[rails#52698] Fix comparison of Timestamp value for PostgreSQL.

Author: ruyrocha

activerecord/lib/active_record/connection_adapters/postgresql/oid/timestamp.rb

@@ -8,6 +8,13 @@ class Timestamp < DateTime # :nodoc:
           def type
             real_type_unless_aliased(:timestamp)
           end
+
+          def ==(other)
+            precision == other.precision &&
+              scale == other.scale &&
+              limit == other.limit &&
+              type == other.type
+          end
         end
       end
     end

activerecord/test/cases/adapters/postgresql/postgresql_adapter_test.rb

@@ -715,6 +715,15 @@ def test_disable_extension_without_schema
         @connection.execute("DROP EXTENSION IF EXISTS hstore")
       end
 
+      def test_time_zone_converter_equals_to_timestamp
+        subtype = ActiveRecord::ConnectionAdapters::PostgreSQL::OID::Timestamp.new
+        value = ActiveRecord::AttributeMethods::TimeZoneConversion::TimeZoneConverter.new(subtype)
+
+        value_from_cache = Marshal.load(Marshal.dump(value))
+
+        assert_equal value, value_from_cache
+      end
+
       private
         def with_postgresql_apdater_decode_dates
           PostgreSQLAdapter.decode_dates = true