'reply-to':
							$reply_to = array_merge( (array) $reply_to, explode( ',', $content ) );
							break;
						default:
							// Add it to our grand headers array.
							$headers[ trim( $name ) ] = trim( $content );
							break;
					}
				}
			}
		}

		// Empty out the values that may be set.
		$phpmailer->clearAllRecipients();
		$phpmailer->clearAttachments();
		$phpmailer->clearCustomHeaders();
		$phpmailer->clearReplyTos();

		// Set "From" name and email.

		// If we don't have a name from the input headers.
		if ( ! isset( $from_name ) ) {
			$from_name = 'WordPress';
		}

		/*
		 * If we don't have an email from the input headers, default to wordpress@$sitename
		 * Some hosts will block outgoing mail from this address if it doesn't exist,
		 * but there's no easy alternative. Defaulting to admin_email might appear to be
		 * another option, but some hosts may refuse to relay mail from an unknown domain.
		 * See https://core.trac.wordpress.org/ticket/5007.
		 */
		if ( ! isset( $from_email ) ) {
			// Get the site domain and get rid of www.
			$sitename = strtolower( $_SERVER['SERVER_NAME'] );
			if ( substr( $sitename, 0, 4 ) == 'www.' ) {
				$sitename = substr( $sitename, 4 );
			}

			$from_email = 'wordpress@' . $sitename;
		}

		/**
		 * Filters the email address to send from.
		 *
		 * @since 2.2.0
		 *
		 * @param string $from_email Email address to send from.
		 */
		$from_email = apply_filters( 'wp_mail_from', $from_email );

		/**
		 * Filters the name to associate with the "from" email address.
		 *
		 * @since 2.3.0
		 *
		 * @param string $from_name Name associated with the "from" email address.
		 */
		$from_name = apply_filters( 'wp_mail_from_name', $from_name );

		try {
			$phpmailer->setFrom( $from_email, $from_name, false );
		} catch ( phpmailerException $e ) {
			$mail_error_data                             = compact( 'to', 'subject', 'message', 'headers', 'attachments' );
			$mail_error_data['phpmailer_exception_code'] = $e->getCode();

			/** This filter is documented in wp-includes/pluggable.php */
			do_action( 'wp_mail_failed', new WP_Error( 'wp_mail_failed', $e->getMessage(), $mail_error_data ) );

			return false;
		}

		// Set mail's subject and body.
		$phpmailer->Subject = $subject;
		$phpmailer->Body    = $message;

		// Set destination addresses, using appropriate methods for handling addresses.
		$address_headers = compact( 'to', 'cc', 'bcc', 'reply_to' );

		foreach ( $address_headers as $address_header => $addresses ) {
			if ( empty( $addresses ) ) {
				continue;
			}

			foreach ( (array) $addresses as $address ) {
				try {
					// Break $recipient into name and address parts if in the format "Foo <bar@baz.com>".
					$recipient_name = '';

					if ( preg_match( '/(.*)<(.+)>/', $address, $matches ) ) {
						if ( count( $matches ) == 3 ) {
							$recipient_name = $matches[1];
							$address        = $matches[2];
						}
					}

					switch ( $address_header ) {
						case 'to':
							$phpmailer->addAddress( $address, $recipient_name );
							break;
						case 'cc':
							$phpmailer->addCc( $address, $recipient_name );
							break;
						case 'bcc':
							$phpmailer->addBcc( $address, $recipient_name );
							break;
						case 'reply_to':
							$phpmailer->addReplyTo( $address, $recipient_name );
							break;
					}
				} catch ( phpmailerException $e ) {
					continue;
				}
			}
		}

		// Set to use PHP's mail().
		$phpmailer->isMail();

		// Set Content-Type and charset.

		// If we don't have a content-type from the input headers.
		if ( ! isset( $content_type ) ) {
			$content_type = 'text/plain';
		}

		/**
		 * Filters the wp_mail() content type.
		 *
		 * @since 2.3.0
		 *
		 * @param string $content_type Default wp_mail() content type.
		 */
		$content_type = apply_filters( 'wp_mail_content_type', $content_type );

		$phpmailer->ContentType = $content_type;

		// Set whether it's plaintext, depending on $content_type.
		if ( 'text/html' == $content_type ) {
			$phpmailer->isHTML( true );
		}

		// If we don't have a charset from the input headers.
		if ( ! isset( $charset ) ) {
			$charset = get_bloginfo( 'charset' );
		}

		/**
		 * Filters the default wp_mail() charset.
		 *
		 * @since 2.3.0
		 *
		 * @param string $charset Default email charset.
		 */
		$phpmailer->CharSet = apply_filters( 'wp_mail_charset', $charset );

		// Set custom headers.
		if ( ! empty( $headers ) ) {
			foreach ( (array) $headers as $name => $content ) {
				// Only add custom headers not added automatically by PHPMailer.
				if ( ! in_array( $name, array( 'MIME-Version', 'X-Mailer' ), true ) ) {
					$phpmailer->addCustomHeader( sprintf( '%1$s: %2$s', $name, $content ) );
				}
			}

			if ( false !== stripos( $content_type, 'multipart' ) && ! empty( $boundary ) ) {
				$phpmailer->addCustomHeader( sprintf( "Content-Type: %s;\n\t boundary=\"%s\"", $content_type, $boundary ) );
			}
		}

		if ( ! empty( $attachments ) ) {
			foreach ( $attachments as $attachment ) {
				try {
					$phpmailer->addAttachment( $attachment );
				} catch ( phpmailerException $e ) {
					continue;
				}
			}
		}

		/**
		 * Fires after PHPMailer is initialized.
		 *
		 * @since 2.2.0
		 *
		 * @param PHPMailer $phpmailer The PHPMailer instance (passed by reference).
		 */
		do_action_ref_array( 'phpmailer_init', array( &$phpmailer ) );

