Merge pull request rails#49677 from DmitryPogrebnoy/49670

Make `==(other)` method of AttributeSet safe rails#49670

Author: kamipo

activemodel/lib/active_model/attribute_set.rb

@@ -104,7 +104,7 @@ def reverse_merge!(target_attributes)
     end
 
     def ==(other)
-      attributes == other.attributes
+      other.is_a?(AttributeSet) && attributes == other.send(:attributes)
     end
 
     protected

activemodel/test/cases/attribute_set_test.rb

@@ -279,6 +279,14 @@ def builder.build_from_database(values = {}, additional_types = {})
       assert_not_equal attributes2, attributes3
     end
 
+    test "==(other) is safe to use with any instance" do
+      attribute_set = AttributeSet.new({})
+
+      assert_equal false, attribute_set == nil
+      assert_equal false, attribute_set == 1
+      assert_equal true, attribute_set == attribute_set
+    end
+
     private
       def attributes_with_uninitialized_key
         builder = AttributeSet::Builder.new(foo: Type::Integer.new, bar: Type::Float.new)