Test of value equivalency of row type, feature or bug?

Here is the query:

select t=t from (select 1, null) t;

If I manage to catch the documents, the result of the query should be null, as an equivalency comparison of null-contained row-typed values is null. Surprisingly, the query result turns out to be true.

The query is executed against pg11.

Is this behavior a feature or a bug? 

Regards.