		// Send!
		try {
			return $phpmailer->send();
		} catch ( phpmailerException $e ) {

			$mail_error_data                             = compact( 'to', 'subject', 'message', 'headers', 'attachments' );
			$mail_error_data['phpmailer_exception_code'] = $e->getCode();

			/**
			 * Fires after a phpmailerException is caught.
			 *
			 * @since 4.4.0
			 *
			 * @param WP_Error $error A WP_Error object with the phpmailerException message, and an array
			 *                        containing the mail recipient, subject, message, headers, and attachments.
			 */
			do_action( 'wp_mail_failed', new WP_Error( 'wp_mail_failed', $e->getMessage(), $mail_error_data ) );

			return false;
		}
	}
endif;

if ( ! function_exists( 'wp_authenticate' ) ) :
	/**
	 * Authenticate a user, confirming the login credentials are valid.
	 *
	 * @since 2.5.0
	 * @since 4.5.0 `$username` now accepts an email address.
	 *
	 * @param string $username User's username or email address.
	 * @param string $password User's password.
	 * @return WP_User|WP_Error WP_User object if the credentials are valid,
	 *                          otherwise WP_Error.
	 */
	function wp_authenticate( $username, $password ) {
		$username = sanitize_user( $username );
		$password = trim( $password );

		/**
		 * Filters whether a set of user login credentials are valid.
		 *
		 * A WP_User object is returned if the credentials authenticate a user.
		 * WP_Error or null otherwise.
		 *
		 * @since 2.8.0
		 * @since 4.5.0 `$username` now accepts an email address.
		 *
		 * @param null|WP_User|WP_Error $user     WP_User if the user is authenticated.
		 *                                        WP_Error or null otherwise.
		 * @param string                $username Username or email address.
		 * @param string                $password User password
		 */
		$user = apply_filters( 'authenticate', null, $username, $password );

		if ( null == $user ) {
			// TODO: What should the error message be? (Or would these even happen?)
			// Only needed if all authentication handlers fail to return anything.
			$user = new WP_Error( 'authentication_failed', __( '<strong>Error</strong>: Invalid username, email address or incorrect password.' ) );
		}

		$ignore_codes = array( 'empty_username', 'empty_password' );

		if ( is_wp_error( $user ) && ! in_array( $user->get_error_code(), $ignore_codes, true ) ) {
			$error = $user;

			/**
			 * Fires after a user login has failed.
			 *
			 * @since 2.5.0
			 * @since 4.5.0 The value of `$username` can now be an email address.
			 * @since 5.4.0 The `$error` parameter was added.
			 *
			 * @param string   $username Username or email address.
			 * @param WP_Error $error    A WP_Error object with the authentication failure details.
			 */
			do_action( 'wp_login_failed', $username, $error );
		}

		return $user;
	}
endif;

if ( ! function_exists( 'wp_logout' ) ) :
	/**
	 * Log the current user out.
	 *
	 * @since 2.5.0
	 */
	function wp_logout() {
		$user_id = get_current_user_id();

		wp_destroy_current_session();
		wp_clear_auth_cookie();
		wp_set_current_user( 0 );

		/**
		 * Fires after a user is logged out.
		 *
		 * @since 1.5.0
		 * @since 5.5.0 Added the `$user_id` parameter.
		 *
		 * @param int $user_id ID of the user that was logged out.
		 */
		do_action( 'wp_logout', $user_id );
	}
endif;

if ( ! function_exists( 'wp_validate_auth_cookie' ) ) :
	/**
	 * Validates authentication cookie.
	 *
	 * The checks include making sure that the authentication cookie is set and
	 * pulling in the contents (if $cookie is not used).
	 *
	 * Makes sure the cookie is not expired. Verifies the hash in cookie is what is
	 * should be and compares the two.
	 *
	 * @since 2.5.0
	 *
	 * @global int $login_grace_period
	 *
	 * @param string $cookie Optional. If used, will validate contents instead of cookie's.
	 * @param string $scheme Optional. The cookie scheme to use: 'auth', 'secure_auth', or 'logged_in'.
	 * @return int|false User ID if valid cookie, false if invalid.
	 */
	function wp_validate_auth_cookie( $cookie = '', $scheme = '' ) {
		$cookie_elements = wp_parse_auth_cookie( $cookie, $scheme );
		if ( ! $cookie_elements ) {
			/**
			 * Fires if an authentication cookie is malformed.
			 *
			 * @since 2.7.0
			 *
			 * @param string $cookie Malformed auth cookie.
			 * @param string $scheme Authentication scheme. Values include 'auth', 'secure_auth',
			 *                       or 'logged_in'.
			 */
			do_action( 'auth_cookie_malformed', $cookie, $scheme );
			return false;
		}

		$scheme     = $cookie_elements['scheme'];
		$username   = $cookie_elements['username'];
		$hmac       = $cookie_elements['hmac'];
		$token      = $cookie_elements['token'];
		$expired    = $cookie_elements['expiration'];
		$expiration = $cookie_elements['expiration'];

		// Allow a grace period for POST and Ajax requests.
		if ( wp_doing_ajax() || 'POST' == $_SERVER['REQUEST_METHOD'] ) {
			$expired += HOUR_IN_SECONDS;
		}

		// Quick check to see if an honest cookie has expired.
		if ( $expired < time() ) {
			/**
			 * Fires once an authentication cookie has expired.
			 *
			 * @since 2.7.0
			 *
			 * @param string[] $cookie_elements An array of data for the authentication cookie.
			 */
			do_action( 'auth_cookie_expired', $cookie_elements );
			return false;
		}

