On 13 July 2010 16:50, Dave Page <dpage@pgadmin.org> wrote:
> On Tue, Jul 13, 2010 at 4:48 PM, Thom Brown <thombrown@gmail.com> wrote:
>> On 13 July 2010 16:44, Thom Brown <thombrown@gmail.com> wrote:
>>> On 13 July 2010 16:31, Dave Page <dpage@pgadmin.org> wrote:
>>>> We had a report of the above error from a pgAdmin user testing
>>>> 1.12.0b3 with PG 9.0b3. The (highly simplified) query below works fine
>>>> as a superuser:
>>>>
>>>> SELECT pg_get_expr(proargdefaults, 'pg_catalog.pg_class'::regclass)
>>>> FROM pg_proc pr
>>>> LEFT OUTER JOIN pg_description des ON des.objoid=pr.oid
>>>>
>>>> Run as a regular user though, we get the error. If I remove the join,
>>>> it works fine as the normal user. This is in a database owned by the
>>>> regular user.
>>>>
>>>> Am I missing something obvious, or is there a bug here? pg_get_expr is
>>>> used pretty extensively in pgAdmin, so we're obviously keen to ensure
>>>> it works :-)
>>>>
>>>
>>> I tested this on both beta2 and beta3 and can confirm that it works on
>>> beta2 but produces the following error in beta3:
>>>
>>> ********** Error **********
>>>
>>> ERROR: argument to pg_get_expr() must come from system catalogs
>>> SQL state: 42501
>>>
>>> Thom
>>>
>>
>> And here's why:
>> http://archives.postgresql.org/pgsql-committers/2010-06/msg00259.php
>>
>> "stringToNode() and deparse_expression_pretty() crash on invalid input,
>> but we have nevertheless exposed them to users via pg_get_expr(). It would
>> be too much maintenance effort to rigorously check the input, so put a hack
>> in place instead to restrict pg_get_expr() so that the argument must come
>> from one of the system catalog columns known to contain valid expressions."
>
> Yeah, I recall that - but... the argument *is* coming from the system
> catalogs, and why is the error only thrown for a non-superuser, when
> the query includes the join?
>
I works if you use pr.proargdefaults so not unresolvable. Maybe it's
because it can't tell where the column's coming from at that point?
Thom
