Can't register TypeHandler after using TypeHandlerRegistry.hasTypeHandler

[waluo]

MyBatis version
3.4.5

For example：

TypeHandlerRegistry tr = ...
tr.register(Address.class, TypeHandlers.jsonPOJO(Address.class));
tr.hasTypeHandler(Address.class);  // which return true

but

TypeHandlerRegistry tr = ...
tr.hasTypeHandler(Address.class);
tr.register(Address.class, TypeHandlers.jsonPOJO(Address.class));
tr.hasTypeHandler(Address.class); // which return false

Where the question is coming.
In org.apache.ibatis.type.TypeHandlerRegistry, NULL_TYPE_HANDLER_MAP is used for representing no handler at all.

  private Map<JdbcType, TypeHandler<?>> getJdbcHandlerMap(Type type) {
    TYPE_HANDLER_MAP.put(type, jdbcHandlerMap == null ? 
                     NULL_TYPE_HANDLER_MAP : jdbcHandlerMap); 
    return jdbcHandlerMap;
  }

And with the following code:

  private void register(Type javaType, JdbcType jdbcType, TypeHandler<?> handler) {
    if (javaType != null) {
      Map<JdbcType, TypeHandler<?>> map = TYPE_HANDLER_MAP.get(javaType);

      // here
      if (map == null) { 
        map = new HashMap<JdbcType, TypeHandler<?>>();
        TYPE_HANDLER_MAP.put(javaType, map);
      }
      map.put(jdbcType, handler);
    }
    ALL_TYPE_HANDLERS_MAP.put(handler.getClass(), handler);
  }

The code if (map == null) uses null represent an empty map instead of using NULL_TYPE_HANDLER_MAP along with, which will make all handlers cannot be registered.

[harawata]

Thank you, @waluo !

[kowalczm]

When we can expect release? 3.4.6 seems to be completed?