diff .svn/pristine/93/936cc88e72764286d1a11efcbdd8c4c81f64c306.svn-base @ 1517:dffacf8a6908 redmine-2.5

Update to Redmine SVN revision 13367 on 2.5-stable branch

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/.svn/pristine/93/936cc88e72764286d1a11efcbdd8c4c81f64c306.svn-base	Tue Sep 09 09:29:00 2014 +0100
@@ -0,0 +1,762 @@
+# Redmine - project management software
+# Copyright (C) 2006-2014  Jean-Philippe Lang
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+
+require "digest/sha1"
+
+class User < Principal
+  include Redmine::SafeAttributes
+
+  # Different ways of displaying/sorting users
+  USER_FORMATS = {
+    :firstname_lastname => {
+        :string => '#{firstname} #{lastname}',
+        :order => %w(firstname lastname id),
+        :setting_order => 1
+      },
+    :firstname_lastinitial => {
+        :string => '#{firstname} #{lastname.to_s.chars.first}.',
+        :order => %w(firstname lastname id),
+        :setting_order => 2
+      },
+    :firstinitial_lastname => {
+        :string => '#{firstname.to_s.gsub(/(([[:alpha:]])[[:alpha:]]*\.?)/, \'\2.\')} #{lastname}',
+        :order => %w(firstname lastname id),
+        :setting_order => 2
+      },
+    :firstname => {
+        :string => '#{firstname}',
+        :order => %w(firstname id),
+        :setting_order => 3
+      },
+    :lastname_firstname => {
+        :string => '#{lastname} #{firstname}',
+        :order => %w(lastname firstname id),
+        :setting_order => 4
+      },
+    :lastname_coma_firstname => {
+        :string => '#{lastname}, #{firstname}',
+        :order => %w(lastname firstname id),
+        :setting_order => 5
+      },
+    :lastname => {
+        :string => '#{lastname}',
+        :order => %w(lastname id),
+        :setting_order => 6
+      },
+    :username => {
+        :string => '#{login}',
+        :order => %w(login id),
+        :setting_order => 7
+      },
+  }
+
+  MAIL_NOTIFICATION_OPTIONS = [
+    ['all', :label_user_mail_option_all],
+    ['selected', :label_user_mail_option_selected],
+    ['only_my_events', :label_user_mail_option_only_my_events],
+    ['only_assigned', :label_user_mail_option_only_assigned],
+    ['only_owner', :label_user_mail_option_only_owner],
+    ['none', :label_user_mail_option_none]
+  ]
+
+  has_and_belongs_to_many :groups,
+                          :join_table   => "#{table_name_prefix}groups_users#{table_name_suffix}",
+                          :after_add    => Proc.new {|user, group| group.user_added(user)},
+                          :after_remove => Proc.new {|user, group| group.user_removed(user)}
+  has_many :changesets, :dependent => :nullify
+  has_one :preference, :dependent => :destroy, :class_name => 'UserPreference'
+  has_one :rss_token, :class_name => 'Token', :conditions => "action='feeds'"
+  has_one :api_token, :class_name => 'Token', :conditions => "action='api'"
+  belongs_to :auth_source
+
+  scope :logged, lambda { where("#{User.table_name}.status <> #{STATUS_ANONYMOUS}") }
+  scope :status, lambda {|arg| where(arg.blank? ? nil : {:status => arg.to_i}) }
+
+  acts_as_customizable
+
+  attr_accessor :password, :password_confirmation, :generate_password
+  attr_accessor :last_before_login_on
+  # Prevents unauthorized assignments
+  attr_protected :login, :admin, :password, :password_confirmation, :hashed_password
+
+  LOGIN_LENGTH_LIMIT = 60
+  MAIL_LENGTH_LIMIT = 60
+
+  validates_presence_of :login, :firstname, :lastname, :mail, :if => Proc.new { |user| !user.is_a?(AnonymousUser) }
+  validates_uniqueness_of :login, :if => Proc.new { |user| user.login_changed? && user.login.present? }, :case_sensitive => false
+  validates_uniqueness_of :mail, :if => Proc.new { |user| user.mail_changed? && user.mail.present? }, :case_sensitive => false
+  # Login must contain letters, numbers, underscores only
+  validates_format_of :login, :with => /\A[a-z0-9_\-@\.]*\z/i
+  validates_length_of :login, :maximum => LOGIN_LENGTH_LIMIT
+  validates_length_of :firstname, :lastname, :maximum => 30
+  validates_format_of :mail, :with => /\A([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})\z/i, :allow_blank => true
+  validates_length_of :mail, :maximum => MAIL_LENGTH_LIMIT, :allow_nil => true
+  validates_confirmation_of :password, :allow_nil => true
