(bug 27046) Do not strip newlines following C++-style // comments. Prior to this...

[mediawiki.git] / includes / User.php

<?php
/**
 * Implements the User class for the %MediaWiki software.
 * @file
 */

/**
 * Int Number of characters in user_token field.
 * @ingroup Constants
 */
define( 'USER_TOKEN_LENGTH', 32 );

/**
 * Int Serialized record version.
 * @ingroup Constants
 */
define( 'MW_USER_VERSION', 8 );

/**
 * String Some punctuation to prevent editing from broken text-mangling proxies.
 * @ingroup Constants
 */
define( 'EDIT_TOKEN_SUFFIX', '+\\' );

/**
 * Thrown by User::setPassword() on error.
 * @ingroup Exception
 */
class PasswordError extends MWException {
        // NOP
}

/**
 * The User object encapsulates all of the user-specific settings (user_id,
 * name, rights, password, 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 {
        /**
         * Global constants made accessible as class constants so that autoloader
         * magic can be used.
         */
        const USER_TOKEN_LENGTH = USER_TOKEN_LENGTH;
        const MW_USER_VERSION = MW_USER_VERSION;
        const EDIT_TOKEN_SUFFIX = EDIT_TOKEN_SUFFIX;

        /**
         * 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
         */
        static $mCacheVars = array(
                // user table
                'mId',
                'mName',
                'mRealName',
                'mPassword',
                'mNewpassword',
                'mNewpassTime',
                'mEmail',
                'mTouched',
                'mToken',
                'mEmailAuthenticated',
                'mEmailToken',
                'mEmailTokenExpires',
                'mRegistration',
                'mEditCount',
                // user_group table
                'mGroups',
                // user_properties table
                'mOptionOverrides',
        );

        /**
         * Array of Strings Core rights.
         * Each of these should have a corresponding message of the form
         * "right-$right".
         * @showinitializer
         */
        static $mCoreRights = array(
                'apihighlimits',
                'autoconfirmed',
                'autopatrol',
                'bigdelete',
                'block',
                'blockemail',
                'bot',
                'browsearchive',
                'createaccount',
                'createpage',
                'createtalk',
                'delete',
                'deletedhistory',
                'deletedtext',
                'deleterevision',
                'disableaccount',
                'edit',
                'editinterface',
                'editusercssjs',
                'hideuser',
                'import',
                'importupload',
                'ipblock-exempt',
                'markbotedits',
                'minoredit',
                'move',
                'movefile',
                'move-rootuserpages',
                'move-subpages',
                'nominornewtalk',
                'noratelimit',
                'override-export-depth',
                'patrol',
                'protect',
                'proxyunbannable',
                'purge',
                'read',
                'reupload',
                'reupload-shared',
                'rollback',
                'selenium',
                'sendemail',
                'siteadmin',
                'suppressionlog',
                'suppressredirect',
                'suppressrevision',
                'trackback',
                'undelete',
                'unwatchedpages',
                'upload',
                'upload_by_url',
                'userrights',
                'userrights-interwiki',
                'writeapi',
        );
        /**
         * String Cached results of getAllRights()
         */
        static $mAllRights = false;

        /** @name Cache variables */
        //@{
        var $mId, $mName, $mRealName, $mPassword, $mNewpassword, $mNewpassTime,
                $mEmail, $mTouched, $mToken, $mEmailAuthenticated,
                $mEmailToken, $mEmailTokenExpires, $mRegistration, $mGroups, $mOptionOverrides;
        //@}

        /**
         * Bool Whether the cache variables have been loaded.
         */
        var $mDataLoaded, $mAuthLoaded, $mOptionsLoaded;

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

        /**
         * Lazy-initialized variables, invalidated with clearInstanceCache
         */
        var $mNewtalk, $mDatePreference, $mBlockedby, $mHash, $mSkin, $mRights,
                $mBlockreason, $mBlock, $mEffectiveGroups, $mBlockedGlobally,
                $mLocked, $mHideName, $mOptions;

        static $idCacheByName = array();

        /**
         * 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()
         */
        function __construct() {
                $this->clearInstanceCache( 'defaults' );
        }

        /**
         * Load the user table data for this object from the source given by mFrom.
         */
        function load() {
                if ( $this->mDataLoaded ) {
                        return;
                }
                wfProfileIn( __METHOD__ );

                # Set it now to avoid infinite recursion in accessors
                $this->mDataLoaded = true;

                switch ( $this->mFrom ) {
                        case 'defaults':
                                $this->loadDefaults();
                                break;
                        case 'name':
                                $this->mId = self::idFromName( $this->mName );
                                if ( !$this->mId ) {
                                        # Nonexistent user placeholder object
                                        $this->loadDefaults( $this->mName );
                                } else {
                                        $this->loadFromId();
                                }
                                break;
                        case 'id':
                                $this->loadFromId();
                                break;
                        case 'session':
                                $this->loadFromSession();
                                wfRunHooks( 'UserLoadAfterLoadFromSession', array( $this ) );
                                break;
                        default:
                                throw new MWException( "Unrecognised value for User->mFrom: \"{$this->mFrom}\"" );
                }
                wfProfileOut( __METHOD__ );
        }

        /**
         * Load user table data, given mId has already been set.
         * @return Bool false if the ID does not exist, true otherwise
         * @private
         */
        function loadFromId() {
                global $wgMemc;
                if ( $this->mId == 0 ) {
                        $this->loadDefaults();
                        return false;
                }

                # Try cache
                $key = wfMemcKey( 'user', 'id', $this->mId );
                $data = $wgMemc->get( $key );
                if ( !is_array( $data ) || $data['mVersion'] < MW_USER_VERSION ) {
                        # Object is expired, load from DB
                        $data = false;
                }

                if ( !$data ) {
                        wfDebug( "User: cache miss for user {$this->mId}\n" );
                        # Load from DB
                        if ( !$this->loadFromDatabase() ) {
                                # Can't load from ID, user is anonymous
                                return false;
                        }
                        $this->saveToCache();
                } else {
                        wfDebug( "User: got user {$this->mId} from cache\n" );
                        # Restore from cache
                        foreach ( self::$mCacheVars as $name ) {
                                $this->$name = $data[$name];
                        }
                }
                return true;
        }

        /**
         * Save user data to the shared cache
         */
        function saveToCache() {
                $this->load();
                $this->loadGroups();
                $this->loadOptions();
                if ( $this->isAnon() ) {
                        // Anonymous users are uncached
                        return;
                }
                $data = array();
                foreach ( self::$mCacheVars as $name ) {
                        $data[$name] = $this->$name;
                }
                $data['mVersion'] = MW_USER_VERSION;
                $key = wfMemcKey( 'user', 'id', $this->mId );
                global $wgMemc;
                $wgMemc->set( $key, $data );
        }


        /** @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 $name String Username, validated by Title::newFromText()
         * @param $validate String|Bool Validate username. Takes the same parameters as
         *    User::getCanonicalName(), except that true is accepted as an alias
         *    for 'valid', for BC.
         *
         * @return 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.
         */
        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';
                        return $u;
                }
        }

        /**
         * Static factory method for creation from a given user ID.
         *
         * @param $id Int Valid user ID
         * @return User The corresponding User object
         */
        static function newFromId( $id ) {
                $u = new User;
                $u->mId = $id;
                $u->mFrom = '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 $code String Confirmation code
         * @return User
         */
        static function newFromConfirmationCode( $code ) {
                $dbr = wfGetDB( DB_SLAVE );
                $id = $dbr->selectField( 'user', 'user_id', array(
                        'user_email_token' => md5( $code ),
                        'user_email_token_expires > ' . $dbr->addQuotes( $dbr->timestamp() ),
                        ) );
                if( $id !== false ) {
                        return User::newFromId( $id );
                } else {
                        return null;
                }
        }

        /**
         * Create a new user object using data from session or cookies. If the
         * login credentials are invalid, the result is an anonymous user.
         *
         * @return User
         */
        static function newFromSession() {
                $user = new User;
                $user->mFrom = 'session';
                return $user;
        }

        /**
         * Create a new user object from a user row.
         * The row should have all fields from the user table in it.
         * @param $row Array A row from the user table
         * @return User
         */
        static function newFromRow( $row ) {
                $user = new User;
                $user->loadFromRow( $row );
                return $user;
        }

        //@}


        /**
         * Get the username corresponding to a given user ID
         * @param $id Int User ID
         * @return String The corresponding username
         */
        static function whoIs( $id ) {
                $dbr = wfGetDB( DB_SLAVE );
                return $dbr->selectField( 'user', 'user_name', array( 'user_id' => $id ), __METHOD__ );
        }

        /**
         * Get the real name of a user given their user ID
         *
         * @param $id Int User ID
         * @return String The corresponding user's real name
         */
        static function whoIsReal( $id ) {
                $dbr = wfGetDB( DB_SLAVE );
                return $dbr->selectField( 'user', 'user_real_name', array( 'user_id' => $id ), __METHOD__ );
        }

        /**
         * Get database id given a user name
         * @param $name String Username
         * @return Int|Null The corresponding user's ID, or null if user is nonexistent
         */
        static function idFromName( $name ) {
                $nt = Title::makeTitleSafe( NS_USER, $name );
                if( is_null( $nt ) ) {
                        # Illegal name
                        return null;
                }

                if ( isset( self::$idCacheByName[$name] ) ) {
                        return self::$idCacheByName[$name];
                }

                $dbr = wfGetDB( DB_SLAVE );
                $s = $dbr->selectRow( 'user', array( 'user_id' ), array( 'user_name' => $nt->getText() ), __METHOD__ );

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

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

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

                return $result;
        }

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

        /**
         * Does the string match an anonymous IPv4 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 $name String to match
         * @return Bool
         */
        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 containins slashes (would mess up subpages),
         * is longer than the maximum allowed username size or doesn't begin with
         * a capital letter.
         *
         * @param $name String to match
         * @return Bool
         */
        static function isValidUserName( $name ) {
                global $wgContLang, $wgMaxNameChars;

                if ( $name == ''
                || User::isIP( $name )
                || strpos( $name, '/' ) !== false
                || strlen( $name ) > $wgMaxNameChars
                || $name != $wgContLang->ucfirst( $name ) ) {
                        wfDebugLog( 'username', __METHOD__ .
                                ": '$name' invalid due to empty, IP, slash, length, or lowercase" );
                        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, $parsed->getPrefixedText() ) ) {
                        wfDebugLog( 'username', __METHOD__ .
                                ": '$name' invalid due to ambiguous prefixes" );
                        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, $name ) ) {
                        wfDebugLog( 'username', __METHOD__ .
                                ": '$name' invalid due to blacklisted characters" );
                        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 $name String to match
         * @return Bool
         */
        static function isUsableName( $name ) {
                global $wgReservedUsernames;
                // Must be a valid username, obviously ;)
                if ( !self::isValidUserName( $name ) ) {
                        return false;
                }

                static $reservedUsernames = false;
                if ( !$reservedUsernames ) {
                        $reservedUsernames = $wgReservedUsernames;
                        wfRunHooks( 'UserGetReservedNames', array( &$reservedUsernames ) );
                }

