FIX: Improve checks for non-human users.

app/controllers/session_controller.rb

@@ -243,7 +243,7 @@ class SessionController < ApplicationController
     RateLimiter.new(nil, "forgot-password-login-min-#{params[:login].to_s[0..100]}", 3, 1.minute).performed!
 
     user = User.find_by_username_or_email(params[:login])
-    user_presence = user.present? && user.id != Discourse::SYSTEM_USER_ID && !user.staged
+    user_presence = user.present? && user.id > 0 && !user.staged
     if user_presence
       email_token = user.email_tokens.create(email: user.email)
       Jobs.enqueue(:critical_user_email, type: :forgot_password, user_id: user.id, email_token: email_token.token)

app/controllers/users_controller.rb

@@ -491,7 +491,7 @@ class UsersController < ApplicationController
       RateLimiter.new(nil, "admin-login-hr-#{request.remote_ip}", 6, 1.hour).performed!
       RateLimiter.new(nil, "admin-login-min-#{request.remote_ip}", 3, 1.minute).performed!
 
-      user = User.where(email: params[:email], admin: true).where.not(id: Discourse::SYSTEM_USER_ID).first
+      user = User.where(email: params[:email], admin: true).human_users.first
       if user
         email_token = user.email_tokens.create(email: user.email)
         Jobs.enqueue(:critical_user_email, type: :admin_login, user_id: user.id, email_token: email_token.token)

app/jobs/scheduled/disable_bootstrap_mode.rb

@@ -4,7 +4,7 @@ module Jobs
 
     def execute(args)
       return unless SiteSetting.bootstrap_mode_enabled
-      total_users = User.where.not(id: Discourse::SYSTEM_USER_ID).count
+      total_users = User.human_users.count
 
       if SiteSetting.bootstrap_mode_min_users == 0 || total_users > SiteSetting.bootstrap_mode_min_users
         SiteSetting.set_and_log('default_trust_level', TrustLevel[0]) if SiteSetting.send('default_trust_level') == TrustLevel[1]

app/models/draft_sequence.rb

@@ -3,7 +3,7 @@ class DraftSequence < ActiveRecord::Base
     user_id = user
     user_id = user.id unless user.class == Fixnum
 
-    return 0 if user_id == Discourse::SYSTEM_USER_ID
+    return 0 if user_id < 0
 
     h = { user_id: user_id, draft_key: key }
     c = DraftSequence.find_by(h)

app/models/post_action.rb

@@ -160,9 +160,12 @@ SQL
 
   def self.clear_flags!(post, moderator)
     # -1 is the automatic system cleary
-    action_type_ids = moderator.id == -1 ?
+    action_type_ids =
-        PostActionType.auto_action_flag_types.values :
+      if moderator.id == Discourse::SYSTEM_USER_ID
+        PostActionType.auto_action_flag_types.values
+      else
         PostActionType.flag_types.values
+      end
 
     actions = PostAction.where(post_id: post.id)
                         .where(post_action_type_id: action_type_ids)
@@ -487,7 +490,7 @@ SQL
                       .flags
                       .joins(:post)
                       .where("posts.topic_id = ?", topic.id)
-                      .where.not(user_id: Discourse::SYSTEM_USER_ID)
+                      .where("post_actions.user_id > 0")
                       .group("post_actions.user_id")
                       .pluck("post_actions.user_id, COUNT(post_id)")
 

app/models/topic_converter.rb

@@ -61,7 +61,7 @@ class TopicConverter
     @topic.notifier.watch_topic!(topic.user_id)
 
     @topic.topic_allowed_users(true).each do |tau|
-      next if tau.user_id == -1 || tau.user_id == topic.user_id
+      next if tau.user_id < 0 || tau.user_id == topic.user_id
       topic.notifier.watch!(tau.user_id)
     end
   end

app/models/user.rb

@@ -900,7 +900,7 @@ class User < ActiveRecord::Base
   end
 
   def is_singular_admin?
-    User.where(admin: true).where.not(id: id).where.not(id: Discourse::SYSTEM_USER_ID).blank?
+    User.where(admin: true).where.not(id: id).human_users.blank?
   end
 
   def logged_out
@@ -925,7 +925,7 @@ class User < ActiveRecord::Base
   end
 
   def clear_global_notice_if_needed
-    return if id == Discourse::SYSTEM_USER_ID
+    return if id < 0
 
     if admin && SiteSetting.has_login_hint
       SiteSetting.has_login_hint = false

app/services/post_alerter.rb

@@ -8,7 +8,7 @@ class PostAlerter
 
   def not_allowed?(user, post)
     user.blank? ||
-    user.id == Discourse::SYSTEM_USER_ID ||
+    user.id < 0 ||
     user.id == post.user_id
   end
 
@@ -269,7 +269,7 @@ class PostAlerter
 
   def create_notification(user, type, post, opts=nil)
     return if user.blank?
-    return if user.id == Discourse::SYSTEM_USER_ID
+    return if user.id < 0
 
     return if type == Notification.types[:liked] && user.user_option.like_notification_frequency == UserOption.like_notification_frequency_type[:never]