There is no need to check `null_relation?` in `empty_scope?`

`values[:extending]` includes `NullRelation` if `null_relation?`.

3 files changed, 8 insertions, 1 deletions

diff --git a/activerecord/lib/active_record/relation.rb b/activerecord/lib/active_record/relation.rb
index c1cdad9c87..cd62b0b881 100644
--- a/activerecord/lib/active_record/relation.rb
+++ b/activerecord/lib/active_record/relation.rb
@@ -689,7 +689,7 @@ module ActiveRecord
     end
 
     def empty_scope? # :nodoc:
-      !null_relation? && @values == klass.unscoped.values
+      @values == klass.unscoped.values
     end
 
     def has_limit_or_offset? # :nodoc:
diff --git a/activerecord/test/cases/relation_test.rb b/activerecord/test/cases/relation_test.rb
index 00a7b3841f..90b208092f 100644
--- a/activerecord/test/cases/relation_test.rb
+++ b/activerecord/test/cases/relation_test.rb
@@ -101,6 +101,9 @@ module ActiveRecord
 
       relation.merge!(relation)
       assert_predicate relation, :empty_scope?
+
+      assert_not_predicate NullPost.all, :empty_scope?
+      assert_not_predicate FirstPost.all, :empty_scope?
     end
 
     def test_bad_constants_raise_errors
diff --git a/activerecord/test/models/post.rb b/activerecord/test/models/post.rb
index 61e5f14100..395b534c63 100644
--- a/activerecord/test/models/post.rb
+++ b/activerecord/test/models/post.rb
@@ -203,6 +203,10 @@ end
 
 class SubAbstractStiPost < AbstractStiPost; end
 
+class NullPost < Post
+  default_scope { none }
+end
+
 class FirstPost < ActiveRecord::Base
   self.inheritance_column = :disabled
   self.table_name = "posts"