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

        /**
         * 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 $name String to match
         * @return Bool
         */
        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. (bug 23080)
                if( strlen( $name ) > 235 ) {
                        wfDebugLog( 'username', __METHOD__ .
                                ": '$name' invalid due to length" );
                        return false;
                }

                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 $password String Desired password
         * @return Bool
         */
        function isValidPassword( $password ) {
                //simple boolean wrapper for getPasswordValidity
                return $this->getPasswordValidity( $password ) === true;
        }

        /**
         * Given unvalidated password input, return error message on failure.
         *
         * @param $password String Desired password
         * @return mixed: true on success, string or array of error message on failure
         */
        function getPasswordValidity( $password ) {
                global $wgMinimalPasswordLength, $wgContLang;

                static $blockedLogins = array(
                        'Useruser' => 'Passpass', 'Useruser1' => 'Passpass1', # r75589
                        'Apitestsysop' => 'testpass', 'Apitestuser' => 'testpass' # r75605
                );

                $result = false; //init $result to false for the internal checks

                if( !wfRunHooks( 'isValidPassword', array( $password, &$result, $this ) ) )
                        return $result;

                if ( $result === false ) {
                        if( strlen( $password ) < $wgMinimalPasswordLength ) {
                                return 'passwordtooshort';
                        } elseif ( $wgContLang->lc( $password ) == $wgContLang->lc( $this->mName ) ) {
                                return 'password-name-match';
                        } elseif ( isset( $blockedLogins[ $this->getName() ] ) && $password == $blockedLogins[ $this->getName() ] ) {
                                return 'password-login-forbidden';
                        } else {
                                //it seems weird returning true here, but this is because of the
                                //initialization of $result to false above. If the hook is never run or it
                                //doesn't modify $result, then we will likely get down into this if with
                                //a valid password.
                                return true;
                        }
                } elseif( $result === true ) {
                        return true;
                } else {
                        return $result; //the isValidPassword hook set a string $result and returned true
                }
        }

        /**
         * Does a string look like an e-mail address?
         *
         * This validates an email address using an HTML5 specification found at:
         * http://www.whatwg.org/specs/web-apps/current-work/multipage/states-of-the-type-attribute.html#valid-e-mail-address
         * Which as of 2011-01-24 says:
         *
         *     A valid e-mail address is a string that matches the ABNF production
         *   1*( atext / "." ) "@" ldh-str *( "." ldh-str ) where atext is defined
         *   in RFC 5322 section 3.2.3, and ldh-str is defined in RFC 1034 section
         *   3.5.
         *
         * This function is an implementation of the specification as requested in
         * bug 22449.
         *
         * Client-side forms will use the same standard validation rules via JS or
         * HTML 5 validation; additional restrictions can be enforced server-side
         * by extensions via the 'isValidEmailAddr' hook.
         *
         * Note that this validation doesn't 100% match RFC 2822, but is believed
         * to be liberal enough for wide use. Some invalid addresses will still
         * pass validation here.
         *
         * @param $addr String E-mail address
         * @return Bool
         */
        public static function isValidEmailAddr( $addr ) {
                $result = null;
                if( !wfRunHooks( 'isValidEmailAddr', array( $addr, &$result ) ) ) {
                        return $result;
                }

                // Please note strings below are enclosed in brackets [], this make the
                // hyphen "-" a range indicator. Hence it is double backslashed below.
                // See bug 26948
                $rfc5322_atext   = "a-z0-9!#$%&'*+\\-\/=?^_`{|}~" ;
                $rfc1034_ldh_str = "a-z0-9\\-" ;

                $HTML5_email_regexp = "/
                ^                      # start of string
                [$rfc5322_atext\\.]+    # user part which is liberal :p
                @                      # 'apostrophe'
                [$rfc1034_ldh_str]+       # First domain part
                (\\.[$rfc1034_ldh_str]+)*  # Following part prefixed with a dot
                $                      # End of string
                /ix" ; // case Insensitive, eXtended

                return (bool) preg_match( $HTML5_email_regexp, $addr );
        }

        /**
         * Given unvalidated user input, return a canonical username, or false if
         * the username is invalid.
         * @param $name String User input
         * @param $validate String|Bool 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
         */
        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
                $t = ( $validate === 'valid' ) ?
                        Title::newFromText( $name ) : Title::makeTitle( NS_USER, $name );
                # Check for invalid titles
                if( is_null( $t ) ) {
                        return false;
                }

                # Reject various classes of invalid names
                global $wgAuth;
                $name = $wgAuth->getCanonicalName( $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 MWException( 'Invalid parameter value for $validate in ' . __METHOD__ );
                }
                return $name;
        }

        /**
         * Count the number of edits of a user
         * @todo It should not be static and some day should be merged as proper member function / deprecated -- domas
         *
         * @param $uid Int User ID to check
         * @return Int the user's edit count
         */
        static function edits( $uid ) {
                wfProfileIn( __METHOD__ );
                $dbr = wfGetDB( DB_SLAVE );
                // check if the user_editcount field has been initialized
                $field = $dbr->selectField(
                        'user', 'user_editcount',
                        array( 'user_id' => $uid ),
                        __METHOD__
                );

                if( $field === null ) { // it has not been initialized. do so.
                        $dbw = wfGetDB( DB_MASTER );
                        $count = $dbr->selectField(
                                'revision', 'count(*)',
                                array( 'rev_user' => $uid ),
                                __METHOD__
                        );
                        $dbw->update(
                                'user',
                                array( 'user_editcount' => $count ),
                                array( 'user_id' => $uid ),
                                __METHOD__
                        );
                } else {
                        $count = $field;
                }
                wfProfileOut( __METHOD__ );
                return $count;
        }

        /**
         * Return a random password. Sourced from mt_rand, so it's not particularly secure.
         * @todo hash random numbers to improve security, like generateToken()
         *
         * @return String new random password
         */
        static function randomPassword() {
                global $wgMinimalPasswordLength;
                $pwchars = 'ABCDEFGHJKLMNPQRSTUVWXYZabcdefghjkmnpqrstuvwxyz';
                $l = strlen( $pwchars ) - 1;

                $pwlength = max( 7, $wgMinimalPasswordLength );
                $digit = mt_rand( 0, $pwlength - 1 );
                $np = '';
                for ( $i = 0; $i < $pwlength; $i++ ) {
                        $np .= $i == $digit ? chr( mt_rand( 48, 57 ) ) : $pwchars{ mt_rand( 0, $l ) };
                }
                return $np;
        }

        /**
         * Set cached properties to default.
         *
         * @note This no longer clears uncached lazy-initialised properties;
         *       the constructor does that instead.
         * @private
         */
        function loadDefaults( $name = false ) {
                wfProfileIn( __METHOD__ );

                global $wgRequest;

                $this->mId = 0;
                $this->mName = $name;
                $this->mRealName = '';
                $this->mPassword = $this->mNewpassword = '';
                $this->mNewpassTime = null;
                $this->mEmail = '';
                $this->mOptionOverrides = null;
                $this->mOptionsLoaded = false;

                if( $wgRequest->getCookie( 'LoggedOut' ) !== null ) {
                        $this->mTouched = wfTimestamp( TS_MW, $wgRequest->getCookie( 'LoggedOut' ) );
                } else {
                        $this->mTouched = '0'; # Allow any pages to be cached
                }

                $this->setToken(); # Random
                $this->mEmailAuthenticated = null;
                $this->mEmailToken = '';
                $this->mEmailTokenExpires = null;
                $this->mRegistration = wfTimestamp( TS_MW );
                $this->mGroups = array();

                wfRunHooks( 'UserLoadDefaults', array( $this, $name ) );

                wfProfileOut( __METHOD__ );
        }

        /**
         * Load user data from the session or login cookie. If there are no valid
         * credentials, initialises the user as an anonymous user.
         * @return Bool True if the user is logged in, false otherwise.
         */
        private function loadFromSession() {
                global $wgRequest, $wgExternalAuthType, $wgAutocreatePolicy;

                $result = null;
                wfRunHooks( 'UserLoadFromSession', array( $this, &$result ) );
                if ( $result !== null ) {
                        return $result;
                }

                if ( $wgExternalAuthType && $wgAutocreatePolicy == 'view' ) {
                        $extUser = ExternalUser::newFromCookie();
                        if ( $extUser ) {
                                # TODO: Automatically create the user here (or probably a bit
                                # lower down, in fact)
                        }
                }

                if ( $wgRequest->getCookie( 'UserID' ) !== null ) {
                        $sId = intval( $wgRequest->getCookie( 'UserID' ) );
                        if( isset( $_SESSION['wsUserID'] ) && $sId != $_SESSION['wsUserID'] ) {
                                $this->loadDefaults(); // Possible collision!
                                wfDebugLog( 'loginSessions', "Session user ID ({$_SESSION['wsUserID']}) and
                                        cookie user ID ($sId) don't match!" );
                                return false;
                        }
                        $_SESSION['wsUserID'] = $sId;
                } else if ( isset( $_SESSION['wsUserID'] ) ) {
                        if ( $_SESSION['wsUserID'] != 0 ) {
                                $sId = $_SESSION['wsUserID'];
                        } else {
                                $this->loadDefaults();
                                return false;
                        }
                } else {
                        $this->loadDefaults();
                        return false;
                }

                if ( isset( $_SESSION['wsUserName'] ) ) {
                        $sName = $_SESSION['wsUserName'];
                } else if ( $wgRequest->getCookie('UserName') !== null ) {
                        $sName = $wgRequest->getCookie('UserName');
                        $_SESSION['wsUserName'] = $sName;
                } else {
                        $this->loadDefaults();
                        return false;
                }

                $this->mId = $sId;
                if ( !$this->loadFromId() ) {
                        # Not a valid ID, loadFromId has switched the object to anon for us
                        return false;
                }

                global $wgBlockDisablesLogin;
                if( $wgBlockDisablesLogin && $this->isBlocked() ) {
                        # User blocked and we've disabled blocked user logins
                        $this->loadDefaults();
                        return false;
                }

                if ( isset( $_SESSION['wsToken'] ) ) {
                        $passwordCorrect = $_SESSION['wsToken'] == $this->mToken;
                        $from = 'session';
                } else if ( $wgRequest->getCookie( 'Token' ) !== null ) {
                        $passwordCorrect = $this->mToken == $wgRequest->getCookie( 'Token' );
                        $from = 'cookie';
                } else {
                        # No session or persistent login cookie
                        $this->loadDefaults();
                        return false;
                }

                if ( ( $sName == $this->mName ) && $passwordCorrect ) {
                        $_SESSION['wsToken'] = $this->mToken;
                        wfDebug( "User: logged in from $from\n" );
                        return true;
                } else {
                        # Invalid credentials
                        wfDebug( "User: can't log in from $from, invalid credentials\n" );
                        $this->loadDefaults();
                        return false;
                }
        }

        /**
         * Load user and user_group data from the database.
         * $this::mId must be set, this is how the user is identified.
         *
         * @return Bool True if the user exists, false if the user is anonymous
         * @private
         */
        function loadFromDatabase() {
                # Paranoia
                $this->mId = intval( $this->mId );

                /** Anonymous user */
                if( !$this->mId ) {
                        $this->loadDefaults();
                        return false;
                }

