Change unapproved and unconfirmed account to not be accessible in the REST API (#17530)

* Change unapproved and unconfirmed account to not be accessible in the REST API

* Change Account#searchable? to reject unconfirmed and unapproved users

* Disable search for unapproved and unconfirmed users in Account.search_for

* Disable search for unapproved and unconfirmed users in Account.advanced_search_for

* Remove unconfirmed and unapproved accounts from Account.searchable scope

* Prevent mentions to unapproved/unconfirmed accounts

* Fix some old tests for Account.advanced_search_for

* Add some Account.advanced_search_for tests for existing behaviors

* Add some tests for Account.search_for

* Add Account.advanced_search_for tests unconfirmed and unapproved accounts

* Add Account.searchable tests

* Fix Account.without_unapproved scope potentially messing with previously-applied scopes

* Allow lookup of unconfirmed/unapproved accounts through /api/v1/accounts/lookup

This is so that the API can still be used to check whether an username is free
to use.

app/controllers/api/v1/accounts_controller.rb

@@ -9,6 +9,8 @@ class Api::V1::AccountsController < Api::BaseController
 
   before_action :require_user!, except: [:show, :create]
   before_action :set_account, except: [:create]
+  before_action :check_account_approval, except: [:create]
+  before_action :check_account_confirmation, except: [:create]
   before_action :check_enabled_registrations, only: [:create]
 
   skip_before_action :require_authenticated_user!, only: :create
@@ -74,6 +76,14 @@ class Api::V1::AccountsController < Api::BaseController
     @account = Account.find(params[:id])
   end
 
+  def check_account_approval
+    raise(ActiveRecord::RecordNotFound) if @account.local? && @account.user_pending?
+  end
+
+  def check_account_confirmation
+    raise(ActiveRecord::RecordNotFound) if @account.local? && !@account.user_confirmed?
+  end
+
   def relationships(**options)
     AccountRelationshipsPresenter.new([@account.id], current_user.account_id, **options)
   end

app/models/account.rb

@@ -109,7 +109,8 @@ class Account < ApplicationRecord
   scope :matches_username, ->(value) { where(arel_table[:username].matches("#{value}%")) }
   scope :matches_display_name, ->(value) { where(arel_table[:display_name].matches("#{value}%")) }
   scope :matches_domain, ->(value) { where(arel_table[:domain].matches("%#{value}%")) }
-  scope :searchable, -> { without_suspended.where(moved_to_account_id: nil) }
+  scope :without_unapproved, -> { left_outer_joins(:user).remote.or(left_outer_joins(:user).merge(User.approved.confirmed)) }
+  scope :searchable, -> { without_unapproved.without_suspended.where(moved_to_account_id: nil) }
   scope :discoverable, -> { searchable.without_silenced.where(discoverable: true).left_outer_joins(:account_stat) }
   scope :followable_by, ->(account) { joins(arel_table.join(Follow.arel_table, Arel::Nodes::OuterJoin).on(arel_table[:id].eq(Follow.arel_table[:target_account_id]).and(Follow.arel_table[:account_id].eq(account.id))).join_sources).where(Follow.arel_table[:id].eq(nil)).joins(arel_table.join(FollowRequest.arel_table, Arel::Nodes::OuterJoin).on(arel_table[:id].eq(FollowRequest.arel_table[:target_account_id]).and(FollowRequest.arel_table[:account_id].eq(account.id))).join_sources).where(FollowRequest.arel_table[:id].eq(nil)) }
   scope :by_recent_status, -> { order(Arel.sql('(case when account_stats.last_status_at is null then 1 else 0 end) asc, account_stats.last_status_at desc, accounts.id desc')) }
@@ -193,7 +194,7 @@ class Account < ApplicationRecord
   end
 
   def searchable?
-    !(suspended? || moved?)
+    !(suspended? || moved?) && (!local? || (approved? && confirmed?))
   end
 
   def possibly_stale?
@@ -461,9 +462,11 @@ class Account < ApplicationRecord
           accounts.*,
           ts_rank_cd(#{TEXTSEARCH}, to_tsquery('simple', :tsquery), 32) AS rank
         FROM accounts
+        LEFT JOIN users ON accounts.id = users.account_id
         WHERE to_tsquery('simple', :tsquery) @@ #{TEXTSEARCH}
           AND accounts.suspended_at IS NULL
           AND accounts.moved_to_account_id IS NULL
+          AND (accounts.domain IS NOT NULL OR (users.approved = TRUE AND users.confirmed_at IS NOT NULL))
         ORDER BY rank DESC
         LIMIT :limit OFFSET :offset
       SQL
@@ -539,9 +542,11 @@ class Account < ApplicationRecord
             (count(f.id) + 1) * ts_rank_cd(#{TEXTSEARCH}, to_tsquery('simple', :tsquery), 32) AS rank
           FROM accounts
           LEFT OUTER JOIN follows AS f ON (accounts.id = f.account_id AND f.target_account_id = :id) OR (accounts.id = f.target_account_id AND f.account_id = :id)
+          LEFT JOIN users ON accounts.id = users.account_id
           WHERE to_tsquery('simple', :tsquery) @@ #{TEXTSEARCH}
             AND accounts.suspended_at IS NULL
             AND accounts.moved_to_account_id IS NULL
+            AND (accounts.domain IS NOT NULL OR (users.approved = TRUE AND users.confirmed_at IS NOT NULL))
           GROUP BY accounts.id
           ORDER BY rank DESC
           LIMIT :limit OFFSET :offset

app/services/process_mentions_service.rb

@@ -37,6 +37,9 @@ class ProcessMentionsService < BaseService
 
       mentioned_account = Account.find_remote(username, domain)
 
+      # Unapproved and unconfirmed accounts should not be mentionable
+      next if mentioned_account&.local? && !(mentioned_account.user_confirmed? && mentioned_account.user_approved?)
+
       # If the account cannot be found or isn't the right protocol,
       # first try to resolve it
       if mention_undeliverable?(mentioned_account)