+  validates_inclusion_of :mail_notification, :in => MAIL_NOTIFICATION_OPTIONS.collect(&:first), :allow_blank => true
+  validate :validate_password_length
+
+  before_create :set_mail_notification
+  before_save   :generate_password_if_needed, :update_hashed_password
+  before_destroy :remove_references_before_destroy
+  after_save :update_notified_project_ids
+
+  scope :in_group, lambda {|group|
+    group_id = group.is_a?(Group) ? group.id : group.to_i
+    where("#{User.table_name}.id IN (SELECT gu.user_id FROM #{table_name_prefix}groups_users#{table_name_suffix} gu WHERE gu.group_id = ?)", group_id)
+  }
+  scope :not_in_group, lambda {|group|
+    group_id = group.is_a?(Group) ? group.id : group.to_i
+    where("#{User.table_name}.id NOT IN (SELECT gu.user_id FROM #{table_name_prefix}groups_users#{table_name_suffix} gu WHERE gu.group_id = ?)", group_id)
+  }
+  scope :sorted, lambda { order(*User.fields_for_order_statement)}
+
+  def set_mail_notification
+    self.mail_notification = Setting.default_notification_option if self.mail_notification.blank?
+    true
+  end
+
+  def update_hashed_password
+    # update hashed_password if password was set
+    if self.password && self.auth_source_id.blank?
+      salt_password(password)
+    end
+  end
+
+  alias :base_reload :reload
+  def reload(*args)
+    @name = nil
+    @projects_by_role = nil
+    @membership_by_project_id = nil
+    @notified_projects_ids = nil
+    @notified_projects_ids_changed = false
+    @builtin_role = nil
+    base_reload(*args)
+  end
+
+  def mail=(arg)
+    write_attribute(:mail, arg.to_s.strip)
+  end
+
+  def identity_url=(url)
+    if url.blank?
+      write_attribute(:identity_url, '')
+    else
+      begin
+        write_attribute(:identity_url, OpenIdAuthentication.normalize_identifier(url))
+      rescue OpenIdAuthentication::InvalidOpenId
+        # Invalid url, don't save
+      end
+    end
+    self.read_attribute(:identity_url)
+  end
+
+  # Returns the user that matches provided login and password, or nil
+  def self.try_to_login(login, password, active_only=true)
+    login = login.to_s
+    password = password.to_s
+
+    # Make sure no one can sign in with an empty login or password
+    return nil if login.empty? || password.empty?
+    user = find_by_login(login)
+    if user
+      # user is already in local database
+      return nil unless user.check_password?(password)
+      return nil if !user.active? && active_only
+    else
+      # user is not yet registered, try to authenticate with available sources
+      attrs = AuthSource.authenticate(login, password)
+      if attrs
+        user = new(attrs)
+        user.login = login
+        user.language = Setting.default_language
+        if user.save
+          user.reload
+          logger.info("User '#{user.login}' created from external auth source: #{user.auth_source.type} - #{user.auth_source.name}") if logger && user.auth_source
+        end
+      end
+    end
+    user.update_column(:last_login_on, Time.now) if user && !user.new_record? && user.active?
+    user
+  rescue => text
+    raise text
+  end
+
+  # Returns the user who matches the given autologin +key+ or nil
+  def self.try_to_autologin(key)
+    user = Token.find_active_user('autologin', key, Setting.autologin.to_i)
+    if user
+      user.update_column(:last_login_on, Time.now)
+      user
+    end
+  end
+
+  def self.name_formatter(formatter = nil)
+    USER_FORMATS[formatter || Setting.user_format] || USER_FORMATS[:firstname_lastname]
+  end
+
+  # Returns an array of fields names than can be used to make an order statement for users
+  # according to how user names are displayed
+  # Examples:
+  #
+  #   User.fields_for_order_statement              => ['users.login', 'users.id']
+  #   User.fields_for_order_statement('authors')   => ['authors.login', 'authors.id']
+  def self.fields_for_order_statement(table=nil)
+    table ||= table_name
+    name_formatter[:order].map {|field| "#{table}.#{field}"}
+  end
+
+  # Return user's full name for display
+  def name(formatter = nil)
+    f = self.class.name_formatter(formatter)
+    if formatter
+      eval('"' + f[:string] + '"')
+    else
+      @name ||= eval('"' + f[:string] + '"')
+    end
+  end
+
+  def active?