                $dbr = wfGetDB( DB_MASTER );
                $s = $dbr->selectRow( 'user', '*', array( 'user_id' => $this->mId ), __METHOD__ );

                wfRunHooks( 'UserLoadFromDatabase', array( $this, &$s ) );

                if ( $s !== false ) {
                        # Initialise user table data
                        $this->loadFromRow( $s );
                        $this->mGroups = 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 $row Array Row from the user table to load.
         */
        function loadFromRow( $row ) {
                $this->mDataLoaded = true;

                if ( isset( $row->user_id ) ) {
                        $this->mId = intval( $row->user_id );
                }
                $this->mName = $row->user_name;
                $this->mRealName = $row->user_real_name;
                $this->mPassword = $row->user_password;
                $this->mNewpassword = $row->user_newpassword;
                $this->mNewpassTime = wfTimestampOrNull( TS_MW, $row->user_newpass_time );
                $this->mEmail = $row->user_email;
                $this->decodeOptions( $row->user_options );
                $this->mTouched = wfTimestamp(TS_MW,$row->user_touched);
                $this->mToken = $row->user_token;
                $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 );
                $this->mEditCount = $row->user_editcount;
        }

        /**
         * Load the groups from the database if they aren't already loaded.
         * @private
         */
        function loadGroups() {
                if ( is_null( $this->mGroups ) ) {
                        $dbr = wfGetDB( DB_MASTER );
                        $res = $dbr->select( 'user_groups',
                                array( 'ug_group' ),
                                array( 'ug_user' => $this->mId ),
                                __METHOD__ );
                        $this->mGroups = array();
                        foreach ( $res as $row ) {
                                $this->mGroups[] = $row->ug_group;
                        }
                }
        }

        /**
         * Clear various cached data stored in this object.
         * @param $reloadFrom String Reload user and user_groups table data from a
         *   given source. May be "name", "id", "defaults", "session", or false for
         *   no reload.
         */
        function clearInstanceCache( $reloadFrom = false ) {
                $this->mNewtalk = -1;
                $this->mDatePreference = null;
                $this->mBlockedby = -1; # Unset
                $this->mHash = false;
                $this->mSkin = null;
                $this->mRights = null;
                $this->mEffectiveGroups = null;
                $this->mOptions = null;

                if ( $reloadFrom ) {
                        $this->mDataLoaded = false;
                        $this->mFrom = $reloadFrom;
                }
        }

        /**
         * Combine the language default options with any site-specific options
         * and add the default language variants.
         *
         * @return Array of String options
         */
        static function getDefaultOptions() {
                global $wgNamespacesToBeSearchedDefault;
                /**
                 * Site defaults will override the global/language defaults
                 */
                global $wgDefaultUserOptions, $wgContLang, $wgDefaultSkin;
                $defOpt = $wgDefaultUserOptions + $wgContLang->getDefaultUserOptionOverrides();

                /**
                 * default language setting
                 */
                $variant = $wgContLang->getDefaultVariant();
                $defOpt['variant'] = $variant;
                $defOpt['language'] = $variant;
                foreach( SearchEngine::searchableNamespaces() as $nsnum => $nsname ) {
                        $defOpt['searchNs'.$nsnum] = !empty( $wgNamespacesToBeSearchedDefault[$nsnum] );
                }
                $defOpt['skin'] = $wgDefaultSkin;

                return $defOpt;
        }

        /**
         * Get a given default option value.
         *
         * @param $opt String 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
         * @private
         * @param $bFromSlave Bool Whether to check the slave database first. To
         *                    improve performance, non-critical checks are done
         *                    against slaves. Check when actually saving should be
         *                    done against master.
         */
        function getBlockedStatus( $bFromSlave = true ) {
                global $wgProxyWhitelist, $wgUser;

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

                wfProfileIn( __METHOD__ );
                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();

                $this->mBlockedby = 0;
                $this->mHideName = 0;
                $this->mAllowUsertalk = 0;

                # Check if we are looking at an IP or a logged-in user
                if ( $this->isIP( $this->getName() ) ) {
                        $ip = $this->getName();
                } else {
                        # Check if we are looking at the current user
                        # If we don't, and the user is logged in, we don't know about
                        # his IP / autoblock status, so ignore autoblock of current user's IP
                        if ( $this->getID() != $wgUser->getID() ) {
                                $ip = '';
                        } else {
                                # Get IP of current user
                                $ip = wfGetIP();
                        }
                }

                if ( $this->isAllowed( 'ipblock-exempt' ) ) {
                        # Exempt from all types of IP-block
                        $ip = '';
                }

                # User/IP blocking
                $this->mBlock = new Block();
                $this->mBlock->fromMaster( !$bFromSlave );
                if ( $this->mBlock->load( $ip , $this->mId ) ) {
                        wfDebug( __METHOD__ . ": Found block.\n" );
                        $this->mBlockedby = $this->mBlock->mBy;
                        if( $this->mBlockedby == 0 )
                                $this->mBlockedby = $this->mBlock->mByName;
                        $this->mBlockreason = $this->mBlock->mReason;
                        $this->mHideName = $this->mBlock->mHideName;
                        $this->mAllowUsertalk = $this->mBlock->mAllowUsertalk;
                        if ( $this->isLoggedIn() && $wgUser->getID() == $this->getID() ) {
                                $this->spreadBlock();
                        }
                } else {
                        // Bug 13611: don't remove mBlock here, to allow account creation blocks to
                        // apply to users. Note that the existence of $this->mBlock is not used to
                        // check for edit blocks, $this->mBlockedby is instead.
                }

                # Proxy blocking
                if ( !$this->isAllowed( 'proxyunbannable' ) && !in_array( $ip, $wgProxyWhitelist ) ) {
                        # Local list
                        if ( wfIsLocallyBlockedProxy( $ip ) ) {
                                $this->mBlockedby = wfMsg( 'proxyblocker' );
                                $this->mBlockreason = wfMsg( 'proxyblockreason' );
                        }

                        # DNSBL
                        if ( !$this->mBlockedby && !$this->getID() ) {
                                if ( $this->isDnsBlacklisted( $ip ) ) {
                                        $this->mBlockedby = wfMsg( 'sorbs' );
                                        $this->mBlockreason = wfMsg( 'sorbsreason' );
                                }
                        }
                }

                # Extensions
                wfRunHooks( 'GetBlockedStatus', array( &$this ) );

                wfProfileOut( __METHOD__ );
        }

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

                if ( !$wgEnableDnsBlacklist && !$wgEnableSorbs )
                        return false;

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

                $urls = array_merge( $wgDnsBlacklistUrls, (array)$wgSorbsUrl );
                return $this->inDnsBlacklist( $ip, $urls );
        }

        /**
         * Whether the given IP is in a given DNS blacklist.
         *
         * @param $ip String IP to check
         * @param $bases String|Array of Strings: URL of the DNS blacklist
         * @return Bool True if blacklisted.
         */
        function inDnsBlacklist( $ip, $bases ) {
                wfProfileIn( __METHOD__ );

                $found = false;
                // FIXME: IPv6 ???  (http://bugs.php.net/bug.php?id=33170)
                if( IP::isIPv4( $ip ) ) {
                        # Reverse IP, bug 21255
                        $ipReversed = implode( '.', array_reverse( explode( '.', $ip ) ) );

                        foreach( (array)$bases as $base ) {
                                # Make hostname
                                $host = "$ipReversed.$base";

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

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

                wfProfileOut( __METHOD__ );
                return $found;
        }

        /**
         * Is this user subject to rate limiting?
         *
         * @return Bool True if rate limited
         */
        public function isPingLimitable() {
                global $wgRateLimitsExcludedGroups;
                global $wgRateLimitsExcludedIPs;
                if( array_intersect( $this->getEffectiveGroups(), $wgRateLimitsExcludedGroups ) ) {
                        // Deprecated, but kept for backwards-compatibility config
                        return false;
                }
                if( in_array( wfGetIP(), $wgRateLimitsExcludedIPs ) ) {
                        // No other good way currently to disable rate limits
                        // for specific IPs. :P
                        // But this is a crappy hack and should die.
                        return false;
                }
                return !$this->isAllowed('noratelimit');
        }

        /**
         * Primitive rate limits: enforce maximum actions per time period
         * to put a brake on flooding.
         *
         * @note When using a shared cache like memcached, IP-address
         * last-hit counters will be shared across wikis.
         *
         * @param $action String Action to enforce; 'edit' if unspecified
         * @return Bool True if a rate limiter was tripped
         */
        function pingLimiter( $action = 'edit' ) {
                # Call the 'PingLimiter' hook
                $result = false;
                if( !wfRunHooks( 'PingLimiter', array( &$this, $action, $result ) ) ) {
                        return $result;
                }

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

                # Some groups shouldn't trigger the ping limiter, ever
                if( !$this->isPingLimitable() )
                        return false;

                global $wgMemc, $wgRateLimitLog;
                wfProfileIn( __METHOD__ );

                $limits = $wgRateLimits[$action];
                $keys = array();
                $id = $this->getId();
                $ip = wfGetIP();
                $userLimit = false;

                if( isset( $limits['anon'] ) && $id == 0 ) {
                        $keys[wfMemcKey( 'limiter', $action, 'anon' )] = $limits['anon'];
                }

                if( isset( $limits['user'] ) && $id != 0 ) {
                        $userLimit = $limits['user'];
                }
                if( $this->isNewbie() ) {
                        if( isset( $limits['newbie'] ) && $id != 0 ) {
                                $keys[wfMemcKey( 'limiter', $action, 'user', $id )] = $limits['newbie'];
                        }
                        if( isset( $limits['ip'] ) ) {
                                $keys["mediawiki:limiter:$action:ip:$ip"] = $limits['ip'];
                        }
                        $matches = array();
                        if( isset( $limits['subnet'] ) && preg_match( '/^(\d+\.\d+\.\d+)\.\d+$/', $ip, $matches ) ) {
                                $subnet = $matches[1];
                                $keys["mediawiki:limiter:$action:subnet:$subnet"] = $limits['subnet'];
                        }
                }
                // Check for group-specific permissions
                // If more than one group applies, use the group with the highest limit
                foreach ( $this->getGroups() as $group ) {
                        if ( isset( $limits[$group] ) ) {
                                if ( $userLimit === false || $limits[$group] > $userLimit ) {
                                        $userLimit = $limits[$group];
                                }
                        }
                }
                // Set the user limit key
                if ( $userLimit !== false ) {
                        wfDebug( __METHOD__ . ": effective user limit: $userLimit\n" );
                        $keys[ wfMemcKey( 'limiter', $action, 'user', $id ) ] = $userLimit;
                }

