backport runner fixes to 3-2-stable

Add a runner hook to Rails::Application and Rails::Engine that requires
ActiveRecord::Base to avoid circular constant loading when using observers.

This commit backports cc7dd66, c0ba0f0 and 8d01c61.

1 files changed, 6 insertions, 0 deletions

diff --git a/activerecord/lib/active_record/railtie.rb b/activerecord/lib/active_record/railtie.rb
index 13b7c6e214..4e39654e5b 100644
--- a/activerecord/lib/active_record/railtie.rb
+++ b/activerecord/lib/active_record/railtie.rb
@@ -30,6 +30,7 @@ module ActiveRecord
     )
 
     rake_tasks do
+      require "active_record/base"
       load "active_record/railties/databases.rake"
     end
 
@@ -38,9 +39,14 @@ module ActiveRecord
     # first time. Also, make it output to STDERR.
     console do |app|
       require "active_record/railties/console_sandbox" if app.sandbox?
+      require "active_record/base"
       ActiveRecord::Base.logger = Logger.new(STDERR)
     end
 
+    runner do |app|
+      require "active_record/base"
+    end
+
     initializer "active_record.initialize_timezone" do
       ActiveSupport.on_load(:active_record) do
         self.time_zone_aware_attributes = true