Re: Add RESPECT/IGNORE NULLS and FROM FIRST/LAST options - Mailing list pgsql-hackers

From Tatsuo Ishii
Subject Re: Add RESPECT/IGNORE NULLS and FROM FIRST/LAST options
Date
Msg-id 20251006.183439.876014721998277138.ishii@postgresql.org
Whole thread Raw
In response to Re: Add RESPECT/IGNORE NULLS and FROM FIRST/LAST options  (Tatsuo Ishii <ishii@postgresql.org>)
List pgsql-hackers
> Thank you for the report!
> 
>> Coverity is not very happy with this patch.
>> It's complaining that the result of window_gettupleslot
>> is not checked, which seems valid:
>> 
>> 1503                 {
>> 1504                     if (fetch_tuple)
>>>>>     CID 1666587:         Error handling issues  (CHECKED_RETURN)
>>>>>     Calling "window_gettupleslot" without checking return value (as is done elsewhere 8 out of 9 times).
>> 1505                         window_gettupleslot(winobj, pos, slot);
>> 1506                     if (!are_peers(winstate, slot, winstate->ss.ss_ScanTupleSlot))
>> 1507                         return -1;
> 
> Yes, I forgot to check the return value of window_gettupleslot.
> 
>> and also that WinGetFuncArgInPartition is dereferencing
>> a possibly-null "isout" pointer at several places, including
>> 
>>>>>     Dereferencing null pointer "isout".
>> 3806                     if (*isout)        /* out of partition? */
>> 
>>>>>     Dereferencing null pointer "isout".
>> 3817         if (!*isout && set_mark)
>> 3818             WinSetMarkPosition(winobj, abs_pos);
>> 
>>>>>     Dereferencing null pointer "isout".
>> 3817         if (!*isout && set_mark)
>> 3818             WinSetMarkPosition(winobj, abs_pos);
>> 
>> The latter complaints seem to be because some places in
>> WinGetFuncArgInPartition check for nullness of that pointer
>> and some do not.  That looks like at least a latent bug
>> to me.
> 
> Agreed.
> 
> Attached is a patch to fix the issue.

Please disregard the v1 patch. It includes a bug: If
WinGetFuncArgInPartition() is called with set_mark == true and isout
== NULL, WinSetMarkPosition() is not called by
WinGetFuncArgInPartition().

I will post v2 patch.

Best regards,
--
Tatsuo Ishii
SRA OSS K.K.
English: http://www.sraoss.co.jp/index_en/
Japanese:http://www.sraoss.co.jp



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