Small query using LATERAL that segfaults Postgres

This small query seems to segfault Postgres.  I've tried on the
version of Postgres 11 that comes with Debian Stable and all versions
on https://www.db-fiddle.com/ including 13 (Beta).  DB Fiddle actually
says "An unexpected error occurred." but I suspect that's the
segfault.

Tom


SELECT
0
FROM (SELECT
      TRUE as "r",
      SUM(0)
      ) as "T1",
LATERAL
(SELECT TRUE as "b"
    UNION ALL
    SELECT
    "r" as "b"
    FROM (SELECT 0 ORDER BY COALESCE(0)) as "T1"
    ) as "T2"
WHERE "b"