+    self.status == STATUS_ACTIVE
+  end
+
+  def registered?
+    self.status == STATUS_REGISTERED
+  end
+
+  def locked?
+    self.status == STATUS_LOCKED
+  end
+
+  def activate
+    self.status = STATUS_ACTIVE
+  end
+
+  def register
+    self.status = STATUS_REGISTERED
+  end
+
+  def lock
+    self.status = STATUS_LOCKED
+  end
+
+  def activate!
+    update_attribute(:status, STATUS_ACTIVE)
+  end
+
+  def register!
+    update_attribute(:status, STATUS_REGISTERED)
+  end
+
+  def lock!
+    update_attribute(:status, STATUS_LOCKED)
+  end
+
+  # Returns true if +clear_password+ is the correct user's password, otherwise false
+  def check_password?(clear_password)
+    if auth_source_id.present?
+      auth_source.authenticate(self.login, clear_password)
+    else
+      User.hash_password("#{salt}#{User.hash_password clear_password}") == hashed_password
+    end
+  end
+
+  # Generates a random salt and computes hashed_password for +clear_password+
+  # The hashed password is stored in the following form: SHA1(salt + SHA1(password))
+  def salt_password(clear_password)
+    self.salt = User.generate_salt
+    self.hashed_password = User.hash_password("#{salt}#{User.hash_password clear_password}")
+  end
+
+  # Does the backend storage allow this user to change their password?
+  def change_password_allowed?
+    return true if auth_source.nil?
+    return auth_source.allow_password_changes?
+  end
+
+  def must_change_password?
+    must_change_passwd? && change_password_allowed?
+  end
+
+  def generate_password?
+    generate_password == '1' || generate_password == true
+  end
+
+  # Generate and set a random password on given length
+  def random_password(length=40)
+    chars = ("a".."z").to_a + ("A".."Z").to_a + ("0".."9").to_a
+    chars -= %w(0 O 1 l)
+    password = ''
+    length.times {|i| password << chars[SecureRandom.random_number(chars.size)] }
+    self.password = password
+    self.password_confirmation = password
+    self
+  end
+
+  def pref
+    self.preference ||= UserPreference.new(:user => self)
+  end
+
+  def time_zone
+    @time_zone ||= (self.pref.time_zone.blank? ? nil : ActiveSupport::TimeZone[self.pref.time_zone])
+  end
+
+  def force_default_language?
+    Setting.force_default_language_for_loggedin?
+  end
+
+  def language
+    if force_default_language?
+      Setting.default_language
+    else
+      super
+    end
+  end
+
+  def wants_comments_in_reverse_order?
+    self.pref[:comments_sorting] == 'desc'
+  end
+
+  # Return user's RSS key (a 40 chars long string), used to access feeds
+  def rss_key
+    if rss_token.nil?
+      create_rss_token(:action => 'feeds')
+    end
+    rss_token.value
+  end
+
+  # Return user's API key (a 40 chars long string), used to access the API
+  def api_key
+    if api_token.nil?
+      create_api_token(:action => 'api')
+    end
+    api_token.value
+  end
+
+  # Return an array of project ids for which the user has explicitly turned mail notifications on
+  def notified_projects_ids
+    @notified_projects_ids ||= memberships.select {|m| m.mail_notification?}.collect(&:project_id)
+  end
+
+  def notified_project_ids=(ids)
+    @notified_projects_ids_changed = true
+    @notified_projects_ids = ids
+  end
+
+  # Updates per project notifications (after_save callback)
+  def update_notified_project_ids
+    if @notified_projects_ids_changed
+      ids = (mail_notification == 'selected' ? Array.wrap(notified_projects_ids).reject(&:blank?) : [])
+      members.update_all(:mail_notification => false)
+      members.where(:project_id => ids).update_all(:mail_notification => true) if ids.any?