                $triggered = false;
                foreach( $keys as $key => $limit ) {
                        list( $max, $period ) = $limit;
                        $summary = "(limit $max in {$period}s)";
                        $count = $wgMemc->get( $key );
                        // Already pinged?
                        if( $count ) {
                                if( $count > $max ) {
                                        wfDebug( __METHOD__ . ": tripped! $key at $count $summary\n" );
                                        if( $wgRateLimitLog ) {
                                                @error_log( wfTimestamp( TS_MW ) . ' ' . wfWikiID() . ': ' . $this->getName() . " tripped $key at $count $summary\n", 3, $wgRateLimitLog );
                                        }
                                        $triggered = true;
                                } else {
                                        wfDebug( __METHOD__ . ": ok. $key at $count $summary\n" );
                                }
                        } else {
                                wfDebug( __METHOD__ . ": adding record for $key $summary\n" );
                                $wgMemc->add( $key, 0, intval( $period ) ); // first ping
                        }
                        $wgMemc->incr( $key );
                }

                wfProfileOut( __METHOD__ );
                return $triggered;
        }

        /**
         * Check if user is blocked
         *
         * @param $bFromSlave Bool Whether to check the slave database instead of the master
         * @return Bool True if blocked, false otherwise
         */
        function isBlocked( $bFromSlave = true ) { // hacked from false due to horrible probs on site
                $this->getBlockedStatus( $bFromSlave );
                return $this->mBlockedby !== 0;
        }

        /**
         * Check if user is blocked from editing a particular article
         *
         * @param $title Title to check
         * @param $bFromSlave Bool whether to check the slave database instead of the master
         * @return Bool
         */
        function isBlockedFrom( $title, $bFromSlave = false ) {
                global $wgBlockAllowsUTEdit;
                wfProfileIn( __METHOD__ );

                $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" );
                }

                wfRunHooks( 'UserIsBlockedFrom', array( $this, $title, &$blocked, &$allowUsertalk ) );

                wfProfileOut( __METHOD__ );
                return $blocked;
        }

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

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

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

        /**
         * Check if user is blocked on all wikis.
         * Do not use for actual edit permission checks!
         * This is intented for quick UI checks.
         *
         * @param $ip String IP address, uses current client if none given
         * @return Bool True if blocked, false otherwise
         */
        function isBlockedGlobally( $ip = '' ) {
                if( $this->mBlockedGlobally !== null ) {
                        return $this->mBlockedGlobally;
                }
                // User is already an IP?
                if( IP::isIPAddress( $this->getName() ) ) {
                        $ip = $this->getName();
                } else if( !$ip ) {
                        $ip = wfGetIP();
                }
                $blocked = false;
                wfRunHooks( 'UserIsBlockedGlobally', array( &$this, $ip, &$blocked ) );
                $this->mBlockedGlobally = (bool)$blocked;
                return $this->mBlockedGlobally;
        }

        /**
         * Check if user account is locked
         *
         * @return Bool True if locked, false otherwise
         */
        function isLocked() {
                if( $this->mLocked !== null ) {
                        return $this->mLocked;
                }
                global $wgAuth;
                $authUser = $wgAuth->getUserInstance( $this );
                $this->mLocked = (bool)$authUser->isLocked();
                return $this->mLocked;
        }

        /**
         * Check if user account is hidden
         *
         * @return Bool True if hidden, false otherwise
         */
        function isHidden() {
                if( $this->mHideName !== null ) {
                        return $this->mHideName;
                }
                $this->getBlockedStatus();
                if( !$this->mHideName ) {
                        global $wgAuth;
                        $authUser = $wgAuth->getUserInstance( $this );
                        $this->mHideName = (bool)$authUser->isHidden();
                }
                return $this->mHideName;
        }

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

        /**
         * Set the user and reload all fields according to a given ID
         * @param $v Int User ID to reload
         */
        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
         */
        function getName() {
                if ( !$this->mDataLoaded && $this->mFrom == 'name' ) {
                        # Special case optimisation
                        return $this->mName;
                } else {
                        $this->load();
                        if ( $this->mName === false ) {
                                # Clean up IPs
                                $this->mName = IP::sanitizeIP( wfGetIP() );
                        }
                        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 rougly the same function, when the named user
         * does not exist.
         * @param $str String New user name to set
         */
        function setName( $str ) {
                $this->load();
                $this->mName = $str;
        }

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

        /**
         * Check if the user has new messages.
         * @return Bool True if the user has new messages
         */
        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 $wgMemc;
                                $key = wfMemcKey( 'newtalk', 'ip', $this->getName() );
                                $newtalk = $wgMemc->get( $key );
                                if( strval( $newtalk ) !== '' ) {
                                        $this->mNewtalk = (bool)$newtalk;
                                } else {
                                        // Since we are caching this, make sure it is up to date by getting it
                                        // from the master
                                        $this->mNewtalk = $this->checkNewtalk( 'user_ip', $this->getName(), true );
                                        $wgMemc->set( $key, (int)$this->mNewtalk, 1800 );
                                }
                        } else {
                                $this->mNewtalk = $this->checkNewtalk( 'user_id', $this->mId );
                        }
                }

                return (bool)$this->mNewtalk;
        }

        /**
         * Return the talk page(s) this user has new messages on.
         * @return Array of String page URLs
         */
        function getNewMessageLinks() {
                $talks = array();
                if( !wfRunHooks( 'UserRetrieveNewTalks', array( &$this, &$talks ) ) )
                        return $talks;

                if( !$this->getNewtalk() )
                        return array();
                $up = $this->getUserPage();
                $utp = $up->getTalkPage();
                return array( array( 'wiki' => wfWikiID(), 'link' => $utp->getLocalURL() ) );
        }

        /**
         * Internal uncached check for new messages
         *
         * @see getNewtalk()
         * @param $field String 'user_ip' for anonymous users, 'user_id' otherwise
         * @param $id String|Int User's IP address for anonymous users, User ID otherwise
         * @param $fromMaster Bool true to fetch from the master, false for a slave
         * @return Bool True if the user has new messages
         * @private
         */
        function checkNewtalk( $field, $id, $fromMaster = false ) {
                if ( $fromMaster ) {
                        $db = wfGetDB( DB_MASTER );
                } else {
                        $db = wfGetDB( DB_SLAVE );
                }
                $ok = $db->selectField( 'user_newtalk', $field,
                        array( $field => $id ), __METHOD__ );
                return $ok !== false;
        }

        /**
         * Add or update the new messages flag
         * @param $field String 'user_ip' for anonymous users, 'user_id' otherwise
         * @param $id String|Int User's IP address for anonymous users, User ID otherwise
         * @return Bool True if successful, false otherwise
         * @private
         */
        function updateNewtalk( $field, $id ) {
                $dbw = wfGetDB( DB_MASTER );
                $dbw->insert( 'user_newtalk',
                        array( $field => $id ),
                        __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 $field String 'user_ip' for anonymous users, 'user_id' otherwise
         * @param $id String|Int User's IP address for anonymous users, User ID otherwise
         * @return Bool True if successful, false otherwise
         * @private
         */
        function deleteNewtalk( $field, $id ) {
                $dbw = wfGetDB( DB_MASTER );
                $dbw->delete( 'user_newtalk',
                        array( $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 $val Bool Whether the user has new messages
         */
        function setNewtalk( $val ) {
                if( wfReadOnly() ) {
                        return;
                }

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

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

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

                if( $this->isAnon() ) {
                        // Anons have a separate memcached space, since
                        // user records aren't kept for them.
                        $key = wfMemcKey( 'newtalk', 'ip', $id );
                        $wgMemc->set( $key, $val ? 1 : 0, 1800 );
                }
                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 static function newTouchedTimestamp() {
                global $wgClockSkewFudge;
                return wfTimestamp( TS_MW, time() + $wgClockSkewFudge );
        }

        /**
         * Clear user data from memcached.
         * Use after applying fun updates to the database; caller's
         * responsibility to update user_touched if appropriate.
         *
         * Called implicitly from invalidateCache() and saveSettings().
         */
        private function clearSharedCache() {
                $this->load();
                if( $this->mId ) {
                        global $wgMemc;
                        $wgMemc->delete( wfMemcKey( 'user', 'id', $this->mId ) );
                }
        }

        /**
         * Immediately touch the user data cache for this account.
         * Updates user_touched field, and removes account data from memcached
         * for reload on the next hit.
         */
        function invalidateCache() {
                if( wfReadOnly() ) {
                        return;
                }
                $this->load();
                if( $this->mId ) {
                        $this->mTouched = self::newTouchedTimestamp();

                        $dbw = wfGetDB( DB_MASTER );
                        $dbw->update( 'user',
                                array( 'user_touched' => $dbw->timestamp( $this->mTouched ) ),
                                array( 'user_id' => $this->mId ),
                                __METHOD__ );

                        $this->clearSharedCache();
                }
        }

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

        /**
         * Get the user touched timestamp
         * @return String timestamp
         */
        function getTouched() {
                $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.
         *
         * @param $str String New password to set
         * @throws PasswordError on failure
         */
        function setPassword( $str ) {
                global $wgAuth;

                if( $str !== null ) {
                        if( !$wgAuth->allowPasswordChange() ) {
                                throw new PasswordError( wfMsg( 'password-change-forbidden' ) );
                        }

                        if( !$this->isValidPassword( $str ) ) {
                                global $wgMinimalPasswordLength;
                                $valid = $this->getPasswordValidity( $str );
                                if ( is_array( $valid ) ) {
                                        $message = array_shift( $valid );
                                        $params = $valid;
                                } else {
                                        $message = $valid;
                                        $params = array( $wgMinimalPasswordLength );
                                }
                                throw new PasswordError( wfMsgExt( $message, array( 'parsemag' ), $params ) );
                        }
                }

                if( !$wgAuth->setPassword( $this, $str ) ) {
                        throw new PasswordError( wfMsg( 'externaldberror' ) );
                }

                $this->setInternalPassword( $str );

                return true;
        }

        /**
         * Set the password and reset the random token unconditionally.
         *
         * @param $str String New password to set
         */
        function setInternalPassword( $str ) {
                $this->load();
                $this->setToken();

                if( $str === null ) {
                        // Save an invalid hash...
                        $this->mPassword = '';
                } else {
                        $this->mPassword = self::crypt( $str );
                }
                $this->mNewpassword = '';
                $this->mNewpassTime = null;
        }

        /**
         * Get the user's current token.
         * @return String Token
         */
        function getToken() {
                $this->load();
                return $this->mToken;
        }

        /**
         * Set the random token (used for persistent authentication)
         * Called from loadDefaults() among other places.
         *
         * @param $token String If specified, set the token to this value
         * @private
         */
        function setToken( $token = false ) {
                global $wgSecretKey, $wgProxyKey;
                $this->load();
                if ( !$token ) {
                        if ( $wgSecretKey ) {
                                $key = $wgSecretKey;
                        } elseif ( $wgProxyKey ) {
                                $key = $wgProxyKey;
                        } else {
                                $key = microtime();
                        }
                        $this->mToken = md5( $key . mt_rand( 0, 0x7fffffff ) . wfWikiID() . $this->mId );
                } else {
                        $this->mToken = $token;
                }
        }

        /**
         * Set the cookie password
         *
         * @param $str String New cookie password
         * @private
         */
        function setCookiePassword( $str ) {
                $this->load();
                $this->mCookiePassword = md5( $str );
        }

        /**
         * Set the password for a password reminder or new account email
         *
         * @param $str String New password to set
         * @param $throttle Bool If true, reset the throttle timestamp to the present
         */
        function setNewpassword( $str, $throttle = true ) {
                $this->load();
                $this->mNewpassword = self::crypt( $str );
                if ( $throttle ) {
                        $this->mNewpassTime = wfTimestampNow();
                }
        }

