Re: BUG #1502: hash_seq_search might return removed entry

Tom Lane wrote:

>"Thomas" <thhal(at)mailblocks(dot)com> writes:
>
>
>>The hash_seq_search keeps track of what element that it should return next
>>in a HASH_SEQ_STATUS struct when it peruses a bucket. Removing that element
>>from the table won't change anything since the struct remains unaffected. It
>>still holds onto that element and hence, will return it on next iteration.
>>
>>
>
>This isn't a bug; it's the designed way for it to work. It's up to
>callers to avoid causing a problem.
>
>
This report origins from the hackers thread "SPI_finish and
RegisterExprContextCallback" where you indicated that my report did not
properly describe a problem. Since my report was correct and since you
stated that "hash_seq_search() shouldn't return any already-dropped
entries." I was led me to believe that it was *not* designed to do that.

Anyway, the AtCommit_Portals doesn't avoid this problem and the end
result for me is the same regardless of where the error is. I can't drop
portals using a ExprContextCallback and I'd like to know the best way to
fix it. I can contribute a patch but I want you to decide what needs to
be fixed.

Regards,
Thomas Hallgren