+    end
+  end
+  private :update_notified_project_ids
+
+  def valid_notification_options
+    self.class.valid_notification_options(self)
+  end
+
+  # Only users that belong to more than 1 project can select projects for which they are notified
+  def self.valid_notification_options(user=nil)
+    # Note that @user.membership.size would fail since AR ignores
+    # :include association option when doing a count
+    if user.nil? || user.memberships.length < 1
+      MAIL_NOTIFICATION_OPTIONS.reject {|option| option.first == 'selected'}
+    else
+      MAIL_NOTIFICATION_OPTIONS
+    end
+  end
+
+  # Find a user account by matching the exact login and then a case-insensitive
+  # version.  Exact matches will be given priority.
+  def self.find_by_login(login)
+    login = Redmine::CodesetUtil.replace_invalid_utf8(login.to_s)
+    if login.present?
+      # First look for an exact match
+      user = where(:login => login).detect {|u| u.login == login}
+      unless user
+        # Fail over to case-insensitive if none was found
+        user = where("LOWER(login) = ?", login.downcase).first
+      end
+      user
+    end
+  end
+
+  def self.find_by_rss_key(key)
+    Token.find_active_user('feeds', key)
+  end
+
+  def self.find_by_api_key(key)
+    Token.find_active_user('api', key)
+  end
+
+  # Makes find_by_mail case-insensitive
+  def self.find_by_mail(mail)
+    where("LOWER(mail) = ?", mail.to_s.downcase).first
+  end
+
+  # Returns true if the default admin account can no longer be used
+  def self.default_admin_account_changed?
+    !User.active.find_by_login("admin").try(:check_password?, "admin")
+  end
+
+  def to_s
+    name
+  end
+
+  CSS_CLASS_BY_STATUS = {
+    STATUS_ANONYMOUS  => 'anon',
+    STATUS_ACTIVE     => 'active',
+    STATUS_REGISTERED => 'registered',
+    STATUS_LOCKED     => 'locked'
+  }
+
+  def css_classes
+    "user #{CSS_CLASS_BY_STATUS[status]}"
+  end
+
+  # Returns the current day according to user's time zone
+  def today
+    if time_zone.nil?
+      Date.today
+    else
+      Time.now.in_time_zone(time_zone).to_date
+    end
+  end
+
+  # Returns the day of +time+ according to user's time zone
+  def time_to_date(time)
+    if time_zone.nil?
+      time.to_date
+    else
+      time.in_time_zone(time_zone).to_date
+    end
+  end
+
+  def logged?
+    true
+  end
+
+  def anonymous?
+    !logged?
+  end
+
+  # Returns user's membership for the given project
+  # or nil if the user is not a member of project
+  def membership(project)
+    project_id = project.is_a?(Project) ? project.id : project
+
+    @membership_by_project_id ||= Hash.new {|h, project_id|
+      h[project_id] = memberships.where(:project_id => project_id).first
+    }
+    @membership_by_project_id[project_id]
+  end
+
+  # Returns the user's bult-in role
+  def builtin_role
+    @builtin_role ||= Role.non_member
+  end
+
+  # Return user's roles for project
+  def roles_for_project(project)
+    roles = []
+    # No role on archived projects
+    return roles if project.nil? || project.archived?
+    if membership = membership(project)
+      roles = membership.roles
+    else
+      roles << builtin_role
+    end
+    roles
+  end
+
+  # Return true if the user is a member of project
+  def member_of?(project)
+    projects.to_a.include?(project)
+  end
+
+  # Returns a hash of user's projects grouped by roles
+  def projects_by_role
+    return @projects_by_role if @projects_by_role
+
+    @projects_by_role = Hash.new([])
+    memberships.each do |membership|
+      if membership.project
+        membership.roles.each do |role|
+          @projects_by_role[role] = [] unless @projects_by_role.key?(role)
+          @projects_by_role[role] << membership.project
+        end
+      end
+    end
+    @projects_by_role.each do |role, projects|
+      projects.uniq!
