Merge pull request #29181 from kamipo/fix_circular_left_joins_with_scoping

Fix crashing on circular left join references with scoping

activerecord/lib/active_record/reflection.rb

@@ -199,7 +199,7 @@ def join_scopes(table, predicate_builder) # :nodoc:
       def klass_join_scope(table, predicate_builder) # :nodoc:
         if klass.current_scope
           klass.current_scope.clone.tap { |scope|
-            scope.joins_values = []
+            scope.joins_values = scope.left_outer_joins_values = [].freeze
           }
         else
           relation = ActiveRecord::Relation.create(

activerecord/test/cases/scoping/relation_scoping_test.rb

@@ -229,12 +229,19 @@ def test_current_scope_does_not_pollute_sibling_subclasses
     end
   end
 
-  def test_circular_joins_with_current_scope_does_not_crash
+  def test_circular_joins_with_scoping_does_not_crash
     posts = Post.joins(comments: :post).scoping do
-      Post.current_scope.first(10)
+      Post.first(10)
     end
     assert_equal posts, Post.joins(comments: :post).first(10)
   end
+
+  def test_circular_left_joins_with_scoping_does_not_crash
+    posts = Post.left_joins(comments: :post).scoping do
+      Post.first(10)
+    end
+    assert_equal posts, Post.left_joins(comments: :post).first(10)
+  end
 end
 
 class NestedRelationScopingTest < ActiveRecord::TestCase