ApiPageSet: Use processTitlesArray() in getRedirectTargets()

[mediawiki.git] / includes / user / User.php

<?php
/**
 * Implements the User class for the %MediaWiki software.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 */

use MediaWiki\MediaWikiServices;
use MediaWiki\Session\SessionManager;
use MediaWiki\Session\Token;
use MediaWiki\Auth\AuthManager;
use MediaWiki\Auth\AuthenticationResponse;
use MediaWiki\Auth\AuthenticationRequest;
use Wikimedia\ScopedCallback;

/**
 * String Some punctuation to prevent editing from broken text-mangling proxies.
 * @deprecated since 1.27, use \MediaWiki\Session\Token::SUFFIX
 * @ingroup Constants
 */
define( 'EDIT_TOKEN_SUFFIX', Token::SUFFIX );

/**
 * The User object encapsulates all of the user-specific settings (user_id,
 * name, rights, email address, options, last login time). Client
 * classes use the getXXX() functions to access these fields. These functions
 * do all the work of determining whether the user is logged in,
 * whether the requested option can be satisfied from cookies or
 * whether a database query is needed. Most of the settings needed
 * for rendering normal pages are set in the cookie to minimize use
 * of the database.
 */
class User implements IDBAccessObject {
        /**
         * @const int Number of characters in user_token field.
         */
        const TOKEN_LENGTH = 32;

        /**
         * @const string An invalid value for user_token
         */
        const INVALID_TOKEN = '*** INVALID ***';

        /**
         * Global constant made accessible as class constants so that autoloader
         * magic can be used.
         * @deprecated since 1.27, use \MediaWiki\Session\Token::SUFFIX
         */
        const EDIT_TOKEN_SUFFIX = EDIT_TOKEN_SUFFIX;

        /**
         * @const int Serialized record version.
         */
        const VERSION = 11;

        /**
         * Exclude user options that are set to their default value.
         * @since 1.25
         */
        const GETOPTIONS_EXCLUDE_DEFAULTS = 1;

        /**
         * @since 1.27
         */
        const CHECK_USER_RIGHTS = true;

        /**
         * @since 1.27
         */
        const IGNORE_USER_RIGHTS = false;

        /**
         * Array of Strings List of member variables which are saved to the
         * shared cache (memcached). Any operation which changes the
         * corresponding database fields must call a cache-clearing function.
         * @showinitializer
         */
        protected static $mCacheVars = [
                // user table
                'mId',
                'mName',
                'mRealName',
                'mEmail',
                'mTouched',
                'mToken',
                'mEmailAuthenticated',
                'mEmailToken',
                'mEmailTokenExpires',
                'mRegistration',
                'mEditCount',
                // user_groups table
                'mGroupMemberships',
                // user_properties table
                'mOptionOverrides',
        ];

        /**
         * Array of Strings Core rights.
         * Each of these should have a corresponding message of the form
         * "right-$right".
         * @showinitializer
         */
        protected static $mCoreRights = [
                'apihighlimits',
                'applychangetags',
                'autoconfirmed',
                'autocreateaccount',
                'autopatrol',
                'bigdelete',
                'block',
                'blockemail',
                'bot',
                'browsearchive',
                'changetags',
                'createaccount',
                'createpage',
                'createtalk',
                'delete',
                'deletechangetags',
                'deletedhistory',
                'deletedtext',
                'deletelogentry',
                'deleterevision',
                'edit',
                'editcontentmodel',
                'editinterface',
                'editprotected',
                'editmyoptions',
                'editmyprivateinfo',
                'editmyusercss',
                'editmyuserjs',
                'editmywatchlist',
                'editsemiprotected',
                'editusercssjs', # deprecated
                'editusercss',
                'edituserjs',
                'hideuser',
                'import',
                'importupload',
                'ipblock-exempt',
                'managechangetags',
                'markbotedits',
                'mergehistory',
                'minoredit',
                'move',
                'movefile',
                'move-categorypages',
                'move-rootuserpages',
                'move-subpages',
                'nominornewtalk',
                'noratelimit',
                'override-export-depth',
                'pagelang',
                'patrol',
                'patrolmarks',
                'protect',
                'purge',
                'read',
                'reupload',
                'reupload-own',
                'reupload-shared',
                'rollback',
                'sendemail',
                'siteadmin',
                'suppressionlog',
                'suppressredirect',
                'suppressrevision',
                'unblockself',
                'undelete',
                'unwatchedpages',
                'upload',
                'upload_by_url',
                'userrights',
                'userrights-interwiki',
                'viewmyprivateinfo',
                'viewmywatchlist',
                'viewsuppressed',
                'writeapi',
        ];

        /**
         * String Cached results of getAllRights()
         */
        protected static $mAllRights = false;

        /** Cache variables */
        // @{
        /** @var int */
        public $mId;
        /** @var string */
        public $mName;
        /** @var string */
        public $mRealName;

        /** @var string */
        public $mEmail;
        /** @var string TS_MW timestamp from the DB */
        public $mTouched;
        /** @var string TS_MW timestamp from cache */
        protected $mQuickTouched;
        /** @var string */
        protected $mToken;
        /** @var string */
        public $mEmailAuthenticated;
        /** @var string */
        protected $mEmailToken;
        /** @var string */
        protected $mEmailTokenExpires;
        /** @var string */
        protected $mRegistration;
        /** @var int */
        protected $mEditCount;
        /**
         * @var array No longer used since 1.29; use User::getGroups() instead
         * @deprecated since 1.29
         */
        private $mGroups;
        /** @var array Associative array of (group name => UserGroupMembership object) */
        protected $mGroupMemberships;
        /** @var array */
        protected $mOptionOverrides;
        // @}

        /**
         * Bool Whether the cache variables have been loaded.
         */
        // @{
        public $mOptionsLoaded;

        /**
         * Array with already loaded items or true if all items have been loaded.
         */
        protected $mLoadedItems = [];
        // @}

        /**
         * String Initialization data source if mLoadedItems!==true. May be one of:
         *  - 'defaults'   anonymous user initialised from class defaults
         *  - 'name'       initialise from mName
         *  - 'id'         initialise from mId
         *  - 'session'    log in from session if possible
         *
         * Use the User::newFrom*() family of functions to set this.
         */
        public $mFrom;

        /**
         * Lazy-initialized variables, invalidated with clearInstanceCache
         */
        protected $mNewtalk;
        /** @var string */
        protected $mDatePreference;
        /** @var string */
        public $mBlockedby;
        /** @var string */
        protected $mHash;
        /** @var array */
        public $mRights;
        /** @var string */
        protected $mBlockreason;
        /** @var array */
        protected $mEffectiveGroups;
        /** @var array */
        protected $mImplicitGroups;
        /** @var array */
        protected $mFormerGroups;
        /** @var Block */
        protected $mGlobalBlock;
        /** @var bool */
        protected $mLocked;
        /** @var bool */
        public $mHideName;
        /** @var array */
        public $mOptions;

        /** @var WebRequest */
        private $mRequest;

        /** @var Block */
        public $mBlock;

        /** @var bool */
        protected $mAllowUsertalk;

        /** @var Block */
        private $mBlockedFromCreateAccount = false;

        /** @var integer User::READ_* constant bitfield used to load data */
        protected $queryFlagsUsed = self::READ_NORMAL;

        /** @var string Indicates type of block (used for eventlogging)
         * Permitted values: 'cookie-block', 'proxy-block', 'openproxy-block', 'xff-block',
         * 'config-block'
         */
        public $blockTrigger = false;

        public static $idCacheByName = [];

        /**
         * Lightweight constructor for an anonymous user.
         * Use the User::newFrom* factory functions for other kinds of users.
         *
         * @see newFromName()
         * @see newFromId()
         * @see newFromConfirmationCode()
         * @see newFromSession()
         * @see newFromRow()
         */
        public function __construct() {
                $this->clearInstanceCache( 'defaults' );
        }

        /**
         * @return string
         */
        public function __toString() {
                return (string)$this->getName();
        }

        /**
         * Test if it's safe to load this User object.
         *
         * You should typically check this before using $wgUser or
         * RequestContext::getUser in a method that might be called before the
         * system has been fully initialized. If the object is unsafe, you should
         * use an anonymous user:
         * \code
         * $user = $wgUser->isSafeToLoad() ? $wgUser : new User;
         * \endcode
         *
         * @since 1.27
         * @return bool
         */
        public function isSafeToLoad() {
                global $wgFullyInitialised;

                // The user is safe to load if:
                // * MW_NO_SESSION is undefined AND $wgFullyInitialised is true (safe to use session data)
                // * mLoadedItems === true (already loaded)
                // * mFrom !== 'session' (sessions not involved at all)

                return ( !defined( 'MW_NO_SESSION' ) && $wgFullyInitialised ) ||
                        $this->mLoadedItems === true || $this->mFrom !== 'session';
        }

        /**
         * Load the user table data for this object from the source given by mFrom.
         *
         * @param integer $flags User::READ_* constant bitfield
         */
        public function load( $flags = self::READ_NORMAL ) {
                global $wgFullyInitialised;

                if ( $this->mLoadedItems === true ) {
                        return;
                }

                // Set it now to avoid infinite recursion in accessors
                $oldLoadedItems = $this->mLoadedItems;
                $this->mLoadedItems = true;
                $this->queryFlagsUsed = $flags;

                // If this is called too early, things are likely to break.
                if ( !$wgFullyInitialised && $this->mFrom === 'session' ) {
                        \MediaWiki\Logger\LoggerFactory::getInstance( 'session' )
                                ->warning( 'User::loadFromSession called before the end of Setup.php', [
                                        'exception' => new Exception( 'User::loadFromSession called before the end of Setup.php' ),
                                ] );
                        $this->loadDefaults();
                        $this->mLoadedItems = $oldLoadedItems;
                        return;
                }

                switch ( $this->mFrom ) {
                        case 'defaults':
                                $this->loadDefaults();
                                break;
                        case 'name':
                                // Make sure this thread sees its own changes
                                if ( wfGetLB()->hasOrMadeRecentMasterChanges() ) {
                                        $flags |= self::READ_LATEST;
                                        $this->queryFlagsUsed = $flags;
                                }

                                $this->mId = self::idFromName( $this->mName, $flags );
                                if ( !$this->mId ) {
                                        // Nonexistent user placeholder object
                                        $this->loadDefaults( $this->mName );
                                } else {
                                        $this->loadFromId( $flags );
                                }
                                break;
                        case 'id':
                                $this->loadFromId( $flags );
                                break;
                        case 'session':
                                if ( !$this->loadFromSession() ) {
                                        // Loading from session failed. Load defaults.
                                        $this->loadDefaults();
                                }
                                Hooks::run( 'UserLoadAfterLoadFromSession', [ $this ] );
                                break;
                        default:
                                throw new UnexpectedValueException(
                                        "Unrecognised value for User->mFrom: \"{$this->mFrom}\"" );
                }
        }

        /**
         * Load user table data, given mId has already been set.
         * @param integer $flags User::READ_* constant bitfield
         * @return bool False if the ID does not exist, true otherwise
         */
        public function loadFromId( $flags = self::READ_NORMAL ) {
                if ( $this->mId == 0 ) {
                        // Anonymous users are not in the database (don't need cache)
                        $this->loadDefaults();
                        return false;
                }

                // Try cache (unless this needs data from the master DB).
                // NOTE: if this thread called saveSettings(), the cache was cleared.
                $latest = DBAccessObjectUtils::hasFlags( $flags, self::READ_LATEST );
                if ( $latest ) {
                        if ( !$this->loadFromDatabase( $flags ) ) {
                                // Can't load from ID
                                return false;
                        }
                } else {
                        $this->loadFromCache();
                }

                $this->mLoadedItems = true;
                $this->queryFlagsUsed = $flags;

                return true;
        }

        /**
         * @since 1.27
         * @param string $wikiId
         * @param integer $userId
         */
        public static function purge( $wikiId, $userId ) {
                $cache = ObjectCache::getMainWANInstance();
                $key = $cache->makeGlobalKey( 'user', 'id', $wikiId, $userId );
                $cache->delete( $key );
        }

        /**
         * @since 1.27
         * @param WANObjectCache $cache
         * @return string
         */
        protected function getCacheKey( WANObjectCache $cache ) {
                return $cache->makeGlobalKey( 'user', 'id', wfWikiID(), $this->mId );
        }

        /**
         * @param WANObjectCache $cache
         * @return string[]
         * @since 1.28
         */
        public function getMutableCacheKeys( WANObjectCache $cache ) {
                $id = $this->getId();

                return $id ? [ $this->getCacheKey( $cache ) ] : [];
        }

        /**
         * Load user data from shared cache, given mId has already been set.
         *
         * @return bool True
         * @since 1.25
         */
        protected function loadFromCache() {
                $cache = ObjectCache::getMainWANInstance();
                $data = $cache->getWithSetCallback(
                        $this->getCacheKey( $cache ),
                        $cache::TTL_HOUR,
                        function ( $oldValue, &$ttl, array &$setOpts ) use ( $cache ) {
                                $setOpts += Database::getCacheSetOptions( wfGetDB( DB_REPLICA ) );
                                wfDebug( "User: cache miss for user {$this->mId}\n" );

                                $this->loadFromDatabase( self::READ_NORMAL );
                                $this->loadGroups();
                                $this->loadOptions();

                                $data = [];
                                foreach ( self::$mCacheVars as $name ) {
                                        $data[$name] = $this->$name;
                                }

                                $ttl = $cache->adaptiveTTL( wfTimestamp( TS_UNIX, $this->mTouched ), $ttl );

                                return $data;

                        },
                        [ 'pcTTL' => $cache::TTL_PROC_LONG, 'version' => self::VERSION ]
                );

                // Restore from cache
                foreach ( self::$mCacheVars as $name ) {
                        $this->$name = $data[$name];
                }

                return true;
        }

        /** @name newFrom*() static factory methods */
        // @{

        /**
         * Static factory method for creation from username.
         *
         * This is slightly less efficient than newFromId(), so use newFromId() if
         * you have both an ID and a name handy.
         *
         * @param string $name Username, validated by Title::newFromText()
         * @param string|bool $validate Validate username. Takes the same parameters as
         *  User::getCanonicalName(), except that true is accepted as an alias
         *  for 'valid', for BC.
         *
         * @return User|bool User object, or false if the username is invalid
         *  (e.g. if it contains illegal characters or is an IP address). If the
         *  username is not present in the database, the result will be a user object
         *  with a name, zero user ID and default settings.
         */
        public static function newFromName( $name, $validate = 'valid' ) {
                if ( $validate === true ) {
                        $validate = 'valid';
                }
                $name = self::getCanonicalName( $name, $validate );
                if ( $name === false ) {
                        return false;
                } else {
                        // Create unloaded user object
                        $u = new User;
                        $u->mName = $name;
                        $u->mFrom = 'name';
                        $u->setItemLoaded( 'name' );
                        return $u;
                }
        }

        /**
         * Static factory method for creation from a given user ID.
         *
         * @param int $id Valid user ID
         * @return User The corresponding User object
         */
        public static function newFromId( $id ) {
                $u = new User;
                $u->mId = $id;
                $u->mFrom = 'id';
                $u->setItemLoaded( 'id' );
                return $u;
        }

        /**
         * Factory method to fetch whichever user has a given email confirmation code.
         * This code is generated when an account is created or its e-mail address
         * has changed.
         *
         * If the code is invalid or has expired, returns NULL.
         *
         * @param string $code Confirmation code
         * @param int $flags User::READ_* bitfield
         * @return User|null
         */
        public static function newFromConfirmationCode( $code, $flags = 0 ) {
                $db = ( $flags & self::READ_LATEST ) == self::READ_LATEST
                        ? wfGetDB( DB_MASTER )
                        : wfGetDB( DB_REPLICA );

                $id = $db->selectField(
                        'user',
                        'user_id',
                        [
                                'user_email_token' => md5( $code ),
                                'user_email_token_expires > ' . $db->addQuotes( $db->timestamp() ),
                        ]
                );

                return $id ? User::newFromId( $id ) : null;
        }

        /**
         * Create a new user object using data from session. If the login
         * credentials are invalid, the result is an anonymous user.
         *
         * @param WebRequest|null $request Object to use; $wgRequest will be used if omitted.
         * @return User
         */
        public static function newFromSession( WebRequest $request = null ) {
                $user = new User;
                $user->mFrom = 'session';
                $user->mRequest = $request;
                return $user;
        }

        /**
         * Create a new user object from a user row.
         * The row should have the following fields from the user table in it:
         * - either user_name or user_id to load further data if needed (or both)
         * - user_real_name
         * - all other fields (email, etc.)
         * It is useless to provide the remaining fields if either user_id,
         * user_name and user_real_name are not provided because the whole row
         * will be loaded once more from the database when accessing them.
         *
         * @param stdClass $row A row from the user table
         * @param array $data Further data to load into the object (see User::loadFromRow for valid keys)
         * @return User
         */
        public static function newFromRow( $row, $data = null ) {
                $user = new User;
                $user->loadFromRow( $row, $data );
                return $user;
        }

        /**
         * Static factory method for creation of a "system" user from username.
         *
         * A "system" user is an account that's used to attribute logged actions
         * taken by MediaWiki itself, as opposed to a bot or human user. Examples
         * might include the 'Maintenance script' or 'Conversion script' accounts
         * used by various scripts in the maintenance/ directory or accounts such
         * as 'MediaWiki message delivery' used by the MassMessage extension.
         *
         * This can optionally create the user if it doesn't exist, and "steal" the
         * account if it does exist.
         *
         * "Stealing" an existing user is intended to make it impossible for normal
         * authentication processes to use the account, effectively disabling the
         * account for normal use:
         * - Email is invalidated, to prevent account recovery by emailing a
         *   temporary password and to disassociate the account from the existing
         *   human.
         * - The token is set to a magic invalid value, to kill existing sessions
         *   and to prevent $this->setToken() calls from resetting the token to a
         *   valid value.
         * - SessionManager is instructed to prevent new sessions for the user, to
         *   do things like deauthorizing OAuth consumers.
         * - AuthManager is instructed to revoke access, to invalidate or remove
         *   passwords and other credentials.
         *
         * @param string $name Username
         * @param array $options Options are:
         *  - validate: As for User::getCanonicalName(), default 'valid'
         *  - create: Whether to create the user if it doesn't already exist, default true
         *  - steal: Whether to "disable" the account for normal use if it already
         *    exists, default false
         * @return User|null
         * @since 1.27
         */
        public static function newSystemUser( $name, $options = [] ) {
                $options += [
                        'validate' => 'valid',
                        'create' => true,
                        'steal' => false,
                ];

                $name = self::getCanonicalName( $name, $options['validate'] );
                if ( $name === false ) {
                        return null;
                }

                $fields = self::selectFields();

                $dbw = wfGetDB( DB_MASTER );
                $row = $dbw->selectRow(
                        'user',
                        $fields,
                        [ 'user_name' => $name ],
                        __METHOD__
                );
                if ( !$row ) {
                        // No user. Create it?
                        return $options['create'] ? self::createNew( $name, [ 'token' => self::INVALID_TOKEN ] ) : null;
                }
                $user = self::newFromRow( $row );

                // A user is considered to exist as a non-system user if it can
                // authenticate, or has an email set, or has a non-invalid token.
                if ( $user->mEmail || $user->mToken !== self::INVALID_TOKEN ||
                        AuthManager::singleton()->userCanAuthenticate( $name )
                ) {
                        // User exists. Steal it?
                        if ( !$options['steal'] ) {
                                return null;
                        }

                        AuthManager::singleton()->revokeAccessForUser( $name );

                        $user->invalidateEmail();
                        $user->mToken = self::INVALID_TOKEN;
                        $user->saveSettings();
                        SessionManager::singleton()->preventSessionsForUser( $user->getName() );
                }

                return $user;
        }

        // @}

        /**
         * Get the username corresponding to a given user ID
         * @param int $id User ID
         * @return string|bool The corresponding username
         */
        public static function whoIs( $id ) {
                return UserCache::singleton()->getProp( $id, 'name' );
        }

        /**
         * Get the real name of a user given their user ID
         *
         * @param int $id User ID
         * @return string|bool The corresponding user's real name
         */
        public static function whoIsReal( $id ) {
                return UserCache::singleton()->getProp( $id, 'real_name' );
        }

        /**
         * Get database id given a user name
         * @param string $name Username
         * @param integer $flags User::READ_* constant bitfield
         * @return int|null The corresponding user's ID, or null if user is nonexistent
         */
        public static function idFromName( $name, $flags = self::READ_NORMAL ) {
                $nt = Title::makeTitleSafe( NS_USER, $name );
                if ( is_null( $nt ) ) {
                        // Illegal name
                        return null;
                }

                if ( !( $flags & self::READ_LATEST ) && isset( self::$idCacheByName[$name] ) ) {
                        return self::$idCacheByName[$name];
                }

                list( $index, $options ) = DBAccessObjectUtils::getDBOptions( $flags );
                $db = wfGetDB( $index );

                $s = $db->selectRow(
                        'user',
                        [ 'user_id' ],
                        [ 'user_name' => $nt->getText() ],
                        __METHOD__,
                        $options
                );

                if ( $s === false ) {
                        $result = null;
                } else {
                        $result = $s->user_id;
                }

                self::$idCacheByName[$name] = $result;

                if ( count( self::$idCacheByName ) > 1000 ) {
                        self::$idCacheByName = [];
                }

                return $result;
        }

        /**
         * Reset the cache used in idFromName(). For use in tests.
         */
        public static function resetIdByNameCache() {
                self::$idCacheByName = [];
        }

