Revert "ARel only requires the connection from the AR class. Simply return the AR class rather than jump through hoops and store ivars"

This reverts commit d65e3b481e72e8c76818a94353e9ac315c7c0272.

1 files changed, 8 insertions, 2 deletions

diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb
index 4e743ec826..8750e226b9 100644
--- a/activerecord/lib/active_record/base.rb
+++ b/activerecord/lib/active_record/base.rb
@@ -747,7 +747,7 @@ module ActiveRecord #:nodoc:
         undefine_attribute_methods
         reset_column_cache
         @column_names = @content_columns = @dynamic_methods_hash = @inheritance_column = nil
-        @relation = nil
+        @arel_engine = @relation = nil
       end
 
       def reset_column_cache # :nodoc:
@@ -856,7 +856,13 @@ module ActiveRecord #:nodoc:
       end
 
       def arel_engine
-        self
+        @arel_engine ||= begin
+          if self == ActiveRecord::Base
+            ActiveRecord::Base
+          else
+            connection_handler.connection_pools[name] ? self : superclass.arel_engine
+          end
+        end
       end
 
       # Returns a scope for this class without taking into account the default_scope.