		$user = get_user_by( 'login', $username );
		if ( ! $user ) {
			/**
			 * Fires if a bad username is entered in the user authentication process.
			 *
			 * @since 2.7.0
			 *
			 * @param string[] $cookie_elements An array of data for the authentication cookie.
			 */
			do_action( 'auth_cookie_bad_username', $cookie_elements );
			return false;
		}

		$pass_frag = substr( $user->user_pass, 8, 4 );

		$key = wp_hash( $username . '|' . $pass_frag . '|' . $expiration . '|' . $token, $scheme );

		// If ext/hash is not present, compat.php's hash_hmac() does not support sha256.
		$algo = function_exists( 'hash' ) ? 'sha256' : 'sha1';
		$hash = hash_hmac( $algo, $username . '|' . $expiration . '|' . $token, $key );

		if ( ! hash_equals( $hash, $hmac ) ) {
			/**
			 * Fires if a bad authentication cookie hash is encountered.
			 *
			 * @since 2.7.0
			 *
			 * @param string[] $cookie_elements An array of data for the authentication cookie.
			 */
			do_action( 'auth_cookie_bad_hash', $cookie_elements );
			return false;
		}

		$manager = WP_Session_Tokens::get_instance( $user->ID );
		if ( ! $manager->verify( $token ) ) {
			/**
			 * Fires if a bad session token is encountered.
			 *
			 * @since 4.0.0
			 *
			 * @param string[] $cookie_elements An array of data for the authentication cookie.
			 */
			do_action( 'auth_cookie_bad_session_token', $cookie_elements );
			return false;
		}

		// Ajax/POST grace period set above.
		if ( $expiration < time() ) {
			$GLOBALS['login_grace_period'] = 1;
		}

		/**
		 * Fires once an authentication cookie has been validated.
		 *
		 * @since 2.7.0
		 *
		 * @param string[] $cookie_elements An array of data for the authentication cookie.
		 * @param WP_User  $user            User object.
		 */
		do_action( 'auth_cookie_valid', $cookie_elements, $user );

		return $user->ID;
	}
endif;

if ( ! function_exists( 'wp_generate_auth_cookie' ) ) :
	/**
	 * Generates authentication cookie contents.
	 *
	 * @since 2.5.0
	 * @since 4.0.0 The `$token` parameter was added.
	 *
	 * @param int    $user_id    User ID.
	 * @param int    $expiration The time the cookie expires as a UNIX timestamp.
	 * @param string $scheme     Optional. The cookie scheme to use: 'auth', 'secure_auth', or 'logged_in'.
	 *                           Default 'auth'.
	 * @param string $token      User's session token to use for this cookie.
	 * @return string Authentication cookie contents. Empty string if user does not exist.
	 */
	function wp_generate_auth_cookie( $user_id, $expiration, $scheme = 'auth', $token = '' ) {
		$user = get_userdata( $user_id );
		if ( ! $user ) {
			return '';
		}

		if ( ! $token ) {
			$manager = WP_Session_Tokens::get_instance( $user_id );
			$token   = $manager->create( $expiration );
		}

		$pass_frag = substr( $user->user_pass, 8, 4 );

		$key = wp_hash( $user->user_login . '|' . $pass_frag . '|' . $expiration . '|' . $token, $scheme );

		// If ext/hash is not present, compat.php's hash_hmac() does not support sha256.
		$algo = function_exists( 'hash' ) ? 'sha256' : 'sha1';
		$hash = hash_hmac( $algo, $user->user_login . '|' . $expiration . '|' . $token, $key );

		$cookie = $user->user_login . '|' . $expiration . '|' . $token . '|' . $hash;

		/**
		 * Filters the authentication cookie.
		 *
		 * @since 2.5.0
		 * @since 4.0.0 The `$token` parameter was added.
		 *
		 * @param string $cookie     Authentication cookie.
		 * @param int    $user_id    User ID.
		 * @param int    $expiration The time the cookie expires as a UNIX timestamp.
		 * @param string $scheme     Cookie scheme used. Accepts 'auth', 'secure_auth', or 'logged_in'.
		 * @param string $token      User's session token used.
		 */
		return apply_filters( 'auth_cookie', $cookie, $user_id, $expiration, $scheme, $token );
	}
endif;

if ( ! function_exists( 'wp_parse_auth_cookie' ) ) :
	/**
	 * Parses a cookie into its components.
	 *
	 * @since 2.7.0
	 *
	 * @param string $cookie Authentication cookie.
	 * @param string $scheme Optional. The cookie scheme to use: 'auth', 'secure_auth', or 'logged_in'.
	 * @return string[]|false Authentication cookie components.
	 */
	function wp_parse_auth_cookie( $cookie = '', $scheme = '' ) {
		if ( empty( $cookie ) ) {
			switch ( $scheme ) {
				case 'auth':
					$cookie_name = AUTH_COOKIE;
					break;
				case 'secure_auth':
					$cookie_name = SECURE_AUTH_COOKIE;
					break;
				case 'logged_in':
					$cookie_name = LOGGED_IN_COOKIE;
					break;
				default:
					if ( is_ssl() ) {
						$cookie_name = SECURE_AUTH_COOKIE;
						$scheme      = 'secure_auth';
					} else {
						$cookie_name = AUTH_COOKIE;
						$scheme      = 'auth';
					}
			}

			if ( empty( $_COOKIE[ $cookie_name ] ) ) {
				return false;
			}
			$cookie = $_COOKIE[ $cookie_name ];
		}

