Merge pull request #15676 from sgrif/sg-object-hash

Defer to super, rather than re-implementing Object#hash

activerecord/lib/active_record/core.rb

@@ -380,7 +380,11 @@ def ==(comparison_object)
     # Delegates to id in order to allow two records of the same type and id to work with something like:
     #   [ Person.find(1), Person.find(2), Person.find(3) ] & [ Person.find(1), Person.find(4) ] # => [ Person.find(1) ]
     def hash
-      (id || object_id).hash
+      if id
+        id.hash
+      else
+        super
+      end
     end
 
     # Clone and freeze the attributes hash such that associations are still