        /**
         * Has password reminder email been sent within the last
         * $wgPasswordReminderResendTime hours?
         * @return Bool
         */
        function isPasswordReminderThrottled() {
                global $wgPasswordReminderResendTime;
                $this->load();
                if ( !$this->mNewpassTime || !$wgPasswordReminderResendTime ) {
                        return false;
                }
                $expiry = wfTimestamp( TS_UNIX, $this->mNewpassTime ) + $wgPasswordReminderResendTime * 3600;
                return time() < $expiry;
        }

        /**
         * Get the user's e-mail address
         * @return String User's email address
         */
        function getEmail() {
                $this->load();
                wfRunHooks( 'UserGetEmail', array( $this, &$this->mEmail ) );
                return $this->mEmail;
        }

        /**
         * Get the timestamp of the user's e-mail authentication
         * @return String TS_MW timestamp
         */
        function getEmailAuthenticationTimestamp() {
                $this->load();
                wfRunHooks( 'UserGetEmailAuthenticationTimestamp', array( $this, &$this->mEmailAuthenticated ) );
                return $this->mEmailAuthenticated;
        }

        /**
         * Set the user's e-mail address
         * @param $str String New e-mail address
         */
        function setEmail( $str ) {
                $this->load();
                $this->mEmail = $str;
                wfRunHooks( 'UserSetEmail', array( $this, &$this->mEmail ) );
        }

        /**
         * Get the user's real name
         * @return String User's real name
         */
        function getRealName() {
                $this->load();
                return $this->mRealName;
        }

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

        /**
         * Get the user's current setting for a given option.
         *
         * @param $oname String The option to check
         * @param $defaultOverride String A default value returned if the option does not exist
         * @return String User's current value for the option
         * @see getBoolOption()
         * @see getIntOption()
         */
        function getOption( $oname, $defaultOverride = null ) {
                $this->loadOptions();

                if ( is_null( $this->mOptions ) ) {
                        if($defaultOverride != '') {
                                return $defaultOverride;
                        }
                        $this->mOptions = User::getDefaultOptions();
                }

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

        /**
         * Get all user's options
         *
         * @return array
         */
        public function getOptions() {
                $this->loadOptions();
                return $this->mOptions;
        }

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


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

        /**
         * Set the given option for a user.
         *
         * @param $oname String The option to set
         * @param $val mixed New value to set
         */
        function setOption( $oname, $val ) {
                $this->load();
                $this->loadOptions();

                if ( $oname == 'skin' ) {
                        # Clear cached skin, so the new one displays immediately in Special:Preferences
                        $this->mSkin = null;
                }

                // Explicitly NULL values should refer to defaults
                global $wgDefaultUserOptions;
                if( is_null( $val ) && isset( $wgDefaultUserOptions[$oname] ) ) {
                        $val = $wgDefaultUserOptions[$oname];
                }

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

        /**
         * Reset all options to the site defaults
         */
        function resetOptions() {
                $this->mOptions = User::getDefaultOptions();
        }

        /**
         * Get the user's preferred date format.
         * @return String User's preferred date format
         */
        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;
        }

        /**
         * Get the user preferred stub threshold
         */
        function getStubThreshold() {
                global $wgMaxArticleSize; # Maximum article size, in Kb
                $threshold = intval( $this->getOption( '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 of String permission names
         */
        function getRights() {
                if ( is_null( $this->mRights ) ) {
                        $this->mRights = self::getGroupPermissions( $this->getEffectiveGroups() );
                        wfRunHooks( 'UserGetRights', array( $this, &$this->mRights ) );
                        // Force reindexation of rights when a hook has unset one of them
                        $this->mRights = array_values( $this->mRights );
                }
                return $this->mRights;
        }

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

        /**
         * 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 $recache Bool Whether to avoid the cache
         * @return Array of String internal group names
         */
        function getEffectiveGroups( $recache = false ) {
                if ( $recache || is_null( $this->mEffectiveGroups ) ) {
                        wfProfileIn( __METHOD__ );
                        $this->mEffectiveGroups = $this->getGroups();
                        $this->mEffectiveGroups[] = '*';
                        if( $this->getId() ) {
                                $this->mEffectiveGroups[] = 'user';

                                $this->mEffectiveGroups = array_unique( array_merge(
                                        $this->mEffectiveGroups,
                                        Autopromote::getAutopromoteGroups( $this )
                                ) );

                                # Hook for additional groups
                                wfRunHooks( 'UserEffectiveGroups', array( &$this, &$this->mEffectiveGroups ) );
                        }
                        wfProfileOut( __METHOD__ );
                }
                return $this->mEffectiveGroups;
        }

        /**
         * Get the user's edit count.
         * @return Int
         */
        function getEditCount() {
                if( $this->getId() ) {
                        if ( !isset( $this->mEditCount ) ) {
                                /* Populate the count, if it has not been populated yet */
                                $this->mEditCount = User::edits( $this->mId );
                        }
                        return $this->mEditCount;
                } else {
                        /* nil */
                        return null;
                }
        }

        /**
         * Add the user to the given group.
         * This takes immediate effect.
         * @param $group String Name of the group to add
         */
        function addGroup( $group ) {
                $dbw = wfGetDB( DB_MASTER );
                if( $this->getId() ) {
                        $dbw->insert( 'user_groups',
                                array(
                                        'ug_user'  => $this->getID(),
                                        'ug_group' => $group,
                                ),
                                __METHOD__,
                                array( 'IGNORE' ) );
                }

                $this->loadGroups();
                $this->mGroups[] = $group;
                $this->mRights = User::getGroupPermissions( $this->getEffectiveGroups( true ) );

                $this->invalidateCache();
        }

        /**
         * Remove the user from the given group.
         * This takes immediate effect.
         * @param $group String Name of the group to remove
         */
        function removeGroup( $group ) {
                $this->load();
                $dbw = wfGetDB( DB_MASTER );
                $dbw->delete( 'user_groups',
                        array(
                                'ug_user'  => $this->getID(),
                                'ug_group' => $group,
                        ), __METHOD__ );

                $this->loadGroups();
                $this->mGroups = array_diff( $this->mGroups, array( $group ) );
                $this->mRights = User::getGroupPermissions( $this->getEffectiveGroups( true ) );

                $this->invalidateCache();
        }

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

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

        /**
         * Check if user is allowed to access a feature / make an action
         * @param $action String action to be checked
         * @return Boolean: True if action is allowed, else false
         */
        function isAllowed( $action = '' ) {
                if ( $action === '' ) {
                        return true; // In the spirit of DWIM
                }
                # Patrolling may not be enabled
                if( $action === 'patrol' || $action === 'autopatrol' ) {
                        global $wgUseRCPatrol, $wgUseNPPatrol;
                        if( !$wgUseRCPatrol && !$wgUseNPPatrol )
                                return false;
                }
                # 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 Boolean: True or false
         */
        public function useRCPatrol() {
                global $wgUseRCPatrol;
                return( $wgUseRCPatrol && ( $this->isAllowed( 'patrol' ) || $this->isAllowed( '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->isAllowed( 'patrol' ) || $this->isAllowed( 'patrolmarks' ) ) );
        }

        /**
         * Get the current skin, loading it if required, and setting a title
         * @param $t Title: the title to use in the skin
         * @return Skin The current skin
         * @todo: FIXME : need to check the old failback system [AV]
         */
        function getSkin( $t = null ) {
                if ( $t ) {
                        $skin = $this->createSkinObject();
                        $skin->setTitle( $t );
                        return $skin;
                } else {
                        if ( !$this->mSkin ) {
                                $this->mSkin = $this->createSkinObject();
                        }

                        if ( !$this->mSkin->getTitle() ) {
                                global $wgOut;
                                $t = $wgOut->getTitle();
                                $this->mSkin->setTitle($t);
                        }

                        return $this->mSkin;
                }
        }

        // Creates a Skin object, for getSkin()
        private function createSkinObject() {
                wfProfileIn( __METHOD__ );

                global $wgHiddenPrefs;
                if( !in_array( 'skin', $wgHiddenPrefs ) ) {
                        global $wgRequest;
                        # get the user skin
                        $userSkin = $this->getOption( 'skin' );
                        $userSkin = $wgRequest->getVal( 'useskin', $userSkin );
                } else {
                        # if we're not allowing users to override, then use the default
                        global $wgDefaultSkin;
                        $userSkin = $wgDefaultSkin;
                }

                $skin = Skin::newFromKey( $userSkin );
                wfProfileOut( __METHOD__ );

                return $skin;
        }

        /**
         * Check the watched status of an article.
         * @param $title Title of the article to look at
         * @return Bool
         */
        function isWatched( $title ) {
                $wl = WatchedItem::fromUserTitle( $this, $title );
                return $wl->isWatched();
        }

        /**
         * Watch an article.
         * @param $title Title of the article to look at
         */
        function addWatch( $title ) {
                $wl = WatchedItem::fromUserTitle( $this, $title );
                $wl->addWatch();
                $this->invalidateCache();
        }

        /**
         * Stop watching an article.
         * @param $title Title of the article to look at
         */
        function removeWatch( $title ) {
                $wl = WatchedItem::fromUserTitle( $this, $title );
                $wl->removeWatch();
                $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.
         * @param $title Title of the article to look at
         */
        function clearNotification( &$title ) {
                global $wgUser, $wgUseEnotif, $wgShowUpdatedMarker;

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

                if( $title->getNamespace() == NS_USER_TALK &&
                        $title->getText() == $this->getName() ) {
                        if( !wfRunHooks( 'UserClearNewTalkNotification', array( &$this ) ) )
                                return;
                        $this->setNewtalk( false );
                }

                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 slave
                // If this is the user's newtalk page, we always update the timestamp
                if( $title->getNamespace() == NS_USER_TALK &&
                        $title->getText() == $wgUser->getName() )
                {
                        $watched = true;
                } elseif ( $this->getId() == $wgUser->getId() ) {
                        $watched = $title->userIsWatching();
                } else {
                        $watched = true;
                }

                // If the page is watched by the user (or may be watched), update the timestamp on any
                // any matching rows
                if ( $watched ) {
                        $dbw = wfGetDB( DB_MASTER );
                        $dbw->update( 'watchlist',
                                        array( /* SET */
                                                'wl_notificationtimestamp' => null
                                        ), array( /* WHERE */
                                                'wl_title' => $title->getDBkey(),
                                                'wl_namespace' => $title->getNamespace(),
                                                'wl_user' => $this->getID()
                                        ), __METHOD__
                        );
                }
        }

        /**
         * 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.
         *
         * @param $currentUser Int User ID
         */
        function clearAllNotifications( $currentUser ) {
                global $wgUseEnotif, $wgShowUpdatedMarker;
                if ( !$wgUseEnotif && !$wgShowUpdatedMarker ) {
                        $this->setNewtalk( false );
                        return;
                }
                if( $currentUser != 0 )  {
                        $dbw = wfGetDB( DB_MASTER );
                        $dbw->update( 'watchlist',
                                array( /* SET */
                                        'wl_notificationtimestamp' => null
                                ), array( /* WHERE */
                                        'wl_user' => $currentUser
                                ), __METHOD__
                        );
                #       We also need to clear here the "you have new message" notification for the own user_talk page
                #       This is cleared one page view later in Article::viewUpdates();
                }
        }