		$cookie_elements = explode( '|', $cookie );
		if ( count( $cookie_elements ) !== 4 ) {
			return false;
		}

		list( $username, $expiration, $token, $hmac ) = $cookie_elements;

		return compact( 'username', 'expiration', 'token', 'hmac', 'scheme' );
	}
endif;

if ( ! function_exists( 'wp_set_auth_cookie' ) ) :
	/**
	 * Sets the authentication cookies based on user ID.
	 *
	 * The $remember parameter increases the time that the cookie will be kept. The
	 * default the cookie is kept without remembering is two days. When $remember is
	 * set, the cookies will be kept for 14 days or two weeks.
	 *
	 * @since 2.5.0
	 * @since 4.3.0 Added the `$token` parameter.
	 *
	 * @param int         $user_id  User ID.
	 * @param bool        $remember Whether to remember the user.
	 * @param bool|string $secure   Whether the auth cookie should only be sent over HTTPS. Default is an empty
	 *                              string which means the value of `is_ssl()` will be used.
	 * @param string      $token    Optional. User's session token to use for this cookie.
	 */
	function wp_set_auth_cookie( $user_id, $remember = false, $secure = '', $token = '' ) {
		if ( $remember ) {
			/**
			 * Filters the duration of the authentication cookie expiration period.
			 *
			 * @since 2.8.0
			 *
			 * @param int  $length   Duration of the expiration period in seconds.
			 * @param int  $user_id  User ID.
			 * @param bool $remember Whether to remember the user login. Default false.
			 */
			$expiration = time() + apply_filters( 'auth_cookie_expiration', 14 * DAY_IN_SECONDS, $user_id, $remember );

			/*
			 * Ensure the browser will continue to send the cookie after the expiration time is reached.
			 * Needed for the login grace period in wp_validate_auth_cookie().
			 */
			$expire = $expiration + ( 12 * HOUR_IN_SECONDS );
		} else {
			/** This filter is documented in wp-includes/pluggable.php */
			$expiration = time() + apply_filters( 'auth_cookie_expiration', 2 * DAY_IN_SECONDS, $user_id, $remember );
			$expire     = 0;
		}

		if ( '' === $secure ) {
			$secure = is_ssl();
		}

		// Front-end cookie is secure when the auth cookie is secure and the site's home URL uses HTTPS.
		$secure_logged_in_cookie = $secure && 'https' === parse_url( get_option( 'home' ), PHP_URL_SCHEME );

		/**
		 * Filters whether the auth cookie should only be sent over HTTPS.
		 *
		 * @since 3.1.0
		 *
		 * @param bool $secure  Whether the cookie should only be sent over HTTPS.
		 * @param int  $user_id User ID.
		 */
		$secure = apply_filters( 'secure_auth_cookie', $secure, $user_id );

		/**
		 * Filters whether the logged in cookie should only be sent over HTTPS.
		 *
		 * @since 3.1.0
		 *
		 * @param bool $secure_logged_in_cookie Whether the logged in cookie should only be sent over HTTPS.
		 * @param int  $user_id                 User ID.
		 * @param bool $secure                  Whether the auth cookie should only be sent over HTTPS.
		 */
		$secure_logged_in_cookie = apply_filters( 'secure_logged_in_cookie', $secure_logged_in_cookie, $user_id, $secure );

		if ( $secure ) {
			$auth_cookie_name = SECURE_AUTH_COOKIE;
			$scheme           = 'secure_auth';
		} else {
			$auth_cookie_name = AUTH_COOKIE;
			$scheme           = 'auth';
		}

		if ( '' === $token ) {
			$manager = WP_Session_Tokens::get_instance( $user_id );
			$token   = $manager->create( $expiration );
		}

		$auth_cookie      = wp_generate_auth_cookie( $user_id, $expiration, $scheme, $token );
		$logged_in_cookie = wp_generate_auth_cookie( $user_id, $expiration, 'logged_in', $token );

		/**
		 * Fires immediately before the authentication cookie is set.
		 *
		 * @since 2.5.0
		 * @since 4.9.0 The `$token` parameter was added.
		 *
		 * @param string $auth_cookie Authentication cookie value.
		 * @param int    $expire      The time the login grace period expires as a UNIX timestamp.
		 *                            Default is 12 hours past the cookie's expiration time.
		 * @param int    $expiration  The time when the authentication cookie expires as a UNIX timestamp.
		 *                            Default is 14 days from now.
		 * @param int    $user_id     User ID.
		 * @param string $scheme      Authentication scheme. Values include 'auth' or 'secure_auth'.
		 * @param string $token       User's session token to use for this cookie.
		 */
		do_action( 'set_auth_cookie', $auth_cookie, $expire, $expiration, $user_id, $scheme, $token );

		/**
		 * Fires immediately before the logged-in authentication cookie is set.
		 *
		 * @since 2.6.0
		 * @since 4.9.0 The `$token` parameter was added.
		 *
		 * @param string $logged_in_cookie The logged-in cookie value.
		 * @param int    $expire           The time the login grace period expires as a UNIX timestamp.
		 *                                 Default is 12 hours past the cookie's expiration time.
		 * @param int    $expiration       The time when the logged-in authentication cookie expires as a UNIX timestamp.
		 *                                 Default is 14 days from now.
		 * @param int    $user_id          User ID.
		 * @param string $scheme           Authentication scheme. Default 'logged_in'.
		 * @param string $token            User's session token to use for this cookie.
		 */
		do_action( 'set_logged_in_cookie', $logged_in_cookie, $expire, $expiration, $user_id, 'logged_in', $token );

