Re: pg_receivexlog: spurious error message connecting to 9.3

On Tue, Nov 24, 2015 at 7:00 PM, Marco Nenciarini
<marco.nenciarini@2ndquadrant.it> wrote:
> Hi Robert,
>
> On 17/11/15 20:10, Robert Haas wrote:
>> On Tue, Nov 10, 2015 at 1:35 AM, Craig Ringer <craig@2ndquadrant.com> wrote:
>>> On 10 November 2015 at 01:47, Marco Nenciarini
>>> <marco.nenciarini@2ndquadrant.it> wrote:
>>>
>>>> I've attached a little patch that removes the errors when connected to 9.3.
>>>
>>> Looks good to me. No point confusing users.
>>>
>>> The other callers of RunIdentifySystem are pg_basebackup and
>>> pg_receivelogical.
>>>
>>> pg_basebackup doesn't ask for the db_name (passes null).
>>>
>>> pg_receivelogical handles it being null already (and if it didn't,
>>> it'd die with or without this patch).
>>>
>>> pg_receivexlog expects it to be null and fails gracefully if it isn't.
>>>
>>> So this change just removes some pointless noise.
>>
>> The fprintf(stderr, ...) does not cause a non-local exit, so the
>> "else" just after it should be deleted.  Otherwise, when that branch
>> is taken, *db_name doesn't get initialized at all.
>>
>> Actually, I'd suggest doing it like the attached instead, which seems
>> a bit tighter.
>>
>
> I agree, your patch is better.

+        else if (PQserverVersion(conn) >= 90400)            fprintf(stderr,                    _("%s: could not
identifysystem: got %d rows and
 
%d fields, expected %d rows and %d or more fields\n"),                    progname, PQntuples(res), PQnfields(res), 1,
4);   }
 

In the above case, PQclear(res) should be called and FALSE should be returned?

Regards,

-- 
Fujii Masao