        /**
         * Set this user's options from an encoded string
         * @param $str String Encoded options to import
         * @private
         */
        function decodeOptions( $str ) {
                if( !$str )
                        return;

                $this->mOptionsLoaded = true;
                $this->mOptionOverrides = array();

                // If an option is not set in $str, use the default value
                $this->mOptions = self::getDefaultOptions();

                $a = explode( "\n", $str );
                foreach ( $a as $s ) {
                        $m = array();
                        if ( preg_match( "/^(.[^=]*)=(.*)$/", $s, $m ) ) {
                                $this->mOptions[$m[1]] = $m[2];
                                $this->mOptionOverrides[$m[1]] = $m[2];
                        }
                }
        }

        /**
         * Set a cookie on the user's client. Wrapper for
         * WebResponse::setCookie
         * @param $name String Name of the cookie to set
         * @param $value String Value to set
         * @param $exp Int Expiration time, as a UNIX time value;
         *                   if 0 or not specified, use the default $wgCookieExpiration
         */
        protected function setCookie( $name, $value, $exp = 0 ) {
                global $wgRequest;
                $wgRequest->response()->setcookie( $name, $value, $exp );
        }

        /**
         * Clear a cookie on the user's client
         * @param $name String Name of the cookie to clear
         */
        protected function clearCookie( $name ) {
                $this->setCookie( $name, '', time() - 86400 );
        }

        /**
         * Set the default cookies for this session on the user's client.
         */
        function setCookies() {
                $this->load();
                if ( 0 == $this->mId ) return;
                $session = array(
                        'wsUserID' => $this->mId,
                        'wsToken' => $this->mToken,
                        'wsUserName' => $this->getName()
                );
                $cookies = array(
                        'UserID' => $this->mId,
                        'UserName' => $this->getName(),
                );
                if ( 1 == $this->getOption( 'rememberpassword' ) ) {
                        $cookies['Token'] = $this->mToken;
                } else {
                        $cookies['Token'] = false;
                }

                wfRunHooks( 'UserSetCookies', array( $this, &$session, &$cookies ) );
                #check for null, since the hook could cause a null value
                if ( !is_null( $session ) && isset( $_SESSION ) ){
                        $_SESSION = $session + $_SESSION;
                }
                foreach ( $cookies as $name => $value ) {
                        if ( $value === false ) {
                                $this->clearCookie( $name );
                        } else {
                                $this->setCookie( $name, $value );
                        }
                }
        }

        /**
         * Log this user out.
         */
        function logout() {
                if( wfRunHooks( 'UserLogout', array( &$this ) ) ) {
                        $this->doLogout();
                }
        }

        /**
         * Clear the user's cookies and session, and reset the instance cache.
         * @private
         * @see logout()
         */
        function doLogout() {
                $this->clearInstanceCache( 'defaults' );

                $_SESSION['wsUserID'] = 0;

                $this->clearCookie( 'UserID' );
                $this->clearCookie( 'Token' );

                # Remember when user logged out, to prevent seeing cached pages
                $this->setCookie( 'LoggedOut', wfTimestampNow(), time() + 86400 );
        }

        /**
         * Save this user's settings into the database.
         * @todo Only rarely do all these fields need to be set!
         */
        function saveSettings() {
                $this->load();
                if ( wfReadOnly() ) { return; }
                if ( 0 == $this->mId ) { return; }

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

                $dbw = wfGetDB( DB_MASTER );
                $dbw->update( 'user',
                        array( /* SET */
                                'user_name' => $this->mName,
                                'user_password' => $this->mPassword,
                                'user_newpassword' => $this->mNewpassword,
                                'user_newpass_time' => $dbw->timestampOrNull( $this->mNewpassTime ),
                                'user_real_name' => $this->mRealName,
                                'user_email' => $this->mEmail,
                                'user_email_authenticated' => $dbw->timestampOrNull( $this->mEmailAuthenticated ),
                                'user_options' => '',
                                'user_touched' => $dbw->timestamp( $this->mTouched ),
                                'user_token' => $this->mToken,
                                'user_email_token' => $this->mEmailToken,
                                'user_email_token_expires' => $dbw->timestampOrNull( $this->mEmailTokenExpires ),
                        ), array( /* WHERE */
                                'user_id' => $this->mId
                        ), __METHOD__
                );

                $this->saveOptions();

                wfRunHooks( 'UserSaveSettings', array( $this ) );
                $this->clearSharedCache();
                $this->getUserPage()->invalidateCache();
        }

        /**
         * If only this user's username is known, and it exists, return the user ID.
         * @return Int
         */
        function idForName() {
                $s = trim( $this->getName() );
                if ( $s === '' ) return 0;

                $dbr = wfGetDB( DB_SLAVE );
                $id = $dbr->selectField( 'user', 'user_id', array( 'user_name' => $s ), __METHOD__ );
                if ( $id === false ) {
                        $id = 0;
                }
                return $id;
        }

        /**
         * Add a user to the database, return the user object
         *
         * @param $name String Username to add
         * @param $params Array of Strings Non-default parameters to save to the database:
         *   - password             The user's password. Password logins will be disabled if this is omitted.
         *   - newpassword          A temporary password mailed to the user
         *   - 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 object, or null if the username already exists
         */
        static function createNew( $name, $params = array() ) {
                $user = new User;
                $user->load();
                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' );

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

        /**
         * Add this existing user object to the database
         */
        function addToDatabase() {
                $this->load();
                $dbw = wfGetDB( DB_MASTER );
                $seqVal = $dbw->nextSequenceValue( 'user_user_id_seq' );
                $dbw->insert( 'user',
                        array(
                                'user_id' => $seqVal,
                                'user_name' => $this->mName,
                                'user_password' => $this->mPassword,
                                'user_newpassword' => $this->mNewpassword,
                                'user_newpass_time' => $dbw->timestampOrNull( $this->mNewpassTime ),
                                'user_email' => $this->mEmail,
                                'user_email_authenticated' => $dbw->timestampOrNull( $this->mEmailAuthenticated ),
                                'user_real_name' => $this->mRealName,
                                'user_options' => '',
                                'user_token' => $this->mToken,
                                'user_registration' => $dbw->timestamp( $this->mRegistration ),
                                'user_editcount' => 0,
                        ), __METHOD__
                );
                $this->mId = $dbw->insertId();

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

                $this->saveOptions();
        }

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

                $userblock = Block::newFromDB( '', $this->mId );
                if ( !$userblock ) {
                        return;
                }

                $userblock->doAutoblock( wfGetIP() );
        }

        /**
         * Generate a string which will be different for any combination of
         * user options which would produce different parser output.
         * This will be used as part of the hash key for the parser cache,
         * so users with the same options can share the same cached data
         * safely.
         *
         * Extensions which require it should install 'PageRenderingHash' hook,
         * which will give them a chance to modify this key based on their own
         * settings.
         *
         * @deprecated @since 1.17 use the ParserOptions object to get the relevant options
         * @return String Page rendering hash
         */
        function getPageRenderingHash() {
                global $wgUseDynamicDates, $wgRenderHashAppend, $wgLang, $wgContLang;
                if( $this->mHash ){
                        return $this->mHash;
                }
                wfDeprecated( __METHOD__ );

                // stubthreshold is only included below for completeness,
                // since it disables the parser cache, its value will always
                // be 0 when this function is called by parsercache.

                $confstr =        $this->getOption( 'math' );
                $confstr .= '!' . $this->getStubThreshold();
                if ( $wgUseDynamicDates ) { # This is wrong (bug 24714)
                        $confstr .= '!' . $this->getDatePreference();
                }
                $confstr .= '!' . ( $this->getOption( 'numberheadings' ) ? '1' : '' );
                $confstr .= '!' . $wgLang->getCode();
                $confstr .= '!' . $this->getOption( 'thumbsize' );
                // add in language specific options, if any
                $extra = $wgContLang->getExtraHashOptions();
                $confstr .= $extra;

                // Since the skin could be overloading link(), it should be
                // included here but in practice, none of our skins do that.

                $confstr .= $wgRenderHashAppend;

                // Give a chance for extensions to modify the hash, if they have
                // extra options or other effects on the parser cache.
                wfRunHooks( 'PageRenderingHash', array( &$confstr ) );

                // Make it a valid memcached key fragment
                $confstr = str_replace( ' ', '_', $confstr );
                $this->mHash = $confstr;
                return $confstr;
        }

        /**
         * Get whether the user is explicitly blocked from account creation.
         * @return Bool
         */
        function isBlockedFromCreateAccount() {
                $this->getBlockedStatus();
                return $this->mBlock && $this->mBlock->mCreateAccount;
        }

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

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

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

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

        /**
         * Get the maximum valid user ID.
         * @return Integer: User ID
         * @static
         */
        function getMaxID() {
                static $res; // cache

                if ( isset( $res ) ) {
                        return $res;
                } else {
                        $dbr = wfGetDB( DB_SLAVE );
                        return $res = $dbr->selectField( 'user', 'max(user_id)', false, __METHOD__ );
                }
        }

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

        /**
         * Check to see if the given clear-text password is one of the accepted passwords
         * @param $password String: user password.
         * @return Boolean: True if the given password is correct, otherwise False.
         */
        function checkPassword( $password ) {
                global $wgAuth;
                $this->load();

                // Even though we stop people from creating passwords that
                // are shorter than this, doesn't mean people wont be able
                // to. Certain authentication plugins do NOT want to save
                // domain passwords in a mysql database, so we should
                // check this (in case $wgAuth->strict() is false).
                if( !$this->isValidPassword( $password ) ) {
                        return false;
                }

                if( $wgAuth->authenticate( $this->getName(), $password ) ) {
                        return true;
                } elseif( $wgAuth->strict() ) {
                        /* Auth plugin doesn't allow local authentication */
                        return false;
                } elseif( $wgAuth->strictUserAuth( $this->getName() ) ) {
                        /* Auth plugin doesn't allow local authentication for this user name */
                        return false;
                }
                if ( self::comparePasswords( $this->mPassword, $password, $this->mId ) ) {
                        return true;
                } elseif ( function_exists( 'iconv' ) ) {
                        # Some wikis were converted from ISO 8859-1 to UTF-8, the passwords can't be converted
                        # Check for this with iconv
                        $cp1252Password = iconv( 'UTF-8', 'WINDOWS-1252//TRANSLIT', $password );
                        if ( self::comparePasswords( $this->mPassword, $cp1252Password, $this->mId ) ) {
                                return true;
                        }
                }
                return false;
        }

        /**
         * Check if the given clear-text password matches the temporary password
         * sent by e-mail for password reset operations.
         * @return Boolean: True if matches, false otherwise
         */
        function checkTemporaryPassword( $plaintext ) {
                global $wgNewPasswordExpiry;
                if( self::comparePasswords( $this->mNewpassword, $plaintext, $this->getId() ) ) {
                        if ( is_null( $this->mNewpassTime ) ) {
                                return true;
                        }
                        $expiry = wfTimestamp( TS_UNIX, $this->mNewpassTime ) + $wgNewPasswordExpiry;
                        return ( time() < $expiry );
                } else {
                        return false;
                }
        }

