convert order arg to string before checking if we can reverse it

2 files changed, 6 insertions, 2 deletions

diff --git a/activerecord/lib/active_record/relation/query_methods.rb b/activerecord/lib/active_record/relation/query_methods.rb
index 34723b0b4f..db7fe8123d 100644
--- a/activerecord/lib/active_record/relation/query_methods.rb
+++ b/activerecord/lib/active_record/relation/query_methods.rb
@@ -1097,6 +1097,10 @@ module ActiveRecord
       end
 
       def does_not_support_reverse?(order)
+        # Account for String subclasses like Arel::Nodes::SqlLiteral that
+        # override methods like #count.
+        order = String.new(order) unless order.instance_of?(String)
+
         # Uses SQL function with multiple arguments.
         (order.include?(",") && order.split(",").find { |section| section.count("(") != section.count(")") }) ||
           # Uses "nulls first" like construction.
diff --git a/activerecord/test/cases/relations_test.rb b/activerecord/test/cases/relations_test.rb
index f3f82e7591..4c865ef965 100644
--- a/activerecord/test/cases/relations_test.rb
+++ b/activerecord/test/cases/relations_test.rb
@@ -248,9 +248,9 @@ class RelationTest < ActiveRecord::TestCase
   end
 
   def test_reverse_order_with_function_other_predicates
-    topics = Topic.order("author_name, length(title), id").reverse_order
+    topics = Topic.order(Arel.sql("author_name, length(title), id")).reverse_order
     assert_equal topics(:second).title, topics.first.title
-    topics = Topic.order("length(author_name), id, length(title)").reverse_order
+    topics = Topic.order(Arel.sql("length(author_name), id, length(title)")).reverse_order
     assert_equal topics(:fifth).title, topics.first.title
   end