		/**
		 * Allows preventing auth cookies from actually being sent to the client.
		 *
		 * @since 4.7.4
		 *
		 * @param bool $send Whether to send auth cookies to the client.
		 */
		if ( ! apply_filters( 'send_auth_cookies', true ) ) {
			return;
		}

		setcookie( $auth_cookie_name, $auth_cookie, $expire, PLUGINS_COOKIE_PATH, COOKIE_DOMAIN, $secure, true );
		setcookie( $auth_cookie_name, $auth_cookie, $expire, ADMIN_COOKIE_PATH, COOKIE_DOMAIN, $secure, true );
		setcookie( LOGGED_IN_COOKIE, $logged_in_cookie, $expire, COOKIEPATH, COOKIE_DOMAIN, $secure_logged_in_cookie, true );
		if ( COOKIEPATH != SITECOOKIEPATH ) {
			setcookie( LOGGED_IN_COOKIE, $logged_in_cookie, $expire, SITECOOKIEPATH, COOKIE_DOMAIN, $secure_logged_in_cookie, true );
		}
	}
endif;

if ( ! function_exists( 'wp_clear_auth_cookie' ) ) :
	/**
	 * Removes all of the cookies associated with authentication.
	 *
	 * @since 2.5.0
	 */
	function wp_clear_auth_cookie() {
		/**
		 * Fires just before the authentication cookies are cleared.
		 *
		 * @since 2.7.0
		 */
		do_action( 'clear_auth_cookie' );

		/** This filter is documented in wp-includes/pluggable.php */
		if ( ! apply_filters( 'send_auth_cookies', true ) ) {
			return;
		}

		// Auth cookies.
		setcookie( AUTH_COOKIE, ' ', time() - YEAR_IN_SECONDS, ADMIN_COOKIE_PATH, COOKIE_DOMAIN );
		setcookie( SECURE_AUTH_COOKIE, ' ', time() - YEAR_IN_SECONDS, ADMIN_COOKIE_PATH, COOKIE_DOMAIN );
		setcookie( AUTH_COOKIE, ' ', time() - YEAR_IN_SECONDS, PLUGINS_COOKIE_PATH, COOKIE_DOMAIN );
		setcookie( SECURE_AUTH_COOKIE, ' ', time() - YEAR_IN_SECONDS, PLUGINS_COOKIE_PATH, COOKIE_DOMAIN );
		setcookie( LOGGED_IN_COOKIE, ' ', time() - YEAR_IN_SECONDS, COOKIEPATH, COOKIE_DOMAIN );
		setcookie( LOGGED_IN_COOKIE, ' ', time() - YEAR_IN_SECONDS, SITECOOKIEPATH, COOKIE_DOMAIN );

		// Settings cookies.
		setcookie( 'wp-settings-' . get_current_user_id(), ' ', time() - YEAR_IN_SECONDS, SITECOOKIEPATH );
		setcookie( 'wp-settings-time-' . get_current_user_id(), ' ', time() - YEAR_IN_SECONDS, SITECOOKIEPATH );

		// Old cookies.
		setcookie( AUTH_COOKIE, ' ', time() - YEAR_IN_SECONDS, COOKIEPATH, COOKIE_DOMAIN );
		setcookie( AUTH_COOKIE, ' ', time() - YEAR_IN_SECONDS, SITECOOKIEPATH, COOKIE_DOMAIN );
		setcookie( SECURE_AUTH_COOKIE, ' ', time() - YEAR_IN_SECONDS, COOKIEPATH, COOKIE_DOMAIN );
		setcookie( SECURE_AUTH_COOKIE, ' ', time() - YEAR_IN_SECONDS, SITECOOKIEPATH, COOKIE_DOMAIN );

		// Even older cookies.
		setcookie( USER_COOKIE, ' ', time() - YEAR_IN_SECONDS, COOKIEPATH, COOKIE_DOMAIN );
		setcookie( PASS_COOKIE, ' ', time() - YEAR_IN_SECONDS, COOKIEPATH, COOKIE_DOMAIN );
		setcookie( USER_COOKIE, ' ', time() - YEAR_IN_SECONDS, SITECOOKIEPATH, COOKIE_DOMAIN );
		setcookie( PASS_COOKIE, ' ', time() - YEAR_IN_SECONDS, SITECOOKIEPATH, COOKIE_DOMAIN );

		// Post password cookie.
		setcookie( 'wp-postpass_' . COOKIEHASH, ' ', time() - YEAR_IN_SECONDS, COOKIEPATH, COOKIE_DOMAIN );
	}
endif;

if ( ! function_exists( 'is_user_logged_in' ) ) :
	/**
	 * Determines whether the current visitor is a logged in user.
	 *
	 * For more information on this and similar theme functions, check out
	 * the {@link https://developer.wordpress.org/themes/basics/conditional-tags/
	 * Conditional Tags} article in the Theme Developer Handbook.
	 *
	 * @since 2.0.0
	 *
	 * @return bool True if user is logged in, false if not logged in.
	 */
	function is_user_logged_in() {
		$user = wp_get_current_user();

		return $user->exists();
	}
endif;

if ( ! function_exists( 'auth_redirect' ) ) :
	/**
	 * Checks if a user is logged in, if not it redirects them to the login page.
	 *
	 * When this code is called from a page, it checks to see if the user viewing the page is logged in.
	 * If the user is not logged in, they are redirected to the login page. The user is redirected
	 * in such a way that, upon logging in, they will be sent directly to the page they were originally
	 * trying to access.
	 *
	 * @since 1.5.0
	 */
	function auth_redirect() {
		$secure = ( is_ssl() || force_ssl_admin() );

		/**
		 * Filters whether to use a secure authentication redirect.
		 *
		 * @since 3.1.0
		 *
		 * @param bool $secure Whether to use a secure authentication redirect. Default false.
		 */
		$secure = apply_filters( 'secure_auth_redirect', $secure );

		// If https is required and request is http, redirect.
		if ( $secure && ! is_ssl() && false !== strpos( $_SERVER['REQUEST_URI'], 'wp-admin' ) ) {
			if ( 0 === strpos( $_SERVER['REQUEST_URI'], 'http' ) ) {
				wp_redirect( set_url_scheme( $_SERVER['REQUEST_URI'], 'https' ) );
				exit();
			} else {
				wp_redirect( 'https://' . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'] );
				exit();
			}
		}