        /**
         * 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.
         *
         * @param $salt String|Array of Strings Optional function-specific data for hashing
         * @return String The new edit token
         */
        function editToken( $salt = '' ) {
                if ( $this->isAnon() ) {
                        return EDIT_TOKEN_SUFFIX;
                } else {
                        if( !isset( $_SESSION['wsEditToken'] ) ) {
                                $token = self::generateToken();
                                $_SESSION['wsEditToken'] = $token;
                        } else {
                                $token = $_SESSION['wsEditToken'];
                        }
                        if( is_array( $salt ) ) {
                                $salt = implode( '|', $salt );
                        }
                        return md5( $token . $salt ) . EDIT_TOKEN_SUFFIX;
                }
        }

        /**
         * Generate a looking random token for various uses.
         *
         * @param $salt String Optional salt value
         * @return String The new random token
         */
        public static function generateToken( $salt = '' ) {
                $token = dechex( mt_rand() ) . dechex( mt_rand() );
                return md5( $token . $salt );
        }

        /**
         * 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 $val String Input value to compare
         * @param $salt String Optional function-specific data for hashing
         * @return Boolean: Whether the token matches
         */
        function matchEditToken( $val, $salt = '' ) {
                $sessionToken = $this->editToken( $salt );
                if ( $val != $sessionToken ) {
                        wfDebug( "User::matchEditToken: broken session data\n" );
                }
                return $val == $sessionToken;
        }

        /**
         * Check given value against the token value stored in the session,
         * ignoring the suffix.
         *
         * @param $val String Input value to compare
         * @param $salt String Optional function-specific data for hashing
         * @return Boolean: Whether the token matches
         */
        function matchEditTokenNoSuffix( $val, $salt = '' ) {
                $sessionToken = $this->editToken( $salt );
                return substr( $sessionToken, 0, 32 ) == substr( $val, 0, 32 );
        }

        /**
         * Generate a new e-mail confirmation token and send a confirmation/invalidation
         * mail to the user's given address.
         *
         * @param $type String: message to send, either "created", "changed" or "set"
         * @return Status object
         */
        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 {
                        $message = 'confirmemail_body_' . $type;
                }

                return $this->sendMail( wfMsg( 'confirmemail_subject' ),
                        wfMsg( $message,
                                wfGetIP(),
                                $this->getName(),
                                $url,
                                $wgLang->timeanddate( $expiration, false ),
                                $invalidateURL,
                                $wgLang->date( $expiration, false ),
                                $wgLang->time( $expiration, false ) ) );
        }

        /**
         * Send an e-mail to this user's account. Does not check for
         * confirmed status or validity.
         *
         * @param $subject String Message subject
         * @param $body String Message body
         * @param $from String Optional From address; if unspecified, default $wgPasswordSender will be used
         * @param $replyto String Reply-To address
         * @return Status
         */
        function sendMail( $subject, $body, $from = null, $replyto = null ) {
                if( is_null( $from ) ) {
                        global $wgPasswordSender, $wgPasswordSenderName;
                        $sender = new MailAddress( $wgPasswordSender, $wgPasswordSenderName );
                } else {
                        $sender = new MailAddress( $from );
                }

                $to = new MailAddress( $this );
                return UserMailer::send( $to, $sender, $subject, $body, $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[out] &$expiration \mixed Accepts the expiration time
         * @return String New token
         * @private
         */
        function confirmationToken( &$expiration ) {
                $now = time();
                $expires = $now + 7 * 24 * 60 * 60;
                $expiration = wfTimestamp( TS_MW, $expires );
                $token = self::generateToken( $this->mId . $this->mEmail . $expires );
                $hash = md5( $token );
                $this->load();
                $this->mEmailToken = $hash;
                $this->mEmailTokenExpires = $expiration;
                return $token;
        }

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

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

        /**
         * Internal function to format the e-mail validation/invalidation URLs.
         * This uses $wgArticlePath directly as 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
         * (bug 6957 with Gmail and Internet Explorer).
         *
         * @param $page String Special page
         * @param $token String Token
         * @return String Formatted URL
         */
        protected function getTokenUrl( $page, $token ) {
                global $wgArticlePath;
                return wfExpandUrl(
                        str_replace(
                                '$1',
                                "Special:$page/$token",
                                $wgArticlePath ) );
        }

        /**
         * Mark the e-mail address confirmed.
         *
         * @note Call saveSettings() after calling this function to commit the change.
         */
        function confirmEmail() {
                $this->setEmailAuthenticationTimestamp( wfTimestampNow() );
                wfRunHooks( 'ConfirmEmailComplete', array( $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.
         */
        function invalidateEmail() {
                $this->load();
                $this->mEmailToken = null;
                $this->mEmailTokenExpires = null;
                $this->setEmailAuthenticationTimestamp( null );
                wfRunHooks( 'InvalidateEmailComplete', array( $this ) );
                return true;
        }

        /**
         * Set the e-mail authentication timestamp.
         * @param $timestamp String TS_MW timestamp
         */
        function setEmailAuthenticationTimestamp( $timestamp ) {
                $this->load();
                $this->mEmailAuthenticated = $timestamp;
                wfRunHooks( 'UserSetEmailAuthenticationTimestamp', array( $this, &$this->mEmailAuthenticated ) );
        }

        /**
         * Is this user allowed to send e-mails within limits of current
         * site configuration?
         * @return Bool
         */
        function canSendEmail() {
                global $wgEnableEmail, $wgEnableUserEmail;
                if( !$wgEnableEmail || !$wgEnableUserEmail || !$this->isAllowed( 'sendemail' ) ) {
                        return false;
                }
                $canSend = $this->isEmailConfirmed();
                wfRunHooks( 'UserCanSendEmail', array( &$this, &$canSend ) );
                return $canSend;
        }

        /**
         * Is this user allowed to receive e-mails within limits of current
         * site configuration?
         * @return Bool
         */
        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
         */
        function isEmailConfirmed() {
                global $wgEmailAuthentication;
                $this->load();
                $confirmed = true;
                if( wfRunHooks( 'EmailConfirmed', array( &$this, &$confirmed ) ) ) {
                        if( $this->isAnon() )
                                return false;
                        if( !self::isValidEmailAddr( $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
         */
        function isEmailConfirmationPending() {
                global $wgEmailAuthentication;
                return $wgEmailAuthentication &&
                        !$this->isEmailConfirmed() &&
                        $this->mEmailToken &&
                        $this->mEmailTokenExpires > wfTimestamp();
        }

        /**
         * Get the timestamp of account creation.
         *
         * @return String|Bool Timestamp of account creation, or false for
         *     non-existent/anonymous user accounts.
         */
        public function getRegistration() {
                return $this->getId() > 0
                        ? $this->mRegistration
                        : false;
        }

        /**
         * 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_SLAVE );
                $time = $dbr->selectField( 'revision', 'rev_timestamp',
                        array( 'rev_user' => $this->getId() ),
                        __METHOD__,
                        array( 'ORDER BY' => 'rev_timestamp ASC' )
                );
                if( !$time ) {
                        return false; // no edits
                }
                return wfTimestamp( TS_MW, $time );
        }

        /**
         * Get the permissions associated with a given list of groups
         *
         * @param $groups Array of Strings List of internal group names
         * @return Array of Strings List of permission key names for given groups combined
         */
        static function getGroupPermissions( $groups ) {
                global $wgGroupPermissions, $wgRevokePermissions;
                $rights = array();
                // 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 $role String Role to check
         * @return Array of Strings List of internal group names with the given permission
         */
        static function getGroupsWithPermission( $role ) {
                global $wgGroupPermissions;
                $allowedGroups = array();
                foreach ( $wgGroupPermissions as $group => $rights ) {
                        if ( isset( $rights[$role] ) && $rights[$role] ) {
                                $allowedGroups[] = $group;
                        }
                }
                return $allowedGroups;
        }

        /**
         * Get the localized descriptive name for a group, if it exists
         *
         * @param $group String Internal group name
         * @return String Localized descriptive group name
         */
        static function getGroupName( $group ) {
                $msg = wfMessage( "group-$group" );
                return $msg->isBlank() ? $group : $msg->text();
        }

        /**
         * Get the localized descriptive name for a member of a group, if it exists
         *
         * @param $group String Internal group name
         * @return String Localized name for group member
         */
        static function getGroupMember( $group ) {
                $msg = wfMessage( "group-$group-member" );
                return $msg->isBlank() ? $group : $msg->text();
        }

        /**
         * 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 of internal group names
         */
        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 Array of permission names
         */
        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::$mCoreRights;
                        }
                        wfRunHooks( 'UserGetAllRights', array( &self::$mAllRights ) );
                }
                return self::$mAllRights;
        }

        /**
         * Get a list of implicit groups
         * @return Array of Strings Array of internal group names
         */
        public static function getImplicitGroups() {
                global $wgImplicitGroups;
                $groups = $wgImplicitGroups;
                wfRunHooks( 'UserGetImplicitGroups', array( &$groups ) );       #deprecated, use $wgImplictGroups instead
                return $groups;
        }

        /**
         * Get the title of a page describing a particular group
         *
         * @param $group String Internal group name
         * @return Title|Bool Title of the page if it exists, false otherwise
         */
        static function getGroupPage( $group ) {
                $msg = wfMessage( 'grouppage-' . $group )->inContentLanguage();
                if( $msg->exists() ) {
                        $title = Title::newFromText( $msg->text() );
                        if( is_object( $title ) )
                                return $title;
                }
                return false;
        }

        /**
         * Create a link to the group in HTML, if available;
         * else return the group name.
         *
         * @param $group String Internal name of the group
         * @param $text String The text of the link
         * @return String HTML link to the group
         */
        static function makeGroupLinkHTML( $group, $text = '' ) {
                if( $text == '' ) {
                        $text = self::getGroupName( $group );
                }
                $title = self::getGroupPage( $group );
                if( $title ) {
                        global $wgUser;
                        $sk = $wgUser->getSkin();
                        return $sk->link( $title, htmlspecialchars( $text ) );
                } else {
                        return $text;
                }
        }

        /**
         * Create a link to the group in Wikitext, if available;
         * else return the group name.
         *
         * @param $group String Internal name of the group
         * @param $text String The text of the link
         * @return String Wikilink to the group
         */
        static function makeGroupLinkWiki( $group, $text = '' ) {
                if( $text == '' ) {
                        $text = self::getGroupName( $group );
                }
                $title = self::getGroupPage( $group );
                if( $title ) {
                        $page = $title->getPrefixedText();
                        return "[[$page|$text]]";
                } else {
                        return $text;
                }
        }

        /**
         * Returns an array of the groups that a particular group can add/remove.
         *
         * @param $group String: 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) )
         */
        static function changeableByGroup( $group ) {
                global $wgAddGroups, $wgRemoveGroups, $wgGroupsAddToSelf, $wgGroupsRemoveFromSelf;

                $groups = array( 'add' => array(), 'remove' => array(), 'add-self' => array(), 'remove-self' => array() );
                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] ) ) {
                } 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] ) ) {
                } 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] ) ) {
                } 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) )
         */
        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 array(
                                'add' => $all,
                                'remove' => $all,
                                'add-self' => array(),
                                'remove-self' => array()
                        );
                }

