Raise an exception when unserialization fails due to a missing class

2 files changed, 10 insertions, 1 deletions

diff --git a/activerecord/lib/active_record/coders/yaml_column.rb b/activerecord/lib/active_record/coders/yaml_column.rb
index 8d22942a06..1aa82f20d6 100644
--- a/activerecord/lib/active_record/coders/yaml_column.rb
+++ b/activerecord/lib/active_record/coders/yaml_column.rb
@@ -33,7 +33,8 @@ module ActiveRecord
           obj ||= object_class.new if object_class != Object
 
           obj
-        rescue ArgumentError, Psych::SyntaxError
+        rescue ArgumentError , Psych::SyntaxError => e
+          raise if e.to_s =~ /undefined class/
           yaml
         end
       end
diff --git a/activerecord/test/cases/coders/yaml_column_test.rb b/activerecord/test/cases/coders/yaml_column_test.rb
index b874adc081..45e986c7b6 100644
--- a/activerecord/test/cases/coders/yaml_column_test.rb
+++ b/activerecord/test/cases/coders/yaml_column_test.rb
@@ -48,6 +48,14 @@ module ActiveRecord
         bad_yaml = '--- {'
         assert_equal bad_yaml, coder.load(bad_yaml)
       end
+
+      def test_load_doesnt_handle_undefined_class_or_module
+        coder = YAMLColumn.new
+        missing_class_yaml = '--- !ruby/object:DoesNotExistAndShouldntEver {}\n'
+        assert_raises(ArgumentError) do
+          coder.load(missing_class_yaml)
+        end
+      end
     end
   end
 end