		/**
		 * Filters the authentication redirect scheme.
		 *
		 * @since 2.9.0
		 *
		 * @param string $scheme Authentication redirect scheme. Default empty.
		 */
		$scheme = apply_filters( 'auth_redirect_scheme', '' );

		$user_id = wp_validate_auth_cookie( '', $scheme );
		if ( $user_id ) {
			/**
			 * Fires before the authentication redirect.
			 *
			 * @since 2.8.0
			 *
			 * @param int $user_id User ID.
			 */
			do_action( 'auth_redirect', $user_id );

			// If the user wants ssl but the session is not ssl, redirect.
			if ( ! $secure && get_user_option( 'use_ssl', $user_id ) && false !== strpos( $_SERVER['REQUEST_URI'], 'wp-admin' ) ) {
				if ( 0 === strpos( $_SERVER['REQUEST_URI'], 'http' ) ) {
					wp_redirect( set_url_scheme( $_SERVER['REQUEST_URI'], 'https' ) );
					exit();
				} else {
					wp_redirect( 'https://' . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'] );
					exit();
				}
			}

			return; // The cookie is good, so we're done.
		}

		// The cookie is no good, so force login.
		nocache_headers();

		$redirect = ( strpos( $_SERVER['REQUEST_URI'], '/options.php' ) && wp_get_referer() ) ? wp_get_referer() : set_url_scheme( 'http://' . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'] );

		$login_url = wp_login_url( $redirect, true );

		wp_redirect( $login_url );
		exit();
	}
endif;

if ( ! function_exists( 'check_admin_referer' ) ) :
	/**
	 * Ensures intent by verifying that a user was referred from another admin page with the correct security nonce.
	 *
	 * This function ensures the user intends to perform a given action, which helps protect against clickjacking style
	 * attacks. It verifies intent, not authorisation, therefore it does not verify the user's capabilities. This should
	 * be performed with `current_user_can()` or similar.
	 *
	 * If the nonce value is invalid, the function will exit with an "Are You Sure?" style message.
	 *
	 * @since 1.2.0
	 * @since 2.5.0 The `$query_arg` parameter was added.
	 *
	 * @param int|string $action    The nonce action.
	 * @param string     $query_arg Optional. Key to check for nonce in `$_REQUEST`. Default '_wpnonce'.
	 * @return int|false 1 if the nonce is valid and generated between 0-12 hours ago,
	 *                   2 if the nonce is valid and generated between 12-24 hours ago.
	 *                   False if the nonce is invalid.
	 */
	function check_admin_referer( $action = -1, $query_arg = '_wpnonce' ) {
		if ( -1 === $action ) {
			_doing_it_wrong( __FUNCTION__, __( 'You should specify a nonce action to be verified by using the first parameter.' ), '3.2.0' );
		}

		$adminurl = strtolower( admin_url() );
		$referer  = strtolower( wp_get_referer() );
		$result   = isset( $_REQUEST[ $query_arg ] ) ? wp_verify_nonce( $_REQUEST[ $query_arg ], $action ) : false;

		/**
		 * Fires once the admin request has been validated or not.
		 *
		 * @since 1.5.1
		 *
		 * @param string    $action The nonce action.
		 * @param false|int $result False if the nonce is invalid, 1 if the nonce is valid and generated between
		 *                          0-12 hours ago, 2 if the nonce is valid and generated between 12-24 hours ago.
		 */
		do_action( 'check_admin_referer', $action, $result );

		if ( ! $result && ! ( -1 === $action && strpos( $referer, $adminurl ) === 0 ) ) {
			wp_nonce_ays( $action );
			die();
		}

		return $result;
	}
endif;

if ( ! function_exists( 'check_ajax_referer' ) ) :
	/**
	 * Verifies the Ajax request to prevent processing requests external of the blog.
	 *
	 * @since 2.0.3
	 *
	 * @param int|string   $action    Action nonce.
	 * @param false|string $query_arg Optional. Key to check for the nonce in `$_REQUEST` (since 2.5). If false,
	 *                                `$_REQUEST` values will be evaluated for '_ajax_nonce', and '_wpnonce'
	 *                                (in that order). Default false.
	 * @param bool         $die       Optional. Whether to die early when the nonce cannot be verified.
	 *                                Default true.
	 * @return int|false 1 if the nonce is valid and generated between 0-12 hours ago,
	 *                   2 if the nonce is valid and generated between 12-24 hours ago.
	 *                   False if the nonce is invalid.
	 */
	function check_ajax_referer( $action = -1, $query_arg = false, $die = true ) {
		if ( -1 == $action ) {
			_doing_it_wrong( __FUNCTION__, __( 'You should specify a nonce action to be verified by using the first parameter.' ), '4.7' );
		}

		$nonce = '';

		if ( $query_arg && isset( $_REQUEST[ $query_arg ] ) ) {
			$nonce = $_REQUEST[ $query_arg ];
		} elseif ( isset( $_REQUEST['_ajax_nonce'] ) ) {
			$nonce = $_REQUEST['_ajax_nonce'];
		} elseif ( isset( $_REQUEST['_wpnonce'] ) ) {
			$nonce = $_REQUEST['_wpnonce'];
		}

		$result = wp_verify_nonce( $nonce, $action );