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

        /**
         * Increment the user's edit-count field.
         * Will have no effect for anonymous users.
         */
        function incEditCount() {
                if( !$this->isAnon() ) {
                        $dbw = wfGetDB( DB_MASTER );
                        $dbw->update( 'user',
                                array( 'user_editcount=user_editcount+1' ),
                                array( 'user_id' => $this->getId() ),
                                __METHOD__ );

                        // Lazy initialization check...
                        if( $dbw->affectedRows() == 0 ) {
                                // Pull from a slave to be less cruel to servers
                                // Accuracy isn't the point anyway here
                                $dbr = wfGetDB( DB_SLAVE );
                                $count = $dbr->selectField( 'revision',
                                        'COUNT(rev_user)',
                                        array( 'rev_user' => $this->getId() ),
                                        __METHOD__ );

                                // Now here's a goddamn hack...
                                if( $dbr !== $dbw ) {
                                        // If we actually have a slave server, the count is
                                        // at least one behind because the current transaction
                                        // has not been committed and replicated.
                                        $count++;
                                } else {
                                        // But if DB_SLAVE is selecting the master, then the
                                        // count we just read includes the revision that was
                                        // just added in the working transaction.
                                }

                                $dbw->update( 'user',
                                        array( 'user_editcount' => $count ),
                                        array( 'user_id' => $this->getId() ),
                                        __METHOD__ );
                        }
                }
                // edit count in user cache too
                $this->invalidateCache();
        }

        /**
         * Get the description of a given right
         *
         * @param $right String Right to query
         * @return String Localized description of the right
         */
        static function getRightDescription( $right ) {
                $key = "right-$right";
                $name = wfMsg( $key );
                return $name == '' || wfEmptyMsg( $key, $name )
                        ? $right
                        : $name;
        }

        /**
         * Make an old-style password hash
         *
         * @param $password String Plain-text password
         * @param $userId String User ID
         * @return String Password hash
         */
        static function oldCrypt( $password, $userId ) {
                global $wgPasswordSalt;
                if ( $wgPasswordSalt ) {
                        return md5( $userId . '-' . md5( $password ) );
                } else {
                        return md5( $password );
                }
        }

        /**
         * Make a new-style password hash
         *
         * @param $password String Plain-text password
         * @param $salt String Optional salt, may be random or the user ID.
         *                     If unspecified or false, will generate one automatically
         * @return String Password hash
         */
        static function crypt( $password, $salt = false ) {
                global $wgPasswordSalt;

                $hash = '';
                if( !wfRunHooks( 'UserCryptPassword', array( &$password, &$salt, &$wgPasswordSalt, &$hash ) ) ) {
                        return $hash;
                }

                if( $wgPasswordSalt ) {
                        if ( $salt === false ) {
                                $salt = substr( wfGenerateToken(), 0, 8 );
                        }
                        return ':B:' . $salt . ':' . md5( $salt . '-' . md5( $password ) );
                } else {
                        return ':A:' . md5( $password );
                }
        }

        /**
         * Compare a password hash with a plain-text password. Requires the user
         * ID if there's a chance that the hash is an old-style hash.
         *
         * @param $hash String Password hash
         * @param $password String Plain-text password to compare
         * @param $userId String User ID for old-style password salt
         * @return Boolean:
         */
        static function comparePasswords( $hash, $password, $userId = false ) {
                $type = substr( $hash, 0, 3 );

                $result = false;
                if( !wfRunHooks( 'UserComparePasswords', array( &$hash, &$password, &$userId, &$result ) ) ) {
                        return $result;
                }

                if ( $type == ':A:' ) {
                        # Unsalted
                        return md5( $password ) === substr( $hash, 3 );
                } elseif ( $type == ':B:' ) {
                        # Salted
                        list( $salt, $realHash ) = explode( ':', substr( $hash, 3 ), 2 );
                        return md5( $salt.'-'.md5( $password ) ) == $realHash;
                } else {
                        # Old-style
                        return self::oldCrypt( $password, $userId ) === $hash;
                }
        }

        /**
         * Add a newuser log entry for this user
         *
         * @param $byEmail Boolean: account made by email?
         * @param $reason String: user supplied reason
         */
        public function addNewUserLogEntry( $byEmail = false, $reason = '' ) {
                global $wgUser, $wgContLang, $wgNewUserLog;
                if( empty( $wgNewUserLog ) ) {
                        return true; // disabled
                }

                if( $this->getName() == $wgUser->getName() ) {
                        $action = 'create';
                } else {
                        $action = 'create2';
                        if ( $byEmail ) {
                                if ( $reason === '' ) {
                                        $reason = wfMsgForContent( 'newuserlog-byemail' );
                                } else {
                                        $reason = $wgContLang->commaList( array(
                                                $reason, wfMsgForContent( 'newuserlog-byemail' ) ) );
                                }
                        }
                }
                $log = new LogPage( 'newusers' );
                $log->addEntry(
                        $action,
                        $this->getUserPage(),
                        $reason,
                        array( $this->getId() )
                );
                return true;
        }

        /**
         * Add an autocreate newuser log entry for this user
         * Used by things like CentralAuth and perhaps other authplugins.
         */
        public function addNewUserLogEntryAutoCreate() {
                global $wgNewUserLog, $wgLogAutocreatedAccounts;
                if( !$wgNewUserLog || !$wgLogAutocreatedAccounts ) {
                        return true; // disabled
                }
                $log = new LogPage( 'newusers', false );
                $log->addEntry( 'autocreate', $this->getUserPage(), '', array( $this->getId() ) );
                return true;
        }

        protected function loadOptions() {
                $this->load();
                if ( $this->mOptionsLoaded || !$this->getId() )
                        return;

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

                // 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 {
                        wfDebug( "User: loading options for user " . $this->getId() . " from database.\n" );
                        // Load from database
                        $dbr = wfGetDB( DB_SLAVE );

                        $res = $dbr->select(
                                'user_properties',
                                '*',
                                array( 'up_user' => $this->getId() ),
                                __METHOD__
                        );

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

                $this->mOptionsLoaded = true;

                wfRunHooks( 'UserLoadOptions', array( $this, &$this->mOptions ) );
        }

        protected function saveOptions() {
                global $wgAllowPrefChange;

                $extuser = ExternalUser::newFromUser( $this );

                $this->loadOptions();
                $dbw = wfGetDB( DB_MASTER );

                $insert_rows = array();

                $saveOptions = $this->mOptions;

                // Allow hooks to abort, for instance to save to a global profile.
                // Reset options to default state before saving.
                if( !wfRunHooks( 'UserSaveOptions', array( $this, &$saveOptions ) ) )
                        return;

                foreach( $saveOptions as $key => $value ) {
                        # Don't bother storing default values
                        if ( ( is_null( self::getDefaultOption( $key ) ) &&
                                        !( $value === false || is_null($value) ) ) ||
                                        $value != self::getDefaultOption( $key ) ) {
                                $insert_rows[] = array(
                                                'up_user' => $this->getId(),
                                                'up_property' => $key,
                                                'up_value' => $value,
                                        );
                        }
                        if ( $extuser && isset( $wgAllowPrefChange[$key] ) ) {
                                switch ( $wgAllowPrefChange[$key] ) {
                                        case 'local':
                                        case 'message':
                                                break;
                                        case 'semiglobal':
                                        case 'global':
                                                $extuser->setPref( $key, $value );
                                }
                        }
                }

                $dbw->begin();
                $dbw->delete( 'user_properties', array( 'up_user' => $this->getId() ), __METHOD__ );
                $dbw->insert( 'user_properties', $insert_rows, __METHOD__ );
                $dbw->commit();
        }

        /**
         * 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.
         *
         * FIXME : This does not belong here; put it in Html or Linker or somewhere
         *
         * @return array Array of HTML attributes suitable for feeding to
         *   Html::element(), directly or indirectly.  (Don't feed to Xml::*()!
         *   That will potentially output invalid XHTML 1.0 Transitional, and will
         *   get confused by the boolean attribute syntax used.)
         */
        public static function passwordChangeInputAttribs() {
                global $wgMinimalPasswordLength;

                if ( $wgMinimalPasswordLength == 0 ) {
                        return array();
                }

                # Note that the pattern requirement will always be satisfied if the
                # input is empty, so we need required in all cases.
                #
                # FIXME (bug 23769): 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 = array();

                # 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'] = wfMsgExt( 'passwordtooshort', 'parsemag',
                                $wgMinimalPasswordLength );
                }
                */

                return $ret;
        }

        /**
         * Format the user message using a hook, a template, or, failing these, a static format.
         * @param $subject   String the subject of the message
         * @param $text      String the content of the message
         * @param $signature String the signature, if provided.
         */
        static protected function formatUserMessage( $subject, $text, $signature ) {
                if ( wfRunHooks( 'FormatUserMessage',
                                array( $subject, &$text, $signature ) ) ) {

                        $signature = empty($signature) ? "~~~~~" : "{$signature} ~~~~~";

                        $template = Title::newFromText( wfMsgForContent( 'usermessage-template' ) );
                        if ( !$template
                                        || $template->getNamespace() !== NS_TEMPLATE
                                        || !$template->exists() ) {
                                $text = "\n== $subject ==\n\n$text\n\n-- $signature";
                        } else {
                                $text = '{{'. $template->getText()
                                        . " | subject=$subject | body=$text | signature=$signature }}";
                        }
                }

                return $text;
        }

        /**
         * Leave a user a message
         * @param $subject String the subject of the message
         * @param $text String the message to leave
         * @param $signature String Text to leave in the signature
         * @param $summary String the summary for this change, defaults to
         *                        "Leave system message."
         * @param $editor User The user leaving the message, defaults to
         *                        "{{MediaWiki:usermessage-editor}}"
         * @param $flags Int default edit flags
         *
         * @return boolean true if it was successful
         */
        public function leaveUserMessage( $subject, $text, $signature = "",
                        $summary = null, $editor = null, $flags = 0 ) {
                if ( !isset( $summary ) ) {
                        $summary = wfMsgForContent( 'usermessage-summary' );
                }

                if ( !isset( $editor ) ) {
                        $editor = User::newFromName( wfMsgForContent( 'usermessage-editor' ) );
                        if ( !$editor->isLoggedIn() ) {
                                $editor->addToDatabase();
                        }
                }

                $article = new Article( $this->getTalkPage() );
                wfRunHooks( 'SetupUserMessageArticle',
                        array( $this, &$article, $subject, $text, $signature, $summary, $editor ) );


                $text = self::formatUserMessage( $subject, $text, $signature );
                $flags = $article->checkFlags( $flags );

                if ( $flags & EDIT_UPDATE ) {
                        $text = $article->getContent() . $text;
                }

                $dbw = wfGetDB( DB_MASTER );
                $dbw->begin();

                try {
                        $status = $article->doEdit( $text, $summary, $flags, false, $editor );
                } catch ( DBQueryError $e ) {
                        $status = Status::newFatal("DB Error");
                }

                if ( $status->isGood() ) {
                        // Set newtalk with the right user ID
                        $this->setNewtalk( true );
                        wfRunHooks( 'AfterUserMessage',
                                array( $this, $article, $subject, $text, $signature, $summary, $editor ) );
                        $dbw->commit();
                } else {
                        // The article was concurrently created
                        wfDebug( __METHOD__ . ": Error ".$status->getWikiText() );
                        $dbw->rollback();
                }

                return $status->isGood();
        }
}