        /**
         * Does the string match an anonymous IP address?
         *
         * This function exists for username validation, in order to reject
         * usernames which are similar in form to IP addresses. Strings such
         * as 300.300.300.300 will return true because it looks like an IP
         * address, despite not being strictly valid.
         *
         * We match "\d{1,3}\.\d{1,3}\.\d{1,3}\.xxx" as an anonymous IP
         * address because the usemod software would "cloak" anonymous IP
         * addresses like this, if we allowed accounts like this to be created
         * new users could get the old edits of these anonymous users.
         *
         * @param string $name Name to match
         * @return bool
         */
        public static function isIP( $name ) {
                return preg_match( '/^\d{1,3}\.\d{1,3}\.\d{1,3}\.(?:xxx|\d{1,3})$/', $name )
                        || IP::isIPv6( $name );
        }

        /**
         * Is the input a valid username?
         *
         * Checks if the input is a valid username, we don't want an empty string,
         * an IP address, anything that contains slashes (would mess up subpages),
         * is longer than the maximum allowed username size or doesn't begin with
         * a capital letter.
         *
         * @param string $name Name to match
         * @return bool
         */
        public static function isValidUserName( $name ) {
                global $wgContLang, $wgMaxNameChars;

                if ( $name == ''
                        || User::isIP( $name )
                        || strpos( $name, '/' ) !== false
                        || strlen( $name ) > $wgMaxNameChars
                        || $name != $wgContLang->ucfirst( $name )
                ) {
                        return false;
                }

                // Ensure that the name can't be misresolved as a different title,
                // such as with extra namespace keys at the start.
                $parsed = Title::newFromText( $name );
                if ( is_null( $parsed )
                        || $parsed->getNamespace()
                        || strcmp( $name, $parsed->getPrefixedText() ) ) {
                        return false;
                }

                // Check an additional blacklist of troublemaker characters.
                // Should these be merged into the title char list?
                $unicodeBlacklist = '/[' .
                        '\x{0080}-\x{009f}' . # iso-8859-1 control chars
                        '\x{00a0}' .          # non-breaking space
                        '\x{2000}-\x{200f}' . # various whitespace
                        '\x{2028}-\x{202f}' . # breaks and control chars
                        '\x{3000}' .          # ideographic space
                        '\x{e000}-\x{f8ff}' . # private use
                        ']/u';
                if ( preg_match( $unicodeBlacklist, $name ) ) {
                        return false;
                }

                return true;
        }

        /**
         * Usernames which fail to pass this function will be blocked
         * from user login and new account registrations, but may be used
         * internally by batch processes.
         *
         * If an account already exists in this form, login will be blocked
         * by a failure to pass this function.
         *
         * @param string $name Name to match
         * @return bool
         */
        public static function isUsableName( $name ) {
                global $wgReservedUsernames;
                // Must be a valid username, obviously ;)
                if ( !self::isValidUserName( $name ) ) {
                        return false;
                }

                static $reservedUsernames = false;
                if ( !$reservedUsernames ) {
                        $reservedUsernames = $wgReservedUsernames;
                        Hooks::run( 'UserGetReservedNames', [ &$reservedUsernames ] );
                }

                // Certain names may be reserved for batch processes.
                foreach ( $reservedUsernames as $reserved ) {
                        if ( substr( $reserved, 0, 4 ) == 'msg:' ) {
                                $reserved = wfMessage( substr( $reserved, 4 ) )->inContentLanguage()->text();
                        }
                        if ( $reserved == $name ) {
                                return false;
                        }
                }
                return true;
        }

        /**
         * Return the users who are members of the given group(s). In case of multiple groups,
         * users who are members of at least one of them are returned.
         *
         * @param string|array $groups A single group name or an array of group names
         * @param int $limit Max number of users to return. The actual limit will never exceed 5000
         *   records; larger values are ignored.
         * @param int $after ID the user to start after
         * @return UserArrayFromResult
         */
        public static function findUsersByGroup( $groups, $limit = 5000, $after = null ) {
                if ( $groups === [] ) {
                        return UserArrayFromResult::newFromIDs( [] );
                }

                $groups = array_unique( (array)$groups );
                $limit = min( 5000, $limit );

                $conds = [ 'ug_group' => $groups ];
                if ( $after !== null ) {
                        $conds[] = 'ug_user > ' . (int)$after;
                }

                $dbr = wfGetDB( DB_REPLICA );
                $ids = $dbr->selectFieldValues(
                        'user_groups',
                        'ug_user',
                        $conds,
                        __METHOD__,
                        [
                                'DISTINCT' => true,
                                'ORDER BY' => 'ug_user',
                                'LIMIT' => $limit,
                        ]
                ) ?: [];
                return UserArray::newFromIDs( $ids );
        }

        /**
         * Usernames which fail to pass this function will be blocked
         * from new account registrations, but may be used internally
         * either by batch processes or by user accounts which have
         * already been created.
         *
         * Additional blacklisting may be added here rather than in
         * isValidUserName() to avoid disrupting existing accounts.
         *
         * @param string $name String to match
         * @return bool
         */
        public static function isCreatableName( $name ) {
                global $wgInvalidUsernameCharacters;

                // Ensure that the username isn't longer than 235 bytes, so that
                // (at least for the builtin skins) user javascript and css files
                // will work. (T25080)
                if ( strlen( $name ) > 235 ) {
                        wfDebugLog( 'username', __METHOD__ .
                                ": '$name' invalid due to length" );
                        return false;
                }

                // Preg yells if you try to give it an empty string
                if ( $wgInvalidUsernameCharacters !== '' ) {
                        if ( preg_match( '/[' . preg_quote( $wgInvalidUsernameCharacters, '/' ) . ']/', $name ) ) {
                                wfDebugLog( 'username', __METHOD__ .
                                        ": '$name' invalid due to wgInvalidUsernameCharacters" );
                                return false;
                        }
                }

                return self::isUsableName( $name );
        }

        /**
         * Is the input a valid password for this user?
         *
         * @param string $password Desired password
         * @return bool
         */
        public function isValidPassword( $password ) {
                // simple boolean wrapper for getPasswordValidity
                return $this->getPasswordValidity( $password ) === true;
        }

        /**
         * Given unvalidated password input, return error message on failure.
         *
         * @param string $password Desired password
         * @return bool|string|array True on success, string or array of error message on failure
         */
        public function getPasswordValidity( $password ) {
                $result = $this->checkPasswordValidity( $password );
                if ( $result->isGood() ) {
                        return true;
                } else {
                        $messages = [];
                        foreach ( $result->getErrorsByType( 'error' ) as $error ) {
                                $messages[] = $error['message'];
                        }
                        foreach ( $result->getErrorsByType( 'warning' ) as $warning ) {
                                $messages[] = $warning['message'];
                        }
                        if ( count( $messages ) === 1 ) {
                                return $messages[0];
                        }
                        return $messages;
                }
        }

        /**
         * Check if this is a valid password for this user
         *
         * Create a Status object based on the password's validity.
         * The Status should be set to fatal if the user should not
         * be allowed to log in, and should have any errors that
         * would block changing the password.
         *
         * If the return value of this is not OK, the password
         * should not be checked. If the return value is not Good,
         * the password can be checked, but the user should not be
         * able to set their password to this.
         *
         * @param string $password Desired password
         * @return Status
         * @since 1.23
         */
        public function checkPasswordValidity( $password ) {
                global $wgPasswordPolicy;

                $upp = new UserPasswordPolicy(
                        $wgPasswordPolicy['policies'],
                        $wgPasswordPolicy['checks']
                );

                $status = Status::newGood();
                $result = false; // init $result to false for the internal checks

                if ( !Hooks::run( 'isValidPassword', [ $password, &$result, $this ] ) ) {
                        $status->error( $result );
                        return $status;
                }

                if ( $result === false ) {
                        $status->merge( $upp->checkUserPassword( $this, $password ) );
                        return $status;
                } elseif ( $result === true ) {
                        return $status;
                } else {
                        $status->error( $result );
                        return $status; // the isValidPassword hook set a string $result and returned true
                }
        }

        /**
         * Given unvalidated user input, return a canonical username, or false if
         * the username is invalid.
         * @param string $name User input
         * @param string|bool $validate Type of validation to use:
         *   - false        No validation
         *   - 'valid'      Valid for batch processes
         *   - 'usable'     Valid for batch processes and login
         *   - 'creatable'  Valid for batch processes, login and account creation
         *
         * @throws InvalidArgumentException
         * @return bool|string
         */
        public static function getCanonicalName( $name, $validate = 'valid' ) {
                // Force usernames to capital
                global $wgContLang;
                $name = $wgContLang->ucfirst( $name );

                # Reject names containing '#'; these will be cleaned up
                # with title normalisation, but then it's too late to
                # check elsewhere
                if ( strpos( $name, '#' ) !== false ) {
                        return false;
                }

                // Clean up name according to title rules,
                // but only when validation is requested (T14654)
                $t = ( $validate !== false ) ?
                        Title::newFromText( $name, NS_USER ) : Title::makeTitle( NS_USER, $name );
                // Check for invalid titles
                if ( is_null( $t ) || $t->getNamespace() !== NS_USER || $t->isExternal() ) {
                        return false;
                }

                // Reject various classes of invalid names
                $name = AuthManager::callLegacyAuthPlugin(
                        'getCanonicalName', [ $t->getText() ], $t->getText()
                );

                switch ( $validate ) {
                        case false:
                                break;
                        case 'valid':
                                if ( !User::isValidUserName( $name ) ) {
                                        $name = false;
                                }
                                break;
                        case 'usable':
                                if ( !User::isUsableName( $name ) ) {
                                        $name = false;
                                }
                                break;
                        case 'creatable':
                                if ( !User::isCreatableName( $name ) ) {
                                        $name = false;
                                }
                                break;
                        default:
                                throw new InvalidArgumentException(
                                        'Invalid parameter value for $validate in ' . __METHOD__ );
                }
                return $name;
        }

        /**
         * Return a random password.
         *
         * @deprecated since 1.27, use PasswordFactory::generateRandomPasswordString()
         * @return string New random password
         */
        public static function randomPassword() {
                global $wgMinimalPasswordLength;
                return PasswordFactory::generateRandomPasswordString( $wgMinimalPasswordLength );
        }

        /**
         * Set cached properties to default.
         *
         * @note This no longer clears uncached lazy-initialised properties;
         *       the constructor does that instead.
         *
         * @param string|bool $name
         */
        public function loadDefaults( $name = false ) {
                $this->mId = 0;
                $this->mName = $name;
                $this->mRealName = '';
                $this->mEmail = '';
                $this->mOptionOverrides = null;
                $this->mOptionsLoaded = false;

                $loggedOut = $this->mRequest && !defined( 'MW_NO_SESSION' )
                        ? $this->mRequest->getSession()->getLoggedOutTimestamp() : 0;
                if ( $loggedOut !== 0 ) {
                        $this->mTouched = wfTimestamp( TS_MW, $loggedOut );
                } else {
                        $this->mTouched = '1'; # Allow any pages to be cached
                }

                $this->mToken = null; // Don't run cryptographic functions till we need a token
                $this->mEmailAuthenticated = null;
                $this->mEmailToken = '';
                $this->mEmailTokenExpires = null;
                $this->mRegistration = wfTimestamp( TS_MW );
                $this->mGroupMemberships = [];

                Hooks::run( 'UserLoadDefaults', [ $this, $name ] );
        }

        /**
         * Return whether an item has been loaded.
         *
         * @param string $item Item to check. Current possibilities:
         *   - id
         *   - name
         *   - realname
         * @param string $all 'all' to check if the whole object has been loaded
         *   or any other string to check if only the item is available (e.g.
         *   for optimisation)
         * @return bool
         */
        public function isItemLoaded( $item, $all = 'all' ) {
                return ( $this->mLoadedItems === true && $all === 'all' ) ||
                        ( isset( $this->mLoadedItems[$item] ) && $this->mLoadedItems[$item] === true );
        }

        /**
         * Set that an item has been loaded
         *
         * @param string $item
         */
        protected function setItemLoaded( $item ) {
                if ( is_array( $this->mLoadedItems ) ) {
                        $this->mLoadedItems[$item] = true;
                }
        }

        /**
         * Load user data from the session.
         *
         * @return bool True if the user is logged in, false otherwise.
         */
        private function loadFromSession() {
                // Deprecated hook
                $result = null;
                Hooks::run( 'UserLoadFromSession', [ $this, &$result ], '1.27' );
                if ( $result !== null ) {
                        return $result;
                }

                // MediaWiki\Session\Session already did the necessary authentication of the user
                // returned here, so just use it if applicable.
                $session = $this->getRequest()->getSession();
                $user = $session->getUser();
                if ( $user->isLoggedIn() ) {
                        $this->loadFromUserObject( $user );

                        // If this user is autoblocked, set a cookie to track the Block. This has to be done on
                        // every session load, because an autoblocked editor might not edit again from the same
                        // IP address after being blocked.
                        $config = RequestContext::getMain()->getConfig();
                        if ( $config->get( 'CookieSetOnAutoblock' ) === true ) {
                                $block = $this->getBlock();
                                $shouldSetCookie = $this->getRequest()->getCookie( 'BlockID' ) === null
                                        && $block
                                        && $block->getType() === Block::TYPE_USER
                                        && $block->isAutoblocking();
                                if ( $shouldSetCookie ) {
                                        wfDebug( __METHOD__ . ': User is autoblocked, setting cookie to track' );
                                        $block->setCookie( $this->getRequest()->response() );
                                }
                        }

                        // Other code expects these to be set in the session, so set them.
                        $session->set( 'wsUserID', $this->getId() );
                        $session->set( 'wsUserName', $this->getName() );
                        $session->set( 'wsToken', $this->getToken() );
                        return true;
                }
                return false;
        }

        /**
         * Load user and user_group data from the database.
         * $this->mId must be set, this is how the user is identified.
         *
         * @param integer $flags User::READ_* constant bitfield
         * @return bool True if the user exists, false if the user is anonymous
         */
        public function loadFromDatabase( $flags = self::READ_LATEST ) {
                // Paranoia
                $this->mId = intval( $this->mId );

                if ( !$this->mId ) {
                        // Anonymous users are not in the database
                        $this->loadDefaults();
                        return false;
                }

                list( $index, $options ) = DBAccessObjectUtils::getDBOptions( $flags );
                $db = wfGetDB( $index );

                $s = $db->selectRow(
                        'user',
                        self::selectFields(),
                        [ 'user_id' => $this->mId ],
                        __METHOD__,
                        $options
                );

                $this->queryFlagsUsed = $flags;
                Hooks::run( 'UserLoadFromDatabase', [ $this, &$s ] );

                if ( $s !== false ) {
                        // Initialise user table data
                        $this->loadFromRow( $s );
                        $this->mGroupMemberships = null; // deferred
                        $this->getEditCount(); // revalidation for nulls
                        return true;
                } else {
                        // Invalid user_id
                        $this->mId = 0;
                        $this->loadDefaults();
                        return false;
                }
        }

        /**
         * Initialize this object from a row from the user table.
         *
         * @param stdClass $row Row from the user table to load.
         * @param array $data Further user data to load into the object
         *
         *  user_groups   Array of arrays or stdClass result rows out of the user_groups
         *                table. Previously you were supposed to pass an array of strings
         *                here, but we also need expiry info nowadays, so an array of
         *                strings is ignored.
         *  user_properties   Array with properties out of the user_properties table
         */
        protected function loadFromRow( $row, $data = null ) {
                $all = true;

                $this->mGroupMemberships = null; // deferred

                if ( isset( $row->user_name ) ) {
                        $this->mName = $row->user_name;
                        $this->mFrom = 'name';
                        $this->setItemLoaded( 'name' );
                } else {
                        $all = false;
                }

                if ( isset( $row->user_real_name ) ) {
                        $this->mRealName = $row->user_real_name;
                        $this->setItemLoaded( 'realname' );
                } else {
                        $all = false;
                }

                if ( isset( $row->user_id ) ) {
                        $this->mId = intval( $row->user_id );
                        $this->mFrom = 'id';
                        $this->setItemLoaded( 'id' );
                } else {
                        $all = false;
                }

                if ( isset( $row->user_id ) && isset( $row->user_name ) ) {
                        self::$idCacheByName[$row->user_name] = $row->user_id;
                }

                if ( isset( $row->user_editcount ) ) {
                        $this->mEditCount = $row->user_editcount;
                } else {
                        $all = false;
                }

                if ( isset( $row->user_touched ) ) {
                        $this->mTouched = wfTimestamp( TS_MW, $row->user_touched );
                } else {
                        $all = false;
                }

                if ( isset( $row->user_token ) ) {
                        // The definition for the column is binary(32), so trim the NULs
                        // that appends. The previous definition was char(32), so trim
                        // spaces too.
                        $this->mToken = rtrim( $row->user_token, " \0" );
                        if ( $this->mToken === '' ) {
                                $this->mToken = null;
                        }
                } else {
                        $all = false;
                }

                if ( isset( $row->user_email ) ) {
                        $this->mEmail = $row->user_email;
                        $this->mEmailAuthenticated = wfTimestampOrNull( TS_MW, $row->user_email_authenticated );
                        $this->mEmailToken = $row->user_email_token;
                        $this->mEmailTokenExpires = wfTimestampOrNull( TS_MW, $row->user_email_token_expires );
                        $this->mRegistration = wfTimestampOrNull( TS_MW, $row->user_registration );
                } else {
                        $all = false;
                }

                if ( $all ) {
                        $this->mLoadedItems = true;
                }

                if ( is_array( $data ) ) {
                        if ( isset( $data['user_groups'] ) && is_array( $data['user_groups'] ) ) {
                                if ( !count( $data['user_groups'] ) ) {
                                        $this->mGroupMemberships = [];
                                } else {
                                        $firstGroup = reset( $data['user_groups'] );
                                        if ( is_array( $firstGroup ) || is_object( $firstGroup ) ) {
                                                $this->mGroupMemberships = [];
                                                foreach ( $data['user_groups'] as $row ) {
                                                        $ugm = UserGroupMembership::newFromRow( (object)$row );
                                                        $this->mGroupMemberships[$ugm->getGroup()] = $ugm;
                                                }
                                        }
                                }
                        }
                        if ( isset( $data['user_properties'] ) && is_array( $data['user_properties'] ) ) {
                                $this->loadOptions( $data['user_properties'] );
                        }
                }
        }

        /**
         * Load the data for this user object from another user object.
         *
         * @param User $user
         */
        protected function loadFromUserObject( $user ) {
                $user->load();
                foreach ( self::$mCacheVars as $var ) {
                        $this->$var = $user->$var;
                }
        }

        /**
         * Load the groups from the database if they aren't already loaded.
         */
        private function loadGroups() {
                if ( is_null( $this->mGroupMemberships ) ) {
                        $db = ( $this->queryFlagsUsed & self::READ_LATEST )
                                ? wfGetDB( DB_MASTER )
                                : wfGetDB( DB_REPLICA );
                        $this->mGroupMemberships = UserGroupMembership::getMembershipsForUser(
                                $this->mId, $db );
                }
        }

        /**
         * Add the user to the group if he/she meets given criteria.
         *
         * Contrary to autopromotion by \ref $wgAutopromote, the group will be
         *   possible to remove manually via Special:UserRights. In such case it
         *   will not be re-added automatically. The user will also not lose the
         *   group if they no longer meet the criteria.
         *
         * @param string $event Key in $wgAutopromoteOnce (each one has groups/criteria)
         *
         * @return array Array of groups the user has been promoted to.
         *
         * @see $wgAutopromoteOnce
         */
        public function addAutopromoteOnceGroups( $event ) {
                global $wgAutopromoteOnceLogInRC;

                if ( wfReadOnly() || !$this->getId() ) {
                        return [];
                }

                $toPromote = Autopromote::getAutopromoteOnceGroups( $this, $event );
                if ( !count( $toPromote ) ) {
                        return [];
                }

                if ( !$this->checkAndSetTouched() ) {
                        return []; // raced out (bug T48834)
                }

                $oldGroups = $this->getGroups(); // previous groups
                foreach ( $toPromote as $group ) {
                        $this->addGroup( $group );
                }
                // update groups in external authentication database
                Hooks::run( 'UserGroupsChanged', [ $this, $toPromote, [], false, false ] );
                AuthManager::callLegacyAuthPlugin( 'updateExternalDBGroups', [ $this, $toPromote ] );

                $newGroups = array_merge( $oldGroups, $toPromote ); // all groups

                $logEntry = new ManualLogEntry( 'rights', 'autopromote' );
                $logEntry->setPerformer( $this );
                $logEntry->setTarget( $this->getUserPage() );
                $logEntry->setParameters( [
                        '4::oldgroups' => $oldGroups,
                        '5::newgroups' => $newGroups,
                ] );
                $logid = $logEntry->insert();
                if ( $wgAutopromoteOnceLogInRC ) {
                        $logEntry->publish( $logid );
                }

                return $toPromote;
        }

        /**
         * Builds update conditions. Additional conditions may be added to $conditions to
         * protected against race conditions using a compare-and-set (CAS) mechanism
         * based on comparing $this->mTouched with the user_touched field.
         *
         * @param Database $db
         * @param array $conditions WHERE conditions for use with Database::update
         * @return array WHERE conditions for use with Database::update
         */
        protected function makeUpdateConditions( Database $db, array $conditions ) {
                if ( $this->mTouched ) {
                        // CAS check: only update if the row wasn't changed sicne it was loaded.
                        $conditions['user_touched'] = $db->timestamp( $this->mTouched );
                }

                return $conditions;
        }

        /**
         * Bump user_touched if it didn't change since this object was loaded
         *
         * On success, the mTouched field is updated.
         * The user serialization cache is always cleared.
         *
         * @return bool Whether user_touched was actually updated
         * @since 1.26
         */
        protected function checkAndSetTouched() {
                $this->load();

                if ( !$this->mId ) {
                        return false; // anon
                }

                // Get a new user_touched that is higher than the old one
                $newTouched = $this->newTouchedTimestamp();

