"variable not found in subplan target list"

I have to run now so can't dissect it, but while running sqlsmith on the
SQL/JSON patch after Justin's report, I got $SUBJECT in this query:

MERGE INTO public.target_parted as target_0
USING (select
subq_0.c5 as c0,
subq_0.c0 as c1,
ref_0.a as c2,
subq_0.c1 as c3,
subq_0.c9 as c4,
(select c from public.prt2_m_p3 limit 1 offset 1)
as c5,
subq_0.c8 as c6,
ref_0.a as c7,
subq_0.c7 as c8,
subq_0.c1 as c9,
pg_catalog.system_user() as c10
from
public.itest1 as ref_0
left join (select
ref_1.matches as c0,
ref_1.typ as c1,
ref_1.colname as c2,
(select slotname from public.iface limit 1 offset 44)
as c3,
ref_1.matches as c4,
ref_1.op as c5,
ref_1.matches as c6,
ref_1.value as c7,
ref_1.op as c8,
ref_1.op as c9,
ref_1.typ as c10
from
public.brinopers_multi as ref_1
where cast(null as polygon) <@ (select polygon from public.tab_core_types limit 1 offset 22)
) as subq_0
on (cast(null as macaddr8) >= cast(null as macaddr8))
where subq_0.c10 > subq_0.c2
limit 49) as subq_1
ON target_0.b = subq_1.c2
WHEN MATCHED
AND (cast(null as box) |>> cast(null as box))
or (cast(null as lseg) ?-| (select s from public.lseg_tbl limit 1 offset 6)
)
THEN DELETE
WHEN NOT MATCHED AND (EXISTS (
select
21 as c0,
subq_2.c0 as c1
from
public.itest14 as sample_0 tablesample system (3.6)
inner join public.num_exp_sqrt as sample_1 tablesample bernoulli (0.3)
on (cast(null as "char") <= cast(null as "char")),
lateral (select
sample_1.id as c0
from
public.a as ref_2
where (cast(null as lseg) <@ cast(null as line))
or ((select b3 from public.bit_defaults limit 1 offset 80)
<> (select b3 from public.bit_defaults limit 1 offset 4)
)
limit 158) as subq_2
where (cast(null as name) !~ (select t from public.test_tsvector limit 1 offset 5)
)
and ((select bool from public.tab_core_types limit 1 offset 61)
< (select pg_catalog.bool_or(v) from public.rtest_view1)
)))
or (18 is NULL)
THEN INSERT VALUES ( pg_catalog.int4um(
cast(public.func_with_bad_set() as int4)), 13)
WHEN MATCHED AND ((24 is not NULL)
or (true))
or (cast(null as "timestamp") <= cast(null as timestamptz))
THEN UPDATE set
b = target_0.b

Ugh.

I got no more SQL/JSON related crashes so far.

--
Álvaro Herrera PostgreSQL Developer — https://www.EnterpriseDB.com/
"No hay ausente sin culpa ni presente sin disculpa" (Prov. francés)