Re: BUG #17368: Assert failed in GetSafeSnapshot() for SERIALIZABLE READ ONLY DEFERRABLE transaction

Hi Thomas,

08.03.2023 14:57, Thomas Munro wrote:
> On Tue, Mar 7, 2023 at 12:39 PM Thomas Munro <thomas(dot)munro(at)gmail(dot)com> wrote:
>> Scratch that. I like the more ambitious idea better. I originally
>> thought it would be less back-patchable, but that's nonsense -- this
>> was a straight up thinko in ancient commit bdaabb9b and we should just
>> fix it properly. That is, we should treat this case as a
>> generalisation of the the PredXact->WritableSxactCount == 0 case, it's
>> just that we had to do more work to figure that out. Here's a patch
>> like that.
> Here's a better version. I plan to push this tomorrow if there are no
> objections.

Just in case you find a test for the fix useful, maybe the attached
patch could be added to the commit.
(It triggers the assert on unpatched master.)

Best regards,
Alexander