                $dbw = wfGetDB( DB_MASTER );
                $dbw->update( 'user',
                        [ 'user_touched' => $dbw->timestamp( $newTouched ) ],
                        $this->makeUpdateConditions( $dbw, [
                                'user_id' => $this->mId,
                        ] ),
                        __METHOD__
                );
                $success = ( $dbw->affectedRows() > 0 );

                if ( $success ) {
                        $this->mTouched = $newTouched;
                        $this->clearSharedCache();
                } else {
                        // Clears on failure too since that is desired if the cache is stale
                        $this->clearSharedCache( 'refresh' );
                }

                return $success;
        }

        /**
         * Clear various cached data stored in this object. The cache of the user table
         * data (i.e. self::$mCacheVars) is not cleared unless $reloadFrom is given.
         *
         * @param bool|string $reloadFrom Reload user and user_groups table data from a
         *   given source. May be "name", "id", "defaults", "session", or false for no reload.
         */
        public function clearInstanceCache( $reloadFrom = false ) {
                $this->mNewtalk = -1;
                $this->mDatePreference = null;
                $this->mBlockedby = -1; # Unset
                $this->mHash = false;
                $this->mRights = null;
                $this->mEffectiveGroups = null;
                $this->mImplicitGroups = null;
                $this->mGroupMemberships = null;
                $this->mOptions = null;
                $this->mOptionsLoaded = false;
                $this->mEditCount = null;

                if ( $reloadFrom ) {
                        $this->mLoadedItems = [];
                        $this->mFrom = $reloadFrom;
                }
        }

        /**
         * Combine the language default options with any site-specific options
         * and add the default language variants.
         *
         * @return array Array of String options
         */
        public static function getDefaultOptions() {
                global $wgNamespacesToBeSearchedDefault, $wgDefaultUserOptions, $wgContLang, $wgDefaultSkin;

                static $defOpt = null;
                static $defOptLang = null;

                if ( $defOpt !== null && $defOptLang === $wgContLang->getCode() ) {
                        // $wgContLang does not change (and should not change) mid-request,
                        // but the unit tests change it anyway, and expect this method to
                        // return values relevant to the current $wgContLang.
                        return $defOpt;
                }

                $defOpt = $wgDefaultUserOptions;
                // Default language setting
                $defOptLang = $wgContLang->getCode();
                $defOpt['language'] = $defOptLang;
                foreach ( LanguageConverter::$languagesWithVariants as $langCode ) {
                        $defOpt[$langCode == $wgContLang->getCode() ? 'variant' : "variant-$langCode"] = $langCode;
                }

                // NOTE: don't use SearchEngineConfig::getSearchableNamespaces here,
                // since extensions may change the set of searchable namespaces depending
                // on user groups/permissions.
                foreach ( $wgNamespacesToBeSearchedDefault as $nsnum => $val ) {
                        $defOpt['searchNs' . $nsnum] = (boolean)$val;
                }
                $defOpt['skin'] = Skin::normalizeKey( $wgDefaultSkin );

                Hooks::run( 'UserGetDefaultOptions', [ &$defOpt ] );

                return $defOpt;
        }

        /**
         * Get a given default option value.
         *
         * @param string $opt Name of option to retrieve
         * @return string Default option value
         */
        public static function getDefaultOption( $opt ) {
                $defOpts = self::getDefaultOptions();
                if ( isset( $defOpts[$opt] ) ) {
                        return $defOpts[$opt];
                } else {
                        return null;
                }
        }

        /**
         * Get blocking information
         * @param bool $bFromSlave Whether to check the replica DB first.
         *   To improve performance, non-critical checks are done against replica DBs.
         *   Check when actually saving should be done against master.
         */
        private function getBlockedStatus( $bFromSlave = true ) {
                global $wgProxyWhitelist, $wgUser, $wgApplyIpBlocksToXff, $wgSoftBlockRanges;

                if ( -1 != $this->mBlockedby ) {
                        return;
                }

                wfDebug( __METHOD__ . ": checking...\n" );

                // Initialize data...
                // Otherwise something ends up stomping on $this->mBlockedby when
                // things get lazy-loaded later, causing false positive block hits
                // due to -1 !== 0. Probably session-related... Nothing should be
                // overwriting mBlockedby, surely?
                $this->load();

                # We only need to worry about passing the IP address to the Block generator if the
                # user is not immune to autoblocks/hardblocks, and they are the current user so we
                # know which IP address they're actually coming from
                $ip = null;
                if ( !$this->isAllowed( 'ipblock-exempt' ) ) {
                        // $wgUser->getName() only works after the end of Setup.php. Until
                        // then, assume it's a logged-out user.
                        $globalUserName = $wgUser->isSafeToLoad()
                                ? $wgUser->getName()
                                : IP::sanitizeIP( $wgUser->getRequest()->getIP() );
                        if ( $this->getName() === $globalUserName ) {
                                $ip = $this->getRequest()->getIP();
                        }
                }

                // User/IP blocking
                $block = Block::newFromTarget( $this, $ip, !$bFromSlave );

                // Cookie blocking
                if ( !$block instanceof Block ) {
                        $block = $this->getBlockFromCookieValue( $this->getRequest()->getCookie( 'BlockID' ) );
                }

                // Proxy blocking
                if ( !$block instanceof Block && $ip !== null && !in_array( $ip, $wgProxyWhitelist ) ) {
                        // Local list
                        if ( self::isLocallyBlockedProxy( $ip ) ) {
                                $block = new Block( [
                                        'byText' => wfMessage( 'proxyblocker' )->text(),
                                        'reason' => wfMessage( 'proxyblockreason' )->text(),
                                        'address' => $ip,
                                        'systemBlock' => 'proxy',
                                ] );
                                $this->blockTrigger = 'proxy-block';
                        } elseif ( $this->isAnon() && $this->isDnsBlacklisted( $ip ) ) {
                                $block = new Block( [
                                        'byText' => wfMessage( 'sorbs' )->text(),
                                        'reason' => wfMessage( 'sorbsreason' )->text(),
                                        'address' => $ip,
                                        'systemBlock' => 'dnsbl',
                                ] );
                                $this->blockTrigger = 'openproxy-block';
                        }
                }

                // (T25343) Apply IP blocks to the contents of XFF headers, if enabled
                if ( !$block instanceof Block
                        && $wgApplyIpBlocksToXff
                        && $ip !== null
                        && !in_array( $ip, $wgProxyWhitelist )
                ) {
                        $xff = $this->getRequest()->getHeader( 'X-Forwarded-For' );
                        $xff = array_map( 'trim', explode( ',', $xff ) );
                        $xff = array_diff( $xff, [ $ip ] );
                        $xffblocks = Block::getBlocksForIPList( $xff, $this->isAnon(), !$bFromSlave );
                        $block = Block::chooseBlock( $xffblocks, $xff );
                        if ( $block instanceof Block ) {
                                # Mangle the reason to alert the user that the block
                                # originated from matching the X-Forwarded-For header.
                                $block->mReason = wfMessage( 'xffblockreason', $block->mReason )->text();
                                $this->blockTrigger = 'xff-block';
                        }
                }

                if ( !$block instanceof Block
                        && $ip !== null
                        && $this->isAnon()
                        && IP::isInRanges( $ip, $wgSoftBlockRanges )
                ) {
                        $block = new Block( [
                                'address' => $ip,
                                'byText' => 'MediaWiki default',
                                'reason' => wfMessage( 'softblockrangesreason', $ip )->text(),
                                'anonOnly' => true,
                                'systemBlock' => 'wgSoftBlockRanges',
                        ] );
                        $this->blockTrigger = 'config-block';
                }

                if ( $block instanceof Block ) {
                        wfDebug( __METHOD__ . ": Found block.\n" );
                        $this->mBlock = $block;
                        $this->mBlockedby = $block->getByName();
                        $this->mBlockreason = $block->mReason;
                        $this->mHideName = $block->mHideName;
                        $this->mAllowUsertalk = !$block->prevents( 'editownusertalk' );
                } else {
                        $this->mBlockedby = '';
                        $this->mHideName = 0;
                        $this->mAllowUsertalk = false;
                        $this->blockTrigger = false;
                }

                // Avoid PHP 7.1 warning of passing $this by reference
                $user = $this;
                // Extensions
                Hooks::run( 'GetBlockedStatus', [ &$user ] );
        }

        /**
         * Try to load a Block from an ID given in a cookie value.
         * @param string|null $blockCookieVal The cookie value to check.
         * @return Block|bool The Block object, or false if none could be loaded.
         */
        protected function getBlockFromCookieValue( $blockCookieVal ) {
                // Make sure there's something to check. The cookie value must start with a number.
                if ( strlen( $blockCookieVal ) < 1 || !is_numeric( substr( $blockCookieVal, 0, 1 ) ) ) {
                        return false;
                }
                // Load the Block from the ID in the cookie.
                $blockCookieId = Block::getIdFromCookieValue( $blockCookieVal );
                if ( $blockCookieId !== null ) {
                        // An ID was found in the cookie.
                        $tmpBlock = Block::newFromID( $blockCookieId );
                        if ( $tmpBlock instanceof Block ) {
                                // Check the validity of the block.
                                $blockIsValid = $tmpBlock->getType() == Block::TYPE_USER
                                        && !$tmpBlock->isExpired()
                                        && $tmpBlock->isAutoblocking();
                                $config = RequestContext::getMain()->getConfig();
                                $useBlockCookie = ( $config->get( 'CookieSetOnAutoblock' ) === true );
                                if ( $blockIsValid && $useBlockCookie ) {
                                        // Use the block.
                                        $this->blockTrigger = 'cookie-block';
                                        return $tmpBlock;
                                } else {
                                        // If the block is not valid, clear the block cookie (but don't delete it,
                                        // because it needs to be cleared from LocalStorage as well and an empty string
                                        // value is checked for in the mediawiki.user.blockcookie module).
                                        $tmpBlock->setCookie( $this->getRequest()->response(), true );
                                }
                        }
                }
                return false;
        }

        /**
         * Whether the given IP is in a DNS blacklist.
         *
         * @param string $ip IP to check
         * @param bool $checkWhitelist Whether to check the whitelist first
         * @return bool True if blacklisted.
         */
        public function isDnsBlacklisted( $ip, $checkWhitelist = false ) {
                global $wgEnableDnsBlacklist, $wgDnsBlacklistUrls, $wgProxyWhitelist;

                if ( !$wgEnableDnsBlacklist ) {
                        return false;
                }

                if ( $checkWhitelist && in_array( $ip, $wgProxyWhitelist ) ) {
                        return false;
                }

                return $this->inDnsBlacklist( $ip, $wgDnsBlacklistUrls );
        }

        /**
         * Whether the given IP is in a given DNS blacklist.
         *
         * @param string $ip IP to check
         * @param string|array $bases Array of Strings: URL of the DNS blacklist
         * @return bool True if blacklisted.
         */
        public function inDnsBlacklist( $ip, $bases ) {
                $found = false;
                // @todo FIXME: IPv6 ???  (https://bugs.php.net/bug.php?id=33170)
                if ( IP::isIPv4( $ip ) ) {
                        // Reverse IP, T23255
                        $ipReversed = implode( '.', array_reverse( explode( '.', $ip ) ) );

                        foreach ( (array)$bases as $base ) {
                                // Make hostname
                                // If we have an access key, use that too (ProjectHoneypot, etc.)
                                $basename = $base;
                                if ( is_array( $base ) ) {
                                        if ( count( $base ) >= 2 ) {
                                                // Access key is 1, base URL is 0
                                                $host = "{$base[1]}.$ipReversed.{$base[0]}";
                                        } else {
                                                $host = "$ipReversed.{$base[0]}";
                                        }
                                        $basename = $base[0];
                                } else {
                                        $host = "$ipReversed.$base";
                                }

                                // Send query
                                $ipList = gethostbynamel( $host );

                                if ( $ipList ) {
                                        wfDebugLog( 'dnsblacklist', "Hostname $host is {$ipList[0]}, it's a proxy says $basename!" );
                                        $found = true;
                                        break;
                                } else {
                                        wfDebugLog( 'dnsblacklist', "Requested $host, not found in $basename." );
                                }
                        }
                }

                return $found;
        }

        /**
         * Check if an IP address is in the local proxy list
         *
         * @param string $ip
         *
         * @return bool
         */
        public static function isLocallyBlockedProxy( $ip ) {
                global $wgProxyList;

                if ( !$wgProxyList ) {
                        return false;
                }

                if ( !is_array( $wgProxyList ) ) {
                        // Load values from the specified file
                        $wgProxyList = array_map( 'trim', file( $wgProxyList ) );
                }

                if ( is_array( $wgProxyList ) ) {
                        if (
                                // Look for IP as value
                                array_search( $ip, $wgProxyList ) !== false ||
                                // Look for IP as key (for backwards-compatility)
                                array_key_exists( $ip, $wgProxyList )
                        ) {
                                return true;
                        }
                }

                return false;
        }

        /**
         * Is this user subject to rate limiting?
         *
         * @return bool True if rate limited
         */
        public function isPingLimitable() {
                global $wgRateLimitsExcludedIPs;
                if ( IP::isInRanges( $this->getRequest()->getIP(), $wgRateLimitsExcludedIPs ) ) {
                        // No other good way currently to disable rate limits
                        // for specific IPs. :P
                        // But this is a crappy hack and should die.
                        return false;
                }
                return !$this->isAllowed( 'noratelimit' );
        }

        /**
         * Primitive rate limits: enforce maximum actions per time period
         * to put a brake on flooding.
         *
         * The method generates both a generic profiling point and a per action one
         * (suffix being "-$action".
         *
         * @note When using a shared cache like memcached, IP-address
         * last-hit counters will be shared across wikis.
         *
         * @param string $action Action to enforce; 'edit' if unspecified
         * @param int $incrBy Positive amount to increment counter by [defaults to 1]
         * @return bool True if a rate limiter was tripped
         */
        public function pingLimiter( $action = 'edit', $incrBy = 1 ) {
                // Avoid PHP 7.1 warning of passing $this by reference
                $user = $this;
                // Call the 'PingLimiter' hook
                $result = false;
                if ( !Hooks::run( 'PingLimiter', [ &$user, $action, &$result, $incrBy ] ) ) {
                        return $result;
                }

                global $wgRateLimits;
                if ( !isset( $wgRateLimits[$action] ) ) {
                        return false;
                }

                $limits = array_merge(
                        [ '&can-bypass' => true ],
                        $wgRateLimits[$action]
                );

                // Some groups shouldn't trigger the ping limiter, ever
                if ( $limits['&can-bypass'] && !$this->isPingLimitable() ) {
                        return false;
                }

                $keys = [];
                $id = $this->getId();
                $userLimit = false;
                $isNewbie = $this->isNewbie();

                if ( $id == 0 ) {
                        // limits for anons
                        if ( isset( $limits['anon'] ) ) {
                                $keys[wfMemcKey( 'limiter', $action, 'anon' )] = $limits['anon'];
                        }
                } else {
                        // limits for logged-in users
                        if ( isset( $limits['user'] ) ) {
                                $userLimit = $limits['user'];
                        }
                        // limits for newbie logged-in users
                        if ( $isNewbie && isset( $limits['newbie'] ) ) {
                                $keys[wfMemcKey( 'limiter', $action, 'user', $id )] = $limits['newbie'];
                        }
                }

                // limits for anons and for newbie logged-in users
                if ( $isNewbie ) {
                        // ip-based limits
                        if ( isset( $limits['ip'] ) ) {
                                $ip = $this->getRequest()->getIP();
                                $keys["mediawiki:limiter:$action:ip:$ip"] = $limits['ip'];
                        }
                        // subnet-based limits
                        if ( isset( $limits['subnet'] ) ) {
                                $ip = $this->getRequest()->getIP();
                                $subnet = IP::getSubnet( $ip );
                                if ( $subnet !== false ) {
                                        $keys["mediawiki:limiter:$action:subnet:$subnet"] = $limits['subnet'];
                                }
                        }
                }

                // Check for group-specific permissions
                // If more than one group applies, use the group with the highest limit ratio (max/period)
                foreach ( $this->getGroups() as $group ) {
                        if ( isset( $limits[$group] ) ) {
                                if ( $userLimit === false
                                        || $limits[$group][0] / $limits[$group][1] > $userLimit[0] / $userLimit[1]
                                ) {
                                        $userLimit = $limits[$group];
                                }
                        }
                }

                // Set the user limit key
                if ( $userLimit !== false ) {
                        list( $max, $period ) = $userLimit;
                        wfDebug( __METHOD__ . ": effective user limit: $max in {$period}s\n" );
                        $keys[wfMemcKey( 'limiter', $action, 'user', $id )] = $userLimit;
                }

                // ip-based limits for all ping-limitable users
                if ( isset( $limits['ip-all'] ) ) {
                        $ip = $this->getRequest()->getIP();
                        // ignore if user limit is more permissive
                        if ( $isNewbie || $userLimit === false
                                || $limits['ip-all'][0] / $limits['ip-all'][1] > $userLimit[0] / $userLimit[1] ) {
                                $keys["mediawiki:limiter:$action:ip-all:$ip"] = $limits['ip-all'];
                        }
                }

                // subnet-based limits for all ping-limitable users
                if ( isset( $limits['subnet-all'] ) ) {
                        $ip = $this->getRequest()->getIP();
                        $subnet = IP::getSubnet( $ip );
                        if ( $subnet !== false ) {
                                // ignore if user limit is more permissive
                                if ( $isNewbie || $userLimit === false
                                        || $limits['ip-all'][0] / $limits['ip-all'][1]
                                        > $userLimit[0] / $userLimit[1] ) {
                                        $keys["mediawiki:limiter:$action:subnet-all:$subnet"] = $limits['subnet-all'];
                                }
                        }
                }

                $cache = ObjectCache::getLocalClusterInstance();

                $triggered = false;
                foreach ( $keys as $key => $limit ) {
                        list( $max, $period ) = $limit;
                        $summary = "(limit $max in {$period}s)";
                        $count = $cache->get( $key );
                        // Already pinged?
                        if ( $count ) {
                                if ( $count >= $max ) {
                                        wfDebugLog( 'ratelimit', "User '{$this->getName()}' " .
                                                "(IP {$this->getRequest()->getIP()}) tripped $key at $count $summary" );
                                        $triggered = true;
                                } else {
                                        wfDebug( __METHOD__ . ": ok. $key at $count $summary\n" );
                                }
                        } else {
                                wfDebug( __METHOD__ . ": adding record for $key $summary\n" );
                                if ( $incrBy > 0 ) {
                                        $cache->add( $key, 0, intval( $period ) ); // first ping
                                }
                        }
                        if ( $incrBy > 0 ) {
                                $cache->incr( $key, $incrBy );
                        }
                }

                return $triggered;
        }

        /**
         * Check if user is blocked
         *
         * @param bool $bFromSlave Whether to check the replica DB instead of
         *   the master. Hacked from false due to horrible probs on site.
         * @return bool True if blocked, false otherwise
         */
        public function isBlocked( $bFromSlave = true ) {
                return $this->getBlock( $bFromSlave ) instanceof Block && $this->getBlock()->prevents( 'edit' );
        }

        /**
         * Get the block affecting the user, or null if the user is not blocked
         *
         * @param bool $bFromSlave Whether to check the replica DB instead of the master
         * @return Block|null
         */
        public function getBlock( $bFromSlave = true ) {
                $this->getBlockedStatus( $bFromSlave );
                return $this->mBlock instanceof Block ? $this->mBlock : null;
        }

        /**
         * Check if user is blocked from editing a particular article
         *
         * @param Title $title Title to check
         * @param bool $bFromSlave Whether to check the replica DB instead of the master
         * @return bool
         */
        public function isBlockedFrom( $title, $bFromSlave = false ) {
                global $wgBlockAllowsUTEdit;

                $blocked = $this->isBlocked( $bFromSlave );
                $allowUsertalk = ( $wgBlockAllowsUTEdit ? $this->mAllowUsertalk : false );
                // If a user's name is suppressed, they cannot make edits anywhere
                if ( !$this->mHideName && $allowUsertalk && $title->getText() === $this->getName()
                        && $title->getNamespace() == NS_USER_TALK ) {
                        $blocked = false;
                        wfDebug( __METHOD__ . ": self-talk page, ignoring any blocks\n" );
                }

                Hooks::run( 'UserIsBlockedFrom', [ $this, $title, &$blocked, &$allowUsertalk ] );

                return $blocked;
        }

        /**
         * If user is blocked, return the name of the user who placed the block
         * @return string Name of blocker
         */
        public function blockedBy() {
                $this->getBlockedStatus();
                return $this->mBlockedby;
        }

        /**
         * If user is blocked, return the specified reason for the block
         * @return string Blocking reason
         */
        public function blockedFor() {
                $this->getBlockedStatus();
                return $this->mBlockreason;
        }

        /**
         * If user is blocked, return the ID for the block
         * @return int Block ID
         */
        public function getBlockId() {
                $this->getBlockedStatus();
                return ( $this->mBlock ? $this->mBlock->getId() : false );
        }

        /**
         * Check if user is blocked on all wikis.
         * Do not use for actual edit permission checks!
         * This is intended for quick UI checks.
         *
         * @param string $ip IP address, uses current client if none given
         * @return bool True if blocked, false otherwise
         */
        public function isBlockedGlobally( $ip = '' ) {
                return $this->getGlobalBlock( $ip ) instanceof Block;
        }

        /**
         * Check if user is blocked on all wikis.
         * Do not use for actual edit permission checks!
         * This is intended for quick UI checks.
         *
         * @param string $ip IP address, uses current client if none given
         * @return Block|null Block object if blocked, null otherwise
         * @throws FatalError
         * @throws MWException
         */
        public function getGlobalBlock( $ip = '' ) {
                if ( $this->mGlobalBlock !== null ) {
                        return $this->mGlobalBlock ?: null;
                }
                // User is already an IP?
                if ( IP::isIPAddress( $this->getName() ) ) {
                        $ip = $this->getName();
                } elseif ( !$ip ) {
                        $ip = $this->getRequest()->getIP();
                }
                // Avoid PHP 7.1 warning of passing $this by reference
                $user = $this;
                $blocked = false;
                $block = null;
                Hooks::run( 'UserIsBlockedGlobally', [ &$user, $ip, &$blocked, &$block ] );

                if ( $blocked && $block === null ) {
                        // back-compat: UserIsBlockedGlobally didn't have $block param first
                        $block = new Block( [
                                'address' => $ip,
                                'systemBlock' => 'global-block'
                        ] );
                }

