Re: Segfault on exclusion constraint violation

On 02/02/2015 04:38 PM, Tom Lane wrote:
> Heikki Linnakangas <hlinnakangas@vmware.com> writes:
>> 9.4 and master segfaults, if an insertion would need to wait for another
>> transaction to finish because of an exclusion constraint. To reproduce:
>> ...
>> This only happens with assertions enabled. The culprit is commit
>> f88d4cfc9d417dac2ee41a8f5e593898e56fd2bd, which added the 'ctid'
>> argument to XactLockTableWait. check_exclusion_constraint calls
>> index_endscan() just before XactLockTableWait, but that free's the
>> memory the ctid points to.
>
>> I'll write up a patch to change those call sites to use local variables.
>> Hopefully it's trivial enough to still include in 9.4.1, although time
>> is really running out..
>
> If the only known bad consequence requires assertions enabled, I think
> it would be more prudent to *not* try to fix this in haste.

Ok, I'll wait until after the release.

- Heikki