+    end
+
+    @projects_by_role
+  end
+
+  # Returns true if user is arg or belongs to arg
+  def is_or_belongs_to?(arg)
+    if arg.is_a?(User)
+      self == arg
+    elsif arg.is_a?(Group)
+      arg.users.include?(self)
+    else
+      false
+    end
+  end
+
+  # Return true if the user is allowed to do the specified action on a specific context
+  # Action can be:
+  # * a parameter-like Hash (eg. :controller => 'projects', :action => 'edit')
+  # * a permission Symbol (eg. :edit_project)
+  # Context can be:
+  # * a project : returns true if user is allowed to do the specified action on this project
+  # * an array of projects : returns true if user is allowed on every project
+  # * nil with options[:global] set : check if user has at least one role allowed for this action,
+  #   or falls back to Non Member / Anonymous permissions depending if the user is logged
+  def allowed_to?(action, context, options={}, &block)
+    if context && context.is_a?(Project)
+      return false unless context.allows_to?(action)
+      # Admin users are authorized for anything else
+      return true if admin?
+
+      roles = roles_for_project(context)
+      return false unless roles
+      roles.any? {|role|
+        (context.is_public? || role.member?) &&
+        role.allowed_to?(action) &&
+        (block_given? ? yield(role, self) : true)
+      }
+    elsif context && context.is_a?(Array)
+      if context.empty?
+        false
+      else
+        # Authorize if user is authorized on every element of the array
+        context.map {|project| allowed_to?(action, project, options, &block)}.reduce(:&)
+      end
+    elsif options[:global]
+      # Admin users are always authorized
+      return true if admin?
+
+      # authorize if user has at least one role that has this permission
+      roles = memberships.collect {|m| m.roles}.flatten.uniq
+      roles << (self.logged? ? Role.non_member : Role.anonymous)
+      roles.any? {|role|
+        role.allowed_to?(action) &&
+        (block_given? ? yield(role, self) : true)
+      }
+    else
+      false
+    end
+  end
+
+  # Is the user allowed to do the specified action on any project?
+  # See allowed_to? for the actions and valid options.
+  def allowed_to_globally?(action, options, &block)
+    allowed_to?(action, nil, options.reverse_merge(:global => true), &block)
+  end
+
+  # Returns true if the user is allowed to delete the user's own account
+  def own_account_deletable?
+    Setting.unsubscribe? &&
+      (!admin? || User.active.where("admin = ? AND id <> ?", true, id).exists?)
+  end
+
+  safe_attributes 'login',
+    'firstname',
+    'lastname',
+    'mail',
+    'mail_notification',
+    'notified_project_ids',
+    'language',
+    'custom_field_values',
+    'custom_fields',
+    'identity_url'
+
+  safe_attributes 'status',
+    'auth_source_id',
+    'generate_password',
+    'must_change_passwd',
+    :if => lambda {|user, current_user| current_user.admin?}
+
+  safe_attributes 'group_ids',
+    :if => lambda {|user, current_user| current_user.admin? && !user.new_record?}
+
+  # Utility method to help check if a user should be notified about an
+  # event.
+  #
+  # TODO: only supports Issue events currently
+  def notify_about?(object)
+    if mail_notification == 'all'
+      true
+    elsif mail_notification.blank? || mail_notification == 'none'
+      false
+    else
+      case object
+      when Issue
+        case mail_notification
+        when 'selected', 'only_my_events'
+          # user receives notifications for created/assigned issues on unselected projects
+          object.author == self || is_or_belongs_to?(object.assigned_to) || is_or_belongs_to?(object.assigned_to_was)
+        when 'only_assigned'
+          is_or_belongs_to?(object.assigned_to) || is_or_belongs_to?(object.assigned_to_was)
+        when 'only_owner'
+          object.author == self
+        end
+      when News
+        # always send to project members except when mail_notification is set to 'none'
+        true
+      end
+    end
+  end
+
+  def self.current=(user)
+    Thread.current[:current_user] = user
+  end
+
+  def self.current
+    Thread.current[:current_user] ||= User.anonymous
+  end
+
+  # Returns the anonymous user.  If the anonymous user does not exist, it is created.  There can be only
+  # one anonymous user per database.
+  def self.anonymous
+    anonymous_user = AnonymousUser.first
+    if anonymous_user.nil?
+      anonymous_user = AnonymousUser.create(:lastname => 'Anonymous', :firstname => '', :mail => '', :login => '', :status => 0)
+      raise 'Unable to create the anonymous user.' if anonymous_user.new_record?