                $this->mGlobalBlock = $blocked ? $block : false;
                return $this->mGlobalBlock ?: null;
        }

        /**
         * Check if user account is locked
         *
         * @return bool True if locked, false otherwise
         */
        public function isLocked() {
                if ( $this->mLocked !== null ) {
                        return $this->mLocked;
                }
                // Avoid PHP 7.1 warning of passing $this by reference
                $user = $this;
                $authUser = AuthManager::callLegacyAuthPlugin( 'getUserInstance', [ &$user ], null );
                $this->mLocked = $authUser && $authUser->isLocked();
                Hooks::run( 'UserIsLocked', [ $this, &$this->mLocked ] );
                return $this->mLocked;
        }

        /**
         * Check if user account is hidden
         *
         * @return bool True if hidden, false otherwise
         */
        public function isHidden() {
                if ( $this->mHideName !== null ) {
                        return $this->mHideName;
                }
                $this->getBlockedStatus();
                if ( !$this->mHideName ) {
                        // Avoid PHP 7.1 warning of passing $this by reference
                        $user = $this;
                        $authUser = AuthManager::callLegacyAuthPlugin( 'getUserInstance', [ &$user ], null );
                        $this->mHideName = $authUser && $authUser->isHidden();
                        Hooks::run( 'UserIsHidden', [ $this, &$this->mHideName ] );
                }
                return $this->mHideName;
        }

        /**
         * Get the user's ID.
         * @return int The user's ID; 0 if the user is anonymous or nonexistent
         */
        public function getId() {
                if ( $this->mId === null && $this->mName !== null && User::isIP( $this->mName ) ) {
                        // Special case, we know the user is anonymous
                        return 0;
                } elseif ( !$this->isItemLoaded( 'id' ) ) {
                        // Don't load if this was initialized from an ID
                        $this->load();
                }

                return (int)$this->mId;
        }

        /**
         * Set the user and reload all fields according to a given ID
         * @param int $v User ID to reload
         */
        public function setId( $v ) {
                $this->mId = $v;
                $this->clearInstanceCache( 'id' );
        }

        /**
         * Get the user name, or the IP of an anonymous user
         * @return string User's name or IP address
         */
        public function getName() {
                if ( $this->isItemLoaded( 'name', 'only' ) ) {
                        // Special case optimisation
                        return $this->mName;
                } else {
                        $this->load();
                        if ( $this->mName === false ) {
                                // Clean up IPs
                                $this->mName = IP::sanitizeIP( $this->getRequest()->getIP() );
                        }
                        return $this->mName;
                }
        }

        /**
         * Set the user name.
         *
         * This does not reload fields from the database according to the given
         * name. Rather, it is used to create a temporary "nonexistent user" for
         * later addition to the database. It can also be used to set the IP
         * address for an anonymous user to something other than the current
         * remote IP.
         *
         * @note User::newFromName() has roughly the same function, when the named user
         * does not exist.
         * @param string $str New user name to set
         */
        public function setName( $str ) {
                $this->load();
                $this->mName = $str;
        }

        /**
         * Get the user's name escaped by underscores.
         * @return string Username escaped by underscores.
         */
        public function getTitleKey() {
                return str_replace( ' ', '_', $this->getName() );
        }

        /**
         * Check if the user has new messages.
         * @return bool True if the user has new messages
         */
        public function getNewtalk() {
                $this->load();

                // Load the newtalk status if it is unloaded (mNewtalk=-1)
                if ( $this->mNewtalk === -1 ) {
                        $this->mNewtalk = false; # reset talk page status

                        // Check memcached separately for anons, who have no
                        // entire User object stored in there.
                        if ( !$this->mId ) {
                                global $wgDisableAnonTalk;
                                if ( $wgDisableAnonTalk ) {
                                        // Anon newtalk disabled by configuration.
                                        $this->mNewtalk = false;
                                } else {
                                        $this->mNewtalk = $this->checkNewtalk( 'user_ip', $this->getName() );
                                }
                        } else {
                                $this->mNewtalk = $this->checkNewtalk( 'user_id', $this->mId );
                        }
                }

                return (bool)$this->mNewtalk;
        }

        /**
         * Return the data needed to construct links for new talk page message
         * alerts. If there are new messages, this will return an associative array
         * with the following data:
         *     wiki: The database name of the wiki
         *     link: Root-relative link to the user's talk page
         *     rev: The last talk page revision that the user has seen or null. This
         *         is useful for building diff links.
         * If there are no new messages, it returns an empty array.
         * @note This function was designed to accomodate multiple talk pages, but
         * currently only returns a single link and revision.
         * @return array
         */
        public function getNewMessageLinks() {
                // Avoid PHP 7.1 warning of passing $this by reference
                $user = $this;
                $talks = [];
                if ( !Hooks::run( 'UserRetrieveNewTalks', [ &$user, &$talks ] ) ) {
                        return $talks;
                } elseif ( !$this->getNewtalk() ) {
                        return [];
                }
                $utp = $this->getTalkPage();
                $dbr = wfGetDB( DB_REPLICA );
                // Get the "last viewed rev" timestamp from the oldest message notification
                $timestamp = $dbr->selectField( 'user_newtalk',
                        'MIN(user_last_timestamp)',
                        $this->isAnon() ? [ 'user_ip' => $this->getName() ] : [ 'user_id' => $this->getId() ],
                        __METHOD__ );
                $rev = $timestamp ? Revision::loadFromTimestamp( $dbr, $utp, $timestamp ) : null;
                return [ [ 'wiki' => wfWikiID(), 'link' => $utp->getLocalURL(), 'rev' => $rev ] ];
        }

        /**
         * Get the revision ID for the last talk page revision viewed by the talk
         * page owner.
         * @return int|null Revision ID or null
         */
        public function getNewMessageRevisionId() {
                $newMessageRevisionId = null;
                $newMessageLinks = $this->getNewMessageLinks();
                if ( $newMessageLinks ) {
                        // Note: getNewMessageLinks() never returns more than a single link
                        // and it is always for the same wiki, but we double-check here in
                        // case that changes some time in the future.
                        if ( count( $newMessageLinks ) === 1
                                && $newMessageLinks[0]['wiki'] === wfWikiID()
                                && $newMessageLinks[0]['rev']
                        ) {
                                /** @var Revision $newMessageRevision */
                                $newMessageRevision = $newMessageLinks[0]['rev'];
                                $newMessageRevisionId = $newMessageRevision->getId();
                        }
                }
                return $newMessageRevisionId;
        }

        /**
         * Internal uncached check for new messages
         *
         * @see getNewtalk()
         * @param string $field 'user_ip' for anonymous users, 'user_id' otherwise
         * @param string|int $id User's IP address for anonymous users, User ID otherwise
         * @return bool True if the user has new messages
         */
        protected function checkNewtalk( $field, $id ) {
                $dbr = wfGetDB( DB_REPLICA );

                $ok = $dbr->selectField( 'user_newtalk', $field, [ $field => $id ], __METHOD__ );

                return $ok !== false;
        }

        /**
         * Add or update the new messages flag
         * @param string $field 'user_ip' for anonymous users, 'user_id' otherwise
         * @param string|int $id User's IP address for anonymous users, User ID otherwise
         * @param Revision|null $curRev New, as yet unseen revision of the user talk page. Ignored if null.
         * @return bool True if successful, false otherwise
         */
        protected function updateNewtalk( $field, $id, $curRev = null ) {
                // Get timestamp of the talk page revision prior to the current one
                $prevRev = $curRev ? $curRev->getPrevious() : false;
                $ts = $prevRev ? $prevRev->getTimestamp() : null;
                // Mark the user as having new messages since this revision
                $dbw = wfGetDB( DB_MASTER );
                $dbw->insert( 'user_newtalk',
                        [ $field => $id, 'user_last_timestamp' => $dbw->timestampOrNull( $ts ) ],
                        __METHOD__,
                        'IGNORE' );
                if ( $dbw->affectedRows() ) {
                        wfDebug( __METHOD__ . ": set on ($field, $id)\n" );
                        return true;
                } else {
                        wfDebug( __METHOD__ . " already set ($field, $id)\n" );
                        return false;
                }
        }

        /**
         * Clear the new messages flag for the given user
         * @param string $field 'user_ip' for anonymous users, 'user_id' otherwise
         * @param string|int $id User's IP address for anonymous users, User ID otherwise
         * @return bool True if successful, false otherwise
         */
        protected function deleteNewtalk( $field, $id ) {
                $dbw = wfGetDB( DB_MASTER );
                $dbw->delete( 'user_newtalk',
                        [ $field => $id ],
                        __METHOD__ );
                if ( $dbw->affectedRows() ) {
                        wfDebug( __METHOD__ . ": killed on ($field, $id)\n" );
                        return true;
                } else {
                        wfDebug( __METHOD__ . ": already gone ($field, $id)\n" );
                        return false;
                }
        }

        /**
         * Update the 'You have new messages!' status.
         * @param bool $val Whether the user has new messages
         * @param Revision $curRev New, as yet unseen revision of the user talk
         *   page. Ignored if null or !$val.
         */
        public function setNewtalk( $val, $curRev = null ) {
                if ( wfReadOnly() ) {
                        return;
                }

                $this->load();
                $this->mNewtalk = $val;

                if ( $this->isAnon() ) {
                        $field = 'user_ip';
                        $id = $this->getName();
                } else {
                        $field = 'user_id';
                        $id = $this->getId();
                }

                if ( $val ) {
                        $changed = $this->updateNewtalk( $field, $id, $curRev );
                } else {
                        $changed = $this->deleteNewtalk( $field, $id );
                }

                if ( $changed ) {
                        $this->invalidateCache();
                }
        }

        /**
         * Generate a current or new-future timestamp to be stored in the
         * user_touched field when we update things.
         * @return string Timestamp in TS_MW format
         */
        private function newTouchedTimestamp() {
                global $wgClockSkewFudge;

                $time = wfTimestamp( TS_MW, time() + $wgClockSkewFudge );
                if ( $this->mTouched && $time <= $this->mTouched ) {
                        $time = wfTimestamp( TS_MW, wfTimestamp( TS_UNIX, $this->mTouched ) + 1 );
                }

                return $time;
        }

        /**
         * Clear user data from memcached
         *
         * Use after applying updates to the database; caller's
         * responsibility to update user_touched if appropriate.
         *
         * Called implicitly from invalidateCache() and saveSettings().
         *
         * @param string $mode Use 'refresh' to clear now; otherwise before DB commit
         */
        public function clearSharedCache( $mode = 'changed' ) {
                if ( !$this->getId() ) {
                        return;
                }

                $cache = ObjectCache::getMainWANInstance();
                $key = $this->getCacheKey( $cache );
                if ( $mode === 'refresh' ) {
                        $cache->delete( $key, 1 );
                } else {
                        wfGetDB( DB_MASTER )->onTransactionPreCommitOrIdle(
                                function() use ( $cache, $key ) {
                                        $cache->delete( $key );
                                },
                                __METHOD__
                        );
                }
        }

        /**
         * Immediately touch the user data cache for this account
         *
         * Calls touch() and removes account data from memcached
         */
        public function invalidateCache() {
                $this->touch();
                $this->clearSharedCache();
        }

        /**
         * Update the "touched" timestamp for the user
         *
         * This is useful on various login/logout events when making sure that
         * a browser or proxy that has multiple tenants does not suffer cache
         * pollution where the new user sees the old users content. The value
         * of getTouched() is checked when determining 304 vs 200 responses.
         * Unlike invalidateCache(), this preserves the User object cache and
         * avoids database writes.
         *
         * @since 1.25
         */
        public function touch() {
                $id = $this->getId();
                if ( $id ) {
                        $key = wfMemcKey( 'user-quicktouched', 'id', $id );
                        ObjectCache::getMainWANInstance()->touchCheckKey( $key );
                        $this->mQuickTouched = null;
                }
        }

        /**
         * Validate the cache for this account.
         * @param string $timestamp A timestamp in TS_MW format
         * @return bool
         */
        public function validateCache( $timestamp ) {
                return ( $timestamp >= $this->getTouched() );
        }

        /**
         * Get the user touched timestamp
         *
         * Use this value only to validate caches via inequalities
         * such as in the case of HTTP If-Modified-Since response logic
         *
         * @return string TS_MW Timestamp
         */
        public function getTouched() {
                $this->load();

                if ( $this->mId ) {
                        if ( $this->mQuickTouched === null ) {
                                $key = wfMemcKey( 'user-quicktouched', 'id', $this->mId );
                                $cache = ObjectCache::getMainWANInstance();

                                $this->mQuickTouched = wfTimestamp( TS_MW, $cache->getCheckKeyTime( $key ) );
                        }

                        return max( $this->mTouched, $this->mQuickTouched );
                }

                return $this->mTouched;
        }

        /**
         * Get the user_touched timestamp field (time of last DB updates)
         * @return string TS_MW Timestamp
         * @since 1.26
         */
        public function getDBTouched() {
                $this->load();

                return $this->mTouched;
        }

        /**
         * Set the password and reset the random token.
         * Calls through to authentication plugin if necessary;
         * will have no effect if the auth plugin refuses to
         * pass the change through or if the legal password
         * checks fail.
         *
         * As a special case, setting the password to null
         * wipes it, so the account cannot be logged in until
         * a new password is set, for instance via e-mail.
         *
         * @deprecated since 1.27, use AuthManager instead
         * @param string $str New password to set
         * @throws PasswordError On failure
         * @return bool
         */
        public function setPassword( $str ) {
                return $this->setPasswordInternal( $str );
        }

        /**
         * Set the password and reset the random token unconditionally.
         *
         * @deprecated since 1.27, use AuthManager instead
         * @param string|null $str New password to set or null to set an invalid
         *  password hash meaning that the user will not be able to log in
         *  through the web interface.
         */
        public function setInternalPassword( $str ) {
                $this->setPasswordInternal( $str );
        }

        /**
         * Actually set the password and such
         * @since 1.27 cannot set a password for a user not in the database
         * @param string|null $str New password to set or null to set an invalid
         *  password hash meaning that the user will not be able to log in
         *  through the web interface.
         * @return bool Success
         */
        private function setPasswordInternal( $str ) {
                $manager = AuthManager::singleton();

                // If the user doesn't exist yet, fail
                if ( !$manager->userExists( $this->getName() ) ) {
                        throw new LogicException( 'Cannot set a password for a user that is not in the database.' );
                }

                $status = $this->changeAuthenticationData( [
                        'username' => $this->getName(),
                        'password' => $str,
                        'retype' => $str,
                ] );
                if ( !$status->isGood() ) {
                        \MediaWiki\Logger\LoggerFactory::getInstance( 'authentication' )
                                ->info( __METHOD__ . ': Password change rejected: '
                                        . $status->getWikiText( null, null, 'en' ) );
                        return false;
                }

                $this->setOption( 'watchlisttoken', false );
                SessionManager::singleton()->invalidateSessionsForUser( $this );

                return true;
        }

        /**
         * Changes credentials of the user.
         *
         * This is a convenience wrapper around AuthManager::changeAuthenticationData.
         * Note that this can return a status that isOK() but not isGood() on certain types of failures,
         * e.g. when no provider handled the change.
         *
         * @param array $data A set of authentication data in fieldname => value format. This is the
         *   same data you would pass the changeauthenticationdata API - 'username', 'password' etc.
         * @return Status
         * @since 1.27
         */
        public function changeAuthenticationData( array $data ) {
                $manager = AuthManager::singleton();
                $reqs = $manager->getAuthenticationRequests( AuthManager::ACTION_CHANGE, $this );
                $reqs = AuthenticationRequest::loadRequestsFromSubmission( $reqs, $data );

                $status = Status::newGood( 'ignored' );
                foreach ( $reqs as $req ) {
                        $status->merge( $manager->allowsAuthenticationDataChange( $req ), true );
                }
                if ( $status->getValue() === 'ignored' ) {
                        $status->warning( 'authenticationdatachange-ignored' );
                }

                if ( $status->isGood() ) {
                        foreach ( $reqs as $req ) {
                                $manager->changeAuthenticationData( $req );
                        }
                }
                return $status;
        }

        /**
         * Get the user's current token.
         * @param bool $forceCreation Force the generation of a new token if the
         *   user doesn't have one (default=true for backwards compatibility).
         * @return string|null Token
         */
        public function getToken( $forceCreation = true ) {
                global $wgAuthenticationTokenVersion;

                $this->load();
                if ( !$this->mToken && $forceCreation ) {
                        $this->setToken();
                }

                if ( !$this->mToken ) {
                        // The user doesn't have a token, return null to indicate that.
                        return null;
                } elseif ( $this->mToken === self::INVALID_TOKEN ) {
                        // We return a random value here so existing token checks are very
                        // likely to fail.
                        return MWCryptRand::generateHex( self::TOKEN_LENGTH );
                } elseif ( $wgAuthenticationTokenVersion === null ) {
                        // $wgAuthenticationTokenVersion not in use, so return the raw secret
                        return $this->mToken;
                } else {
                        // $wgAuthenticationTokenVersion in use, so hmac it.
                        $ret = MWCryptHash::hmac( $wgAuthenticationTokenVersion, $this->mToken, false );

                        // The raw hash can be overly long. Shorten it up.
                        $len = max( 32, self::TOKEN_LENGTH );
                        if ( strlen( $ret ) < $len ) {
                                // Should never happen, even md5 is 128 bits
                                throw new \UnexpectedValueException( 'Hmac returned less than 128 bits' );
                        }
                        return substr( $ret, -$len );
                }
        }

        /**
         * Set the random token (used for persistent authentication)
         * Called from loadDefaults() among other places.
         *
         * @param string|bool $token If specified, set the token to this value
         */
        public function setToken( $token = false ) {
                $this->load();
                if ( $this->mToken === self::INVALID_TOKEN ) {
                        \MediaWiki\Logger\LoggerFactory::getInstance( 'session' )
                                ->debug( __METHOD__ . ": Ignoring attempt to set token for system user \"$this\"" );
                } elseif ( !$token ) {
                        $this->mToken = MWCryptRand::generateHex( self::TOKEN_LENGTH );
                } else {
                        $this->mToken = $token;
                }
        }

        /**
         * Set the password for a password reminder or new account email
         *
         * @deprecated Removed in 1.27. Use PasswordReset instead.
         * @param string $str New password to set or null to set an invalid
         *  password hash meaning that the user will not be able to use it
         * @param bool $throttle If true, reset the throttle timestamp to the present
         */
        public function setNewpassword( $str, $throttle = true ) {
                throw new BadMethodCallException( __METHOD__ . ' has been removed in 1.27' );
        }

        /**
         * Get the user's e-mail address
         * @return string User's email address
         */
        public function getEmail() {
                $this->load();
                Hooks::run( 'UserGetEmail', [ $this, &$this->mEmail ] );
                return $this->mEmail;
        }

        /**
         * Get the timestamp of the user's e-mail authentication
         * @return string TS_MW timestamp
         */
        public function getEmailAuthenticationTimestamp() {
                $this->load();
                Hooks::run( 'UserGetEmailAuthenticationTimestamp', [ $this, &$this->mEmailAuthenticated ] );
                return $this->mEmailAuthenticated;
        }

        /**
         * Set the user's e-mail address
         * @param string $str New e-mail address
         */
        public function setEmail( $str ) {
                $this->load();
                if ( $str == $this->mEmail ) {
                        return;
                }
                $this->invalidateEmail();
                $this->mEmail = $str;
                Hooks::run( 'UserSetEmail', [ $this, &$this->mEmail ] );
        }

        /**
         * Set the user's e-mail address and a confirmation mail if needed.
         *
         * @since 1.20
         * @param string $str New e-mail address
         * @return Status
         */
        public function setEmailWithConfirmation( $str ) {
                global $wgEnableEmail, $wgEmailAuthentication;

                if ( !$wgEnableEmail ) {
                        return Status::newFatal( 'emaildisabled' );
                }

                $oldaddr = $this->getEmail();
                if ( $str === $oldaddr ) {
                        return Status::newGood( true );
                }

                $type = $oldaddr != '' ? 'changed' : 'set';
                $notificationResult = null;

                if ( $wgEmailAuthentication ) {
                        // Send the user an email notifying the user of the change in registered
                        // email address on their previous email address
                        if ( $type == 'changed' ) {
                                $change = $str != '' ? 'changed' : 'removed';
                                $notificationResult = $this->sendMail(
                                        wfMessage( 'notificationemail_subject_' . $change )->text(),
                                        wfMessage( 'notificationemail_body_' . $change,
                                                $this->getRequest()->getIP(),
                                                $this->getName(),
                                                $str )->text()
                                );
                        }
                }

                $this->setEmail( $str );

                if ( $str !== '' && $wgEmailAuthentication ) {
                        // Send a confirmation request to the new address if needed
                        $result = $this->sendConfirmationMail( $type );

                        if ( $notificationResult !== null ) {
                                $result->merge( $notificationResult );
                        }

                        if ( $result->isGood() ) {
                                // Say to the caller that a confirmation and notification mail has been sent
                                $result->value = 'eauth';
                        }
                } else {
                        $result = Status::newGood( true );
                }

                return $result;
        }

        /**
         * Get the user's real name
         * @return string User's real name
         */
        public function getRealName() {
                if ( !$this->isItemLoaded( 'realname' ) ) {
                        $this->load();
                }

                return $this->mRealName;
        }

        /**
         * Set the user's real name
         * @param string $str New real name
         */
        public function setRealName( $str ) {
                $this->load();
                $this->mRealName = $str;
        }