		/**
		 * Fires once the Ajax request has been validated or not.
		 *
		 * @since 2.1.0
		 *
		 * @param string    $action The Ajax nonce action.
		 * @param false|int $result False if the nonce is invalid, 1 if the nonce is valid and generated between
		 *                          0-12 hours ago, 2 if the nonce is valid and generated between 12-24 hours ago.
		 */
		do_action( 'check_ajax_referer', $action, $result );

		if ( $die && false === $result ) {
			if ( wp_doing_ajax() ) {
				wp_die( -1, 403 );
			} else {
				die( '-1' );
			}
		}

		return $result;
	}
endif;

if ( ! function_exists( 'wp_redirect' ) ) :
	/**
	 * Redirects to another page.
	 *
	 * Note: wp_redirect() does not exit automatically, and should almost always be
	 * followed by a call to `exit;`:
	 *
	 *     wp_redirect( $url );
	 *     exit;
	 *
	 * Exiting can also be selectively manipulated by using wp_redirect() as a conditional
	 * in conjunction with the {@see 'wp_redirect'} and {@see 'wp_redirect_location'} filters:
	 *
	 *     if ( wp_redirect( $url ) ) {
	 *         exit;
	 *     }
	 *
	 * @since 1.5.1
	 * @since 5.1.0 The `$x_redirect_by` parameter was added.
	 * @since 5.4.0 On invalid status codes, wp_die() is called.
	 *
	 * @global bool $is_IIS
	 *
	 * @param string $location      The path or URL to redirect to.
	 * @param int    $status        Optional. HTTP response status code to use. Default '302' (Moved Temporarily).
	 * @param string $x_redirect_by Optional. The application doing the redirect. Default 'WordPress'.
	 * @return bool False if the redirect was cancelled, true otherwise.
	 */
	function wp_redirect( $location, $status = 302, $x_redirect_by = 'WordPress' ) {
		global $is_IIS;

		/**
		 * Filters the redirect location.
		 *
		 * @since 2.1.0
		 *
		 * @param string $location The path or URL to redirect to.
		 * @param int    $status   The HTTP response status code to use.
		 */
		$location = apply_filters( 'wp_redirect', $location, $status );

		/**
		 * Filters the redirect HTTP response status code to use.
		 *
		 * @since 2.3.0
		 *
		 * @param int    $status   The HTTP response status code to use.
		 * @param string $location The path or URL to redirect to.
		 */
		$status = apply_filters( 'wp_redirect_status', $status, $location );

		if ( ! $location ) {
			return false;
		}

		if ( $status < 300 || 399 < $status ) {
			wp_die( __( 'HTTP redirect status code must be a redirection code, 3xx.' ) );
		}

		$location = wp_sanitize_redirect( $location );

		if ( ! $is_IIS && PHP_SAPI != 'cgi-fcgi' ) {
			status_header( $status ); // This causes problems on IIS and some FastCGI setups.
		}

		/**
		 * Filters the X-Redirect-By header.
		 *
		 * Allows applications to identify themselves when they're doing a redirect.
		 *
		 * @since 5.1.0
		 *
		 * @param string $x_redirect_by The application doing the redirect.
		 * @param int    $status        Status code to use.
		 * @param string $location      The path to redirect to.
		 */
		$x_redirect_by = apply_filters( 'x_redirect_by', $x_redirect_by, $status, $location );
		if ( is_string( $x_redirect_by ) ) {
			header( "X-Redirect-By: $x_redirect_by" );
		}

		header( "Location: $location", true, $status );

		return true;
	}
endif;

if ( ! function_exists( 'wp_sanitize_redirect' ) ) :
	/**
	 * Sanitizes a URL for use in a redirect.
	 *
	 * @since 2.3.0
	 *
	 * @param string $location The path to redirect to.
	 * @return string Redirect-sanitized URL.
	 */
	function wp_sanitize_redirect( $location ) {
		// Encode spaces.
		$location = str_replace( ' ', '%20', $location );

		$regex    = '/
		(
			(?: [\xC2-\xDF][\x80-\xBF]        # double-byte sequences   110xxxxx 10xxxxxx
			|   \xE0[\xA0-\xBF][\x80-\xBF]    # triple-byte sequences   1110xxxx 10xxxxxx * 2
			|   [\xE1-\xEC][\x80-\xBF]{2}
			|   \xED[\x80-\x9F][\x80-\xBF]
			|   [\xEE-\xEF][\x80-\xBF]{2}
			|   \xF0[\x90-\xBF][\x80-\xBF]{2} # four-byte sequences   11110xxx 10xxxxxx * 3
			|   [\xF1-\xF3][\x80-\xBF]{3}
			|   \xF4[\x80-\x8F][\x80-\xBF]{2}
		){1,40}                              # ...one or more times
		)/x';
		$location = preg_replace_callback( $regex, '_wp_sanitize_utf8_in_redirect', $location );
		$location = preg_replace( '|[^a-z0-9-~+_.?#=&;,/:%!*\[\]()@]|i', '', $location );
		$location = wp_kses_no_null( $location );

		// Remove %0D and %0A from location.
		$strip = array( '%0d', '%0a', '%0D', '%0A' );
		return _deep_replace( $strip, $location );
	}

	/**
	 * URL encode UTF-8 characters in a URL.
	 *
	 * @ignore
	 * @since 4.2.0
	 * @access private
	 *
	 * @see wp_sanitize_redirect()
	 *
	 * @param array $matches RegEx matches against the redirect location.
	 * @return string URL-encoded version of the first RegEx match.
	 */
	function _wp_sanitize_utf8_in_redirect( $matches ) {
		return urlencode( $matches[0] );
	}
endif;

if ( ! function_exists( 'wp_safe_redirect' ) ) :
	/**
	 * Performs a safe (local) redirect, using wp_redirect().
	 *
	 * Checks whether the $location is using an allowed host, if it has an absolute
	 * path. A plugin can therefore set or remove allowed host(s) to or from the
	 * list.
	 *
	 * If the host is not allowed, then the redirect defaults to wp-admin on the siteurl
	 * instead. This prevents malicious redirects which redirect to another host,
	 * but only used in a few places.
	 *
	 * Note: wp_safe_redirect() does not exit automatically, and should almost always be
	 * followed by a call to `exit;`:
	 *
	 *     wp_safe_redirect( $url );
	 *     exit;
	 *
	 * Exiting can also be selectively manipulated by using wp_safe_redirect() as a conditional
	 * in conjunction with the {@see 'wp_redirect'} and {@see 'wp_redirect_location'} filters:
	 *
	 *     if ( wp_safe_redirect( $url ) ) {
	 *         exit;
	 *     }
	 *
	 * @since 2.3.0
	 * @since 5.1.0 The return value from wp_redirect() is now passed on, and the `$x_redirect_by` parameter was added.
	 *
	 * @param string $location      The path or URL to redirect to.
	 * @param int    $status        Optional. HTTP response status code to use. Default '302' (Moved Temporarily).
	 * @param string $x_redirect_by Optional. The application doing the redirect. Default 'WordPress'.
	 * @return bool  $redirect False if the redirect was cancelled, true otherwise.
	 */
	function wp_safe_redirect( $location, $status = 302, $x_redirect_by = 'WordPress' ) {

