[YSQL] Error/crash on complex row compare

[jasonyb]

Jira Link: DB-19798

Description

Commit afc424d introduces illogical code scan_plan->bind_key_attnums[current->sk_attno], causing errors and segfaults. For example,

create table t4(v1 int, a uuid, v2 int, b timestamptz, PRIMARY KEY(b asc, v1, a asc));
insert into t4 (a, b, v1) values ('00000000-0000-0000-0000-000000000000', '2021-01-01 00:00:00', 1);
insert into t4 (a, b, v1) values ('00000000-0000-0000-0000-000000000001', '2021-01-01 00:00:00', 2);
explain (costs off) select * from t4 where (b, a) >= ('2021-01-01 00:00:00', '00000000-0000-0000-0000-000000000001');

                                                             QUERY PLAN                                                             
------------------------------------------------------------------------------------------------------------------------------------
 Index Scan using t4_pkey on t4
   Index Cond: (ROW(b, a) >= ROW('2021-01-01 00:00:00-08'::timestamp with time zone, '00000000-0000-0000-0000-000000000001'::uuid))
(2 rows)

select * from t4 where (b, a) >= ('2021-01-01 00:00:00', '00000000-0000-0000-0000-000000000001');

ERROR:  invalid system attribute number 0

If you have a complicated schema/query involving row compare, you may be affected.

Prior versions up to 2.20 should be affected, but backporting to 2.20 can be deprioritized as it's not very active and this is an edge case.

Issue Type

kind/bug

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