        /**
         * Get the user's current setting for a given option.
         *
         * @param string $oname The option to check
         * @param string $defaultOverride A default value returned if the option does not exist
         * @param bool $ignoreHidden Whether to ignore the effects of $wgHiddenPrefs
         * @return string|null User's current value for the option
         * @see getBoolOption()
         * @see getIntOption()
         */
        public function getOption( $oname, $defaultOverride = null, $ignoreHidden = false ) {
                global $wgHiddenPrefs;
                $this->loadOptions();

                # We want 'disabled' preferences to always behave as the default value for
                # users, even if they have set the option explicitly in their settings (ie they
                # set it, and then it was disabled removing their ability to change it).  But
                # we don't want to erase the preferences in the database in case the preference
                # is re-enabled again.  So don't touch $mOptions, just override the returned value
                if ( !$ignoreHidden && in_array( $oname, $wgHiddenPrefs ) ) {
                        return self::getDefaultOption( $oname );
                }

                if ( array_key_exists( $oname, $this->mOptions ) ) {
                        return $this->mOptions[$oname];
                } else {
                        return $defaultOverride;
                }
        }

        /**
         * Get all user's options
         *
         * @param int $flags Bitwise combination of:
         *   User::GETOPTIONS_EXCLUDE_DEFAULTS  Exclude user options that are set
         *                                      to the default value. (Since 1.25)
         * @return array
         */
        public function getOptions( $flags = 0 ) {
                global $wgHiddenPrefs;
                $this->loadOptions();
                $options = $this->mOptions;

                # We want 'disabled' preferences to always behave as the default value for
                # users, even if they have set the option explicitly in their settings (ie they
                # set it, and then it was disabled removing their ability to change it).  But
                # we don't want to erase the preferences in the database in case the preference
                # is re-enabled again.  So don't touch $mOptions, just override the returned value
                foreach ( $wgHiddenPrefs as $pref ) {
                        $default = self::getDefaultOption( $pref );
                        if ( $default !== null ) {
                                $options[$pref] = $default;
                        }
                }

                if ( $flags & self::GETOPTIONS_EXCLUDE_DEFAULTS ) {
                        $options = array_diff_assoc( $options, self::getDefaultOptions() );
                }

                return $options;
        }

        /**
         * Get the user's current setting for a given option, as a boolean value.
         *
         * @param string $oname The option to check
         * @return bool User's current value for the option
         * @see getOption()
         */
        public function getBoolOption( $oname ) {
                return (bool)$this->getOption( $oname );
        }

        /**
         * Get the user's current setting for a given option, as an integer value.
         *
         * @param string $oname The option to check
         * @param int $defaultOverride A default value returned if the option does not exist
         * @return int User's current value for the option
         * @see getOption()
         */
        public function getIntOption( $oname, $defaultOverride = 0 ) {
                $val = $this->getOption( $oname );
                if ( $val == '' ) {
                        $val = $defaultOverride;
                }
                return intval( $val );
        }

        /**
         * Set the given option for a user.
         *
         * You need to call saveSettings() to actually write to the database.
         *
         * @param string $oname The option to set
         * @param mixed $val New value to set
         */
        public function setOption( $oname, $val ) {
                $this->loadOptions();

                // Explicitly NULL values should refer to defaults
                if ( is_null( $val ) ) {
                        $val = self::getDefaultOption( $oname );
                }

                $this->mOptions[$oname] = $val;
        }

        /**
         * Get a token stored in the preferences (like the watchlist one),
         * resetting it if it's empty (and saving changes).
         *
         * @param string $oname The option name to retrieve the token from
         * @return string|bool User's current value for the option, or false if this option is disabled.
         * @see resetTokenFromOption()
         * @see getOption()
         * @deprecated since 1.26 Applications should use the OAuth extension
         */
        public function getTokenFromOption( $oname ) {
                global $wgHiddenPrefs;

                $id = $this->getId();
                if ( !$id || in_array( $oname, $wgHiddenPrefs ) ) {
                        return false;
                }

                $token = $this->getOption( $oname );
                if ( !$token ) {
                        // Default to a value based on the user token to avoid space
                        // wasted on storing tokens for all users. When this option
                        // is set manually by the user, only then is it stored.
                        $token = hash_hmac( 'sha1', "$oname:$id", $this->getToken() );
                }

                return $token;
        }

        /**
         * Reset a token stored in the preferences (like the watchlist one).
         * *Does not* save user's preferences (similarly to setOption()).
         *
         * @param string $oname The option name to reset the token in
         * @return string|bool New token value, or false if this option is disabled.
         * @see getTokenFromOption()
         * @see setOption()
         */
        public function resetTokenFromOption( $oname ) {
                global $wgHiddenPrefs;
                if ( in_array( $oname, $wgHiddenPrefs ) ) {
                        return false;
                }

                $token = MWCryptRand::generateHex( 40 );
                $this->setOption( $oname, $token );
                return $token;
        }

        /**
         * Return a list of the types of user options currently returned by
         * User::getOptionKinds().
         *
         * Currently, the option kinds are:
         * - 'registered' - preferences which are registered in core MediaWiki or
         *                  by extensions using the UserGetDefaultOptions hook.
         * - 'registered-multiselect' - as above, using the 'multiselect' type.
         * - 'registered-checkmatrix' - as above, using the 'checkmatrix' type.
         * - 'userjs' - preferences with names starting with 'userjs-', intended to
         *              be used by user scripts.
         * - 'special' - "preferences" that are not accessible via User::getOptions
         *               or User::setOptions.
         * - 'unused' - preferences about which MediaWiki doesn't know anything.
         *              These are usually legacy options, removed in newer versions.
         *
         * The API (and possibly others) use this function to determine the possible
         * option types for validation purposes, so make sure to update this when a
         * new option kind is added.
         *
         * @see User::getOptionKinds
         * @return array Option kinds
         */
        public static function listOptionKinds() {
                return [
                        'registered',
                        'registered-multiselect',
                        'registered-checkmatrix',
                        'userjs',
                        'special',
                        'unused'
                ];
        }

        /**
         * Return an associative array mapping preferences keys to the kind of a preference they're
         * used for. Different kinds are handled differently when setting or reading preferences.
         *
         * See User::listOptionKinds for the list of valid option types that can be provided.
         *
         * @see User::listOptionKinds
         * @param IContextSource $context
         * @param array $options Assoc. array with options keys to check as keys.
         *   Defaults to $this->mOptions.
         * @return array The key => kind mapping data
         */
        public function getOptionKinds( IContextSource $context, $options = null ) {
                $this->loadOptions();
                if ( $options === null ) {
                        $options = $this->mOptions;
                }

                $prefs = Preferences::getPreferences( $this, $context );
                $mapping = [];

                // Pull out the "special" options, so they don't get converted as
                // multiselect or checkmatrix.
                $specialOptions = array_fill_keys( Preferences::getSaveBlacklist(), true );
                foreach ( $specialOptions as $name => $value ) {
                        unset( $prefs[$name] );
                }

                // Multiselect and checkmatrix options are stored in the database with
                // one key per option, each having a boolean value. Extract those keys.
                $multiselectOptions = [];
                foreach ( $prefs as $name => $info ) {
                        if ( ( isset( $info['type'] ) && $info['type'] == 'multiselect' ) ||
                                        ( isset( $info['class'] ) && $info['class'] == 'HTMLMultiSelectField' ) ) {
                                $opts = HTMLFormField::flattenOptions( $info['options'] );
                                $prefix = isset( $info['prefix'] ) ? $info['prefix'] : $name;

                                foreach ( $opts as $value ) {
                                        $multiselectOptions["$prefix$value"] = true;
                                }

                                unset( $prefs[$name] );
                        }
                }
                $checkmatrixOptions = [];
                foreach ( $prefs as $name => $info ) {
                        if ( ( isset( $info['type'] ) && $info['type'] == 'checkmatrix' ) ||
                                        ( isset( $info['class'] ) && $info['class'] == 'HTMLCheckMatrix' ) ) {
                                $columns = HTMLFormField::flattenOptions( $info['columns'] );
                                $rows = HTMLFormField::flattenOptions( $info['rows'] );
                                $prefix = isset( $info['prefix'] ) ? $info['prefix'] : $name;

                                foreach ( $columns as $column ) {
                                        foreach ( $rows as $row ) {
                                                $checkmatrixOptions["$prefix$column-$row"] = true;
                                        }
                                }

                                unset( $prefs[$name] );
                        }
                }

                // $value is ignored
                foreach ( $options as $key => $value ) {
                        if ( isset( $prefs[$key] ) ) {
                                $mapping[$key] = 'registered';
                        } elseif ( isset( $multiselectOptions[$key] ) ) {
                                $mapping[$key] = 'registered-multiselect';
                        } elseif ( isset( $checkmatrixOptions[$key] ) ) {
                                $mapping[$key] = 'registered-checkmatrix';
                        } elseif ( isset( $specialOptions[$key] ) ) {
                                $mapping[$key] = 'special';
                        } elseif ( substr( $key, 0, 7 ) === 'userjs-' ) {
                                $mapping[$key] = 'userjs';
                        } else {
                                $mapping[$key] = 'unused';
                        }
                }

                return $mapping;
        }

        /**
         * Reset certain (or all) options to the site defaults
         *
         * The optional parameter determines which kinds of preferences will be reset.
         * Supported values are everything that can be reported by getOptionKinds()
         * and 'all', which forces a reset of *all* preferences and overrides everything else.
         *
         * @param array|string $resetKinds Which kinds of preferences to reset. Defaults to
         *  array( 'registered', 'registered-multiselect', 'registered-checkmatrix', 'unused' )
         *  for backwards-compatibility.
         * @param IContextSource|null $context Context source used when $resetKinds
         *  does not contain 'all', passed to getOptionKinds().
         *  Defaults to RequestContext::getMain() when null.
         */
        public function resetOptions(
                $resetKinds = [ 'registered', 'registered-multiselect', 'registered-checkmatrix', 'unused' ],
                IContextSource $context = null
        ) {
                $this->load();
                $defaultOptions = self::getDefaultOptions();

                if ( !is_array( $resetKinds ) ) {
                        $resetKinds = [ $resetKinds ];
                }

                if ( in_array( 'all', $resetKinds ) ) {
                        $newOptions = $defaultOptions;
                } else {
                        if ( $context === null ) {
                                $context = RequestContext::getMain();
                        }

                        $optionKinds = $this->getOptionKinds( $context );
                        $resetKinds = array_intersect( $resetKinds, self::listOptionKinds() );
                        $newOptions = [];

                        // Use default values for the options that should be deleted, and
                        // copy old values for the ones that shouldn't.
                        foreach ( $this->mOptions as $key => $value ) {
                                if ( in_array( $optionKinds[$key], $resetKinds ) ) {
                                        if ( array_key_exists( $key, $defaultOptions ) ) {
                                                $newOptions[$key] = $defaultOptions[$key];
                                        }
                                } else {
                                        $newOptions[$key] = $value;
                                }
                        }
                }

                Hooks::run( 'UserResetAllOptions', [ $this, &$newOptions, $this->mOptions, $resetKinds ] );

                $this->mOptions = $newOptions;
                $this->mOptionsLoaded = true;
        }

        /**
         * Get the user's preferred date format.
         * @return string User's preferred date format
         */
        public function getDatePreference() {
                // Important migration for old data rows
                if ( is_null( $this->mDatePreference ) ) {
                        global $wgLang;
                        $value = $this->getOption( 'date' );
                        $map = $wgLang->getDatePreferenceMigrationMap();
                        if ( isset( $map[$value] ) ) {
                                $value = $map[$value];
                        }
                        $this->mDatePreference = $value;
                }
                return $this->mDatePreference;
        }

        /**
         * Determine based on the wiki configuration and the user's options,
         * whether this user must be over HTTPS no matter what.
         *
         * @return bool
         */
        public function requiresHTTPS() {
                global $wgSecureLogin;
                if ( !$wgSecureLogin ) {
                        return false;
                } else {
                        $https = $this->getBoolOption( 'prefershttps' );
                        Hooks::run( 'UserRequiresHTTPS', [ $this, &$https ] );
                        if ( $https ) {
                                $https = wfCanIPUseHTTPS( $this->getRequest()->getIP() );
                        }
                        return $https;
                }
        }

        /**
         * Get the user preferred stub threshold
         *
         * @return int
         */
        public function getStubThreshold() {
                global $wgMaxArticleSize; # Maximum article size, in Kb
                $threshold = $this->getIntOption( 'stubthreshold' );
                if ( $threshold > $wgMaxArticleSize * 1024 ) {
                        // If they have set an impossible value, disable the preference
                        // so we can use the parser cache again.
                        $threshold = 0;
                }
                return $threshold;
        }

        /**
         * Get the permissions this user has.
         * @return array Array of String permission names
         */
        public function getRights() {
                if ( is_null( $this->mRights ) ) {
                        $this->mRights = self::getGroupPermissions( $this->getEffectiveGroups() );
                        Hooks::run( 'UserGetRights', [ $this, &$this->mRights ] );

                        // Deny any rights denied by the user's session, unless this
                        // endpoint has no sessions.
                        if ( !defined( 'MW_NO_SESSION' ) ) {
                                $allowedRights = $this->getRequest()->getSession()->getAllowedUserRights();
                                if ( $allowedRights !== null ) {
                                        $this->mRights = array_intersect( $this->mRights, $allowedRights );
                                }
                        }

                        // Force reindexation of rights when a hook has unset one of them
                        $this->mRights = array_values( array_unique( $this->mRights ) );

                        // If block disables login, we should also remove any
                        // extra rights blocked users might have, in case the
                        // blocked user has a pre-existing session (T129738).
                        // This is checked here for cases where people only call
                        // $user->isAllowed(). It is also checked in Title::checkUserBlock()
                        // to give a better error message in the common case.
                        $config = RequestContext::getMain()->getConfig();
                        if (
                                $this->isLoggedIn() &&
                                $config->get( 'BlockDisablesLogin' ) &&
                                $this->isBlocked()
                        ) {
                                $anon = new User;
                                $this->mRights = array_intersect( $this->mRights, $anon->getRights() );
                        }
                }
                return $this->mRights;
        }

        /**
         * Get the list of explicit group memberships this user has.
         * The implicit * and user groups are not included.
         * @return array Array of String internal group names
         */
        public function getGroups() {
                $this->load();
                $this->loadGroups();
                return array_keys( $this->mGroupMemberships );
        }

        /**
         * Get the list of explicit group memberships this user has, stored as
         * UserGroupMembership objects. Implicit groups are not included.
         *
         * @return array Associative array of (group name as string => UserGroupMembership object)
         * @since 1.29
         */
        public function getGroupMemberships() {
                $this->load();
                $this->loadGroups();
                return $this->mGroupMemberships;
        }

        /**
         * Get the list of implicit group memberships this user has.
         * This includes all explicit groups, plus 'user' if logged in,
         * '*' for all accounts, and autopromoted groups
         * @param bool $recache Whether to avoid the cache
         * @return array Array of String internal group names
         */
        public function getEffectiveGroups( $recache = false ) {
                if ( $recache || is_null( $this->mEffectiveGroups ) ) {
                        $this->mEffectiveGroups = array_unique( array_merge(
                                $this->getGroups(), // explicit groups
                                $this->getAutomaticGroups( $recache ) // implicit groups
                        ) );
                        // Avoid PHP 7.1 warning of passing $this by reference
                        $user = $this;
                        // Hook for additional groups
                        Hooks::run( 'UserEffectiveGroups', [ &$user, &$this->mEffectiveGroups ] );
                        // Force reindexation of groups when a hook has unset one of them
                        $this->mEffectiveGroups = array_values( array_unique( $this->mEffectiveGroups ) );
                }
                return $this->mEffectiveGroups;
        }

        /**
         * Get the list of implicit group memberships this user has.
         * This includes 'user' if logged in, '*' for all accounts,
         * and autopromoted groups
         * @param bool $recache Whether to avoid the cache
         * @return array Array of String internal group names
         */
        public function getAutomaticGroups( $recache = false ) {
                if ( $recache || is_null( $this->mImplicitGroups ) ) {
                        $this->mImplicitGroups = [ '*' ];
                        if ( $this->getId() ) {
                                $this->mImplicitGroups[] = 'user';

                                $this->mImplicitGroups = array_unique( array_merge(
                                        $this->mImplicitGroups,
                                        Autopromote::getAutopromoteGroups( $this )
                                ) );
                        }
                        if ( $recache ) {
                                // Assure data consistency with rights/groups,
                                // as getEffectiveGroups() depends on this function
                                $this->mEffectiveGroups = null;
                        }
                }
                return $this->mImplicitGroups;
        }

        /**
         * Returns the groups the user has belonged to.
         *
         * The user may still belong to the returned groups. Compare with getGroups().
         *
         * The function will not return groups the user had belonged to before MW 1.17
         *
         * @return array Names of the groups the user has belonged to.
         */
        public function getFormerGroups() {
                $this->load();

                if ( is_null( $this->mFormerGroups ) ) {
                        $db = ( $this->queryFlagsUsed & self::READ_LATEST )
                                ? wfGetDB( DB_MASTER )
                                : wfGetDB( DB_REPLICA );
                        $res = $db->select( 'user_former_groups',
                                [ 'ufg_group' ],
                                [ 'ufg_user' => $this->mId ],
                                __METHOD__ );
                        $this->mFormerGroups = [];
                        foreach ( $res as $row ) {
                                $this->mFormerGroups[] = $row->ufg_group;
                        }
                }

                return $this->mFormerGroups;
        }

        /**
         * Get the user's edit count.
         * @return int|null Null for anonymous users
         */
        public function getEditCount() {
                if ( !$this->getId() ) {
                        return null;
                }

                if ( $this->mEditCount === null ) {
                        /* Populate the count, if it has not been populated yet */
                        $dbr = wfGetDB( DB_REPLICA );
                        // check if the user_editcount field has been initialized
                        $count = $dbr->selectField(
                                'user', 'user_editcount',
                                [ 'user_id' => $this->mId ],
                                __METHOD__
                        );

                        if ( $count === null ) {
                                // it has not been initialized. do so.
                                $count = $this->initEditCount();
                        }
                        $this->mEditCount = $count;
                }
                return (int)$this->mEditCount;
        }

        /**
         * Add the user to the given group. This takes immediate effect.
         * If the user is already in the group, the expiry time will be updated to the new
         * expiry time. (If $expiry is omitted or null, the membership will be altered to
         * never expire.)
         *
         * @param string $group Name of the group to add
         * @param string $expiry Optional expiry timestamp in any format acceptable to
         *   wfTimestamp(), or null if the group assignment should not expire
         * @return bool
         */
        public function addGroup( $group, $expiry = null ) {
                $this->load();
                $this->loadGroups();

                if ( $expiry ) {
                        $expiry = wfTimestamp( TS_MW, $expiry );
                }

                if ( !Hooks::run( 'UserAddGroup', [ $this, &$group, &$expiry ] ) ) {
                        return false;
                }

                // create the new UserGroupMembership and put it in the DB
                $ugm = new UserGroupMembership( $this->mId, $group, $expiry );
                if ( !$ugm->insert( true ) ) {
                        return false;
                }

                $this->mGroupMemberships[$group] = $ugm;

                // Refresh the groups caches, and clear the rights cache so it will be
                // refreshed on the next call to $this->getRights().
                $this->getEffectiveGroups( true );
                $this->mRights = null;

                $this->invalidateCache();

                return true;
        }

        /**
         * Remove the user from the given group.
         * This takes immediate effect.
         * @param string $group Name of the group to remove
         * @return bool
         */
        public function removeGroup( $group ) {
                $this->load();

                if ( !Hooks::run( 'UserRemoveGroup', [ $this, &$group ] ) ) {
                        return false;
                }

                $ugm = UserGroupMembership::getMembership( $this->mId, $group );
                // delete the membership entry
                if ( !$ugm || !$ugm->delete() ) {
                        return false;
                }

                $this->loadGroups();
                unset( $this->mGroupMemberships[$group] );

                // Refresh the groups caches, and clear the rights cache so it will be
                // refreshed on the next call to $this->getRights().
                $this->getEffectiveGroups( true );
                $this->mRights = null;

                $this->invalidateCache();

                return true;
        }

        /**
         * Get whether the user is logged in
         * @return bool
         */
        public function isLoggedIn() {
                return $this->getId() != 0;
        }

        /**
         * Get whether the user is anonymous
         * @return bool
         */
        public function isAnon() {
                return !$this->isLoggedIn();
        }

        /**
         * @return bool Whether this user is flagged as being a bot role account
         * @since 1.28
         */
        public function isBot() {
                if ( in_array( 'bot', $this->getGroups() ) && $this->isAllowed( 'bot' ) ) {
                        return true;
                }

                $isBot = false;
                Hooks::run( "UserIsBot", [ $this, &$isBot ] );

                return $isBot;
        }

        /**
         * Check if user is allowed to access a feature / make an action
         *
         * @param string ... Permissions to test
         * @return bool True if user is allowed to perform *any* of the given actions
         */
        public function isAllowedAny() {
                $permissions = func_get_args();
                foreach ( $permissions as $permission ) {
                        if ( $this->isAllowed( $permission ) ) {
                                return true;
                        }
                }
                return false;
        }

        /**
         *
         * @param string ... Permissions to test
         * @return bool True if the user is allowed to perform *all* of the given actions
         */
        public function isAllowedAll() {
                $permissions = func_get_args();
                foreach ( $permissions as $permission ) {
                        if ( !$this->isAllowed( $permission ) ) {
                                return false;
                        }
                }
                return true;
        }

        /**
         * Internal mechanics of testing a permission
         * @param string $action
         * @return bool
         */
        public function isAllowed( $action = '' ) {
                if ( $action === '' ) {
                        return true; // In the spirit of DWIM
                }
                // Use strict parameter to avoid matching numeric 0 accidentally inserted
                // by misconfiguration: 0 == 'foo'
                return in_array( $action, $this->getRights(), true );
        }