+    end
+    anonymous_user
+  end
+
+  # Salts all existing unsalted passwords
+  # It changes password storage scheme from SHA1(password) to SHA1(salt + SHA1(password))
+  # This method is used in the SaltPasswords migration and is to be kept as is
+  def self.salt_unsalted_passwords!
+    transaction do
+      User.where("salt IS NULL OR salt = ''").find_each do |user|
+        next if user.hashed_password.blank?
+        salt = User.generate_salt
+        hashed_password = User.hash_password("#{salt}#{user.hashed_password}")
+        User.where(:id => user.id).update_all(:salt => salt, :hashed_password => hashed_password)
+      end
+    end
+  end
+
+  protected
+
+  def validate_password_length
+    return if password.blank? && generate_password?
+    # Password length validation based on setting
+    if !password.nil? && password.size < Setting.password_min_length.to_i
+      errors.add(:password, :too_short, :count => Setting.password_min_length.to_i)
+    end
+  end
+
+  private
+
+  def generate_password_if_needed
+    if generate_password? && auth_source.nil?
+      length = [Setting.password_min_length.to_i + 2, 10].max
+      random_password(length)
+    end
+  end
+
+  # Removes references that are not handled by associations
+  # Things that are not deleted are reassociated with the anonymous user
+  def remove_references_before_destroy
+    return if self.id.nil?
+
+    substitute = User.anonymous
+    Attachment.where(['author_id = ?', id]).update_all(['author_id = ?', substitute.id]) 
+    Comment.where(['author_id = ?', id]).update_all(['author_id = ?', substitute.id])
+    Issue.where(['author_id = ?', id]).update_all(['author_id = ?', substitute.id])
+    Issue.where(['assigned_to_id = ?', id]).update_all('assigned_to_id = NULL')
+    Journal.where(['user_id = ?', id]).update_all(['user_id = ?', substitute.id]) 
+    JournalDetail.
+      where(["property = 'attr' AND prop_key = 'assigned_to_id' AND old_value = ?", id.to_s]).
+      update_all(['old_value = ?', substitute.id.to_s])
+    JournalDetail.
+      where(["property = 'attr' AND prop_key = 'assigned_to_id' AND value = ?", id.to_s]).
+      update_all(['value = ?', substitute.id.to_s]) 
+    Message.where(['author_id = ?', id]).update_all(['author_id = ?', substitute.id])
+    News.where(['author_id = ?', id]).update_all(['author_id = ?', substitute.id])
+    # Remove private queries and keep public ones
+    ::Query.delete_all ['user_id = ? AND visibility = ?', id, ::Query::VISIBILITY_PRIVATE]
+    ::Query.where(['user_id = ?', id]).update_all(['user_id = ?', substitute.id])
+    TimeEntry.where(['user_id = ?', id]).update_all(['user_id = ?', substitute.id])
+    Token.delete_all ['user_id = ?', id]
+    Watcher.delete_all ['user_id = ?', id]
+    WikiContent.where(['author_id = ?', id]).update_all(['author_id = ?', substitute.id])
+    WikiContent::Version.where(['author_id = ?', id]).update_all(['author_id = ?', substitute.id])
+  end
+
+  # Return password digest
+  def self.hash_password(clear_password)
+    Digest::SHA1.hexdigest(clear_password || "")
+  end
+
+  # Returns a 128bits random salt as a hex string (32 chars long)
+  def self.generate_salt
+    Redmine::Utils.random_hex(16)
+  end
+
+end
+
+class AnonymousUser < User
+  validate :validate_anonymous_uniqueness, :on => :create
+
+  def validate_anonymous_uniqueness
+    # There should be only one AnonymousUser in the database
+    errors.add :base, 'An anonymous user already exists.' if AnonymousUser.exists?
+  end
+
+  def available_custom_fields
+    []
+  end
+
+  # Overrides a few properties
+  def logged?; false end
+  def admin; false end
+  def name(*args); I18n.t(:label_user_anonymous) end
+  def mail; nil end
+  def time_zone; nil end
+  def rss_key; nil end
+
+  def pref
+    UserPreference.new(:user => self)
+  end
+
+  # Returns the user's bult-in role
+  def builtin_role
+    @builtin_role ||= Role.anonymous
+  end
+
+  def membership(*args)
+    nil
+  end
+
+  def member_of?(*args)
+    false
+  end
+
+  # Anonymous user can not be destroyed
+  def destroy
+    false
+  end
+end