		// Need to look at the URL the way it will end up in wp_redirect().
		$location = wp_sanitize_redirect( $location );

		/**
		 * Filters the redirect fallback URL for when the provided redirect is not safe (local).
		 *
		 * @since 4.3.0
		 *
		 * @param string $fallback_url The fallback URL to use by default.
		 * @param int    $status       The HTTP response status code to use.
		 */
		$location = wp_validate_redirect( $location, apply_filters( 'wp_safe_redirect_fallback', admin_url(), $status ) );

		return wp_redirect( $location, $status, $x_redirect_by );
	}
endif;

if ( ! function_exists( 'wp_validate_redirect' ) ) :
	/**
	 * Validates a URL for use in a redirect.
	 *
	 * Checks whether the $location is using an allowed host, if it has an absolute
	 * path. A plugin can therefore set or remove allowed host(s) to or from the
	 * list.
	 *
	 * If the host is not allowed, then the redirect is to $default supplied
	 *
	 * @since 2.8.1
	 *
	 * @param string $location The redirect to validate
	 * @param string $default  The value to return if $location is not allowed
	 * @return string redirect-sanitized URL
	 */
	function wp_validate_redirect( $location, $default = '' ) {
		$location = trim( $location, " \t\n\r\0\x08\x0B" );
		// Browsers will assume 'http' is your protocol, and will obey a redirect to a URL starting with '//'.
		if ( substr( $location, 0, 2 ) == '//' ) {
			$location = 'http:' . $location;
		}

		// In PHP 5 parse_url() may fail if the URL query part contains 'http://'.
		// See https://bugs.php.net/bug.php?id=38143
		$cut  = strpos( $location, '?' );
		$test = $cut ? substr( $location, 0, $cut ) : $location;

		$lp = parse_url( $test );

		// Give up if malformed URL.
		if ( false === $lp ) {
			return $default;
		}

		// Allow only 'http' and 'https' schemes. No 'data:', etc.
		if ( isset( $lp['scheme'] ) && ! ( 'http' == $lp['scheme'] || 'https' == $lp['scheme'] ) ) {
			return $default;
		}

		if ( ! isset( $lp['host'] ) && ! empty( $lp['path'] ) && '/' !== $lp['path'][0] ) {
			$path = '';
			if ( ! empty( $_SERVER['REQUEST_URI'] ) ) {
				$path = dirname( parse_url( 'http://placeholder' . $_SERVER['REQUEST_URI'], PHP_URL_PATH ) . '?' );
				$path = wp_normalize_path( $path );
			}
			$location = '/' . ltrim( $path . '/', '/' ) . $location;
		}

		// Reject if certain components are set but host is not.
		// This catches URLs like https:host.com for which parse_url() does not set the host field.
		if ( ! isset( $lp['host'] ) && ( isset( $lp['scheme'] ) || isset( $lp['user'] ) || isset( $lp['pass'] ) || isset( $lp['port'] ) ) ) {
			return $default;
		}

		// Reject malformed components parse_url() can return on odd inputs.
		foreach ( array( 'user', 'pass', 'host' ) as $component ) {
			if ( isset( $lp[ $component ] ) && strpbrk( $lp[ $component ], ':/?#@' ) ) {
				return $default;
			}
		}

		$wpp = parse_url( home_url() );

		/**
		 * Filters the whitelist of hosts to redirect to.
		 *
		 * @since 2.3.0
		 *
		 * @param string[] $hosts An array of allowed host names.
		 * @param string   $host  The host name of the redirect destination; empty string if not set.
		 */
		$allowed_hosts = (array) apply_filters( 'allowed_redirect_hosts', array( $wpp['host'] ), isset( $lp['host'] ) ? $lp['host'] : '' );

		if ( isset( $lp['host'] ) && ( ! in_array( $lp['host'], $allowed_hosts, true ) && strtolower( $wpp['host'] ) !== $lp['host'] ) ) {
			$location = $default;
		}

		return $location;
	}
endif;

if ( ! function_exists( 'wp_notify_postauthor' ) ) :
	/**
	 * Notify an author (and/or others) of a comment/trackback/pingback on a post.
	 *
	 * @since 1.0.0
	 *
	 * @param int|WP_Comment  $comment_id Comment ID or WP_Comment object.
	 * @param string          $deprecated Not used
	 * @return bool True on completion. False if no email addresses were specified.
	 */
	function wp_notify_postauthor( $comment_id, $deprecated = null ) {
		if ( null !== $deprecated ) {
			_deprecated_argument( __FUNCTION__, '3.8.0' );
		}

		$comment = get_comment( $comment_id );
		if ( empty( $comment ) || empty( $comment->comment_post_ID ) ) {
			return false;
		}

		$post   = get_post( $comment->comment_post_ID );
		$author = get_userdata( $post->post_author );

		// Who to notify? By default, just the post author, but others can be added.
		$emails = array();
		if ( $author ) {
			$emails[] = $author->user_email;
		}

		/**
		 * Filters the list of …

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