        /**
         * Check whether to enable recent changes patrol features for this user
         * @return bool True or false
         */
        public function useRCPatrol() {
                global $wgUseRCPatrol;
                return $wgUseRCPatrol && $this->isAllowedAny( 'patrol', 'patrolmarks' );
        }

        /**
         * Check whether to enable new pages patrol features for this user
         * @return bool True or false
         */
        public function useNPPatrol() {
                global $wgUseRCPatrol, $wgUseNPPatrol;
                return (
                        ( $wgUseRCPatrol || $wgUseNPPatrol )
                                && ( $this->isAllowedAny( 'patrol', 'patrolmarks' ) )
                );
        }

        /**
         * Check whether to enable new files patrol features for this user
         * @return bool True or false
         */
        public function useFilePatrol() {
                global $wgUseRCPatrol, $wgUseFilePatrol;
                return (
                        ( $wgUseRCPatrol || $wgUseFilePatrol )
                                && ( $this->isAllowedAny( 'patrol', 'patrolmarks' ) )
                );
        }

        /**
         * Get the WebRequest object to use with this object
         *
         * @return WebRequest
         */
        public function getRequest() {
                if ( $this->mRequest ) {
                        return $this->mRequest;
                } else {
                        global $wgRequest;
                        return $wgRequest;
                }
        }

        /**
         * Check the watched status of an article.
         * @since 1.22 $checkRights parameter added
         * @param Title $title Title of the article to look at
         * @param bool $checkRights Whether to check 'viewmywatchlist'/'editmywatchlist' rights.
         *     Pass User::CHECK_USER_RIGHTS or User::IGNORE_USER_RIGHTS.
         * @return bool
         */
        public function isWatched( $title, $checkRights = self::CHECK_USER_RIGHTS ) {
                if ( $title->isWatchable() && ( !$checkRights || $this->isAllowed( 'viewmywatchlist' ) ) ) {
                        return MediaWikiServices::getInstance()->getWatchedItemStore()->isWatched( $this, $title );
                }
                return false;
        }

        /**
         * Watch an article.
         * @since 1.22 $checkRights parameter added
         * @param Title $title Title of the article to look at
         * @param bool $checkRights Whether to check 'viewmywatchlist'/'editmywatchlist' rights.
         *     Pass User::CHECK_USER_RIGHTS or User::IGNORE_USER_RIGHTS.
         */
        public function addWatch( $title, $checkRights = self::CHECK_USER_RIGHTS ) {
                if ( !$checkRights || $this->isAllowed( 'editmywatchlist' ) ) {
                        MediaWikiServices::getInstance()->getWatchedItemStore()->addWatchBatchForUser(
                                $this,
                                [ $title->getSubjectPage(), $title->getTalkPage() ]
                        );
                }
                $this->invalidateCache();
        }

        /**
         * Stop watching an article.
         * @since 1.22 $checkRights parameter added
         * @param Title $title Title of the article to look at
         * @param bool $checkRights Whether to check 'viewmywatchlist'/'editmywatchlist' rights.
         *     Pass User::CHECK_USER_RIGHTS or User::IGNORE_USER_RIGHTS.
         */
        public function removeWatch( $title, $checkRights = self::CHECK_USER_RIGHTS ) {
                if ( !$checkRights || $this->isAllowed( 'editmywatchlist' ) ) {
                        $store = MediaWikiServices::getInstance()->getWatchedItemStore();
                        $store->removeWatch( $this, $title->getSubjectPage() );
                        $store->removeWatch( $this, $title->getTalkPage() );
                }
                $this->invalidateCache();
        }

        /**
         * Clear the user's notification timestamp for the given title.
         * If e-notif e-mails are on, they will receive notification mails on
         * the next change of the page if it's watched etc.
         * @note If the user doesn't have 'editmywatchlist', this will do nothing.
         * @param Title $title Title of the article to look at
         * @param int $oldid The revision id being viewed. If not given or 0, latest revision is assumed.
         */
        public function clearNotification( &$title, $oldid = 0 ) {
                global $wgUseEnotif, $wgShowUpdatedMarker;

                // Do nothing if the database is locked to writes
                if ( wfReadOnly() ) {
                        return;
                }

                // Do nothing if not allowed to edit the watchlist
                if ( !$this->isAllowed( 'editmywatchlist' ) ) {
                        return;
                }

                // If we're working on user's talk page, we should update the talk page message indicator
                if ( $title->getNamespace() == NS_USER_TALK && $title->getText() == $this->getName() ) {
                        // Avoid PHP 7.1 warning of passing $this by reference
                        $user = $this;
                        if ( !Hooks::run( 'UserClearNewTalkNotification', [ &$user, $oldid ] ) ) {
                                return;
                        }

                        // Try to update the DB post-send and only if needed...
                        DeferredUpdates::addCallableUpdate( function() use ( $title, $oldid ) {
                                if ( !$this->getNewtalk() ) {
                                        return; // no notifications to clear
                                }

                                // Delete the last notifications (they stack up)
                                $this->setNewtalk( false );

                                // If there is a new, unseen, revision, use its timestamp
                                $nextid = $oldid
                                        ? $title->getNextRevisionID( $oldid, Title::GAID_FOR_UPDATE )
                                        : null;
                                if ( $nextid ) {
                                        $this->setNewtalk( true, Revision::newFromId( $nextid ) );
                                }
                        } );
                }

                if ( !$wgUseEnotif && !$wgShowUpdatedMarker ) {
                        return;
                }

                if ( $this->isAnon() ) {
                        // Nothing else to do...
                        return;
                }

                // Only update the timestamp if the page is being watched.
                // The query to find out if it is watched is cached both in memcached and per-invocation,
                // and when it does have to be executed, it can be on a replica DB
                // If this is the user's newtalk page, we always update the timestamp
                $force = '';
                if ( $title->getNamespace() == NS_USER_TALK && $title->getText() == $this->getName() ) {
                        $force = 'force';
                }

                MediaWikiServices::getInstance()->getWatchedItemStore()
                        ->resetNotificationTimestamp( $this, $title, $force, $oldid );
        }

        /**
         * Resets all of the given user's page-change notification timestamps.
         * If e-notif e-mails are on, they will receive notification mails on
         * the next change of any watched page.
         * @note If the user doesn't have 'editmywatchlist', this will do nothing.
         */
        public function clearAllNotifications() {
                global $wgUseEnotif, $wgShowUpdatedMarker;
                // Do nothing if not allowed to edit the watchlist
                if ( wfReadOnly() || !$this->isAllowed( 'editmywatchlist' ) ) {
                        return;
                }

                if ( !$wgUseEnotif && !$wgShowUpdatedMarker ) {
                        $this->setNewtalk( false );
                        return;
                }

                $id = $this->getId();
                if ( !$id ) {
                        return;
                }

                $dbw = wfGetDB( DB_MASTER );
                $asOfTimes = array_unique( $dbw->selectFieldValues(
                        'watchlist',
                        'wl_notificationtimestamp',
                        [ 'wl_user' => $id, 'wl_notificationtimestamp IS NOT NULL' ],
                        __METHOD__,
                        [ 'ORDER BY' => 'wl_notificationtimestamp DESC', 'LIMIT' => 500 ]
                ) );
                if ( !$asOfTimes ) {
                        return;
                }
                // Immediately update the most recent touched rows, which hopefully covers what
                // the user sees on the watchlist page before pressing "mark all pages visited"....
                $dbw->update(
                        'watchlist',
                        [ 'wl_notificationtimestamp' => null ],
                        [ 'wl_user' => $id, 'wl_notificationtimestamp' => $asOfTimes ],
                        __METHOD__
                );
                // ...and finish the older ones in a post-send update with lag checks...
                DeferredUpdates::addUpdate( new AutoCommitUpdate(
                        $dbw,
                        __METHOD__,
                        function () use ( $dbw, $id ) {
                                global $wgUpdateRowsPerQuery;

                                $lbFactory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
                                $ticket = $lbFactory->getEmptyTransactionTicket( __METHOD__ );
                                $asOfTimes = array_unique( $dbw->selectFieldValues(
                                        'watchlist',
                                        'wl_notificationtimestamp',
                                        [ 'wl_user' => $id, 'wl_notificationtimestamp IS NOT NULL' ],
                                        __METHOD__
                                ) );
                                foreach ( array_chunk( $asOfTimes, $wgUpdateRowsPerQuery ) as $asOfTimeBatch ) {
                                        $dbw->update(
                                                'watchlist',
                                                [ 'wl_notificationtimestamp' => null ],
                                                [ 'wl_user' => $id, 'wl_notificationtimestamp' => $asOfTimeBatch ],
                                                __METHOD__
                                        );
                                        $lbFactory->commitAndWaitForReplication( __METHOD__, $ticket );
                                }
                        }
                ) );
                // We also need to clear here the "you have new message" notification for the own
                // user_talk page; it's cleared one page view later in WikiPage::doViewUpdates().
        }

        /**
         * Compute experienced level based on edit count and registration date.
         *
         * @return string 'newcomer', 'learner', or 'experienced'
         */
        public function getExperienceLevel() {
                global $wgLearnerEdits,
                        $wgExperiencedUserEdits,
                        $wgLearnerMemberSince,
                        $wgExperiencedUserMemberSince;

                if ( $this->isAnon() ) {
                        return false;
                }

                $editCount = $this->getEditCount();
                $registration = $this->getRegistration();
                $now = time();
                $learnerRegistration = wfTimestamp( TS_MW, $now - $wgLearnerMemberSince * 86400 );
                $experiencedRegistration = wfTimestamp( TS_MW, $now - $wgExperiencedUserMemberSince * 86400 );

                if (
                        $editCount < $wgLearnerEdits ||
                        $registration > $learnerRegistration
                ) {
                        return 'newcomer';
                } elseif (
                        $editCount > $wgExperiencedUserEdits &&
                        $registration <= $experiencedRegistration
                ) {
                        return 'experienced';
                } else {
                        return 'learner';
                }
        }

        /**
         * Set a cookie on the user's client. Wrapper for
         * WebResponse::setCookie
         * @deprecated since 1.27
         * @param string $name Name of the cookie to set
         * @param string $value Value to set
         * @param int $exp Expiration time, as a UNIX time value;
         *                   if 0 or not specified, use the default $wgCookieExpiration
         * @param bool $secure
         *  true: Force setting the secure attribute when setting the cookie
         *  false: Force NOT setting the secure attribute when setting the cookie
         *  null (default): Use the default ($wgCookieSecure) to set the secure attribute
         * @param array $params Array of options sent passed to WebResponse::setcookie()
         * @param WebRequest|null $request WebRequest object to use; $wgRequest will be used if null
         *        is passed.
         */
        protected function setCookie(
                $name, $value, $exp = 0, $secure = null, $params = [], $request = null
        ) {
                wfDeprecated( __METHOD__, '1.27' );
                if ( $request === null ) {
                        $request = $this->getRequest();
                }
                $params['secure'] = $secure;
                $request->response()->setCookie( $name, $value, $exp, $params );
        }

        /**
         * Clear a cookie on the user's client
         * @deprecated since 1.27
         * @param string $name Name of the cookie to clear
         * @param bool $secure
         *  true: Force setting the secure attribute when setting the cookie
         *  false: Force NOT setting the secure attribute when setting the cookie
         *  null (default): Use the default ($wgCookieSecure) to set the secure attribute
         * @param array $params Array of options sent passed to WebResponse::setcookie()
         */
        protected function clearCookie( $name, $secure = null, $params = [] ) {
                wfDeprecated( __METHOD__, '1.27' );
                $this->setCookie( $name, '', time() - 86400, $secure, $params );
        }

        /**
         * Set an extended login cookie on the user's client. The expiry of the cookie
         * is controlled by the $wgExtendedLoginCookieExpiration configuration
         * variable.
         *
         * @see User::setCookie
         *
         * @deprecated since 1.27
         * @param string $name Name of the cookie to set
         * @param string $value Value to set
         * @param bool $secure
         *  true: Force setting the secure attribute when setting the cookie
         *  false: Force NOT setting the secure attribute when setting the cookie
         *  null (default): Use the default ($wgCookieSecure) to set the secure attribute
         */
        protected function setExtendedLoginCookie( $name, $value, $secure ) {
                global $wgExtendedLoginCookieExpiration, $wgCookieExpiration;

                wfDeprecated( __METHOD__, '1.27' );

                $exp = time();
                $exp += $wgExtendedLoginCookieExpiration !== null
                        ? $wgExtendedLoginCookieExpiration
                        : $wgCookieExpiration;

                $this->setCookie( $name, $value, $exp, $secure );
        }

        /**
         * Persist this user's session (e.g. set cookies)
         *
         * @param WebRequest|null $request WebRequest object to use; $wgRequest will be used if null
         *        is passed.
         * @param bool $secure Whether to force secure/insecure cookies or use default
         * @param bool $rememberMe Whether to add a Token cookie for elongated sessions
         */
        public function setCookies( $request = null, $secure = null, $rememberMe = false ) {
                $this->load();
                if ( 0 == $this->mId ) {
                        return;
                }

                $session = $this->getRequest()->getSession();
                if ( $request && $session->getRequest() !== $request ) {
                        $session = $session->sessionWithRequest( $request );
                }
                $delay = $session->delaySave();

                if ( !$session->getUser()->equals( $this ) ) {
                        if ( !$session->canSetUser() ) {
                                \MediaWiki\Logger\LoggerFactory::getInstance( 'session' )
                                        ->warning( __METHOD__ .
                                                ": Cannot save user \"$this\" to a user \"{$session->getUser()}\"'s immutable session"
                                        );
                                return;
                        }
                        $session->setUser( $this );
                }

                $session->setRememberUser( $rememberMe );
                if ( $secure !== null ) {
                        $session->setForceHTTPS( $secure );
                }

                $session->persist();

                ScopedCallback::consume( $delay );
        }

        /**
         * Log this user out.
         */
        public function logout() {
                // Avoid PHP 7.1 warning of passing $this by reference
                $user = $this;
                if ( Hooks::run( 'UserLogout', [ &$user ] ) ) {
                        $this->doLogout();
                }
        }

        /**
         * Clear the user's session, and reset the instance cache.
         * @see logout()
         */
        public function doLogout() {
                $session = $this->getRequest()->getSession();
                if ( !$session->canSetUser() ) {
                        \MediaWiki\Logger\LoggerFactory::getInstance( 'session' )
                                ->warning( __METHOD__ . ": Cannot log out of an immutable session" );
                        $error = 'immutable';
                } elseif ( !$session->getUser()->equals( $this ) ) {
                        \MediaWiki\Logger\LoggerFactory::getInstance( 'session' )
                                ->warning( __METHOD__ .
                                        ": Cannot log user \"$this\" out of a user \"{$session->getUser()}\"'s session"
                                );
                        // But we still may as well make this user object anon
                        $this->clearInstanceCache( 'defaults' );
                        $error = 'wronguser';
                } else {
                        $this->clearInstanceCache( 'defaults' );
                        $delay = $session->delaySave();
                        $session->unpersist(); // Clear cookies (T127436)
                        $session->setLoggedOutTimestamp( time() );
                        $session->setUser( new User );
                        $session->set( 'wsUserID', 0 ); // Other code expects this
                        $session->resetAllTokens();
                        ScopedCallback::consume( $delay );
                        $error = false;
                }
                \MediaWiki\Logger\LoggerFactory::getInstance( 'authevents' )->info( 'Logout', [
                        'event' => 'logout',
                        'successful' => $error === false,
                        'status' => $error ?: 'success',
                ] );
        }

        /**
         * Save this user's settings into the database.
         * @todo Only rarely do all these fields need to be set!
         */
        public function saveSettings() {
                if ( wfReadOnly() ) {
                        // @TODO: caller should deal with this instead!
                        // This should really just be an exception.
                        MWExceptionHandler::logException( new DBExpectedError(
                                null,
                                "Could not update user with ID '{$this->mId}'; DB is read-only."
                        ) );
                        return;
                }

                $this->load();
                if ( 0 == $this->mId ) {
                        return; // anon
                }

                // Get a new user_touched that is higher than the old one.
                // This will be used for a CAS check as a last-resort safety
                // check against race conditions and replica DB lag.
                $newTouched = $this->newTouchedTimestamp();

                $dbw = wfGetDB( DB_MASTER );
                $dbw->update( 'user',
                        [ /* SET */
                                'user_name' => $this->mName,
                                'user_real_name' => $this->mRealName,
                                'user_email' => $this->mEmail,
                                'user_email_authenticated' => $dbw->timestampOrNull( $this->mEmailAuthenticated ),
                                'user_touched' => $dbw->timestamp( $newTouched ),
                                'user_token' => strval( $this->mToken ),
                                'user_email_token' => $this->mEmailToken,
                                'user_email_token_expires' => $dbw->timestampOrNull( $this->mEmailTokenExpires ),
                        ], $this->makeUpdateConditions( $dbw, [ /* WHERE */
                                'user_id' => $this->mId,
                        ] ), __METHOD__
                );

                if ( !$dbw->affectedRows() ) {
                        // Maybe the problem was a missed cache update; clear it to be safe
                        $this->clearSharedCache( 'refresh' );
                        // User was changed in the meantime or loaded with stale data
                        $from = ( $this->queryFlagsUsed & self::READ_LATEST ) ? 'master' : 'replica';
                        throw new MWException(
                                "CAS update failed on user_touched for user ID '{$this->mId}' (read from $from);" .
                                " the version of the user to be saved is older than the current version."
                        );
                }

                $this->mTouched = $newTouched;
                $this->saveOptions();

                Hooks::run( 'UserSaveSettings', [ $this ] );
                $this->clearSharedCache();
                $this->getUserPage()->invalidateCache();
        }

        /**
         * If only this user's username is known, and it exists, return the user ID.
         *
         * @param int $flags Bitfield of User:READ_* constants; useful for existence checks
         * @return int
         */
        public function idForName( $flags = 0 ) {
                $s = trim( $this->getName() );
                if ( $s === '' ) {
                        return 0;
                }

                $db = ( ( $flags & self::READ_LATEST ) == self::READ_LATEST )
                        ? wfGetDB( DB_MASTER )
                        : wfGetDB( DB_REPLICA );

                $options = ( ( $flags & self::READ_LOCKING ) == self::READ_LOCKING )
                        ? [ 'LOCK IN SHARE MODE' ]
                        : [];

                $id = $db->selectField( 'user',
                        'user_id', [ 'user_name' => $s ], __METHOD__, $options );

                return (int)$id;
        }

        /**
         * Add a user to the database, return the user object
         *
         * @param string $name Username to add
         * @param array $params Array of Strings Non-default parameters to save to
         *   the database as user_* fields:
         *   - email: The user's email address.
         *   - email_authenticated: The email authentication timestamp.
         *   - real_name: The user's real name.
         *   - options: An associative array of non-default options.
         *   - token: Random authentication token. Do not set.
         *   - registration: Registration timestamp. Do not set.
         *
         * @return User|null User object, or null if the username already exists.
         */
        public static function createNew( $name, $params = [] ) {
                foreach ( [ 'password', 'newpassword', 'newpass_time', 'password_expires' ] as $field ) {
                        if ( isset( $params[$field] ) ) {
                                wfDeprecated( __METHOD__ . " with param '$field'", '1.27' );
                                unset( $params[$field] );
                        }
                }

                $user = new User;
                $user->load();
                $user->setToken(); // init token
                if ( isset( $params['options'] ) ) {
                        $user->mOptions = $params['options'] + (array)$user->mOptions;
                        unset( $params['options'] );
                }
                $dbw = wfGetDB( DB_MASTER );
                $seqVal = $dbw->nextSequenceValue( 'user_user_id_seq' );

                $noPass = PasswordFactory::newInvalidPassword()->toString();

                $fields = [
                        'user_id' => $seqVal,
                        'user_name' => $name,
                        'user_password' => $noPass,
                        'user_newpassword' => $noPass,
                        'user_email' => $user->mEmail,
                        'user_email_authenticated' => $dbw->timestampOrNull( $user->mEmailAuthenticated ),
                        'user_real_name' => $user->mRealName,
                        'user_token' => strval( $user->mToken ),
                        'user_registration' => $dbw->timestamp( $user->mRegistration ),
                        'user_editcount' => 0,
                        'user_touched' => $dbw->timestamp( $user->newTouchedTimestamp() ),
                ];
                foreach ( $params as $name => $value ) {
                        $fields["user_$name"] = $value;
                }
                $dbw->insert( 'user', $fields, __METHOD__, [ 'IGNORE' ] );
                if ( $dbw->affectedRows() ) {
                        $newUser = User::newFromId( $dbw->insertId() );
                } else {
                        $newUser = null;
                }
                return $newUser;
        }

        /**
         * Add this existing user object to the database. If the user already
         * exists, a fatal status object is returned, and the user object is
         * initialised with the data from the database.
         *
         * Previously, this function generated a DB error due to a key conflict
         * if the user already existed. Many extension callers use this function
         * in code along the lines of:
         *
         *   $user = User::newFromName( $name );
         *   if ( !$user->isLoggedIn() ) {
         *       $user->addToDatabase();
         *   }
         *   // do something with $user...
         *
         * However, this was vulnerable to a race condition (T18020). By
         * initialising the user object if the user exists, we aim to support this
         * calling sequence as far as possible.
         *
         * Note that if the user exists, this function will acquire a write lock,
         * so it is still advisable to make the call conditional on isLoggedIn(),
         * and to commit the transaction after calling.
         *
         * @throws MWException
         * @return Status
         */
        public function addToDatabase() {
                $this->load();
                if ( !$this->mToken ) {
                        $this->setToken(); // init token
                }

                $this->mTouched = $this->newTouchedTimestamp();

                $noPass = PasswordFactory::newInvalidPassword()->toString();

