Assertion failure in get_appendrel_parampathinfo

Postgres 9.4beta2 and later crashes given the following query:

BEGIN;

CREATE TABLE k (
id int
);
CREATE UNIQUE INDEX k_idx ON k (id);

INSERT INTO k VALUES(1);

CREATE TABLE link (
source int,
target int
);
CREATE UNIQUE INDEX l_idx ON link (source, target);

CREATE TABLE b (
id int
);
CREATE UNIQUE INDEX b_idx ON b (id);

CREATE TABLE d () INHERITS (b);
CREATE UNIQUE INDEX d_idx ON d (id);

ANALYZE;

SELECT
1
FROM
k AS k1
WHERE
EXISTS (
(SELECT
True
FROM
k AS k2

INNER JOIN (
link

INNER JOIN

(SELECT id FROM b
UNION ALL SELECT id FROM d) AS v

ON (link.target = v.id)

) ON (k2.id = link.source
AND k1.id = link.source)
)
);

ROLLBACK;

Which generates the following query plan:

QUERY PLAN
──────────────────────────────────────────────────────────────────────────────────────────────────
Seq Scan on k k1 (cost=0.00..1.33 rows=1 width=0)
Filter: (SubPlan 1)
SubPlan 1
-> Nested Loop (cost=0.15..44.43 rows=264 width=0)
-> Seq Scan on k k2 (cost=0.00..1.01 rows=1 width=4)
Filter: (id = k1.id)
-> Nested Loop (cost=0.15..40.77 rows=264 width=4)
-> Append (cost=0.00..40.18 rows=3 width=4)
-> Seq Scan on b (cost=0.00..0.00 rows=1 width=4)
Filter: (id = id)
-> Index Only Scan using d_idx on d d_1 (cost=0.15..0.18 rows=1 width=4)
Index Cond: (id = id)
-> Seq Scan on d (cost=0.00..40.00 rows=1 width=4)
Filter: (id = id)
-> Index Only Scan using l_idx on link (cost=0.15..0.19 rows=1 width=8)
Index Cond: ((source = k1.id) AND (target = b.id))
Planning time: 0.411 ms
(17 rows)

Traceback:

#0 0x00007fc0e05cc2f7 in raise () from /lib64/libc.so.6
#1 0x00007fc0e05cd638 in abort () from /lib64/libc.so.6
#2 0x00000000008e9445 in ExceptionalCondition (conditionName=0xa75e10 "!(!bms_overlap(appendrel->relids, required_outer))", errorType=0xa75b5a "FailedAssertion", fileName=0xa75b50 "relnode.c", lineNumber=983) at assert.c:54
#3 0x0000000000720dda in get_appendrel_parampathinfo (appendrel=0x13f6340, required_outer=0x1400c90) at relnode.c:983
#4 0x0000000000718b55 in create_append_path (rel=0x13f6340, subpaths=0x1403ff0, required_outer=0x1400c90) at pathnode.c:897
#5 0x00000000006d309a in set_append_rel_pathlist (root=0x13ef630, rel=0x13f6340, rti=3, rte=0x13ecbd8) at allpaths.c:855
#6 0x00000000006d23e1 in set_rel_pathlist (root=0x13ef630, rel=0x13f6340, rti=3, rte=0x13ecbd8) at allpaths.c:320
#7 0x00000000006d21c2 in set_base_rel_pathlists (root=0x13ef630) at allpaths.c:222
#8 0x00000000006d202f in make_one_rel (root=0x13ef630, joinlist=0x13f5cf0) at allpaths.c:152
#9 0x00000000006f846f in query_planner (root=0x13ef630, tlist=0x0, qp_callback=0x6fc460 <standard_qp_callback>, qp_extra=0x7fffe32c28a0) at planmain.c:236
#10 0x00000000006fa484 in grouping_planner (root=0x13ef630, tuple_fraction=1) at planner.c:1288
#11 0x00000000006f91d1 in subquery_planner (glob=0x1380d00, parse=0x13ec4d8, parent_root=0x13825b8, hasRecursion=0 '\000', tuple_fraction=1, subroot=0x7fffe32c2aa8) at planner.c:573
#12 0x000000000070288f in make_subplan (root=0x13825b8, orig_subquery=0x137dcd8, subLinkType=EXISTS_SUBLINK, subLinkId=0, testexpr=0x0, isTopQual=1 '\001') at subselect.c:490
#13 0x0000000000704b77 in process_sublinks_mutator (node=0x13ec480, context=0x7fffe32c2ba0) at subselect.c:1862
#14 0x0000000000704ada in SS_process_sublinks (root=0x13825b8, expr=0x13ec480, isQual=1 '\001') at subselect.c:1835
#15 0x00000000006f941c in preprocess_expression (root=0x13825b8, expr=0x13ec480, kind=0) at planner.c:693
#16 0x00000000006f94fc in preprocess_qual_conditions (root=0x13825b8, jtnode=0x1382850) at planner.c:738
#17 0x00000000006f8dae in subquery_planner (glob=0x1380d00, parse=0x137d8a0, parent_root=0x0, hasRecursion=0 '\000', tuple_fraction=0, subroot=0x7fffe32c2d48) at planner.c:443
#18 0x00000000006f86f8 in standard_planner (parse=0x137d8a0, cursorOptions=0, boundParams=0x0) at planner.c:210
#19 0x00000000006f855c in planner (parse=0x137d8a0, cursorOptions=0, boundParams=0x0) at planner.c:139
#20 0x00000000007b04c7 in pg_plan_query (querytree=0x137d8a0, cursorOptions=0, boundParams=0x0) at postgres.c:750
#21 0x00000000007b057a in pg_plan_queries (querytrees=0x1382580, cursorOptions=0, boundParams=0x0) at postgres.c:809
#22 0x00000000007b0885 in exec_simple_query (query_string=0x1309788 "BEGIN;\n\nCREATE TABLE k (\n id int\n);\nCREATE UNIQUE INDEX k_idx ON k (id);\n\nINSERT INTO k VALUES(1);\n\nCREATE TABLE link (\n source int,\n target int\n);\nCREATE UNIQUE INDEX l_idx ON link (source, "...) at postgres.c:974
#23 0x00000000007b4de6 in PostgresMain (argc=10, argv=0x12b5040, dbname=0x12d2350 "template1", username=0x12bcc60 "elvis") at postgres.c:4010
#24 0x000000000069757e in main (argc=10, argv=0x12b5040) at main.c:215

Elvis