CURSOR fetching error when used subquery with limit

[ereutt]

Steps to reproduce:

DECLARE ctest SCROLL CURSOR FOR SELECT 'aaaaa' FROM(SELECT relname FROM pg_class LIMIT 1) subquery;
 FETCH NEXT FROM ctest;

Expected:

 DECLARE CURSOR
 ?column? 
----------
 aaaaa
(1 row)

Actual:
ERROR: cache lookup failed for relation 0

This reproduced only for LIMIT in subquery. Cursors with subquery without LIMIT or LIMIT not in subquery are processed as expected