                $dbw = wfGetDB( DB_MASTER );
                $seqVal = $dbw->nextSequenceValue( 'user_user_id_seq' );
                $dbw->insert( 'user',
                        [
                                'user_id' => $seqVal,
                                'user_name' => $this->mName,
                                'user_password' => $noPass,
                                'user_newpassword' => $noPass,
                                'user_email' => $this->mEmail,
                                'user_email_authenticated' => $dbw->timestampOrNull( $this->mEmailAuthenticated ),
                                'user_real_name' => $this->mRealName,
                                'user_token' => strval( $this->mToken ),
                                'user_registration' => $dbw->timestamp( $this->mRegistration ),
                                'user_editcount' => 0,
                                'user_touched' => $dbw->timestamp( $this->mTouched ),
                        ], __METHOD__,
                        [ 'IGNORE' ]
                );
                if ( !$dbw->affectedRows() ) {
                        // Use locking reads to bypass any REPEATABLE-READ snapshot.
                        $this->mId = $dbw->selectField(
                                'user',
                                'user_id',
                                [ 'user_name' => $this->mName ],
                                __METHOD__,
                                [ 'LOCK IN SHARE MODE' ]
                        );
                        $loaded = false;
                        if ( $this->mId ) {
                                if ( $this->loadFromDatabase( self::READ_LOCKING ) ) {
                                        $loaded = true;
                                }
                        }
                        if ( !$loaded ) {
                                throw new MWException( __METHOD__ . ": hit a key conflict attempting " .
                                        "to insert user '{$this->mName}' row, but it was not present in select!" );
                        }
                        return Status::newFatal( 'userexists' );
                }
                $this->mId = $dbw->insertId();
                self::$idCacheByName[$this->mName] = $this->mId;

                // Clear instance cache other than user table data, which is already accurate
                $this->clearInstanceCache();

                $this->saveOptions();
                return Status::newGood();
        }

        /**
         * If this user is logged-in and blocked,
         * block any IP address they've successfully logged in from.
         * @return bool A block was spread
         */
        public function spreadAnyEditBlock() {
                if ( $this->isLoggedIn() && $this->isBlocked() ) {
                        return $this->spreadBlock();
                }

                return false;
        }

        /**
         * If this (non-anonymous) user is blocked,
         * block the IP address they've successfully logged in from.
         * @return bool A block was spread
         */
        protected function spreadBlock() {
                wfDebug( __METHOD__ . "()\n" );
                $this->load();
                if ( $this->mId == 0 ) {
                        return false;
                }

                $userblock = Block::newFromTarget( $this->getName() );
                if ( !$userblock ) {
                        return false;
                }

                return (bool)$userblock->doAutoblock( $this->getRequest()->getIP() );
        }

        /**
         * Get whether the user is explicitly blocked from account creation.
         * @return bool|Block
         */
        public function isBlockedFromCreateAccount() {
                $this->getBlockedStatus();
                if ( $this->mBlock && $this->mBlock->prevents( 'createaccount' ) ) {
                        return $this->mBlock;
                }

                # T15611: if the IP address the user is trying to create an account from is
                # blocked with createaccount disabled, prevent new account creation there even
                # when the user is logged in
                if ( $this->mBlockedFromCreateAccount === false && !$this->isAllowed( 'ipblock-exempt' ) ) {
                        $this->mBlockedFromCreateAccount = Block::newFromTarget( null, $this->getRequest()->getIP() );
                }
                return $this->mBlockedFromCreateAccount instanceof Block
                        && $this->mBlockedFromCreateAccount->prevents( 'createaccount' )
                        ? $this->mBlockedFromCreateAccount
                        : false;
        }

        /**
         * Get whether the user is blocked from using Special:Emailuser.
         * @return bool
         */
        public function isBlockedFromEmailuser() {
                $this->getBlockedStatus();
                return $this->mBlock && $this->mBlock->prevents( 'sendemail' );
        }

        /**
         * Get whether the user is allowed to create an account.
         * @return bool
         */
        public function isAllowedToCreateAccount() {
                return $this->isAllowed( 'createaccount' ) && !$this->isBlockedFromCreateAccount();
        }

        /**
         * Get this user's personal page title.
         *
         * @return Title User's personal page title
         */
        public function getUserPage() {
                return Title::makeTitle( NS_USER, $this->getName() );
        }

        /**
         * Get this user's talk page title.
         *
         * @return Title User's talk page title
         */
        public function getTalkPage() {
                $title = $this->getUserPage();
                return $title->getTalkPage();
        }

        /**
         * Determine whether the user is a newbie. Newbies are either
         * anonymous IPs, or the most recently created accounts.
         * @return bool
         */
        public function isNewbie() {
                return !$this->isAllowed( 'autoconfirmed' );
        }

        /**
         * Check to see if the given clear-text password is one of the accepted passwords
         * @deprecated since 1.27, use AuthManager instead
         * @param string $password User password
         * @return bool True if the given password is correct, otherwise False
         */
        public function checkPassword( $password ) {
                $manager = AuthManager::singleton();
                $reqs = AuthenticationRequest::loadRequestsFromSubmission(
                        $manager->getAuthenticationRequests( AuthManager::ACTION_LOGIN ),
                        [
                                'username' => $this->getName(),
                                'password' => $password,
                        ]
                );
                $res = AuthManager::singleton()->beginAuthentication( $reqs, 'null:' );
                switch ( $res->status ) {
                        case AuthenticationResponse::PASS:
                                return true;
                        case AuthenticationResponse::FAIL:
                                // Hope it's not a PreAuthenticationProvider that failed...
                                \MediaWiki\Logger\LoggerFactory::getInstance( 'authentication' )
                                        ->info( __METHOD__ . ': Authentication failed: ' . $res->message->plain() );
                                return false;
                        default:
                                throw new BadMethodCallException(
                                        'AuthManager returned a response unsupported by ' . __METHOD__
                                );
                }
        }

        /**
         * Check if the given clear-text password matches the temporary password
         * sent by e-mail for password reset operations.
         *
         * @deprecated since 1.27, use AuthManager instead
         * @param string $plaintext
         * @return bool True if matches, false otherwise
         */
        public function checkTemporaryPassword( $plaintext ) {
                // Can't check the temporary password individually.
                return $this->checkPassword( $plaintext );
        }

        /**
         * Initialize (if necessary) and return a session token value
         * which can be used in edit forms to show that the user's
         * login credentials aren't being hijacked with a foreign form
         * submission.
         *
         * @since 1.27
         * @param string|array $salt Array of Strings Optional function-specific data for hashing
         * @param WebRequest|null $request WebRequest object to use or null to use $wgRequest
         * @return MediaWiki\Session\Token The new edit token
         */
        public function getEditTokenObject( $salt = '', $request = null ) {
                if ( $this->isAnon() ) {
                        return new LoggedOutEditToken();
                }

                if ( !$request ) {
                        $request = $this->getRequest();
                }
                return $request->getSession()->getToken( $salt );
        }

        /**
         * Initialize (if necessary) and return a session token value
         * which can be used in edit forms to show that the user's
         * login credentials aren't being hijacked with a foreign form
         * submission.
         *
         * The $salt for 'edit' and 'csrf' tokens is the default (empty string).
         *
         * @since 1.19
         * @param string|array $salt Array of Strings Optional function-specific data for hashing
         * @param WebRequest|null $request WebRequest object to use or null to use $wgRequest
         * @return string The new edit token
         */
        public function getEditToken( $salt = '', $request = null ) {
                return $this->getEditTokenObject( $salt, $request )->toString();
        }

        /**
         * Get the embedded timestamp from a token.
         * @deprecated since 1.27, use \MediaWiki\Session\Token::getTimestamp instead.
         * @param string $val Input token
         * @return int|null
         */
        public static function getEditTokenTimestamp( $val ) {
                wfDeprecated( __METHOD__, '1.27' );
                return MediaWiki\Session\Token::getTimestamp( $val );
        }

        /**
         * Check given value against the token value stored in the session.
         * A match should confirm that the form was submitted from the
         * user's own login session, not a form submission from a third-party
         * site.
         *
         * @param string $val Input value to compare
         * @param string $salt Optional function-specific data for hashing
         * @param WebRequest|null $request Object to use or null to use $wgRequest
         * @param int $maxage Fail tokens older than this, in seconds
         * @return bool Whether the token matches
         */
        public function matchEditToken( $val, $salt = '', $request = null, $maxage = null ) {
                return $this->getEditTokenObject( $salt, $request )->match( $val, $maxage );
        }

        /**
         * Check given value against the token value stored in the session,
         * ignoring the suffix.
         *
         * @param string $val Input value to compare
         * @param string $salt Optional function-specific data for hashing
         * @param WebRequest|null $request Object to use or null to use $wgRequest
         * @param int $maxage Fail tokens older than this, in seconds
         * @return bool Whether the token matches
         */
        public function matchEditTokenNoSuffix( $val, $salt = '', $request = null, $maxage = null ) {
                $val = substr( $val, 0, strspn( $val, '0123456789abcdef' ) ) . Token::SUFFIX;
                return $this->matchEditToken( $val, $salt, $request, $maxage );
        }

        /**
         * Generate a new e-mail confirmation token and send a confirmation/invalidation
         * mail to the user's given address.
         *
         * @param string $type Message to send, either "created", "changed" or "set"
         * @return Status
         */
        public function sendConfirmationMail( $type = 'created' ) {
                global $wgLang;
                $expiration = null; // gets passed-by-ref and defined in next line.
                $token = $this->confirmationToken( $expiration );
                $url = $this->confirmationTokenUrl( $token );
                $invalidateURL = $this->invalidationTokenUrl( $token );
                $this->saveSettings();

                if ( $type == 'created' || $type === false ) {
                        $message = 'confirmemail_body';
                } elseif ( $type === true ) {
                        $message = 'confirmemail_body_changed';
                } else {
                        // Messages: confirmemail_body_changed, confirmemail_body_set
                        $message = 'confirmemail_body_' . $type;
                }

                return $this->sendMail( wfMessage( 'confirmemail_subject' )->text(),
                        wfMessage( $message,
                                $this->getRequest()->getIP(),
                                $this->getName(),
                                $url,
                                $wgLang->userTimeAndDate( $expiration, $this ),
                                $invalidateURL,
                                $wgLang->userDate( $expiration, $this ),
                                $wgLang->userTime( $expiration, $this ) )->text() );
        }

        /**
         * Send an e-mail to this user's account. Does not check for
         * confirmed status or validity.
         *
         * @param string $subject Message subject
         * @param string $body Message body
         * @param User|null $from Optional sending user; if unspecified, default
         *   $wgPasswordSender will be used.
         * @param string $replyto Reply-To address
         * @return Status
         */
        public function sendMail( $subject, $body, $from = null, $replyto = null ) {
                global $wgPasswordSender;

                if ( $from instanceof User ) {
                        $sender = MailAddress::newFromUser( $from );
                } else {
                        $sender = new MailAddress( $wgPasswordSender,
                                wfMessage( 'emailsender' )->inContentLanguage()->text() );
                }
                $to = MailAddress::newFromUser( $this );

                return UserMailer::send( $to, $sender, $subject, $body, [
                        'replyTo' => $replyto,
                ] );
        }

        /**
         * Generate, store, and return a new e-mail confirmation code.
         * A hash (unsalted, since it's used as a key) is stored.
         *
         * @note Call saveSettings() after calling this function to commit
         * this change to the database.
         *
         * @param string &$expiration Accepts the expiration time
         * @return string New token
         */
        protected function confirmationToken( &$expiration ) {
                global $wgUserEmailConfirmationTokenExpiry;
                $now = time();
                $expires = $now + $wgUserEmailConfirmationTokenExpiry;
                $expiration = wfTimestamp( TS_MW, $expires );
                $this->load();
                $token = MWCryptRand::generateHex( 32 );
                $hash = md5( $token );
                $this->mEmailToken = $hash;
                $this->mEmailTokenExpires = $expiration;
                return $token;
        }

        /**
         * Return a URL the user can use to confirm their email address.
         * @param string $token Accepts the email confirmation token
         * @return string New token URL
         */
        protected function confirmationTokenUrl( $token ) {
                return $this->getTokenUrl( 'ConfirmEmail', $token );
        }

        /**
         * Return a URL the user can use to invalidate their email address.
         * @param string $token Accepts the email confirmation token
         * @return string New token URL
         */
        protected function invalidationTokenUrl( $token ) {
                return $this->getTokenUrl( 'InvalidateEmail', $token );
        }

        /**
         * Internal function to format the e-mail validation/invalidation URLs.
         * This uses a quickie hack to use the
         * hardcoded English names of the Special: pages, for ASCII safety.
         *
         * @note Since these URLs get dropped directly into emails, using the
         * short English names avoids insanely long URL-encoded links, which
         * also sometimes can get corrupted in some browsers/mailers
         * (T8957 with Gmail and Internet Explorer).
         *
         * @param string $page Special page
         * @param string $token Token
         * @return string Formatted URL
         */
        protected function getTokenUrl( $page, $token ) {
                // Hack to bypass localization of 'Special:'
                $title = Title::makeTitle( NS_MAIN, "Special:$page/$token" );
                return $title->getCanonicalURL();
        }

        /**
         * Mark the e-mail address confirmed.
         *
         * @note Call saveSettings() after calling this function to commit the change.
         *
         * @return bool
         */
        public function confirmEmail() {
                // Check if it's already confirmed, so we don't touch the database
                // and fire the ConfirmEmailComplete hook on redundant confirmations.
                if ( !$this->isEmailConfirmed() ) {
                        $this->setEmailAuthenticationTimestamp( wfTimestampNow() );
                        Hooks::run( 'ConfirmEmailComplete', [ $this ] );
                }
                return true;
        }

        /**
         * Invalidate the user's e-mail confirmation, and unauthenticate the e-mail
         * address if it was already confirmed.
         *
         * @note Call saveSettings() after calling this function to commit the change.
         * @return bool Returns true
         */
        public function invalidateEmail() {
                $this->load();
                $this->mEmailToken = null;
                $this->mEmailTokenExpires = null;
                $this->setEmailAuthenticationTimestamp( null );
                $this->mEmail = '';
                Hooks::run( 'InvalidateEmailComplete', [ $this ] );
                return true;
        }

        /**
         * Set the e-mail authentication timestamp.
         * @param string $timestamp TS_MW timestamp
         */
        public function setEmailAuthenticationTimestamp( $timestamp ) {
                $this->load();
                $this->mEmailAuthenticated = $timestamp;
                Hooks::run( 'UserSetEmailAuthenticationTimestamp', [ $this, &$this->mEmailAuthenticated ] );
        }

        /**
         * Is this user allowed to send e-mails within limits of current
         * site configuration?
         * @return bool
         */
        public function canSendEmail() {
                global $wgEnableEmail, $wgEnableUserEmail;
                if ( !$wgEnableEmail || !$wgEnableUserEmail || !$this->isAllowed( 'sendemail' ) ) {
                        return false;
                }
                $canSend = $this->isEmailConfirmed();
                // Avoid PHP 7.1 warning of passing $this by reference
                $user = $this;
                Hooks::run( 'UserCanSendEmail', [ &$user, &$canSend ] );
                return $canSend;
        }

        /**
         * Is this user allowed to receive e-mails within limits of current
         * site configuration?
         * @return bool
         */
        public function canReceiveEmail() {
                return $this->isEmailConfirmed() && !$this->getOption( 'disablemail' );
        }

        /**
         * Is this user's e-mail address valid-looking and confirmed within
         * limits of the current site configuration?
         *
         * @note If $wgEmailAuthentication is on, this may require the user to have
         * confirmed their address by returning a code or using a password
         * sent to the address from the wiki.
         *
         * @return bool
         */
        public function isEmailConfirmed() {
                global $wgEmailAuthentication;
                $this->load();
                // Avoid PHP 7.1 warning of passing $this by reference
                $user = $this;
                $confirmed = true;
                if ( Hooks::run( 'EmailConfirmed', [ &$user, &$confirmed ] ) ) {
                        if ( $this->isAnon() ) {
                                return false;
                        }
                        if ( !Sanitizer::validateEmail( $this->mEmail ) ) {
                                return false;
                        }
                        if ( $wgEmailAuthentication && !$this->getEmailAuthenticationTimestamp() ) {
                                return false;
                        }
                        return true;
                } else {
                        return $confirmed;
                }
        }

        /**
         * Check whether there is an outstanding request for e-mail confirmation.
         * @return bool
         */
        public function isEmailConfirmationPending() {
                global $wgEmailAuthentication;
                return $wgEmailAuthentication &&
                        !$this->isEmailConfirmed() &&
                        $this->mEmailToken &&
                        $this->mEmailTokenExpires > wfTimestamp();
        }

        /**
         * Get the timestamp of account creation.
         *
         * @return string|bool|null Timestamp of account creation, false for
         *  non-existent/anonymous user accounts, or null if existing account
         *  but information is not in database.
         */
        public function getRegistration() {
                if ( $this->isAnon() ) {
                        return false;
                }
                $this->load();
                return $this->mRegistration;
        }

        /**
         * Get the timestamp of the first edit
         *
         * @return string|bool Timestamp of first edit, or false for
         *  non-existent/anonymous user accounts.
         */
        public function getFirstEditTimestamp() {
                if ( $this->getId() == 0 ) {
                        return false; // anons
                }
                $dbr = wfGetDB( DB_REPLICA );
                $time = $dbr->selectField( 'revision', 'rev_timestamp',
                        [ 'rev_user' => $this->getId() ],
                        __METHOD__,
                        [ 'ORDER BY' => 'rev_timestamp ASC' ]
                );
                if ( !$time ) {
                        return false; // no edits
                }
                return wfTimestamp( TS_MW, $time );
        }

        /**
         * Get the permissions associated with a given list of groups
         *
         * @param array $groups Array of Strings List of internal group names
         * @return array Array of Strings List of permission key names for given groups combined
         */
        public static function getGroupPermissions( $groups ) {
                global $wgGroupPermissions, $wgRevokePermissions;
                $rights = [];
                // grant every granted permission first
                foreach ( $groups as $group ) {
                        if ( isset( $wgGroupPermissions[$group] ) ) {
                                $rights = array_merge( $rights,
                                        // array_filter removes empty items
                                        array_keys( array_filter( $wgGroupPermissions[$group] ) ) );
                        }
                }
                // now revoke the revoked permissions
                foreach ( $groups as $group ) {
                        if ( isset( $wgRevokePermissions[$group] ) ) {
                                $rights = array_diff( $rights,
                                        array_keys( array_filter( $wgRevokePermissions[$group] ) ) );
                        }
                }
                return array_unique( $rights );
        }

        /**
         * Get all the groups who have a given permission
         *
         * @param string $role Role to check
         * @return array Array of Strings List of internal group names with the given permission
         */
        public static function getGroupsWithPermission( $role ) {
                global $wgGroupPermissions;
                $allowedGroups = [];
                foreach ( array_keys( $wgGroupPermissions ) as $group ) {
                        if ( self::groupHasPermission( $group, $role ) ) {
                                $allowedGroups[] = $group;
                        }
                }
                return $allowedGroups;
        }

        /**
         * Check, if the given group has the given permission
         *
         * If you're wanting to check whether all users have a permission, use
         * User::isEveryoneAllowed() instead. That properly checks if it's revoked
         * from anyone.
         *
         * @since 1.21
         * @param string $group Group to check
         * @param string $role Role to check
         * @return bool
         */
        public static function groupHasPermission( $group, $role ) {
                global $wgGroupPermissions, $wgRevokePermissions;
                return isset( $wgGroupPermissions[$group][$role] ) && $wgGroupPermissions[$group][$role]
                        && !( isset( $wgRevokePermissions[$group][$role] ) && $wgRevokePermissions[$group][$role] );
        }

        /**
         * Check if all users may be assumed to have the given permission
         *
         * We generally assume so if the right is granted to '*' and isn't revoked
         * on any group. It doesn't attempt to take grants or other extension
         * limitations on rights into account in the general case, though, as that
         * would require it to always return false and defeat the purpose.
         * Specifically, session-based rights restrictions (such as OAuth or bot
         * passwords) are applied based on the current session.
         *
         * @since 1.22
         * @param string $right Right to check
         * @return bool
         */
        public static function isEveryoneAllowed( $right ) {
                global $wgGroupPermissions, $wgRevokePermissions;
                static $cache = [];

                // Use the cached results, except in unit tests which rely on
                // being able change the permission mid-request
                if ( isset( $cache[$right] ) && !defined( 'MW_PHPUNIT_TEST' ) ) {
                        return $cache[$right];
                }

                if ( !isset( $wgGroupPermissions['*'][$right] ) || !$wgGroupPermissions['*'][$right] ) {
                        $cache[$right] = false;
                        return false;
                }

                // If it's revoked anywhere, then everyone doesn't have it
                foreach ( $wgRevokePermissions as $rights ) {
                        if ( isset( $rights[$right] ) && $rights[$right] ) {
                                $cache[$right] = false;
                                return false;
                        }
                }

                // Remove any rights that aren't allowed to the global-session user,
                // unless there are no sessions for this endpoint.
                if ( !defined( 'MW_NO_SESSION' ) ) {
                        $allowedRights = SessionManager::getGlobalSession()->getAllowedUserRights();
                        if ( $allowedRights !== null && !in_array( $right, $allowedRights, true ) ) {
                                $cache[$right] = false;
                                return false;
                        }
                }

                // Allow extensions to say false
                if ( !Hooks::run( 'UserIsEveryoneAllowed', [ $right ] ) ) {
                        $cache[$right] = false;
                        return false;
                }

                $cache[$right] = true;
                return true;
        }

        /**
         * Get the localized descriptive name for a group, if it exists
         * @deprecated since 1.29 Use UserGroupMembership::getGroupName instead
         *
         * @param string $group Internal group name
         * @return string Localized descriptive group name
         */
        public static function getGroupName( $group ) {
                wfDeprecated( __METHOD__, '1.29' );
                return UserGroupMembership::getGroupName( $group );
        }

