The following bug has been logged on the website:
Bug reference: 14084
Logged by: pguser
Email address: pgu(at)mailcatch(dot)com
PostgreSQL version: 9.5.2
Operating system: all
Description:
http://www.postgresql.org/docs/current/static/queries-limit.html
[...]and LIMIT NULL is the same as omitting the LIMIT clause.
I guess it should be "LIMIT ALL" not "LIMIT NULL"