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* Array parsing incorrectly accepts ragged multidimensional arrays
@ 2023-06-04 22:39 Nikhil Benesch <nikhil.benesch@gmail.com>
0 siblings, 1 reply; 3+ messages in thread
From: Nikhil Benesch @ 2023-06-04 22:39 UTC (permalink / raw)
To: pgsql-bugs@lists.postgresql.org; +Cc: Sean Loiselle <himself@seanloiselle.com>
While working on Postgres-compatible array support in Materialize, my
colleague Sean Loiselle (CC'd) discovered what a class of seemingly
invalid array values that are accepted by Postgres's array input
routine:
benesch=# select '{{{9}},{8},{7}}'::int[];
int4
------
{}
(1 row)
benesch=# select '{{9},{{8}},{7}}'::int[];
int4
------
{}
(1 row)
benesch=# select '{{9},{8},{{7}}}'::int[];
int4
------------------------
{{{9}},{{NULL}},{{7}}}
(1 row)
As far as we can tell, Postgres *should* reject all these array
values, as the elements of each dimension do not have uniform length.
Postgres does correctly reject the analogous test cases with one less
layer of nesting:
benesch=# select '{{1}, 2, 3}'::int[];
ERROR: malformed array literal: "{{1}, 2, 3}"
LINE 1: select '{{1}, 2, 3}'::int[];
^
DETAIL: Unexpected array element.
benesch=# select '{1, {2}, 3}'::int[];
ERROR: malformed array literal: "{1, {2}, 3}"
LINE 1: select '{1, {2}, 3}'::int[];
^
DETAIL: Unexpected "{" character.
benesch=# select '{1, 2, {3}}'::int[];
ERROR: malformed array literal: "{1, 2, {3}}"
LINE 1: select '{1, 2, {3}}'::int[];
^
DETAIL: Unexpected "{" character.
I whipped up a patch that causes Postgres to correctly reject the
three examples above [0], but I am not convinced of its correctness.
Do folks agree that this is a bug? Is it worth me or Sean formally
submitting the proposed patch, or would someone with more experience
like to do a more thorough refactor of the ArrayCount routine?
[0]: https://gist.github.com/benesch/2e77712f81625deeb0e2246098fd8089
^ permalink raw reply [nested|flat] 3+ messages in thread
* Re: Array parsing incorrectly accepts ragged multidimensional arrays
@ 2023-06-04 22:53 Tom Lane <tgl@sss.pgh.pa.us>
parent: Nikhil Benesch <nikhil.benesch@gmail.com>
0 siblings, 1 reply; 3+ messages in thread
From: Tom Lane @ 2023-06-04 22:53 UTC (permalink / raw)
To: Nikhil Benesch <nikhil.benesch@gmail.com>; +Cc: pgsql-bugs@lists.postgresql.org, Sean Loiselle <himself@seanloiselle.com>
Nikhil Benesch <nikhil.benesch@gmail.com> writes:
> While working on Postgres-compatible array support in Materialize, my
> colleague Sean Loiselle (CC'd) discovered what a class of seemingly
> invalid array values that are accepted by Postgres's array input
> routine:
Yeah, see existing thread (and patch) at
https://www.postgresql.org/message-id/flat/2794005.1683042087@sss.pgh.pa.us
Please review that if you'd like.
regards, tom lane
^ permalink raw reply [nested|flat] 3+ messages in thread
* Re: Array parsing incorrectly accepts ragged multidimensional arrays
@ 2023-06-05 01:02 Nikhil Benesch <nikhil.benesch@gmail.com>
parent: Tom Lane <tgl@sss.pgh.pa.us>
0 siblings, 0 replies; 3+ messages in thread
From: Nikhil Benesch @ 2023-06-05 01:02 UTC (permalink / raw)
To: Tom Lane <tgl@sss.pgh.pa.us>; +Cc: pgsql-bugs@lists.postgresql.org, Sean Loiselle <himself@seanloiselle.com>
Ah, thanks for the pointer. Funny how these bugs can go unnoticed for
two decades and then get noticed twice in the same month.
On Sun, Jun 4, 2023 at 6:53 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>
> Nikhil Benesch <nikhil.benesch@gmail.com> writes:
> > While working on Postgres-compatible array support in Materialize, my
> > colleague Sean Loiselle (CC'd) discovered what a class of seemingly
> > invalid array values that are accepted by Postgres's array input
> > routine:
>
> Yeah, see existing thread (and patch) at
>
> https://www.postgresql.org/message-id/flat/2794005.1683042087@sss.pgh.pa.us
>
> Please review that if you'd like.
>
> regards, tom lane
^ permalink raw reply [nested|flat] 3+ messages in thread
end of thread, other threads:[~2023-06-05 01:02 UTC | newest]
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2023-06-04 22:39 Array parsing incorrectly accepts ragged multidimensional arrays Nikhil Benesch <nikhil.benesch@gmail.com>
2023-06-04 22:53 ` Tom Lane <tgl@sss.pgh.pa.us>
2023-06-05 01:02 ` Nikhil Benesch <nikhil.benesch@gmail.com>
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