        /**
         * Get the localized descriptive name for a member of a group, if it exists
         * @deprecated since 1.29 Use UserGroupMembership::getGroupMemberName instead
         *
         * @param string $group Internal group name
         * @param string $username Username for gender (since 1.19)
         * @return string Localized name for group member
         */
        public static function getGroupMember( $group, $username = '#' ) {
                wfDeprecated( __METHOD__, '1.29' );
                return UserGroupMembership::getGroupMemberName( $group, $username );
        }

        /**
         * Return the set of defined explicit groups.
         * The implicit groups (by default *, 'user' and 'autoconfirmed')
         * are not included, as they are defined automatically, not in the database.
         * @return array Array of internal group names
         */
        public static function getAllGroups() {
                global $wgGroupPermissions, $wgRevokePermissions;
                return array_diff(
                        array_merge( array_keys( $wgGroupPermissions ), array_keys( $wgRevokePermissions ) ),
                        self::getImplicitGroups()
                );
        }

        /**
         * Get a list of all available permissions.
         * @return string[] Array of permission names
         */
        public static function getAllRights() {
                if ( self::$mAllRights === false ) {
                        global $wgAvailableRights;
                        if ( count( $wgAvailableRights ) ) {
                                self::$mAllRights = array_unique( array_merge( self::$mCoreRights, $wgAvailableRights ) );
                        } else {
                                self::$mAllRights = self::$mCoreRights;
                        }
                        Hooks::run( 'UserGetAllRights', [ &self::$mAllRights ] );
                }
                return self::$mAllRights;
        }

        /**
         * Get a list of implicit groups
         * @return array Array of Strings Array of internal group names
         */
        public static function getImplicitGroups() {
                global $wgImplicitGroups;

                $groups = $wgImplicitGroups;
                # Deprecated, use $wgImplicitGroups instead
                Hooks::run( 'UserGetImplicitGroups', [ &$groups ], '1.25' );

                return $groups;
        }

        /**
         * Get the title of a page describing a particular group
         * @deprecated since 1.29 Use UserGroupMembership::getGroupPage instead
         *
         * @param string $group Internal group name
         * @return Title|bool Title of the page if it exists, false otherwise
         */
        public static function getGroupPage( $group ) {
                wfDeprecated( __METHOD__, '1.29' );
                return UserGroupMembership::getGroupPage( $group );
        }

        /**
         * Create a link to the group in HTML, if available;
         * else return the group name.
         * @deprecated since 1.29 Use UserGroupMembership::getLink instead, or
         * make the link yourself if you need custom text
         *
         * @param string $group Internal name of the group
         * @param string $text The text of the link
         * @return string HTML link to the group
         */
        public static function makeGroupLinkHTML( $group, $text = '' ) {
                wfDeprecated( __METHOD__, '1.29' );

                if ( $text == '' ) {
                        $text = UserGroupMembership::getGroupName( $group );
                }
                $title = UserGroupMembership::getGroupPage( $group );
                if ( $title ) {
                        return Linker::link( $title, htmlspecialchars( $text ) );
                } else {
                        return htmlspecialchars( $text );
                }
        }

        /**
         * Create a link to the group in Wikitext, if available;
         * else return the group name.
         * @deprecated since 1.29 Use UserGroupMembership::getLink instead, or
         * make the link yourself if you need custom text
         *
         * @param string $group Internal name of the group
         * @param string $text The text of the link
         * @return string Wikilink to the group
         */
        public static function makeGroupLinkWiki( $group, $text = '' ) {
                wfDeprecated( __METHOD__, '1.29' );

                if ( $text == '' ) {
                        $text = UserGroupMembership::getGroupName( $group );
                }
                $title = UserGroupMembership::getGroupPage( $group );
                if ( $title ) {
                        $page = $title->getFullText();
                        return "[[$page|$text]]";
                } else {
                        return $text;
                }
        }

        /**
         * Returns an array of the groups that a particular group can add/remove.
         *
         * @param string $group The group to check for whether it can add/remove
         * @return array Array( 'add' => array( addablegroups ),
         *     'remove' => array( removablegroups ),
         *     'add-self' => array( addablegroups to self),
         *     'remove-self' => array( removable groups from self) )
         */
        public static function changeableByGroup( $group ) {
                global $wgAddGroups, $wgRemoveGroups, $wgGroupsAddToSelf, $wgGroupsRemoveFromSelf;

                $groups = [
                        'add' => [],
                        'remove' => [],
                        'add-self' => [],
                        'remove-self' => []
                ];

                if ( empty( $wgAddGroups[$group] ) ) {
                        // Don't add anything to $groups
                } elseif ( $wgAddGroups[$group] === true ) {
                        // You get everything
                        $groups['add'] = self::getAllGroups();
                } elseif ( is_array( $wgAddGroups[$group] ) ) {
                        $groups['add'] = $wgAddGroups[$group];
                }

                // Same thing for remove
                if ( empty( $wgRemoveGroups[$group] ) ) {
                        // Do nothing
                } elseif ( $wgRemoveGroups[$group] === true ) {
                        $groups['remove'] = self::getAllGroups();
                } elseif ( is_array( $wgRemoveGroups[$group] ) ) {
                        $groups['remove'] = $wgRemoveGroups[$group];
                }

                // Re-map numeric keys of AddToSelf/RemoveFromSelf to the 'user' key for backwards compatibility
                if ( empty( $wgGroupsAddToSelf['user'] ) || $wgGroupsAddToSelf['user'] !== true ) {
                        foreach ( $wgGroupsAddToSelf as $key => $value ) {
                                if ( is_int( $key ) ) {
                                        $wgGroupsAddToSelf['user'][] = $value;
                                }
                        }
                }

                if ( empty( $wgGroupsRemoveFromSelf['user'] ) || $wgGroupsRemoveFromSelf['user'] !== true ) {
                        foreach ( $wgGroupsRemoveFromSelf as $key => $value ) {
                                if ( is_int( $key ) ) {
                                        $wgGroupsRemoveFromSelf['user'][] = $value;
                                }
                        }
                }

                // Now figure out what groups the user can add to him/herself
                if ( empty( $wgGroupsAddToSelf[$group] ) ) {
                        // Do nothing
                } elseif ( $wgGroupsAddToSelf[$group] === true ) {
                        // No idea WHY this would be used, but it's there
                        $groups['add-self'] = User::getAllGroups();
                } elseif ( is_array( $wgGroupsAddToSelf[$group] ) ) {
                        $groups['add-self'] = $wgGroupsAddToSelf[$group];
                }

                if ( empty( $wgGroupsRemoveFromSelf[$group] ) ) {
                        // Do nothing
                } elseif ( $wgGroupsRemoveFromSelf[$group] === true ) {
                        $groups['remove-self'] = User::getAllGroups();
                } elseif ( is_array( $wgGroupsRemoveFromSelf[$group] ) ) {
                        $groups['remove-self'] = $wgGroupsRemoveFromSelf[$group];
                }

                return $groups;
        }

        /**
         * Returns an array of groups that this user can add and remove
         * @return array Array( 'add' => array( addablegroups ),
         *  'remove' => array( removablegroups ),
         *  'add-self' => array( addablegroups to self),
         *  'remove-self' => array( removable groups from self) )
         */
        public function changeableGroups() {
                if ( $this->isAllowed( 'userrights' ) ) {
                        // This group gives the right to modify everything (reverse-
                        // compatibility with old "userrights lets you change
                        // everything")
                        // Using array_merge to make the groups reindexed
                        $all = array_merge( User::getAllGroups() );
                        return [
                                'add' => $all,
                                'remove' => $all,
                                'add-self' => [],
                                'remove-self' => []
                        ];
                }

                // Okay, it's not so simple, we will have to go through the arrays
                $groups = [
                        'add' => [],
                        'remove' => [],
                        'add-self' => [],
                        'remove-self' => []
                ];
                $addergroups = $this->getEffectiveGroups();

                foreach ( $addergroups as $addergroup ) {
                        $groups = array_merge_recursive(
                                $groups, $this->changeableByGroup( $addergroup )
                        );
                        $groups['add'] = array_unique( $groups['add'] );
                        $groups['remove'] = array_unique( $groups['remove'] );
                        $groups['add-self'] = array_unique( $groups['add-self'] );
                        $groups['remove-self'] = array_unique( $groups['remove-self'] );
                }
                return $groups;
        }

        /**
         * Deferred version of incEditCountImmediate()
         */
        public function incEditCount() {
                wfGetDB( DB_MASTER )->onTransactionPreCommitOrIdle(
                        function () {
                                $this->incEditCountImmediate();
                        },
                        __METHOD__
                );
        }

        /**
         * Increment the user's edit-count field.
         * Will have no effect for anonymous users.
         * @since 1.26
         */
        public function incEditCountImmediate() {
                if ( $this->isAnon() ) {
                        return;
                }

                $dbw = wfGetDB( DB_MASTER );
                // No rows will be "affected" if user_editcount is NULL
                $dbw->update(
                        'user',
                        [ 'user_editcount=user_editcount+1' ],
                        [ 'user_id' => $this->getId(), 'user_editcount IS NOT NULL' ],
                        __METHOD__
                );
                // Lazy initialization check...
                if ( $dbw->affectedRows() == 0 ) {
                        // Now here's a goddamn hack...
                        $dbr = wfGetDB( DB_REPLICA );
                        if ( $dbr !== $dbw ) {
                                // If we actually have a replica DB server, the count is
                                // at least one behind because the current transaction
                                // has not been committed and replicated.
                                $this->mEditCount = $this->initEditCount( 1 );
                        } else {
                                // But if DB_REPLICA is selecting the master, then the
                                // count we just read includes the revision that was
                                // just added in the working transaction.
                                $this->mEditCount = $this->initEditCount();
                        }
                } else {
                        if ( $this->mEditCount === null ) {
                                $this->getEditCount();
                                $dbr = wfGetDB( DB_REPLICA );
                                $this->mEditCount += ( $dbr !== $dbw ) ? 1 : 0;
                        } else {
                                $this->mEditCount++;
                        }
                }
                // Edit count in user cache too
                $this->invalidateCache();
        }

        /**
         * Initialize user_editcount from data out of the revision table
         *
         * @param int $add Edits to add to the count from the revision table
         * @return int Number of edits
         */
        protected function initEditCount( $add = 0 ) {
                // Pull from a replica DB to be less cruel to servers
                // Accuracy isn't the point anyway here
                $dbr = wfGetDB( DB_REPLICA );
                $count = (int)$dbr->selectField(
                        'revision',
                        'COUNT(rev_user)',
                        [ 'rev_user' => $this->getId() ],
                        __METHOD__
                );
                $count = $count + $add;

                $dbw = wfGetDB( DB_MASTER );
                $dbw->update(
                        'user',
                        [ 'user_editcount' => $count ],
                        [ 'user_id' => $this->getId() ],
                        __METHOD__
                );

                return $count;
        }

        /**
         * Get the description of a given right
         *
         * @since 1.29
         * @param string $right Right to query
         * @return string Localized description of the right
         */
        public static function getRightDescription( $right ) {
                $key = "right-$right";
                $msg = wfMessage( $key );
                return $msg->isDisabled() ? $right : $msg->text();
        }

        /**
         * Get the name of a given grant
         *
         * @since 1.29
         * @param string $grant Grant to query
         * @return string Localized name of the grant
         */
        public static function getGrantName( $grant ) {
                $key = "grant-$grant";
                $msg = wfMessage( $key );
                return $msg->isDisabled() ? $grant : $msg->text();
        }

        /**
         * Add a newuser log entry for this user.
         * Before 1.19 the return value was always true.
         *
         * @deprecated since 1.27, AuthManager handles logging
         * @param string|bool $action Account creation type.
         *   - String, one of the following values:
         *     - 'create' for an anonymous user creating an account for himself.
         *       This will force the action's performer to be the created user itself,
         *       no matter the value of $wgUser
         *     - 'create2' for a logged in user creating an account for someone else
         *     - 'byemail' when the created user will receive its password by e-mail
         *     - 'autocreate' when the user is automatically created (such as by CentralAuth).
         *   - Boolean means whether the account was created by e-mail (deprecated):
         *     - true will be converted to 'byemail'
         *     - false will be converted to 'create' if this object is the same as
         *       $wgUser and to 'create2' otherwise
         * @param string $reason User supplied reason
         * @return bool true
         */
        public function addNewUserLogEntry( $action = false, $reason = '' ) {
                return true; // disabled
        }

        /**
         * Add an autocreate newuser log entry for this user
         * Used by things like CentralAuth and perhaps other authplugins.
         * Consider calling addNewUserLogEntry() directly instead.
         *
         * @deprecated since 1.27, AuthManager handles logging
         * @return bool
         */
        public function addNewUserLogEntryAutoCreate() {
                $this->addNewUserLogEntry( 'autocreate' );

                return true;
        }

        /**
         * Load the user options either from cache, the database or an array
         *
         * @param array $data Rows for the current user out of the user_properties table
         */
        protected function loadOptions( $data = null ) {
                global $wgContLang;

                $this->load();

                if ( $this->mOptionsLoaded ) {
                        return;
                }

                $this->mOptions = self::getDefaultOptions();

                if ( !$this->getId() ) {
                        // For unlogged-in users, load language/variant options from request.
                        // There's no need to do it for logged-in users: they can set preferences,
                        // and handling of page content is done by $pageLang->getPreferredVariant() and such,
                        // so don't override user's choice (especially when the user chooses site default).
                        $variant = $wgContLang->getDefaultVariant();
                        $this->mOptions['variant'] = $variant;
                        $this->mOptions['language'] = $variant;
                        $this->mOptionsLoaded = true;
                        return;
                }

                // Maybe load from the object
                if ( !is_null( $this->mOptionOverrides ) ) {
                        wfDebug( "User: loading options for user " . $this->getId() . " from override cache.\n" );
                        foreach ( $this->mOptionOverrides as $key => $value ) {
                                $this->mOptions[$key] = $value;
                        }
                } else {
                        if ( !is_array( $data ) ) {
                                wfDebug( "User: loading options for user " . $this->getId() . " from database.\n" );
                                // Load from database
                                $dbr = ( $this->queryFlagsUsed & self::READ_LATEST )
                                        ? wfGetDB( DB_MASTER )
                                        : wfGetDB( DB_REPLICA );

                                $res = $dbr->select(
                                        'user_properties',
                                        [ 'up_property', 'up_value' ],
                                        [ 'up_user' => $this->getId() ],
                                        __METHOD__
                                );

                                $this->mOptionOverrides = [];
                                $data = [];
                                foreach ( $res as $row ) {
                                        $data[$row->up_property] = $row->up_value;
                                }
                        }
                        foreach ( $data as $property => $value ) {
                                $this->mOptionOverrides[$property] = $value;
                                $this->mOptions[$property] = $value;
                        }
                }

                $this->mOptionsLoaded = true;

                Hooks::run( 'UserLoadOptions', [ $this, &$this->mOptions ] );
        }

        /**
         * Saves the non-default options for this user, as previously set e.g. via
         * setOption(), in the database's "user_properties" (preferences) table.
         * Usually used via saveSettings().
         */
        protected function saveOptions() {
                $this->loadOptions();

                // Not using getOptions(), to keep hidden preferences in database
                $saveOptions = $this->mOptions;

                // Allow hooks to abort, for instance to save to a global profile.
                // Reset options to default state before saving.
                if ( !Hooks::run( 'UserSaveOptions', [ $this, &$saveOptions ] ) ) {
                        return;
                }

                $userId = $this->getId();

                $insert_rows = []; // all the new preference rows
                foreach ( $saveOptions as $key => $value ) {
                        // Don't bother storing default values
                        $defaultOption = self::getDefaultOption( $key );
                        if ( ( $defaultOption === null && $value !== false && $value !== null )
                                || $value != $defaultOption
                        ) {
                                $insert_rows[] = [
                                        'up_user' => $userId,
                                        'up_property' => $key,
                                        'up_value' => $value,
                                ];
                        }
                }

                $dbw = wfGetDB( DB_MASTER );

                $res = $dbw->select( 'user_properties',
                        [ 'up_property', 'up_value' ], [ 'up_user' => $userId ], __METHOD__ );

                // Find prior rows that need to be removed or updated. These rows will
                // all be deleted (the latter so that INSERT IGNORE applies the new values).
                $keysDelete = [];
                foreach ( $res as $row ) {
                        if ( !isset( $saveOptions[$row->up_property] )
                                || strcmp( $saveOptions[$row->up_property], $row->up_value ) != 0
                        ) {
                                $keysDelete[] = $row->up_property;
                        }
                }

                if ( count( $keysDelete ) ) {
                        // Do the DELETE by PRIMARY KEY for prior rows.
                        // In the past a very large portion of calls to this function are for setting
                        // 'rememberpassword' for new accounts (a preference that has since been removed).
                        // Doing a blanket per-user DELETE for new accounts with no rows in the table
                        // caused gap locks on [max user ID,+infinity) which caused high contention since
                        // updates would pile up on each other as they are for higher (newer) user IDs.
                        // It might not be necessary these days, but it shouldn't hurt either.
                        $dbw->delete( 'user_properties',
                                [ 'up_user' => $userId, 'up_property' => $keysDelete ], __METHOD__ );
                }
                // Insert the new preference rows
                $dbw->insert( 'user_properties', $insert_rows, __METHOD__, [ 'IGNORE' ] );
        }

        /**
         * Lazily instantiate and return a factory object for making passwords
         *
         * @deprecated since 1.27, create a PasswordFactory directly instead
         * @return PasswordFactory
         */
        public static function getPasswordFactory() {
                wfDeprecated( __METHOD__, '1.27' );
                $ret = new PasswordFactory();
                $ret->init( RequestContext::getMain()->getConfig() );
                return $ret;
        }

        /**
         * Provide an array of HTML5 attributes to put on an input element
         * intended for the user to enter a new password.  This may include
         * required, title, and/or pattern, depending on $wgMinimalPasswordLength.
         *
         * Do *not* use this when asking the user to enter his current password!
         * Regardless of configuration, users may have invalid passwords for whatever
         * reason (e.g., they were set before requirements were tightened up).
         * Only use it when asking for a new password, like on account creation or
         * ResetPass.
         *
         * Obviously, you still need to do server-side checking.
         *
         * NOTE: A combination of bugs in various browsers means that this function
         * actually just returns array() unconditionally at the moment.  May as
         * well keep it around for when the browser bugs get fixed, though.
         *
         * @todo FIXME: This does not belong here; put it in Html or Linker or somewhere
         *
         * @deprecated since 1.27
         * @return array Array of HTML attributes suitable for feeding to
         *   Html::element(), directly or indirectly.  (Don't feed to Xml::*()!
         *   That will get confused by the boolean attribute syntax used.)
         */
        public static function passwordChangeInputAttribs() {
                global $wgMinimalPasswordLength;

                if ( $wgMinimalPasswordLength == 0 ) {
                        return [];
                }

                # Note that the pattern requirement will always be satisfied if the
                # input is empty, so we need required in all cases.

                # @todo FIXME: T25769: This needs to not claim the password is required
                # if e-mail confirmation is being used.  Since HTML5 input validation
                # is b0rked anyway in some browsers, just return nothing.  When it's
                # re-enabled, fix this code to not output required for e-mail
                # registration.
                # $ret = array( 'required' );
                $ret = [];

                # We can't actually do this right now, because Opera 9.6 will print out
                # the entered password visibly in its error message!  When other
                # browsers add support for this attribute, or Opera fixes its support,
                # we can add support with a version check to avoid doing this on Opera
                # versions where it will be a problem.  Reported to Opera as
                # DSK-262266, but they don't have a public bug tracker for us to follow.
                /*
                if ( $wgMinimalPasswordLength > 1 ) {
                        $ret['pattern'] = '.{' . intval( $wgMinimalPasswordLength ) . ',}';
                        $ret['title'] = wfMessage( 'passwordtooshort' )
                                ->numParams( $wgMinimalPasswordLength )->text();
                }
                */

                return $ret;
        }

        /**
         * Return the list of user fields that should be selected to create
         * a new user object.
         * @return array
         */
        public static function selectFields() {
                return [
                        'user_id',
                        'user_name',
                        'user_real_name',
                        'user_email',
                        'user_touched',
                        'user_token',
                        'user_email_authenticated',
                        'user_email_token',
                        'user_email_token_expires',
                        'user_registration',
                        'user_editcount',
                ];
        }

        /**
         * Factory function for fatal permission-denied errors
         *
         * @since 1.22
         * @param string $permission User right required
         * @return Status
         */
        static function newFatalPermissionDeniedStatus( $permission ) {
                global $wgLang;

                $groups = [];
                foreach ( User::getGroupsWithPermission( $permission ) as $group ) {
                        $groups[] = UserGroupMembership::getLink( $group, RequestContext::getMain(), 'wiki' );
                }

                if ( $groups ) {
                        return Status::newFatal( 'badaccess-groups', $wgLang->commaList( $groups ), count( $groups ) );
                } else {
                        return Status::newFatal( 'badaccess-group0' );
                }
        }

        /**
         * Get a new instance of this user that was loaded from the master via a locking read
         *
         * Use this instead of the main context User when updating that user. This avoids races
         * where that user was loaded from a replica DB or even the master but without proper locks.
         *
         * @return User|null Returns null if the user was not found in the DB
         * @since 1.27
         */
        public function getInstanceForUpdate() {
                if ( !$this->getId() ) {
                        return null; // anon
                }

                $user = self::newFromId( $this->getId() );
                if ( !$user->loadFromId( self::READ_EXCLUSIVE ) ) {
                        return null;
                }

                return $user;
        }

        /**
         * Checks if two user objects point to the same user.
         *
         * @since 1.25
         * @param User $user
         * @return bool
         */
        public function equals( User $user ) {
                return $this->getName() === $user->getName();
        }
}